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Naguib GH, Abuelenain D, Mazhar J, Alnowaiser A, Aljawi R, Hamed MT. Maximizing dental composite performance: Strength and hardness enhanced by innovative polymer-coated MgO nanoparticles. J Dent 2024; 149:105271. [PMID: 39069250 DOI: 10.1016/j.jdent.2024.105271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2024] [Revised: 07/23/2024] [Accepted: 07/26/2024] [Indexed: 07/30/2024] Open
Abstract
INTRODUCTION Zein-incorporated magnesium oxide nanoparticles (zMgO NPs) can influence the mechanical properties of dental materials. However, the effect of this addition on the mechanical properties of resin composite has yet to be investigated. The objective of this study was to add various concentrations of zMgO NPs to conventional, flowable, and bulk-fill composite and assess the effect on the compressive strength, flexural strength, and microhardness. METHODOLOGY 150 samples each of conventional composite, flowable composite, and bulk-fill composite (n = 450) were enhanced with concentrations of zMgO NPs at 0 %, 0.3 %, 0.5 %, 1 %, and 2 % (n = 30). 10 samples of each group were randomly allotted to the compressive strength, flexural strength, or hardness test. Characterization of the specimens was performed by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and transmission electron microscopy. Two-way ANOVA test was used to compare between groups, and one-way ANOVA followed by Tukey's test was done at p = 0.05 to determine significance. RESULTS Characterization yielded a uniform distribution of nanoparticles in the matrix and the formation of a new hybrid composite that maintained its properties. Composite of all types enhanced with 0.3 % and 0.5 % zMgO NPs demonstrated a statistically significant increase in compressive strength, flexural strength, and hardness when compared to the control (p < 0.05). The bulk-fill composite with zMgO NPs concentrations of all groups demonstrated a statistically significant increase (p < 0.05) in hardness when compared to the control. CONCLUSION The modified composites' compressive strength, flexural strength, and hardness improved or remained consistent. CLINICAL SIGNIFICANCE An improved dental resin composite will enhance the quality of care and patient experience. The augmented strength and hardness of resin composite is desirable in prolonging the durability of the restoration.
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Affiliation(s)
- Ghada H Naguib
- Department of Restorative Dentistry, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia; Department of Oral Biology, Cairo University School of Dentistry, Cairo, Egypt.
| | - Dalia Abuelenain
- Department of Restorative Dentistry, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia
| | | | - Abeer Alnowaiser
- Department of Pediatric Dentistry, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Rabab Aljawi
- Department of Pediatric Dentistry, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Mohamed T Hamed
- Department of Oral and Maxillofacial Prosthodontics, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia; Department of Fixed Prosthodontics, Cairo University School of Dentistry, Cairo, Egypt
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Loguercio AD, Carpio-Salvatierra B, Ñaupari-Villasante R, Wendlinger M, Armas-Vega A, Cavagnaro S, León A, Aliaga-Galvez R, Gutiérrez MF. Clinical evaluation of a new chemically-cured bulk-fill composite in posterior restorations: 6-month multicenter double-blind randomized clinical trial. J Dent 2024; 149:105246. [PMID: 39025426 DOI: 10.1016/j.jdent.2024.105246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2024] [Revised: 07/12/2024] [Accepted: 07/15/2024] [Indexed: 07/20/2024] Open
Abstract
OBJECTIVE To evaluate the postoperative sensitivity (POS), as well as the clinical performance of posterior restorations using a new chemically-cured bulk-fill composite (Stela Automix and Stela Capsule, SDI) comparing with a light-cured bulk-fill composite after 6 months. METHODS Fifty-five participants with at least three posterior teeth needing restoration were recruited. A total of 165 restorations were performed on Class I or Class II cavities. After the application of Stela primer, the chemically-cured composite (Stela Automix or Stela Capsule) was inserted. For the light-cured composite group, a universal adhesive (Scotchbond Universal) was applied with a bulk-fill composite (Filtek One). Participants were evaluated for spontaneous and stimulated POS in the baseline, after 48 h, 7 days, and 6 months. Additionally, each restoration was assessed using the updated version of FDI criteria after 6 months. The differences in the proportions of the groups were compared by Cochran test statistics (α = 0.05). RESULTS Both chemically-cured composites showed a lower risk of POS compared to the light-cured composite at baseline and up to 48 h (p < 0.04). A significantly lower surface luster and texture was observed for the Stela Capsule composite compared to the light-cured bulk-fill composite (baseline and 6 months; p = 0.03). A significant color mismatch was observed for the light-cured bulk-fill composite compared to the chemically-cured composites (baseline and 6 months; p = 0.03). No significant differences were observed in any other item evaluations (p > 0.05). CONCLUSION Chemically-cured composites exhibit lower postoperative sensitivity and less color mismatch compared to a light-cured bulk-fill composite after 6 months of clinical service. CLINICAL SIGNIFICANCE The chemically-cured composites appear to be an appealing option for restoring posterior teeth, as they exhibit lower postoperative sensitivity compared to a light-cured bulk-fill composite, both at baseline and up to 48 h, and less color mismatch.
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Affiliation(s)
- Alessandro D Loguercio
- State University of Ponta Grossa, School of Dentistry, Ponta Grossa/PR, 84030-000, Brazil; Facultad de Ciencias de la Salud, Carrera de Odontologia, Universidad De Los Hemisferios, Quito 170147, Ecuador
| | - B Carpio-Salvatierra
- State University of Ponta Grossa, School of Dentistry, Ponta Grossa/PR, 84030-000, Brazil
| | - R Ñaupari-Villasante
- State University of Ponta Grossa, School of Dentistry, Ponta Grossa/PR, 84030-000, Brazil
| | - M Wendlinger
- State University of Ponta Grossa, School of Dentistry, Ponta Grossa/PR, 84030-000, Brazil
| | - Ana Armas-Vega
- Facultad de Ciencias de la Salud, Carrera de Odontologia, Universidad De Los Hemisferios, Quito 170147, Ecuador
| | - S Cavagnaro
- Universidad de los Andes, Chile, Facultad de Odontología, Santiago 7550000, Chile
| | - A León
- Universidad de los Andes, Chile, Facultad de Odontología, Santiago 7550000, Chile
| | - R Aliaga-Galvez
- Universidad de los Andes, Chile, Facultad de Odontología, Santiago 7550000, Chile
| | - M F Gutiérrez
- Universidad de los Andes, Chile, Facultad de Odontología, Santiago 7550000, Chile.
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Hatamleh MM, Furuse AY. Bis-EMA/Bis-GMA ratio effects on resin-properties and impregnated fiber-bundles. Dent Mater 2024; 40:1652-1657. [PMID: 39084956 DOI: 10.1016/j.dental.2024.07.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2024] [Accepted: 07/09/2024] [Indexed: 08/02/2024]
Abstract
OBJECTIVES To evaluate the effect of different ratios of Bis-EMA/Bis-GMA resin mixtures on the inherent viscosity and curing-related properties: including degree of cure (DC%), shrinkage strain, Knoop micro-hardness (KH) and flexural strength of resin-impregnated fiber-bundles. METHODS Bis-EMA/Bis-GMA monomers were mixed (by weight) in the following ratios: M1 = 30 %/70 %, M2 = 50 %/50 %, M3 = 70 %/30 %, and M4 = 100 %/0 %. Standard measurements were made of refractive index, viscosity, degree of conversion, shrinkage strain and Knoop hardness (KHN). For 60 % glass fiber-bundles impregnated with 40 % resin, three-point bending test for flexural strength and shrinkage strain were measured. Data were analyzed by One-way ANOVA and Bonferroni post-hoc tests (α = 0.05). RESULTS For resin mixtures, increasing Bis-EMA proportion decreased refractive index (p < 0.05), and viscosity (p < 0.05), and increased monomer conversion (DC%), shrinkage strain and KHN (p < 0.05). DC% increased after 1 h for all resin mixtures. The shrinkage strain and flexural strength of resin-impregnated fiber-bundles reduced with increased Bis-EMA. SIGNIFICANCE Monomeric mixtures with highest amounts of Bis-EMA showed enhancement in several clinically-relevant properties and polymerization of respective resin-impregnated glass fibers. This makes them potential candidates for impregnating glass fibers in fiber-reinforced restorations.
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Affiliation(s)
- Muhanad M Hatamleh
- Department of Applied Dental Sciences, Faculty of Applied Medical Sciences, Jordan University of Science and Technology, PO Box 3030, Irbid 22110, Jordan.
| | - Adilson Yoshio Furuse
- Department of Operative Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, University of São Paulo, Al. Dr. Octávio Pinheiro Brisola - 9-75, Bauru, SP CEP 17012-901, Brazil
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Pereira RP, de Oliveira D, Rocha MG, Roulet JF, Geraldeli S, Sinhoreti M. Effect of butylated hydroxytoluene (BHT) concentrations on polymerization shrinkage stress and other physicochemical properties of experimental resin composites. J Mech Behav Biomed Mater 2024; 157:106652. [PMID: 38970944 DOI: 10.1016/j.jmbbm.2024.106652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2024] [Revised: 06/20/2024] [Accepted: 07/02/2024] [Indexed: 07/08/2024]
Abstract
The present study examined different concentrations of the butylated hydroxytoluene (BHT) inhibitor on the kinetics of conversion, polymerization shrinkage stress, and other correlated physicochemical properties of experimental resin composites (ERC). A model composite was formulated with 75 wt% filler containing 0.5 wt% camphorquinone and 1 wt% amine with BHT concentrations of 0.01 wt% (BHT-0.01); 0.1 wt% (BHT-0.1); 0.25 wt% (BHT-0.25); 0.5 wt% (BHT-0.5); 1 wt% (BHT-1), and control (no BHT). They were tested on polymerization shrinkage stress (PSS; n = 5), degree of conversion (DC; n = 3), maximum polymerization rate (RpMAX; n = 5), water sorption (Wsp; n = 0), and solubility (Wsl; n = 10), flexural strength (FS; n = 10), flexural modulus (FM; n = 10), Knoop microhardness (KH; n = 10), and microhardness reduction (HR; n = 10). Data concerning these tests were submitted to one-way ANOVA and Tukey's test (α = 0.05; β = 0.2). BHT-0.25, BHT-0.5, and BHT-1 showed a gradually significant decrease in PSS (p = 0.037); however, BHT-1 demonstrated a decrease in the physicochemical properties tested. Thus, within the limitations of this study, it was possible to conclude that BHT concentrations between 0.25 and 0.5 wt% are optimal for reducing shrinkage stress without affecting other physicochemical properties of ERCs.
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Affiliation(s)
- Roberta Pinto Pereira
- Department of Restorative Dentistry, Piracicaba Dental School, University of Campinas, Piracicaba, SP, Brazil
| | - Dayane de Oliveira
- Department of Restorative Dental Science, College of Dentistry, University of Florida, Gainesville, FL, USA
| | - Mateus Garcia Rocha
- Department of Restorative Dental Science, College of Dentistry, University of Florida, Gainesville, FL, USA
| | - Jean-François Roulet
- Department of Restorative Dental Science, College of Dentistry, University of Florida, Gainesville, FL, USA
| | - Saulo Geraldeli
- Division of Biomedical Materials, School of Dental Medicine, East Carolina University, Greenville, NC, USA
| | - Mário Sinhoreti
- Department of Restorative Dentistry, Piracicaba Dental School, University of Campinas, Piracicaba, SP, Brazil.
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Lopez C, Nizami B, Robles A, Gummadi S, Lawson NC. Correlation between Dental Composite Filler Percentage and Strength, Modulus, Shrinkage Stress, Translucency, Depth of Cure and Radiopacity. MATERIALS (BASEL, SWITZERLAND) 2024; 17:3901. [PMID: 39203079 PMCID: PMC11355582 DOI: 10.3390/ma17163901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/10/2024] [Revised: 07/28/2024] [Accepted: 08/01/2024] [Indexed: 09/03/2024]
Abstract
Filler content in dental composites is credited for affecting its physical and mechanical properties. This study evaluated the correlation between the filler percentage and strength, modulus, shrinkage stress, depth of cure, translucency and radiopacity of commercially available high- and low-viscosity dental composites. Filler weight percentage (wt%) was determined through the burned ash technique (800 °C for 15 min). Three-point bend flexural strength and modulus were measured according to ISO 4049 with 2 mm × 2 mm × 25 mm bars. Shrinkage stress was evaluated using a universal testing machine in which composite was polymerized through two transparent acrylic rods 2 mm apart. Shrinkage was measured from the maximum force following 500 s. The translucency parameter (TP) was measured as the difference in color (ΔE00) of 1 mm thick specimens against white and black tiles. The depth of cure was measured according to ISO 4049 in a cylindrical metal mold (4 mm diameter) with a 10 s cure. Radiopacity was measured by taking a digital X-ray (70 kVp for 0.32 s at 400 mm distance) of 1 mm thick specimens and comparing the radiopacity to an aluminum step wedge using image analysis software. The correlation between the filler wt% and properties was measured by Pearson's correlation coefficient using SPSS. There was a positive linear correlation between the filler wt% and modulus (r = 0.78, p < 0.01), flexural strength (r = 0.46, p < 0.01) and radiopacity (r = 0.36, p < 0.01) and negative correlation with translucency (r = -0.29, p < 0.01). Filler wt% best predicts the modulus and strength and, to a lesser extent, the radiopacity and translucency. All but two of the high- and low-viscosity composites from the same manufacturer had statistically equivalent strengths as each other; however, the high-viscosity materials almost always had a statistically higher modulus. For two of the flowable composites measured from the same manufacturer (3M and Dentsply), there was a lower shrinkage stress in the bulk-fill version of the material but not for the other two manufacturers (Ivoclar and Tokuyama). All flowable bulk-fill composites achieved a deeper depth of cure than the flowable composite from the same manufacturer other than Omnichroma Flow Bulk.
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Affiliation(s)
- Carolina Lopez
- Private Practice, Bogota 110110, Colombia;
- Division of Biomaterials, School of Dentistry, University of Alabama at Birmingham School of Dentistry, Birmingham, AL 35209, USA;
| | - Bushra Nizami
- Division of Biomaterials, School of Dentistry, University of Alabama at Birmingham School of Dentistry, Birmingham, AL 35209, USA;
| | - Augusto Robles
- Division of General Dental Sciences, School of Dentistry, University of Alabama at Birmingham School of Dentistry, Birmingham, AL 35209, USA; (A.R.); (S.G.)
| | - Snigdha Gummadi
- Division of General Dental Sciences, School of Dentistry, University of Alabama at Birmingham School of Dentistry, Birmingham, AL 35209, USA; (A.R.); (S.G.)
| | - Nathaniel C. Lawson
- Division of Biomaterials, School of Dentistry, University of Alabama at Birmingham School of Dentistry, Birmingham, AL 35209, USA;
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Santos M, Fidalgo-Pereira R, Torres O, Carvalho O, Henriques B, Özcan M, Souza JCM. The impact of inorganic fillers, organic content, and polymerization mode on the degree of conversion of monomers in resin-matrix cements for restorative dentistry: a scoping review. Clin Oral Investig 2024; 28:454. [PMID: 39066793 PMCID: PMC11283416 DOI: 10.1007/s00784-024-05829-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Accepted: 07/13/2024] [Indexed: 07/30/2024]
Abstract
PURPOSE The main aim of the present study was to carry out a scoping review on the differences in degree of conversion of monomers regarding several types resin cements, indirect restorative materials, and light-curing procedures used in dentistry. METHOD A bibliographic review was performed on PubMed using the following search items: "degree of conversion" OR "filler" AND "resin cement" OR "inorganic cement" AND "organic" OR "radiopacity" OR "refractive" OR "transmittance" OR "type" AND "resin composite." The search involved articles published in English language within the last thirteen years. A research question has been formulated following the PICO approach as follow: "How different is the degree of conversion of monomers comparing several types of resin-matrix cements?". RESULTS Within the 15 selected studies, 8 studies reported a high degree of conversion (DC) of the organic matrix ranging from 70 up to 90% while 7 studies showed lower DC values. Dual-cured resin-matrix cements revealed the highest mean values of DC, flexural strength, and hardness when compared with light- and self-polymerized ones. DC mean values of resin-matrix cements light-cured through a ceramic veneer with 0.4 mm thickness were higher (~ 83%) than those recorded for resin-matrix cements light-cured through a thicker ceramic layer of 1.5 mm (~ 77%). CONCLUSIONS The highest percentage of degree of conversion of monomers was reported for dual-cured resin-matrix cements and therefore both chemical and light-induced pathways promoted an enhanced polymerization of the material. Similar degree of conversion of the same resin-matrix cement were recorded when the prosthetic structure showed a low thickness. On thick prosthetic structures, translucent materials are required to allow the light transmission achieving the resin-matrix cement. CLINICAL RELEVANCE The chemical composition of resin-matrix cements and the light-curing mode can affect the polymerization of the organic matrix. Thus, physical properties of the materials can vary leading to early clinical failures at restorative interfaces. Thus, the analysis of the polymerization pathways of resin-matrix cements is significantly beneficial for the clinical performance of the restorative interfaces.
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Affiliation(s)
- Marcionilia Santos
- Oral Pathology and Rehabilitation Research Unit (UNIPRO), University Institute of Health Sciences (IUCS), CESPU, 4585-116, Gandra PRD, Portugal
| | - Rita Fidalgo-Pereira
- Center for Interdisciplinary Research in Health (CIIS), Faculty of Dental Medicine (FMD), Universidade Católica Portuguesa (UCP), 3504-505, Viseu, Portugal
| | - Orlanda Torres
- Oral Pathology and Rehabilitation Research Unit (UNIPRO), University Institute of Health Sciences (IUCS), CESPU, 4585-116, Gandra PRD, Portugal
| | - Oscar Carvalho
- Center for MicroElectroMechanical Systems (CMEMS-UMINHO), University of Minho, Campus Azurém, 4800-058, Guimarães, Portugal
- Associate Laboratory (LABBELS), University of Minho, 4710-057, Guimarães, Braga, Portugal
| | - Bruno Henriques
- Center for MicroElectroMechanical Systems (CMEMS-UMINHO), University of Minho, Campus Azurém, 4800-058, Guimarães, Portugal
- Associate Laboratory (LABBELS), University of Minho, 4710-057, Guimarães, Braga, Portugal
- Ceramic and Composite Materials Research Group (CERMAT), Federal University of Santa Catarina (UFSC), Campus Trindade, Florianópolis, SC, 88040-900, Brazil
| | - Mutlu Özcan
- Clinic for Masticatory Disorders and Dental Biomaterials, Center of Dental Medicine, University of Zurich, 8032, Zurich, Switzerland
| | - Júlio C M Souza
- Center for Interdisciplinary Research in Health (CIIS), Faculty of Dental Medicine (FMD), Universidade Católica Portuguesa (UCP), 3504-505, Viseu, Portugal.
- Center for MicroElectroMechanical Systems (CMEMS-UMINHO), University of Minho, Campus Azurém, 4800-058, Guimarães, Portugal.
- Associate Laboratory (LABBELS), University of Minho, 4710-057, Guimarães, Braga, Portugal.
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Al-Zain AO, Piva E, Pimentel AH, Duarte CG, Valente LL, Isolan CP, Münchow EA. Impact of storage conditions on the fracture reliability and physical properties of a dental resin-based composite. Braz Oral Res 2024; 38:e062. [PMID: 39016368 PMCID: PMC11376674 DOI: 10.1590/1807-3107bor-2024.vol38.0062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Accepted: 10/31/2023] [Indexed: 07/18/2024] Open
Abstract
This study investigated the impact of 'storage condition' and 'period of storage' on selected physico-mechanical properties and fracture reliability of a resin-based composite (RBC). Specimens, prepared from a nanofilled RBC (Filtek Z350 XT; 3M ESPE), underwent tests for degree of conversion (DC), flexural strength (σ), flexural modulus (E), and hardness. The specimens were initially grouped into dry storage at 37°C or wet storage in distilled water at 37°C. Subsequently, they were further divided into four subgroups based on the period of storage: 6, 24, 72, or 168 hours. Specimens tested immediately after preparation served as control. Data analysis employed two-way ANOVA and Weibull analysis (α = 5%). Compared to the control, an increase in DC was observed only after 72 hours of dry storage; σ showed higher values after both dry and wet storage, regardless of the storage period (except for the group wet-stored for 168 hours); E increased with dry storage for at least 24 hours or wet storage for 72 hours; and hardness increased after dry storage for at least 24 hours or wet storage for up to 72 hours. The Weibull modulus remained unchanged under any of the distinct storage conditions. Dry storage resulted in greater characteristic strength than the control, whereas wet storage contributed to higher strength values only at shorter periods (up to 24 hours). Overall, the inherent properties of RBCs with a similar composition to that tested in this study may change with varying storage conditions and periods.
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Affiliation(s)
- Afnan Omar Al-Zain
- King Abdulaziz University, Faculty of Dentistry, Restorative Dentistry Department, Jeddah, Saudi Arabia
| | - Evandro Piva
- Universidade Federal de Pelotas - UFPel, Developmental and Control Center of Biomaterials, Department of Restorative Dentistry, Pelotas, RS. Brazil
| | - Alice Hammes Pimentel
- Universidade Federal de Pelotas - UFPel, Developmental and Control Center of Biomaterials, Department of Restorative Dentistry, Pelotas, RS. Brazil
| | - Camila Gonçalves Duarte
- Universidade Federal do Rio Grande do Sul - UFRGS, School of Dentistry, Graduate Program in Dentistry, Porto Alegre, RS, Brazil
| | - Lisia Lorea Valente
- Universidade Federal de Pelotas - UFPel, Developmental and Control Center of Biomaterials, Department of Restorative Dentistry, Pelotas, RS. Brazil
| | - Cristina Pereira Isolan
- Universidade Federal dos Vales do Jequitinhonha e Mucuri - UFCJM, School of Biological and Health Sciences, Department of Dentistry, Diamantina, MG. Brazil
| | - Eliseu Aldrighi Münchow
- Universidade Federal do Rio Grande do Sul - UFRGS, School of Dentistry, Department of Conservative Dentistry, Porto Alegre, RS, Brazil
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Li H, Yamaguchi S, Lee C, Benalcázar-Jalkh EB, Bonfante EA, Imazato S. In silico nonlinear dynamic finite-element analysis for biaxial flexural strength testing of CAD/CAM materials. J Prosthodont Res 2024; 68:474-481. [PMID: 38171769 DOI: 10.2186/jpr.jpr_d_23_00008] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
PURPOSE The aim of this study was to establish and assess the validity of in silico models of biaxial flexural strength (BFS) tests to reflect in vitro physical properties obtained from two commercially available computer-aided design/computer-aided manufacturing (CAD/CAM) ceramic blocks and one CAD/CAM resin composite block. METHODS In vitro three-point bending and BFS tests were conducted for three CAD/CAM materials (n = 10): Katana Zirconia ST10 (raw material: super-translucent multilayered zirconia, ST10; Kuraray Noritake Dental, Niigata, Japan), Katana Zirconia HT10 (raw material: highly translucent multilayered zirconia, HT10; Kuraray Noritake Dental), and Katana Avencia N (AN; Kuraray Noritake Dental). Densities, flexural moduli, and fracture strains were obtained from the in vitro three-point bending test and used as an input for an in silico nonlinear finite element analysis. The maximum principal stress (MPS) distribution was obtained from an in silico BFS analysis. RESULTS The elastic moduli of AN, HT10, and ST10 were 6.513, 40.039, and 32.600 GPa, respectively. The in silico fracture pattern of ST10 observed after the in silico evaluation was similar to the fracture pattern observed after the in vitro testing. The MPS was registered in the center of the tensile surface for all three specimens. The projections of the supporting balls were in the form of a triple asymmetry. CONCLUSIONS The in silico approach established in this study provided an acceptable reflection of in vitro physical properties, and will be useful to assess biaxial flexural properties of CAD/CAM materials without wastage of materials.
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Affiliation(s)
- Hefei Li
- Department of Dental Biomaterials, Osaka University Graduate School of Dentistry, Suita, Japan
| | - Satoshi Yamaguchi
- Department of Dental Biomaterials, Osaka University Graduate School of Dentistry, Suita, Japan
| | - Chunwoo Lee
- Department of Dental Biomaterials, Osaka University Graduate School of Dentistry, Suita, Japan
| | - Ernesto B Benalcázar-Jalkh
- Department of Prosthodontics and Periodontology, University of São Paulo, Bauru School of Dentistry, Bauru, Brazil
| | - Estevam A Bonfante
- Department of Prosthodontics and Periodontology, University of São Paulo, Bauru School of Dentistry, Bauru, Brazil
| | - Satoshi Imazato
- Department of Dental Biomaterials, Osaka University Graduate School of Dentistry, Suita, Japan
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Mudhaffer S, Althagafi R, Haider J, Satterthwaite J, Silikas N. Effects of printing orientation and artificial ageing on martens hardness and indentation modulus of 3D printed restorative resin materials. Dent Mater 2024; 40:1003-1014. [PMID: 38735775 DOI: 10.1016/j.dental.2024.05.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Revised: 04/29/2024] [Accepted: 05/03/2024] [Indexed: 05/14/2024]
Abstract
BACKGROUND Three-dimensional (3D) printing is increasingly used to fabricate dental restorations due to its enhanced precision, consistency and time and cost-saving advantages. The properties of 3D-printed resin materials can be influenced by the chosen printing orientation which can impact the mechanical characteristics of the final products. PURPOSE The objective of this study was to evaluate the influence of printing orientation and artificial ageing on the Martens hardness (HM) and indentation modulus (EIT) of 3D-printed definitive and temporary dental restorative resins. METHODS Disk specimens (20 mm diameter × 2 mm height) were additively manufactured in three printing orientations (0°, 45°, 90°) using five 3D-printable resins: VarseoSmile Crownplus (VCP), Crowntec (CT), Nextdent C&B MFH (ND), Dima C&B temp (DT), and GC temp print (GC). The specimens were printed using a DLP 3D-printer (ASIGA MAX UV), while LavaTM Ultimate (LU) and Telio CAD (TC) served as milled control materials. Martens hardness (HM) and indentation modulus (EIT) were tested both before and after storage in distilled water and artificial saliva for 1, 30, and 90 days at 37 °C. RESULTS 90° printed specimens exhibited higher HM than the other orientations at certain time points, but no significant differences were observed in HM and EIT between orientations for all 3D-printed materials after 90 days of ageing in both aging media. LU milled control material exhibited the highest HM and EIT among the tested materials, while TC, the other milled control, showed similar values to the 3D printed resins. CT and VCP (definitive resins) and ND displayed higher Martens parameters compared to DT and GC (temporary resins). The hardness of the 3D-printed materials was significantly impacted by artificial ageing compared to the controls, with ND having the least hardness reduction percentage amongst all 3D-printed materials. The hardness reduction percentage in distilled water and artificial saliva was similar for all materials except for TC, where higher reduction was noted in artificial saliva. SIGNIFICANCE The used 3D printed resins cannot yet be considered viable alternatives to milled materials intended for definitive restorations but are preferable for use as temporary restorations.
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Affiliation(s)
- Shaymaa Mudhaffer
- Division of Dentistry, School of Medical Sciences, University of Manchester, Manchester, UK; Substitutive Dental Sciences, Faculty of Dentistry, Taibah University, Madinah, Saudi Arabia.
| | - Rana Althagafi
- Substitutive Dental Sciences, Faculty of Dentistry, Taibah University, Madinah, Saudi Arabia
| | - Julfikar Haider
- Division of Dentistry, School of Medical Sciences, University of Manchester, Manchester, UK; Department of Engineering, Manchester Metropolitan University, Manchester, UK
| | - Julian Satterthwaite
- Division of Dentistry, School of Medical Sciences, University of Manchester, Manchester, UK
| | - Nick Silikas
- Division of Dentistry, School of Medical Sciences, University of Manchester, Manchester, UK.
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10
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Chen Y, Bai X, Xu M, Zhou T, Loh YM, Wang C, Pow EHN, Tsoi JKH. The mechanical, wear, antibacterial properties and biocompatibility of injectable restorative materials under wet challenge. J Dent 2024; 146:105025. [PMID: 38697507 DOI: 10.1016/j.jdent.2024.105025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2024] [Revised: 04/08/2024] [Accepted: 04/24/2024] [Indexed: 05/05/2024] Open
Abstract
OBJECTIVES To evaluate the mechanical, wear, antibacterial properties, and biocompatibility of injectable composite materials. METHODS Two injectable composite resins (GU and BI), one flowable composite resin (FS), and one flowable compomer (DF), in A2 shade, were tested. Mechanical properties were tested via three-point bending test immediately after preparation and after 1-day, 7-day, 14-day, and 30-day water storage. Under water-PMMA slurry immersion, specimens were subjected to a 3-body wear test (10,000 cycles) against stainless steel balls, while the roughness, wear depth, and volume loss were recorded. After 1-day and 3-day MC3T3-E1 cell culture, cell viability was evaluated with CCK-8 test kits, while the cell morphology was observed under CLSM and SEM. Antibacterial properties on S. mutans were assessed via CFU counting, CLSM, and SEM observation. SPSS 26.0 was used for statistical analysis (α = 0.05). RESULTS The mechanical properties were material-dependent and sensitive to water storage. Flexural strength ranked GU > FS > BI > DF at all testing levels. Three nanocomposites had better wear properties than DF. No significant difference on 1-day cell viability was found, but DF showed significantly lower cell proliferation than nanocomposites on 3-day assessment. GU and FS had more favourable cell adhesion and morphology. CFU counting revealed no significant difference, while FS presented a slightly thicker biofilm and BI showed relatively lower bacteria density. CONCLUSIONS Injectable nanocomposites outperformed the compomer regarding mechanical properties, wear resistance, and biocompatibility. The tested materials presented comparable antibacterial behaviours. Flowable resin-based composites' performances are affected by multiple factors, and their compositions can be attributed. CLINICAL SIGNIFICANCE A profound understanding of the mechanical, wear, and biological properties of the restorative material is imperative for the clinical success of dental restorations. The current study demonstrated superior properties of highly filled injectable composite resins, which imply their wider indications and better long-term clinical performances.
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Affiliation(s)
- Yanning Chen
- Dental Materials Science, Applied Oral Sciences and Community Dental Care, Faculty of Dentistry, The University of Hong Kong, Hong Kong Special Administrative Region, PR China
| | - Xuedong Bai
- Dental Materials Science, Applied Oral Sciences and Community Dental Care, Faculty of Dentistry, The University of Hong Kong, Hong Kong Special Administrative Region, PR China
| | - Mengxiao Xu
- Dental Materials Science, Applied Oral Sciences and Community Dental Care, Faculty of Dentistry, The University of Hong Kong, Hong Kong Special Administrative Region, PR China
| | - Tianyu Zhou
- Dental Materials Science, Applied Oral Sciences and Community Dental Care, Faculty of Dentistry, The University of Hong Kong, Hong Kong Special Administrative Region, PR China
| | - Yee Man Loh
- State Key Laboratory of Ultra-precision Machining Technology, Department of Industrial and Systems Engineering, The Hong Kong Polytechnic University, Hong Kong, PR China
| | - Chunjin Wang
- State Key Laboratory of Ultra-precision Machining Technology, Department of Industrial and Systems Engineering, The Hong Kong Polytechnic University, Hong Kong, PR China
| | - Edmond Ho Nang Pow
- Prosthodontics, Restorative Dental Sciences, Faculty of Dentistry, The University of Hong Kong, Hong Kong Special Administrative Region, PR China
| | - James Kit Hon Tsoi
- Dental Materials Science, Applied Oral Sciences and Community Dental Care, Faculty of Dentistry, The University of Hong Kong, Hong Kong Special Administrative Region, PR China.
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Altarazi A, Haider J, Alhotan A, Silikas N, Devlin H. Impact of Artificial Aging on the Physical and Mechanical Characteristics of Denture Base Materials Fabricated via 3D Printing. Int J Biomater 2024; 2024:8060363. [PMID: 38919543 PMCID: PMC11199068 DOI: 10.1155/2024/8060363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Revised: 05/09/2024] [Accepted: 05/31/2024] [Indexed: 06/27/2024] Open
Abstract
Three-dimensional (3D) printing is becoming more prevalent in the dental sector due to its potential to save time for dental practitioners, streamline fabrication processes, enhance precision and consistency in fabricating prosthetic models, and offer cost-effective solutions. However, the effect of aging in artificial saliva of this type of material has not been explored. To assess the physical and mechanical properties of the two types of 3D-printed materials before and after being subjected to artificial saliva, a total of 219 acrylic resin specimens were produced. These specimens were made with two types of 3D-printed materials, namely, NextDent (ND) and Formlabs (FLs), and a Schottlander heat-cured (HC) resin material that was used as a control. Water sorption and solubility specimens (n = 5) were tested after three months of storage in artificial saliva. Moreover, the Vickers hardness, Martens hardness, flexural strength/modulus, and impact strength were evaluated both under dry conditions and after three months of storage in artificial saliva. The degree of conversion (DC), elemental analysis, and filler content were also investigated. The ANOVA showed that 3D-printed resins had significantly greater sorption than the control group (p < 0.05). However, the flexural strength values of the 3D-printed materials were significantly greater (p < 0.05) than those of the heat-cured material. The DC of the 3D-printed resins was lower than that of the control group, but the difference was not significant (p > 0.05). The 3D-printed materials contained significantly more filler than the control (p < 0.05). Moreover, the artificial saliva had a significant effect on the Vickers hardness for all tested groups and on the Martens hardness for the control group only (p < 0.05). Compared with conventional heat-cured materials, 3D-printed denture base materials demonstrated relatively poorer performance in terms of sorption, solubility, and DC but exhibited either comparable or superior mechanical properties. The aging process also influenced the Vickers and Martens' hardness. The strength of the 3D-printed materials was in compliance with ISO recommendations, and the materials could be used alongside conventional heat-cured materials.
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Affiliation(s)
- Ahmed Altarazi
- Division of Dentistry, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester M13 9PL, UK
- Restorative Dental Science, College of Dentistry, Taibah University, Medinah, Saudi Arabia
| | - Julfikar Haider
- Division of Dentistry, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester M13 9PL, UK
- Department of Engineering, Manchester Metropolitan University, Manchester M1 5GD, UK
| | - Abdulaziz Alhotan
- Department of Dental Health, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia
| | - Nick Silikas
- Division of Dentistry, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester M13 9PL, UK
| | - Hugh Devlin
- Division of Dentistry, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester M13 9PL, UK
- School of Dentistry, University of Jordan, Amman, Jordan
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12
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Albelasy EH, Hamama HH, Chew HP, Montasser M, Mahmoud SH. Clinical performance of two ion-releasing bulk-fill composites in class I and class II restorations: A two-year evaluation. J ESTHET RESTOR DENT 2024; 36:723-736. [PMID: 38174898 DOI: 10.1111/jerd.13193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Revised: 11/26/2023] [Accepted: 12/25/2023] [Indexed: 01/05/2024]
Abstract
OBJECTIVES This randomized clinical trial evaluated and compared the 2-year clinical performance of two ion-releasing bulk-fill composites (Cention N and Surefil One) with that of a conventional bulk-fill resin composite (Powerfil) in Class I and II cavities. METHODS Thirty-two patients, each with 3 Class I and/or Class II cavities under occlusion, were enrolled in this trial. A total of 96 restorations were placed, 32 for each material, as follows: a self-adhesive composite; Surefil-one, alkasite; Cention N, and a bulk-fill resin composite; Powerfil. The restorations were placed by a single operator. Clinical evaluation was performed at baseline (1-week), 6-months, 1-year, and 2-years by two independent examiners using the FDI criteria. Intergroup and intragroup comparisons were analyzed using the Kruskal-Wallis and Friedman Tests. Multiple comparisons between groups were analyzed using the Mann-Whitney and Wilcoxon-rank tests. The level of significance was set at α = 0.05. RESULTS Twenty-seven patients with a total of 81 restorations were evaluated at the end of the 2-years with 84.35% recall rates. Clinical success rates were 100%, 100%, and 96.3% for Powerfil, Surefil-one, and Cention N, respectively. Cention N showed a statistically significant (p < 0.05) decreased marginal integrity in comparison with resin composite at the 2-year evaluation. No recurrent decay was detected in any restoration. CONCLUSIONS Both ion-releasing bulk-fill composites provided acceptable clinical performance similar to bulk-fill composite in Class I and II restorations over a 2-year period. CLINICAL RELEVANCE The results of this trial suggests that there is a promising evidence supporting the use of ion-releasing composites.
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Affiliation(s)
- Eman H Albelasy
- Conservative Dentistry Department, Faculty of Dentistry, Mansoura University, Mansoura, Aldakhlia, Egypt
- Minnesota Dental Research Center for Biomaterials and Biomechanics, School of Dentistry, University of Minnesota, Minneapolis, Minnesota, USA
| | - Hamdi H Hamama
- Conservative Dentistry Department, Faculty of Dentistry, Mansoura University, Mansoura, Aldakhlia, Egypt
- Faculty of Dentistry, New-Mansoura University, New-Mansoura, Egypt
| | - Hooi Pin Chew
- Minnesota Dental Research Center for Biomaterials and Biomechanics, School of Dentistry, University of Minnesota, Minneapolis, Minnesota, USA
| | - Marmar Montasser
- Conservative Dentistry Department, Faculty of Dentistry, Mansoura University, Mansoura, Aldakhlia, Egypt
| | - Salah H Mahmoud
- Conservative Dentistry Department, Faculty of Dentistry, Mansoura University, Mansoura, Aldakhlia, Egypt
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Favoreto MW, Carneiro TDS, Ñaupari-Villasante R, Cordeiro DC, Cochinski GD, Machado do Nascimento TVP, Matos TDP, Bandeca MC, Reis A, Loguercio AD. Clinical performance of preheating thermoviscous composite resin for non-carious cervical lesions restoration: A 24-month randomized clinical trial. J Dent 2024; 144:104930. [PMID: 38471581 DOI: 10.1016/j.jdent.2024.104930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Revised: 02/17/2024] [Accepted: 03/05/2024] [Indexed: 03/14/2024] Open
Abstract
OBJECTIVES This 24-month, double-blind, split-mouth randomized clinical trial aimed to compare the retention rates of a preheated thermoviscous composite resin (PHT) compared to a non-heated composite resin (NHT) in non-carious cervical lesions (NCCLs). METHODS A total of 120 restorations were restored on NCCLs using a preheated (VisCalor bulk, Voco GmbH) and a non-heated (Admira Fusion, Voco GmbH) composite resins with 60 restorations per group. A universal adhesive in the selective enamel conditioning was applied. In the PHT group, composite was heated at 68 °C for using a bench heater. In the NHT group, no heating was employed. Both restorative materials were dispensed into caps and inserted into the NCCLs. The restorations were evaluated at baseline, 6, 12, 18, and after 24 months of clinical service using the FDI criteria. Statistical analysis was performed with Kaplan-Meier estimation analysis for retention/fracture rate and Chi-square test for the other FDI parameters (α=0.05). RESULTS After 24 months 108 restorations were assessed. Seven restorations were lost (two for PHT group and five for NHT group), and the retention rates (95 % confidence interval [CI]) were 96.7 % (81.5-99.9) for PHT group and 90.8 % (81.1-96.0) for NHT group, with no statistical differences between them (p > 0.05). The hazard ratio (95 % CI) was 0.52 (0.27 to 1.01), with no significant difference within groups. In terms of all other FDI parameters that were assessed, all restorations were deemed clinically acceptable. CONCLUSIONS Both composites showed high rates of retention rates after 24 months. CLINICAL SIGNIFICANCE The clinical performance of the new preheated thermoviscous was found to be as good as the non-heated composite after 24-month of clinical evaluation in non-carious cervical lesions. REGISTRATION OF CLINICAL TRIALS RBR-6d6gxxz.
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Affiliation(s)
- Michael Willian Favoreto
- Department of Restorative Dentistry, School of Dentistry, State University of Ponta Grossa, Ponta Grossa, Paraná, Brazil; School of Dentistry, Tuiuti University, Curitiba, Paraná, Brazil
| | - Taynara de Souza Carneiro
- Department of Restorative Dentistry, School of Dentistry, State University of Ponta Grossa, Ponta Grossa, Paraná, Brazil; Department of Stomatology, IDIBO research group, Health Sciences Faculty, Rey Juan Carlos University, Alcorcón, Madrid, Spain
| | - Romina Ñaupari-Villasante
- Department of Restorative Dentistry, School of Dentistry, State University of Ponta Grossa, Ponta Grossa, Paraná, Brazil
| | - Deisy Cristina Cordeiro
- Department of Restorative Dentistry, School of Dentistry, State University of Ponta Grossa, Ponta Grossa, Paraná, Brazil
| | - Gabriel David Cochinski
- Department of Restorative Dentistry, School of Dentistry, State University of Ponta Grossa, Ponta Grossa, Paraná, Brazil
| | | | | | - Matheus Coelho Bandeca
- Department of Restorative Dentistry, School of Dentistry, State University of Ponta Grossa, Ponta Grossa, Paraná, Brazil
| | - Alessandra Reis
- Department of Restorative Dentistry, School of Dentistry, State University of Ponta Grossa, Ponta Grossa, Paraná, Brazil.
| | - Alessandro D Loguercio
- Department of Restorative Dentistry, School of Dentistry, State University of Ponta Grossa, Ponta Grossa, Paraná, Brazil.
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Lee CH, Lee IB. Three methods to measure the photopolymerization kinetics for different radiant emittance and composite type. Dent Mater J 2024; 43:207-215. [PMID: 38296511 DOI: 10.4012/dmj.2023-197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/02/2024]
Abstract
Photopolymerization kinetics affects the curing time, degree of conversion, polymerization shrinkage, and mechanical properties of composites. The aim of this study was to compare three methods (temperature, heat flow, and polymerization shrinkage) for photopolymerization kinetics measurement of composites. The photopolymerization kinetics of four composites (2 packable and 2 flowable) were measured with an LED light for 20 s (radiant emittance: 2,100 mW/cm2). For the two packable composites, photopolymerization kinetics was measured with varying the radiant emittance and exposure time. For each measurement method, peak times were determined as the time when maximum temperature rise, heat flow, and shrinkage rate occurred, respectively. The photopolymerization kinetics differed among the measurement methods. The photopolymerization kinetics of composites changed as the radiant emittance and composite type varied. In clinical practice and research on the composite restoration, the kinetics should be considered comprehensively with the complementary use of various measurement methods.
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Affiliation(s)
- Chang-Ha Lee
- Department of Conservative Dentistry, School of Dentistry and Dental Research Institute, Seoul National University
| | - In-Bog Lee
- Department of Conservative Dentistry, School of Dentistry and Dental Research Institute, Seoul National University
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Alshabib A, Silikas N, Watts DC. Properties of model E-glass fiber composites with varying matrix monomer ratios. Dent Mater 2024; 40:441-450. [PMID: 38129191 DOI: 10.1016/j.dental.2023.12.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 12/08/2023] [Accepted: 12/08/2023] [Indexed: 12/23/2023]
Abstract
OBJECTIVE To evaluate properties of fiber-reinforced-composites (FRC) containing Bis-EMA/UDMA monomers but identical dispersed phase (60% wt BaSi glass power +10% wt E-glass fibre). METHODS A control (Group A), monomer mixture comprising 60% Bis-GMA, 30% TEGDMA, and 10% PMMA (typical FRC monomers) was used. The following monomer mass fractions were mixed: 50% bis-GMA plus 50% of different ratios of Bis-EMA+UDMA to produce consistent formulations (Groups B-E) of workable viscosities was also studied. Flexural strength (FS), fracture toughness (KIC), water sorption (SP), solubility (SL) and hygroscopic expansion (HE) were measured. FS and KIC specimens were stored for 1, 7 d, and 30 d in water at 37 °C. SP/SL specimens were water-immersed for 168d, weighed at intervals, then dried for 84 d at 37 °C. To analyze differences in FS, and KIC, a two-way ANOVA and Tukey post-hoc tests (α = 0.05) were conducted. For SP/SL, and HE, one-way ANOVA with subsequent Tukey post-hoc tests (α = 0.05) were utilized. RESULTS FS and KIC for groups A, D, E decreased progressively after 1 d. Groups B and C (highest amounts of Bis-EMA) did not decrease significantly. The modified matrix composites performed significantly better than the control group for SP and HE. The control group outperformed the experimental composites only for SL with up to 250% higher SL for group E (6.9 μg/mm) but still below the maximum permissible threshold of 7.5 μg/mm. SIGNIFICANCE EXPERIMENTAL: composites with highest amounts of Bis-EMA showed improved hydrolytic stability and overall enhancement in several clinically-relevant properties. This makes them potential candidates for alternative matrices to a semi-interpenetrating network in fiber-reinforced composites.
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Affiliation(s)
- Abdulrahman Alshabib
- Department of Restorative Dentistry, College of Dentistry, King Saud University, Riyadh, Saudi Arabia.
| | - Nikolaos Silikas
- Dentistry, School of Medical Sciences, University of Manchester, Manchester, UK
| | - David C Watts
- Dentistry, School of Medical Sciences, University of Manchester, Manchester, UK.
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Thanoon H, Price RB, Watts DC. Thermography and conversion of fast-cure composite photocured with quad-wave and laser curing lights compared to a conventional curing light. Dent Mater 2024; 40:546-556. [PMID: 38326211 DOI: 10.1016/j.dental.2024.01.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 01/24/2024] [Accepted: 01/25/2024] [Indexed: 02/09/2024]
Abstract
OBJECTIVES This study investigated effects of the different emittance-mode protocols from three light curing units (LCUs): (i) a Laser (Monet); (ii) a quad-wave (PinkWave); (iii) a conventional LED (Elipar S10) on the temperature rise (ΔT) and degree of conversion (DC) when photo-curing fast or conventional bulk-fill resin-based composites (RBC). The aim was to correlate ΔT and DC, and the radiant exposure delivered to RBC specimens. METHODS A 3D-printed resin mold of 4 mm depth was filled with two bulk-fill RBCs: Tetric PowerFill® (fast photo-polymerised composite) (TPF) or Tetric EvoCeram® Bulk-Fill (EVO). Three LCUs were used: (i) Monet laser for 1 s and 3 s (MONET-1 s, MONET-3 s); (ii) PinkWave quad-wave used for 3 s in Boost mode (PW-3 s) and for 20 s in standard mode (PW-20 s); (iii) Elipar S10 for 5 s (S10-5 s) and for 20 s in standard mode (S10-20 s). 2-dimensional temperature maps were obtained before, during and for 60 s after the LCU had turned off using a thermal imaging camera. Thermal changes were analysed at five depths: (0, 1, 2, 3, and 4 mm from the top surface of the RBC). The maximum temperature rise (Tmax) and the mean temperature rise (ΔT) were determined. Cylindrical-shaped specimens were prepared from each material using a stainless-steel split mold (4 × 4 mm) and light-cured with the same protocols. The DC was measured for 120 s and at 1 h after LCU had turned off using Fourier Transform Infrared Spectroscopy (FTIR). Data were analysed using Three-way ANOVA, One-way ANOVA, independent t-tests, and Tukey post-hoc tests (p < 0.05). RESULTS Radiant exposures delivered by the various irradiation protocols were between 4.5-30.3 J/cm2. Short exposure times from MONET-1 s and PW-3 s delivered the lowest radiant exposures (4.5 and 5.2 J/cm2, respectively) and produced the lowest ΔT and DC. The longer exposure times in the standard modes of PW-20 s, S10-20 s, and MONET-3 s produced the highest Tmax, ΔT, and DC for both composites. The ΔT range among composites at different depths varied significantly (31.7-49.9 °C). DC of TPF ranged between 30-65% and in EVO between 15.3-56%. TPF had higher Tmax, ΔT for all depths and DC compared to EVO, across the LCU protocols (p < 0.05), except for PW-20 s and MONET-3 s. The coronal part of the restorations (1-2 mm) had the highest ΔT. There was a positive correlation between ΔT and DC at 4-mm depth after 120 s SIGNIFICANCE: Longer, or standard, exposure times of the LCUs delivered greater radiant exposures and had higher DC and ΔT compared to shorter or high-irradiance protocols. The fast photo-polymerised RBC had comparatively superior thermal and conversion outcomes when it received a high irradiance for a short time (1-5 s) compared to the conventional Bulk-Fill RBC.
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Affiliation(s)
- Halah Thanoon
- Division of Dentistry, School of Medical Sciences, University of Manchester, Manchester, UK; Department of Restorative Dentistry, College of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia.
| | - Richard B Price
- Department of Dental Clinical Sciences, Dalhousie University, Halifax, Nova Scotia, Canada
| | - David C Watts
- Division of Dentistry, School of Medical Sciences, University of Manchester, Manchester, UK; Photon Science Institute, University of Manchester, Manchester, UK.
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de Deus RA, Oliveira L, Braga S, Ribeiro M, Price RB, Núñez A, Loguercio AD, Soares CJ. Effect of Radiant Exposure on the Physical and Mechanical Properties of 10 Flowable and High-viscosity Bulk-fill Resin Composites. Oper Dent 2024; 49:136-156. [PMID: 38349819 DOI: 10.2341/23-025-l] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/27/2023] [Indexed: 02/15/2024]
Abstract
OBJECTIVES To evaluate the effect of the different radiant exposures from a multipeak light curing unit on the physical and mechanical properties of flowable and high-viscosity bulk-fill resin-based composites (RBC). METHODS Five flowable bulk-fill RBCs (Tetric N-Flow Bulk-fill, Ivoclar Vivadent; Filtek Bulk Fill Flow, 3M Oral Care; Opus Bulk Fill Flow APS, FGM; Admira Fusion x-base, Voco and; and SDR Plus Bulk Fill Flowable, Dentsply Sirona) and five high-viscosity bulk-fill RBCs (Tetric N-Ceram Bulk-fill, Ivoclar Vivadent; Filtek One Bulk Fill, 3M Oral Care; Opus Bulk Fill APS, FGM; Admira Fusion x-tra, Voco; and SonicFill 2, Kerr) were photo-cured using a VALO Cordless light (Ultradent) for 10, 20, and 40 seconds at an irradiance of 1200, 800, or 400 mW/cm2, resulting in the delivery of 4, 8, 12, 16, 24, 32, or 48 J/cm2. Post-gel shrinkage (Shr) was calculated using strain-gauge test. The degree of conversion (DC, %) was calculated using FTIR. Knoop hardness (KH, N/mm2) and elastic modulus (E, MPa) were measured at the top and bottom surfaces. Logarithmic regressions between the radiant exposures and mechanical properties were calculated. Radiodensity was calculated using digital radiographs. Data of Shr and radiodensity were analyzed using two-way analysis of variance (ANOVA), and the DC, KH, and E data were analyzed with two-way ANOVA using split-plot repeated measurement tests followed by the Tukey test (a = 0.05). RESULTS Delivering higher radiant exposures produced higher Shr values (p<0.001) and higher DC values (R2=0.808-0.922; R2=0.648-0.914, p<0.001), KH (R2=0.707-0.952; R2=0.738-0.919; p<0.001), and E (R2=0.501-0.925; R2=0.823-0.919; p<0.001) values for the flowable and high-viscosity RBCs respectively. Lower KH, E and Shr were observed for the flowable bulk-fill RBCs. All bulk-fill RBCs had a radiopacity level greater than the 4-mm thick aluminum step wedge. The radiant exposure did not affect the radiopacity. CONCLUSION The Shr, DC, KH, and E values were highly correlated to the radiant exposure delivered to the RBCs. The combination of the higher irradiance for longer exposure time that resulted in radiant exposure between 24 J/cm2 to 48 J/cm2 produced better results than delivering 400 mW/cm2 for 40 s (16 J/cm2), and 800 mW/cm2 for 20 seconds (16 J/cm2) or 1200 mW/cm2 for 10 seconds (12 J/cm2). All the bulk-fill RBCs were sufficiently radiopaque compared to 4 mm of aluminum.
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Affiliation(s)
- R A de Deus
- Raissa Albuquerque de Deus, DDS, MSc, Department of Operative Dentistry and Dental Materials, School of Dentistry, Federal University of Uberlândia, Uberlândia, Minas Gerais, Brazil
| | - Lrs Oliveira
- Lais Rani Sales Oliveira, DDS, MSc, PhD, Department of Operative Dentistry and Dental Materials, School of Dentistry, Federal University of Uberlândia, Uberlândia, Minas Gerais, Brazil
| | - Ssl Braga
- Stella Sueli Lourenço Braga, DDS, MSc, PhD, Department of Operative Dentistry and Dental Materials, School of Dentistry, Federal University of Uberlândia, Uberlândia, Minas Gerais, Brazil
| | - Mth Ribeiro
- Maria Tereza Hordones Ribeiro, DDS, MSc, PhD student, Department of Operative Dentistry and Dental Materials, School of Dentistry, Federal University of Uberlândia, Uberlândia, Minas Gerais, Brazil
| | - R B Price
- Richard Bengt Price, DDS, MSc, PhD, Department of Dental Clinical Sciences, Dalhousie University, Halifax, Nova Scotia, Canada
| | - A Núñez
- Alejandra Núñez, DDS, MSc, PhD student, Universidade Estadual de Ponta Grossa, Ponta Grossa, PR, Brazil
| | - A D Loguercio
- Alessandro Dourado Loguercio, DDS, MSc, PhD, School of Dentistry, Universidade Estadual de Ponta Grossa, Ponta Grossa, PR, Brazil
| | - C J Soares
- *Carlos José Soares, DDS, MS, PhD, Department of Operative Dentistry and Dental Materials, School of Dentistry, Federal University of Uberlândia, Uberlândia, Minas Gerais, Brazil
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da Silva EM, Amaral CM, Jardim RN, Barbosa MP, Rabello TB. Influence of Specimen Dimension, Water Immersion Protocol, and Surface Roughness on Water Sorption and Solubility of Resin-Based Restorative Materials. MATERIALS (BASEL, SWITZERLAND) 2024; 17:984. [PMID: 38473457 DOI: 10.3390/ma17050984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 02/16/2024] [Accepted: 02/18/2024] [Indexed: 03/14/2024]
Abstract
The evaluation of water sorption and solubility is pivotal for the development of new resin-based restorative materials with the potential for clinical application. The purpose of the present study was to evaluate the influence of the specimen dimension, water immersion protocol, and surface roughness on the water sorption and solubility of three resin-based restorative materials. Disk-shaped specimens of 15 mm × 1 mm, 10 mm × 1 mm, and 6 mm × 1 mm were produced with a composite resin (Z100), a resin cement (RelyX ARC), and an adhesive system (Single Bond 2-SB2). The specimens were immersed in distilled water according to four protocols: ISO (all the specimens for each group were vertically immersed in 50 mL); IV-10 (the specimens were individually and vertically immersed in 10 mL); IH-10 (the specimens were individually and horizontally immersed in 10 mL); and IH-2 (the specimens were individually and horizontally immersed in 2 mL). The surface roughness (Sa and Sp) was evaluated using an atomic force microscope, and the degree of conversion was determined using FT-IR spectrometry. The specimen dimension and water immersion protocol had no effect on water sorption and solubility. For the three resin-based restorative materials, Sp was higher than Sa. The degree of conversion was not influenced by the specimen dimension. The variations in the specimen dimension and water immersion protocol compared to those determined by ISO 4049 did not prevent the comparison between the values of water sorption and solubility obtained for a given resin-based restorative material.
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Affiliation(s)
- Eduardo Moreira da Silva
- Analytical Laboratory of Restorative Biomaterials-LABiom-R, Faculdade de Odontologia, Universidade Federal Fluminense, Niterói 24040-110, Brazil
| | - Cristiane Mariote Amaral
- Analytical Laboratory of Restorative Biomaterials-LABiom-R, Faculdade de Odontologia, Universidade Federal Fluminense, Niterói 24040-110, Brazil
| | - Renata Nunes Jardim
- Analytical Laboratory of Restorative Biomaterials-LABiom-R, Faculdade de Odontologia, Universidade Federal Fluminense, Niterói 24040-110, Brazil
| | - Marianna Pires Barbosa
- Analytical Laboratory of Restorative Biomaterials-LABiom-R, Faculdade de Odontologia, Universidade Federal Fluminense, Niterói 24040-110, Brazil
| | - Tiago Braga Rabello
- Faculdade de Odontologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, Brazil
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Zhou Z, Guo D, Watts DC, Fischer NG, Fu J. Application and limitations of configuration factor (C-factor) in stress analysis of dental restorations. Dent Mater 2023; 39:1137-1149. [PMID: 37838610 DOI: 10.1016/j.dental.2023.10.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 10/06/2023] [Accepted: 10/06/2023] [Indexed: 10/16/2023]
Abstract
OBJECTIVE The configuration factor (C-factor) is an index used to evaluate the relationship between cavity configuration and the development of polymerization shrinkage stress in dental restorations. Although C-factor has been widely researched, its correlation with stress analysis in dental restorations remains controversial. This review aims to discuss the application and limitations of C-factor and define the restricted conditions under which the C-factor "rule of thumb" is applicable. METHODS A thorough literature review was conducted on the application and limitations of C-factor in stress analysis of dental restorations. This was principally based on MEDLINE/PubMed and Web of Science databases and a review of the relevant studies and publications in scientific papers in international peer-reviewed journals for the specific topic of C-factor and polymerization shrinkage. RESULTS The C-factor alone cannot provide an accurate prediction of the shrinkage stress of restorations and the mechanical behavior of material-tooth interfaces. C-factor is only applicable under one condition not typically seen in clinical practice: low, near-rigid compliance. SIGNIFICANCE Conditions for the application of C-factor have been explicitly defined. A more accurate and precise understanding and utilization of the C-factor is of benefit as it contributes to better understanding of polymerization shrinkage behavior of restorations.
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Affiliation(s)
- Zixuan Zhou
- Department of Prosthodontics, The Affiliated Hospital of Qingdao University, 266000 Qingdao, China; School of Stomatology of Qingdao University, 266003 Qingdao, China
| | - Di Guo
- Department of Prosthodontics, The Affiliated Hospital of Qingdao University, 266000 Qingdao, China; School of Stomatology of Qingdao University, 266003 Qingdao, China
| | - David C Watts
- University of Manchester, School of Medical Sciences, Oxford Road, M13 9PL Manchester, UK
| | - Nicholas G Fischer
- Minnesota Dental Research Center for Biomaterials and Biomechanics, University of Minnesota, Minneapolis, MN 55455, USA.
| | - Jing Fu
- Department of Prosthodontics, The Affiliated Hospital of Qingdao University, 266000 Qingdao, China; School of Stomatology of Qingdao University, 266003 Qingdao, China.
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Alzahrani B, Alshabib A, Awliya W. The Depth of Cure, Sorption and Solubility of Dual-Cured Bulk-Fill Restorative Materials. MATERIALS (BASEL, SWITZERLAND) 2023; 16:6673. [PMID: 37895655 PMCID: PMC10608248 DOI: 10.3390/ma16206673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2023] [Revised: 10/07/2023] [Accepted: 10/11/2023] [Indexed: 10/29/2023]
Abstract
This study aimed to examine depth of cure (DoC), mass change, water sorption and solubility of dual-cured bulk-fill restorative materials (Surfil One and Activa) in comparison with a light-cured bulk-fill composite (Filtek One Bulk-Fill) and a resin-modified glass ionomer (Fuji II LC). Twenty specimens were prepared of each material using stainless steel molds designed with a slot (8 × 4 × 2 mm) and irradiated for either 20 or 40 s. The Vickers hardness (VHN) was measured at every 0.5 mm to assess the DoC after 24 h of storage at 37 °C. The depth of cure was reported as the depth corresponding to 80% of the maximum Vickers hardness. Disc-shaped specimens were prepared of each material (n = 5) to investigate mass change, sorption and solubility after 4 months of water storage. The data were analyzed using a two-way and one-way analysis of variance (ANOVA) followed by the Tukey post hoc test (p ≤ 0.05). Fuji II LC had the greatest DoC while Activa had the lowest. The two different irradiation times did not demonstrate a significant difference in DoC for all dual-cured materials (p > 0.05). Fuji II LC had the highest sorption while Filtek One showed the lowest. Surefil One and Fuji II LC had a negative solubility. This study concluded that dual-cured materials showed different depth of cure values despite having the same setting reaction. Both materials exhibited a high water sorption, which might jeopardize their dimensional stability and effect their clinical performance.
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Affiliation(s)
- Bashayer Alzahrani
- Department of Restorative Dentistry, College of Dentistry, King Saud University P.O. Box 60169, Riyadh 11545, Saudi Arabia;
| | - Abdulrahman Alshabib
- Department of Restorative Dentistry, College of Dentistry, King Saud University P.O. Box 60169, Riyadh 11545, Saudi Arabia;
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21
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Al-Qudah A, Jawad DA, Jaradat M. Periapical Status of Non-Root-Filled Teeth With Amalgam, Composite, or Crown Restorations: A Cross-Sectional Study. Int Dent J 2023; 73:645-650. [PMID: 36543731 PMCID: PMC10541455 DOI: 10.1016/j.identj.2022.11.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 11/22/2022] [Accepted: 11/25/2022] [Indexed: 12/23/2022] Open
Abstract
OBJECTIVES This study aimed to evaluate the periapical status (PAS) of restored non-root-filled (RNRF) teeth amongst a group of patients attending dental teaching clinics at Jordan University of Science & Technology. It also aimed to assess the association of type and quality of coronal restorations and periapical disease. METHODS This was a cross-sectional study. To be included, participants needed to have at least 1 non-root-filled tooth restored with either direct or indirect restoration. A sample of 491 participants was examined. Clinical examination and digital periapical radiographs were used to record material used and assess the quality of the restorations. Chi-square test and logistic regression analysis were used to analyse the association between PAS and gender, age, restoration material/type, and quality. RESULTS Overall, 26.3% of the participants were diagnosed with apical periodontitis (AP) on 1 or more of the examined teeth. No significant differences in the prevalence of AP were observed when comparing amalgam to composite or indirect restorations (P = .386). Furthermore, no association was reported between AP and gender or age, while a significant association was observed with the restoration's quality (P < .001). CONCLUSIONS The high prevalence of AP in the examined sample is of clinical concern and suggests that more attention should be directed towards dental health awareness in Jordan. Teeth restored with inadequate restorations were twice as likely to have AP.
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Affiliation(s)
- Aladdin Al-Qudah
- Department of Conservative Dentistry, Jordan University of Science and Technology, Irbid, Jordan.
| | - Diana Abdul Jawad
- Department of Conservative Dentistry, Jordan University of Science and Technology, Irbid, Jordan
| | - Maram Jaradat
- Department of Conservative Dentistry, Jordan University of Science and Technology, Irbid, Jordan
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Bilgili Can D, Özarslan M. 3D-2D microleakage assessment of preheated bulk-fill composite resin applied with different parameters: a micro-CT analysis. Odontology 2023; 111:942-952. [PMID: 36973535 DOI: 10.1007/s10266-023-00805-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Accepted: 03/14/2023] [Indexed: 03/29/2023]
Abstract
This study evaluated microleakage from class II cavities filled with bulk-fill composite preheated to different temperatures, applied at different thicknesses, and with different polymerization modes. A total of 60 mesio-occlusal cavity were drilled into the extracted human third molars at 2 mm and 4 mm thickness. Preheated bulk-fill composite resin (Viscalor; VOCO, Germany) was applied to the cavities at 68 °C and 37 °C after the adhesive resin was applied, and cured using standard and high-power light-curing modes of a VALO light-curing unit. An incrementally applied microhybrid composite was used as the control. The teeth were subjected to 2000 cycles of heating to 55 °C and cooling to 5 °C with a 30-s hold time. Then, they were immersed in a 50% silver nitrate solution for 24 h and scanned with micro-computed tomography. Scanned data were processed using the CTAn software. Two (2D) and three (3D) dimensional analyses of leached silver nitrate were performed. The data's normality was assessed using the Shapiro-Wilk test before comparisons using a three-way analysis of variance. In both 2D and 3D analysis, bulk-fill composite resin preheated to 68 °C and applied at 2 mm thickness showed less microleakage. In the 3D analysis, restorations applied at 37 °C and 4 mm thickness in high-power mode showed significantly higher values (p < 0.001). Preheated bulk-fill composite resin can be applied at 68 °C and effectively cured at both 2 mm and 4 mm thickness.
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Affiliation(s)
- Dilber Bilgili Can
- Department of Restorative Dentistry, Faculty of Dentistry, Van Yuzuncu Yil University, Van, 65080, Turkey.
| | - Merve Özarslan
- Department of Prosthetic Dentistry, Faculty of Dentistry, Akdeniz University, Antalya, Turkey
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23
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Fidalgo-Pereira R, Carvalho Ó, Catarino SO, Henriques B, Torres O, Braem A, Souza JCM. Effect of inorganic fillers on the light transmission through traditional or flowable resin-matrix composites for restorative dentistry. Clin Oral Investig 2023; 27:5679-5693. [PMID: 37592003 PMCID: PMC10492747 DOI: 10.1007/s00784-023-05189-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 07/28/2023] [Indexed: 08/19/2023]
Abstract
OBJECTIVES The aim of this in vitro study was to evaluate the light transmission through five different resin-matrix composites regarding the inorganic filler content. METHODS Resin-matrix composite disc-shaped specimens were prepared on glass molds. Three traditional resin-matrix composites contained inorganic fillers at 74, 80, and 89 wt. % while two flowable composites revealed 60 and 62.5 wt. % inorganic fillers. Light transmission through the resin-matrix composites was assessed using a spectrophotometer with an integrated monochromator before and after light curing for 10, 20, or 40s. Elastic modulus and nanohardness were evaluated through nanoindentation's tests, while Vicker's hardness was measured by micro-hardness assessment. Chemical analyses were performed by FTIR and EDS, while microstructural analysis was conducted by optical microscopy and scanning electron microscopy. Data were evaluated using two-way ANOVA and Tukey's test (p < 0.05). RESULTS After polymerization, optical transmittance increased for all specimens above 650-nm wavelength irradiation since higher light exposure time leads to increased light transmittance. At 20- or 40-s irradiation, similar light transmittance was recorded for resin composites with 60, 62, 74, or 78-80 wt. % inorganic fillers. The lowest light transmittance was recorded for a resin-matrix composite reinforced with 89 wt. % inorganic fillers. Thus, the size of inorganic fillers ranged from nano- up to micro-scale dimensions and the high content of micro-scale inorganic particles can change the light pathway and decrease the light transmittance through the materials. At 850-nm wavelength, the average ratio between polymerized and non-polymerized specimens increased by 1.6 times for the resin composite with 89 wt. % fillers, while the composites with 60 wt. % fillers revealed an increased ratio by 3.5 times higher than that recorded at 600-nm wavelength. High mean values of elastic modulus, nano-hardness, and micro-hardness were recorded for the resin-matrix composites with the highest inorganic content. CONCLUSIONS A high content of inorganic fillers at 89 wt.% decreased the light transmission through resin-matrix composites. However, certain types of fillers do not interfere on the light transmission, maintaining an optimal polymerization and the physical properties of the resin-matrix composites. CLINICAL SIGNIFICANCE The type and content of inorganic fillers in the chemical composition of resin-matrix composites do affect their polymerization mode. As a consequence, the clinical performance of resin-matrix composites can be compromised, leading to variable physical properties and degradation.
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Affiliation(s)
- Rita Fidalgo-Pereira
- Center for Interdisciplinary Research in Health (CIIS), Faculty of Dental Medicine (FMD), Universidade Católica Portuguesa (UCP), 3504-505, Viseu, Portugal
- University Institute of Health Sciences (IUCS), CESPU, 4585-116, Gandra PRD, Portugal
| | - Óscar Carvalho
- Center for MicroElectroMechanical Systems (CMEMS-UMINHO), University of Minho, 4800-058, Guimarães, Portugal
- LABBELS Associate Laboratory, University of Minho, Guimarães, 4710-057, Braga, Portugal
| | - Susana O Catarino
- Center for MicroElectroMechanical Systems (CMEMS-UMINHO), University of Minho, 4800-058, Guimarães, Portugal
- LABBELS Associate Laboratory, University of Minho, Guimarães, 4710-057, Braga, Portugal
| | - Bruno Henriques
- Center for MicroElectroMechanical Systems (CMEMS-UMINHO), University of Minho, 4800-058, Guimarães, Portugal
- LABBELS Associate Laboratory, University of Minho, Guimarães, 4710-057, Braga, Portugal
- Ceramic and Composite Materials Research Group (CERMAT), Department of Mechanical Engineering (EMC), Federal University of Santa Catarina (UFSC), SC, 88040-900, Florianopolis, Brazil
| | - Orlanda Torres
- Oral Pathology and Rehabilitation Research Unit (UNIPRO), University Institute of Health Sciences (IUCS), CESPU, 4585-116, Gandra, Portugal
| | - Annabel Braem
- Department of Materials Engineering (MTM), Biomaterials and Tissue Engineering Research Group, KU Leuven, 3000, Leuven, Belgium
| | - Júlio C M Souza
- Center for MicroElectroMechanical Systems (CMEMS-UMINHO), University of Minho, 4800-058, Guimarães, Portugal.
- LABBELS Associate Laboratory, University of Minho, Guimarães, 4710-057, Braga, Portugal.
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Maucoski C, Price RB, Arrais CAG. Irradiance from 12 LED light curing units measured using 5 brands of dental radiometers. J ESTHET RESTOR DENT 2023; 35:968-979. [PMID: 37560968 DOI: 10.1111/jerd.13107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 06/29/2023] [Accepted: 07/05/2023] [Indexed: 08/11/2023]
Abstract
OBJECTIVE To evaluate the accuracy of five brands of radiometers in reporting the irradiance (mW/cm2 ) from twelve brands of LCUs compared to a 'Gold Standard' (GS) reference obtained from a hand-held laboratory-grade radiometer. MATERIALS AND METHODS The irradiance was measured from two examples of twelve brands of previously used LCUs on two examples of five brands of dental radiometers. The emission spectrum was also obtained. Irradiance data from each brand of LCU against each meter was analyzed using the Shapiro-Wilk test for normality. The irradiance values were subjected to a two-way ANOVA followed by Bonferroni tests for each LCU brand. Finally, a descriptive analysis was made using a 95% confidence interval around the mean irradiance. RESULTS The power output from the LCUs ranged from 271 mW to 1005 mW. Among the tested radiometers, only the Bluephase Meter II could accurately report the irradiance from 11 out of the 12 brands of LCU evaluated in this study. When measured using the "GS" system, the mean irradiance values from the two examples of nine brands of previously used LCU were not always within ±10% of the irradiance values stated by the manufacturer. CONCLUSIONS The mean irradiance values from 9 of the 12 brands of used LCUs were beyond ±10% of the irradiance values stated by the manufacturer. Only the Bluephase Meter II could accurately report the irradiance from 11 out of the 12 brands of LCU evaluated in this study. CLINICAL SIGNIFICANCE There was a wide range in the power output from the LCUs tested. It was impossible to accurately measure the irradiance from all the LCUs using the dental radiometers examined. However, dental radiometers should still be used in dental offices to monitor the light output from LCUs and verify that they are working correctly before they are used on patients.
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Affiliation(s)
- Cristiane Maucoski
- Department of Restorative Dentistry, State University of Ponta Grossa, Ponta Grossa, Brazil
- Department of Dental Clinical Sciences, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Richard Bengt Price
- Department of Dental Clinical Sciences, Dalhousie University, Halifax, Nova Scotia, Canada
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25
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Favoreto MW, de Souza Carneiro T, Wendlinger M, Ñaupari-Villasante R, de Matos TP, Kunz PM, Reis A, Loguercio AD. Various ways of pre-heating a bulk-fill thermoviscous composite in restoration in non-carious cervical lesions: 12-month randomized clinical trial. Clin Oral Investig 2023; 27:4345-4359. [PMID: 37217713 DOI: 10.1007/s00784-023-05054-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Accepted: 04/30/2023] [Indexed: 05/24/2023]
Abstract
OBJECTIVE The objective of the study is to evaluate through a randomized clinical trial the best method to preheat a composite resin, if using a Caps dispenser device associated with Caps Warmer (CD) or with a VisCalor Caps dispenser/warmer (VD) for restorations in non-carious cervical lesions (NCCLs). MATERIAL AND METHODS One hundred and twenty restorations were distributed to two groups (n = 60) according to the pre-heating way of thermoviscous bulk-fill composite resin. For the CD group, pre-heating was carried at 68 °C using a heating bench for 3 min. For the VD group, pre-heating was performed at 68 °C using a heating gun for 30 s. After that, pre-heated bulk-fill composites were directly inserted in the NCCLs. The total working time was recorded. The restorations were evaluated after 6 and 12 months of clinical performance according to the FDI criteria. Statistical analysis was performed using the Student's t test for unpaired samples for working time, and the Chi-square test for restoration clinical performance (α = 0.05). RESULTS Working time was shorter for VD with a statistically significant difference compared to CD (p = 0.01). Few restorations were lost or fractured after 12 months of clinical evaluation (p > 0.05). The retention rates were 96.7% (CI 95 %: 88.6-99.1%) for CD and 98.3% (CI 95 %: 91.1-99.7%) for VD. The other FDI parameters were considered clinically acceptable. CONCLUSIONS The different pre-heating ways did not influence the clinical performance of thermoviscous bulk-fill composite restorations in NCCLs after 12 months. CLINICAL RELEVANCE Regardless of the bulk-fill thermoviscous composite resin pre-heating ways, the restorations are clinically acceptable after 12 months.
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Affiliation(s)
- Michael Willian Favoreto
- Department of Restorative Dentistry, State University of Ponta Grossa, Rua Carlos Cavalcanti, 4748, Bloco M - Uvaranas, Ponta Grossa, Parana, Brazil
| | - Taynara de Souza Carneiro
- Department of Restorative Dentistry, State University of Ponta Grossa, Rua Carlos Cavalcanti, 4748, Bloco M - Uvaranas, Ponta Grossa, Parana, Brazil
| | - Michel Wendlinger
- Department of Restorative Dentistry, State University of Ponta Grossa, Rua Carlos Cavalcanti, 4748, Bloco M - Uvaranas, Ponta Grossa, Parana, Brazil
| | - Romina Ñaupari-Villasante
- Department of Restorative Dentistry, State University of Ponta Grossa, Rua Carlos Cavalcanti, 4748, Bloco M - Uvaranas, Ponta Grossa, Parana, Brazil
| | | | - Patricia Manozzo Kunz
- Department of Restorative Dentistry, State University of Ponta Grossa, Rua Carlos Cavalcanti, 4748, Bloco M - Uvaranas, Ponta Grossa, Parana, Brazil
- Department of Restorative Dentistry, Tuiuti University of Parana, Parana, Brazil
| | - Alessandra Reis
- Department of Restorative Dentistry, State University of Ponta Grossa, Rua Carlos Cavalcanti, 4748, Bloco M - Uvaranas, Ponta Grossa, Parana, Brazil
| | - Alessandro D Loguercio
- Department of Restorative Dentistry, State University of Ponta Grossa, Rua Carlos Cavalcanti, 4748, Bloco M - Uvaranas, Ponta Grossa, Parana, Brazil.
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Brewster J, Roberts HW. 12-Month flexural mechanical properties of conventional and self-adhesive flowable resin composite materials. Dent Mater J 2023:2023-011. [PMID: 37302821 DOI: 10.4012/dmj.2023-011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The aim of this study was to investigate the 12-month flexural mechanical properties of 23 flowable resin-based composites (FRBC) that included 5 self-adhesive FRBC materials. Specimens were evaluated following ISO 4049:2019 guidelines, but additionally stored in physiologic 0.2M phosphate buffered saline solution being tested at 24 h, 1 week, 1 month, and at 3-, 6-, 9-, and 12-months. While some deviation and degradation were noted at testing intervals, conventional FRBC materials overall demonstrated greater flexural strength than the self-adhesive and compomer materials. Three self-adhesive materials and the compomer were below recommended ISO 4049:2019 flexural strength values at 24 h with another after 6 months storage. Conventional FRBC materials, except at 1 month, overall demonstrated increased flexural modulus than the self-adhesive FRBC materials. Although results were material dependent, conventional FRBC materials demonstrated overall greater flexural mechanical properties as compared to the self-adhesive FRBC materials and the compomer evaluated.
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Maletin A, Ristić I, Nešić A, Knežević MJ, Koprivica DĐ, Cakić S, Ilić D, Milekić B, Puškar T, Pilić B. Development of Light-Polymerized Dental Composite Resin Reinforced with Electrospun Polyamide Layers. Polymers (Basel) 2023; 15:2598. [PMID: 37376244 DOI: 10.3390/polym15122598] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 06/01/2023] [Accepted: 06/02/2023] [Indexed: 06/29/2023] Open
Abstract
As the mechanical properties of resin-based dental composite materials are highly relevant in clinical practice, diverse strategies for their potential enhancement have been proposed in the extant literature, aiming to facilitate their reliable use in dental medicine. In this context, the focus is primarily given to the mechanical properties with the greatest influence on clinical success, i.e., the longevity of the filling in the patient's mouth and its ability to withstand very strong masticatory forces. Guided by these objectives, the goal of the present study was to ascertain whether the reinforcement of dental composite resins with electrospun polyamide (PA) nanofibers would improve the mechanical strength of dental restoration materials. For this purpose, light-cure dental composite resins were interspersed with one and two layers comprising PA nanofibers in order to investigate the influence of such reinforcement on the mechanical properties of the resulting hybrid resins. One set of the obtained samples was investigated as prepared, while another set was immersed in artificial saliva for 14 days and was subsequently subjected to the same set of analyses, namely Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and differential scanning calorimetry (DSC). Findings yielded by the FTIR analysis confirmed the structure of the produced dental composite resin material. They also provided evidence that, while the presence of PA nanofibers did not influence the curing process, it strengthened the dental composite resin. Moreover, flexural strength measurements revealed that the inclusion of a 16 μm-thick PA nanolayer enabled the dental composite resin to withstand a load of 3.2 MPa. These findings were supported by the SEM results, which further indicated that immersing the resin in saline solution resulted in a more compact composite material structure. Finally, DSC results indicated that as-prepared as well as saline-treated reinforced samples had a lower glass transition temperature (Tg) compared to pure resin. Specifically, while pure resin had a Tg of 61.6 °C, each additional PA nanolayer decreased the Tg by about 2 °C, while the further reduction was obtained when samples were immersed in saline for 14 days. These results show that electrospinning is a facile method for producing different nanofibers that can be incorporated into resin-based dental composite materials to modify their mechanical properties. Moreover, while their inclusion strengthens the resin-based dental composite materials, it does not affect the course and outcome of the polymerization reaction, which is an important factor for their use in clinical practice.
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Affiliation(s)
| | - Ivan Ristić
- Faculty of Technology, University of Novi Sad, 21000 Novi Sad, Serbia
| | - Aleksandra Nešić
- Faculty of Technology, University of Novi Sad, 21000 Novi Sad, Serbia
| | | | | | - Suzana Cakić
- Faculty of Technology, University of Niš, 16000 Leskovac, Serbia
| | - Dušica Ilić
- Faculty of Electronic Engineering, University of Niš, 18000 Niš, Serbia
| | - Bojana Milekić
- Faculty of Medicine, University of Novi Sad, 21000 Novi Sad, Serbia
| | - Tatjana Puškar
- Faculty of Medicine, University of Novi Sad, 21000 Novi Sad, Serbia
| | - Branka Pilić
- Faculty of Technology, University of Novi Sad, 21000 Novi Sad, Serbia
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Montoya C, Roldan L, Yu M, Valliani S, Ta C, Yang M, Orrego S. Smart dental materials for antimicrobial applications. Bioact Mater 2023; 24:1-19. [PMID: 36582351 PMCID: PMC9763696 DOI: 10.1016/j.bioactmat.2022.12.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 11/17/2022] [Accepted: 12/01/2022] [Indexed: 12/13/2022] Open
Abstract
Smart biomaterials can sense and react to physiological or external environmental stimuli (e.g., mechanical, chemical, electrical, or magnetic signals). The last decades have seen exponential growth in the use and development of smart dental biomaterials for antimicrobial applications in dentistry. These biomaterial systems offer improved efficacy and controllable bio-functionalities to prevent infections and extend the longevity of dental devices. This review article presents the current state-of-the-art of design, evaluation, advantages, and limitations of bioactive and stimuli-responsive and autonomous dental materials for antimicrobial applications. First, the importance and classification of smart biomaterials are discussed. Second, the categories of bioresponsive antibacterial dental materials are systematically itemized based on different stimuli, including pH, enzymes, light, magnetic field, and vibrations. For each category, their antimicrobial mechanism, applications, and examples are discussed. Finally, we examined the limitations and obstacles required to develop clinically relevant applications of these appealing technologies.
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Affiliation(s)
- Carolina Montoya
- Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, PA, USA
| | - Lina Roldan
- Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, PA, USA
- Bioengineering Research Group (GIB), Universidad EAFIT, Medellín, Colombia
| | - Michelle Yu
- Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, PA, USA
| | - Sara Valliani
- Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, PA, USA
| | - Christina Ta
- Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, PA, USA
| | - Maobin Yang
- Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, PA, USA
- Department of Endodontology, Kornberg School of Dentistry, Temple University, Philadelphia, PA, USA
- Bioengineering Department, College of Engineering, Temple University, Philadelphia, PA, USA
| | - Santiago Orrego
- Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, PA, USA
- Bioengineering Department, College of Engineering, Temple University, Philadelphia, PA, USA
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Leyva Del Rio D, Johnston WM. Effect of monomer composition and filler fraction on surface microhardness and depth of cure of experimental resin composites. Eur J Oral Sci 2023; 131:e12933. [PMID: 37121780 DOI: 10.1111/eos.12933] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Accepted: 03/28/2023] [Indexed: 05/02/2023]
Abstract
This study evaluated microhardness profiles and calculated depths of cure at 80% of the surface microhardness of experimental dental resin composites having different base monomer compositions and different filler fractions. Composites were prepared using four different base monomers (bisphenol A-glycidyl methacrylate [Bis-GMA], urethane dimethacrylate [UDMA], ethoxylated bisphenol-A dimethacrylate [Bis-EMA], and Fit-852) with triethylene glycol dimethacrylate (TEGDMA) used as a co-monomer at three filler:resin matrix weight percent fractions (50:50, 60:40, and 70:30). Uncured material was placed in 3D printed molds and light cured for 40 s from the top surface only. Knoop microhardness was measured at the top of the specimen, and at every 0.5 mm up to 4 mm in depth. Microhardness at the surface increased in all experimental composites as the filler fraction increased. When comparing base monomers, microhardness was the highest in UDMA-based composites, while Bis-GMA-based composites showed the lowest values. When comparing depth of cure as a function of base monomer type, both Bis-GMA and Bis-EMA showed significantly lower values than UDMA or Fit-852. Composites having 50 wt% filler showed a significantly higher depth of cure than those with 60 and 70 wt% filler. Base monomer and filler fraction significantly influence microhardness and depth of cure in these experimental composites.
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Affiliation(s)
- Diana Leyva Del Rio
- The Ohio State University, College of Dentistry, Division of Restorative and Prosthetic Dentistry, Columbus, Ohio, USA
| | - William Michael Johnston
- The Ohio State University, College of Dentistry, Division of Restorative and Prosthetic Dentistry, Columbus, Ohio, USA
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Islam MS, Nassar M, Elsayed MA, Jameel DB, Ahmad TT, Rahman MM. In Vitro Optical and Physical Stability of Resin Composite Materials with Different Filler Characteristics. Polymers (Basel) 2023; 15:polym15092121. [PMID: 37177267 PMCID: PMC10180670 DOI: 10.3390/polym15092121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 04/22/2023] [Accepted: 04/26/2023] [Indexed: 05/15/2023] Open
Abstract
The objective of this study was to compare the physical and optical stability of resin composite materials with different filler characteristics. Ninety-six resin composite blocks (6 mm × 6 mm × 2 mm) were prepared using four different types of resin composite, divided into four groups. Specimens from the same material were randomly divided into four groups (n = 6) and allocated for Vickers hardness (VH), water sorption, solubility (WS/SL), and staining and aging challenges tests. One-way ANOVA showed significant differences in microhardness (p = 0.0001), WS (p = 0.0001), and SL (p = 0.003) among the tested groups. Beautifil II LS recorded the highest hardness, and CharmFil®Flow had the lowest value. Beautifil Injectable X and II LS showed negative WS, whereas the other groups had positive values. All groups showed positive SL. Repeated measures ANOVA showed significant color parameter alteration in the tested groups (p = 0.0001). All groups showed significant color shifting after one week of the staining challenge. Repeated measures ANOVA showed a significant color parameter (p = 0.0001) and weight (p = 0.001) alteration after the aging challenge. The optical and physical stability of resin composites may vary according to filler characteristics. Clinicians should choose the composite as per the desired outcome.
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Affiliation(s)
- Md Sofiqul Islam
- RAK College of Dental Sciences, RAK Medical and Health Sciences University, Ras Al-Khaimah P.O. Box 12973, United Arab Emirates
| | - Mohannad Nassar
- Department of Preventive and Restorative Dentistry, College of Dental Medicine, University of Sharjah, Sharjah P.O. Box 27272, United Arab Emirates
| | - Mohamed Ahmed Elsayed
- RAK College of Dental Sciences, RAK Medical and Health Sciences University, Ras Al-Khaimah P.O. Box 12973, United Arab Emirates
- Department of Endodontics, Faculty of Dentistry, Assiut University, Assiut 71515, Egypt
| | - Dania Burhan Jameel
- RAK College of Dental Sciences, RAK Medical and Health Sciences University, Ras Al-Khaimah P.O. Box 12973, United Arab Emirates
| | - Thana Tariq Ahmad
- RAK College of Dental Sciences, RAK Medical and Health Sciences University, Ras Al-Khaimah P.O. Box 12973, United Arab Emirates
| | - Muhammed Mustahsen Rahman
- RAK College of Dental Sciences, RAK Medical and Health Sciences University, Ras Al-Khaimah P.O. Box 12973, United Arab Emirates
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Kong X, Han Q, Jiang A, Wang Y, Li R, Wang Y, Xiao S, Wei R, Ma Y. BNN/TiO 2 nanocomposite system-modified dental flow resins and the mechanism of the enhancement of mechanical and antibacterial properties. Biomater Sci 2023; 11:2775-2786. [PMID: 36825578 DOI: 10.1039/d2bm01848a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
Robust and antibacterial dental resins are essential for repairing the shape and function of the teeth. However, an ingenious way to achieve a synergistic enhancement of these two properties is still lacking. In this work, guided by molecular dynamics (MD) calculations, a boron nitride nanosheet (BNN)/titanium dioxide (TiO2) nanocomposite system was synthesized and used to modify the dental flow resin to enhance its mechanical and antimicrobial properties. The mechanical and antimicrobial enhancement mechanisms were further explored. The modified resin demonstrated outstanding performance improvement with 88.23%, 58.47%, 82.01%, and 55.06% improvement in compressive strength (CS), microhardness (MH), flexural strength (FS), and elastic modulus (EM), respectively. Moreover, the modified resin could effectively inhibit the growth of Streptococcus mutans (S. mutans) regardless of aging in water and the inhibition rates were more than 90%. In conclusion, the modified resin is expected to be an ideal restorative material for clinical applications.
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Affiliation(s)
- Xinzi Kong
- School/Hospital of Stomatology, Lanzhou University, Lanzhou 730000, PR China.
| | - Qize Han
- School/Hospital of Stomatology, Lanzhou University, Lanzhou 730000, PR China.
| | - Axue Jiang
- School/Hospital of Stomatology, Lanzhou University, Lanzhou 730000, PR China.
| | - Yurui Wang
- School/Hospital of Stomatology, Lanzhou University, Lanzhou 730000, PR China.
| | - Ruizhi Li
- School/Hospital of Stomatology, Lanzhou University, Lanzhou 730000, PR China.
| | - Yuting Wang
- School/Hospital of Stomatology, Lanzhou University, Lanzhou 730000, PR China.
| | - Shengjie Xiao
- School/Hospital of Stomatology, Lanzhou University, Lanzhou 730000, PR China.
| | - Rong Wei
- School/Hospital of Stomatology, Lanzhou University, Lanzhou 730000, PR China.
| | - Yu Ma
- School/Hospital of Stomatology, Lanzhou University, Lanzhou 730000, PR China.
- Key Laboratory of Dental Maxillofacial Reconstruction and Biological Intelligence Manufacturing, Lanzhou University, Lanzhou 730000, PR China
- Biointerfaces Institute, University of Michigan, Ann Arbor, MI 48109, USA
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Nascimento Batista JM, Sinhoreti MAC, Alves Fraga MA, Manoel da Silva MV, Correr AB, Roulet JF, Geraldeli S. Effect of preheating on mechanical properties of a resin-based composite containing elastomeric urethane monomer. J Mech Behav Biomed Mater 2023; 141:105758. [PMID: 36934689 DOI: 10.1016/j.jmbbm.2023.105758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 03/02/2023] [Accepted: 03/03/2023] [Indexed: 03/08/2023]
Abstract
This study investigated the effect of preheating an elastomeric urethane monomer (Exothane-24) experimental resin composite on its physicochemical properties. Two resin matrices were formulated: (a) 50 wt% Bisphenol-glycidyl methacrylate (Bis-GMA) and 50 wt% triethylene glycol dimethacrylate (TEGDMA); and (b) 20 wt% Exothane-24, 40 wt% Bis-GMA and 40 wt% TEGDMA. A photoinitiator system (0.25 wt% camphorquinone and 0.50 wt% ethyl-4-dimethylamino benzoate) and 65 wt% of the inorganic filler (20 wt% 0.05 μm silica and 80 wt% 0.7 μm BaBSiO2 glass) were added to both matrices. These formulations were then assigned to four groups: Exothane-24 (E); Exothane-24 plus preheating (EH); no Exothane-24 (NE); and no Exothane-24 plus preheating (NEH). NEH and EH were preheated at 69 °C. The dependent variables were as follows: film thickness (FT); polymerization shrinkage stress (PSS); gap width (GW); maximum rate of polymerization (Rpmax); and degree of conversion (DC). Data were statistically analyzed by two-way ANOVA and Tukey's test (α = 0.05). Preheating reduced FT for both composites. PSS and GW were significantly lower for EH, when compared with E. The DC for EH and NEH and the Rpmax for EH increased significantly. Preheating improved most of the physicochemical properties (FT, PSS, GW, and DC) of the experimental resin composite containing Exothane-24.
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Affiliation(s)
- João Marcos Nascimento Batista
- Department of Restorative Dentistry, Dental Materials Division, Piracicaba Dental School, University of Campinas, Piracicaba, SP, Brazil
| | - Mário Alexandre Coelho Sinhoreti
- Department of Restorative Dentistry, Dental Materials Division, Piracicaba Dental School, University of Campinas, Piracicaba, SP, Brazil.
| | - May Anny Alves Fraga
- Department of Restorative Dentistry, Dental Materials Division, Piracicaba Dental School, University of Campinas, Piracicaba, SP, Brazil
| | - Marcus Vinícius Manoel da Silva
- Department of Restorative Dentistry, Dental Materials Division, Piracicaba Dental School, University of Campinas, Piracicaba, SP, Brazil
| | - Américo Bortolazzo Correr
- Department of Restorative Dentistry, Dental Materials Division, Piracicaba Dental School, University of Campinas, Piracicaba, SP, Brazil
| | - Jean-François Roulet
- Department of Restorative Dental Science, College of Dentistry, University of Florida, Gainesville, FL, USA
| | - Saulo Geraldeli
- Division of Biomedical Materials, School of Dental Medicine, East Carolina University, Greenville, NC, USA
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Maucoski C, Price RB, Rocha MG, Roulet JF, Sullivan B. Ability of short exposures from laser and quad-wave curing lights to photo-cure bulk-fill resin-based composites. Dent Mater 2023; 39:275-292. [PMID: 36868892 DOI: 10.1016/j.dental.2023.01.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 01/10/2023] [Accepted: 01/25/2023] [Indexed: 03/05/2023]
Abstract
OBJECTIVE This study investigated the ability of a laser, and a 'quad-wave' LCU, to photo-cure paste and flowable bulk-fill resin-based composites (RBCs). METHODS Five LCUs and nine exposure conditions were used. The laser LCU (Monet) used for 1 s and 3 s, the quad-wave LCU (PinkWave) used for 3 s in the Boost and 20 s in the Standard modes, the the multi-peak LCU (Valo X) used for 5 s in the Xtra and 20 s in the Standard modes, were compared to the polywave PowerCure used in the 3 s mode and for 20 s in the Standard mode, and to the mono-peak SmartLite Pro used for 20 s. Two paste consistency bulk-fill RBCs: Filtek One Bulk Fill Shade A2 (3 M), Tetric PowerFill Shade IVA (Ivoclar Vivadent), and two flowable RBCs: Filtek Bulk Fill Flowable Shade A2 (3 M), Tetric PowerFlow Shade IVA (Ivoclar Vivadent) were photo-cured in 4-mm deep x 4-mm diameter metal molds. The light received by these specimens was measured using a spectrometer (Flame-T, Ocean Insight), and the radiant exposure delivered to the top surface of the RBCs was mapped. The immediate degree of conversion (DC) at the bottom, and the 24-hour Vickers Hardness (VH) at the top and bottom of the RBCs were measured and compared. RESULTS The irradiance received by the 4-mm diameter specimens ranged from 1035 mW/cm2 (SmartLite Pro) to 5303 mW/cm2 (Monet). The radiant exposures between 350 and 500 nm delivered to the top surface of the RBCs ranged from 5.3 J/cm2 (Monet in 1 s) to 26.4 J/cm2 (Valo X), although the PinkWave delivered 32.1 J/cm2 in 20 s 350 to 900 nm. All four RBCs achieved their maximum DC and VH values at the bottom when photo-cured for 20 s. The Monet used for 1 s and the PinkWave used for 3 s on the Boost setting delivered the lowest radiant exposures between 420 and 500 nm (5.3 J/cm2 and 3.5 J/cm2 respectively), and they produced the lowest DC and VH values. CONCLUSIONS Despite delivering a high irradiance, the short 1 or 3-s exposures delivered less energy to the RBC than 20-s exposures from LCUs that deliver> 1000 mW/cm2. There was an excellent linear correlation (r > 0.98) between the DC and the VH at the bottom. There was a logarithmic relationship between the DC and the radiant exposure (Pearson's r = 0.87-97) and between the VH and the radiant exposure (Pearson's r = 0.92-0.96) delivered in the 420-500 nm range.
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Affiliation(s)
- Cristiane Maucoski
- Department of Restorative Dentistry, State University of Ponta Grossa, Ponta Grossa, Parana, Brazil; Department of Dental Clinical Sciences, Dalhousie University, Faculty of Dentistry, Halifax, Nova Scotia, Canada
| | - Richard Bengt Price
- Department of Dental Clinical Sciences, Dalhousie University, Faculty of Dentistry, Halifax, Nova Scotia, Canada.
| | - Mateus Garcia Rocha
- Department of Restorative Dental Science, Center of Dental Biomaterials College of Dentistry, University of Florida, Gainesville, FL, USA
| | - Jean-François Roulet
- Department of Restorative Dental Science, Center of Dental Biomaterials College of Dentistry, University of Florida, Gainesville, FL, USA
| | - Braden Sullivan
- Department of Restorative Dentistry, State University of Ponta Grossa, Ponta Grossa, Parana, Brazil
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Degree of conversion of 3D printing resins used for splints and orthodontic appliances under different postpolymerization conditions. Clin Oral Investig 2023:10.1007/s00784-023-04893-8. [PMID: 36757463 DOI: 10.1007/s00784-023-04893-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 02/01/2023] [Indexed: 02/10/2023]
Abstract
OBJECTIVES To measure the degree of conversion (DC) of different 3D printing resins used for splints or orthodontic appliances under different postpolymerization conditions. MATERIALS AND METHODS Five 3D-printed photopolymer resins were studied. Each resin was analyzed in liquid form (n = 15), and then cylindrical specimens (n = 135) were additively manufactured and postcured with Form Cure (Formlabs) at different times (10, 60, and 90 min) and temperatures (20 °C, 60 °C, and 80 °C). The DC of each specimen was measured with Fourier transform infrared spectroscopy (FTIR). The data were statistically analyzed using a 3-way ANOVA followed by Tukey's post hoc test. RESULTS The time and temperature of postpolymerization significantly influenced the DC of each resin: when time and/or temperature increased, the DC increased. For all resins tested, the lowest DC was obtained with a postcuring protocol at 10 min and 20 °C, and the highest DC was obtained at 90 min and 80 °C. However, at 80 °C, the samples showed a yellowish color. CONCLUSIONS With the Form Cure device, the time and temperature of postcuring could have an impact on the DC of the 3D printing resins studied. The DC of the 3D printing resins could be optimized by adjusting the postpolymerization protocol. CLINICAL RELEVANCE Regardless of the resin used, when using the Form Cure device, postcuring at 60 min and 60 °C would be the minimal time and temperature conditions for achieving proper polymerization. Beyond that, it would be preferable to increase the postcuring time to boost the DC.
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Yang J, Silikas N, Watts DC. Polymerization and shrinkage kinetics and fracture toughness of bulk-fill resin-composites. Dent Mater 2022; 38:1934-1941. [PMID: 38709119 DOI: 10.1016/j.dental.2022.10.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 10/14/2022] [Accepted: 10/14/2022] [Indexed: 11/26/2022]
Abstract
OBJECTIVES To determine degree of conversion (DC), maximum polymerization rate (RPmax), polymerization shrinkage (PS), maximum shrinkage rate (PS Rmax) and fracture toughness (KIC) of different types of bulk-fill (BF) composites plus the effect of viscosity reduction techniques. METHODS BF specimens were created in 2 mm deep molds: SonicFill 3 (SF3), Viscalor (VC), One Bulk Fill (OBF) and Beautifil Bulk (BBR). SF3 was applied via sonic insertion using a SonicFill handpiece (Kerr Corp. USA). Viscalor was pre-heated in a Caps Warmer in T3 mode (at 68 °C) for 30 s (T3-30 s) and 3 min (T3-3 min), respectively. Specimens were irradiated at zero distance from the upper surface with an Elipar S10 LED unit (3 M ESPE, USA) of mean irradiance 1200 mW/cm2 for 40 s. Real-time polymerization kinetics and DC at 5 min and 24 h post-irradiation (DC5 min and DC24 h) were measured using ATR-FTIR (n = 3). PS was measured up to 1 h on 1 mm thick discs via the bonded-disk technique (n = 3) and PS Rmax obtained by numerical differentiation (n = 3). For fracture toughness, single-edge-notched specimens (32 × 6 ×3 mm) of each BF composite were prepared and measured by three-point bending after 7 d water storage (n = 5). Data were analysed using One-way ANOVA, independent T-tests and Tukey post-hoc tests (p < 0.05). RESULTS SF3 showed the significantly highest DC5 min, DC24 h and RPmax (p < 0.05), followed by OBF (p < 0.05). Regardless of pre-heating, VC showed comparable conversion kinetics to BBR (p > 0.05). There was no significant difference in PS of these BF composites, except OBF had the highest PS (p > 0.05). However, PS Rmax significantly varied among materials (p = 0.047) and SF3 had the highest PS Rmax. Regarding fracture toughness, BBR had the lowest KIC (p < 0.05), whereas other composites showed similar KIC (p > 0.05). Strong correlations of filler content (wt%)-PS/KIC were found. Different pre-heating times had no significant influences on DC %, RPmax, PS, PS Rmax and KIC of VC (p > 0.05). SIGNIFICANCE Different types of bulk-fill composites showed comparable shrinkage. A highly filled BF giomer composite (BBR) had the lowest fracture toughness, whereas others had similar KIC. Pre-heating had no adverse effects on Viscalor properties. Sonication and pre-heating are beneficial techniques to enhance composite flowability without either increasing shrinkage or reducing fracture toughness.
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Affiliation(s)
- Jiawei Yang
- School of Medical Sciences, University of Manchester, Manchester, UK
| | - Nick Silikas
- School of Medical Sciences, University of Manchester, Manchester, UK
| | - David C Watts
- School of Medical Sciences, University of Manchester, Manchester, UK; Photon Science Institute, University of Manchester, Manchester, UK.
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Labrie D, Price RB, Sullivan B, Salazar AM, Gautam D, Stansbury JW, Ferracane JL. Effect of thickness on the degree of conversion of two bulk-fill and one conventional posterior resin-based composites at high irradiance and high temporal resolution. J Mech Behav Biomed Mater 2022; 136:105489. [PMID: 36206689 DOI: 10.1016/j.jmbbm.2022.105489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 09/22/2022] [Accepted: 09/24/2022] [Indexed: 11/30/2022]
Abstract
OBJECTIVES This study: 1) measures the effect of sample thickness and high irradiance on the depth-dependent time delay before photopolymerization reaction onset; 2) determines if exposure reciprocity exists; 3) measures the conversion rate at four irradiance levels; 4) determines the time, t0, at which the maximum DC rate is reached for two bulk-fill and one conventional posterior resin-based composites (RBCs). METHODS Tetric PowerFill IVA shade (Ivoclar Vivadent) and Aura bulk-fill ultra universal restorative (SDI), and one conventional posterior resin-based composite (RBC), Heliomolar A3 (Ivoclar Vivadent), that were either 0.2 mm, 2 mm, or 4 mm thick were photocured using a modified Bluephase G4 (Ivoclar Vivadent) light-curing unit (LCU) that delivered a single emission band (wavelength centered at 449 nm). The same radiant exposure of 24 J/cm2 was delivered at irradiances ranging from 0.5 to 3 W/cm2 by adjusting the exposure time. PowerFill was also photocured for 3 s or 6 s using a Bluephase PowerCure LCU (Ivoclar Vivadent) on the 3 s mode setting. The degree of conversion (DC) was measured in real-time at a high temporal resolution at 30 °C using Attenuated Total Reflection (ATR) FTIR spectroscopy with a sampling rate of 13 DC data points per second. The DC data were analyzed using a phenomenological autocatalytic model. The RBC viscosity was measured at 21 °C and 30 °C. Light transmission through the RBC samples at 22 °C was monitored with time to calculate the extinction coefficients of the RBCs. RESULTS The time delay before photopolymerization started increased as the RBC thickness increased and the irradiance decreased. An autocatalytic model described the DC data. The time t0 was less than 77 ms for the 0.2 mm thick samples of PowerFill irradiated using the highest irradiance of 3 W/cm2. Among the three RBCs for each sample thickness and irradiance level, the PowerFill had the smallest time t0. There was a time delay of 0.59 s and 1.25 s before the DC started to increase at the bottom of 4 mm thick samples for the PowerFill and Aura, respectively, when an irradiance of 1 W/cm2 was delivered. The time delay increased to 3.65 s for the Aura when an irradiance of 0.5 W/cm2 was delivered. The extinction coefficients near 449 nm were 0.78 mm-1, 0.76 mm-1, and 1.55 mm-1 during the first 2 s after the start of photocuring of PowerFill, Aura, and Heliomolar, respectively. Only PowerFill followed exposure reciprocity. At T = 30 °C, the viscosity was 3400, 17000, and 5200 Paˑs for PowerFill, Aura, and Heliomolar, respectively. SIGNIFICANCE The time delay between when photopolymerization starts at the top and bottom of 2- or 4-mm thick RBC restorations may affect the structural integrity of the bond between the tooth and the bottom of the restoration. Only PowerFill followed exposure reciprocity between irradiance levels of 0.5 to 3 W/cm2. Exposure reciprocity did not occur for Aura or Heliomolar, neither of which are optimized for short light exposure or high irradiance conditions.
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Affiliation(s)
- Daniel Labrie
- Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia, B3H 4R2, Canada.
| | - Richard B Price
- Department of Dental Clinical Sciences, Dalhousie University, Halifax, Nova Scotia, B3H 4R2, Canada
| | - Braden Sullivan
- Department of Dental Clinical Sciences, Dalhousie University, Halifax, Nova Scotia, B3H 4R2, Canada
| | - Austyn M Salazar
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, CO, 80309-0596, United States
| | - Dixa Gautam
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, CO, 80309-0596, United States
| | - Jeffrey W Stansbury
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, CO, 80309-0596, United States; Department of Craniofacial Biology, School of Dental Medicine, University of Colorado, Anschutz Medical Campus, Aurora, CO, 80045, United States
| | - Jack L Ferracane
- Department of Restorative Dentistry, Oregon Health & Science University, Portland, OR, United States
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Babaier R, Haider J, Silikas N, Watts DC. Effect of CAD/CAM aesthetic material thickness and translucency on the polymerisation of light- and dual-cured resin cements. Dent Mater 2022; 38:2073-2083. [DOI: 10.1016/j.dental.2022.11.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 11/11/2022] [Accepted: 11/11/2022] [Indexed: 11/27/2022]
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Sadeghyar A, Lettner S, Watts DC, Schedle A. Alternatives to amalgam: Is pretreatment necessary for effective bonding to dentin? Dent Mater 2022; 38:1703-1709. [PMID: 36115700 DOI: 10.1016/j.dental.2022.08.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 08/29/2022] [Accepted: 08/29/2022] [Indexed: 11/29/2022]
Abstract
OBJECTIVE The aim of this study was to determine whether pretreatment of the dentin surface is beneficial or not by analysis of the bond strengths of four self-adhesive restoratives and four restoration materials where pretreatment of dentin was necessary. METHODS Bovine incisors (n = 160) were ground flat on the labial surfaces to expose dentin using a grinder and silicon carbide (SiC) abrasive papers under running water. Between preparation and bonding procedures, the crowns were stored in Chloramine-T solution at 4 °C. Eight different restorative materials were studied: Activa BioActive (ABA), Cention Forte (CNF), Ceram.x Spectra ST (CXS), Riva self-cure (RSC), Equia Forte (EQF), Fuji II LC (FJI), Ketac Molar (KTM), Surefil one (SFO). Four materials required pretreatment of the dental hard tissue before placement, whereas the other four were self-adhesive (no pretreatment). The specimens were mounted vertically in plaster. A preload of 5 N was applied and the subsequent cross-head speed was 0.8 mm/min. Shear bond strengths (MPa) were calculated as the failure load divided by the bonding area. Failure modes were recorded as adhesive, cohesive or pretest. Data were statistically analyzed via ordinal regression for inference and Tukey's method to adjust for multiple comparisons. All computations were done using R version 4.1.2 (R Core Team 2021). RESULTS Smax (failure stress in MPa) of the combined groups with pretreatment were significantly higher than the self-adhesive materials. The highest frequency of pretest-failure was seen with FJI. Glass-ionomer cements without pretreatment were the only restoratives with pretest failures. Amongst materials without pretreatment, SFO had the highest bond strengths. SIGNIFICANCE The further reduction of the placement steps for materials used as an amalgam alternative, namely the omission of pretreatment of the dentin, results in these self-adhesive materials having lower bond strengths than materials that require pretreatment of the dentin.
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Affiliation(s)
- A Sadeghyar
- University Clinic of Dentistry, Medical University of Vienna, Austria
| | - S Lettner
- University Clinic of Dentistry, Medical University of Vienna, Austria
| | - D C Watts
- School of Medical Sciences and Photon Science Institute, University of Manchester, Manchester, UK
| | - A Schedle
- University Clinic of Dentistry, Medical University of Vienna, Austria.
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Gilli M, Hollaert TG, Setbon HM, des Rieux A, Leprince JG. Quality of Cure in Depth of Commercially Available Bulk-fill Composites: A Layer-by-layer Mechanical and Biological Evaluation. Oper Dent 2022; 47:437-448. [PMID: 35917249 DOI: 10.2341/21-084-l] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/29/2021] [Indexed: 11/23/2022]
Abstract
Despite their popularity, the use of bulk-fill composites remains controversial, both in terms of their properties and their in-depth development. The objectives of the present work were (1) to provide a more comprehensive evaluation of the quality of cure in depth of commercially available bulk-fill composites by combining various key mechanical and biological characterization methods, (2) to evaluate the inter-material differences when optimally cured, and (3) to evaluate the efficiency of an antioxidant-N-acetyl-cysteine (NAC)-to restrain the adverse effects of the leached components on cell viability. Nine bulk-fill composites (including flowable and high-viscosity materials) were investigated and compared to two conventional resin-based composites, one flowable and one high-viscosity restorative material. The materials were injected or packed into Teflon molds of various configurations, up to 6 mm material thickness. They were then light-cured from the top for 20 seconds with Bluephase G2 (Ivoclar Vivadent, irradiance = 1050 mW/cm2). The following physicomechanical properties were measured for the upper (0-2 mm), intermediate (2-4 mm), and lower (4-6 mm) layers: degree of conversion using Raman Spectrometry (DC, in %), microhardness using a Vickers micro-indenter before (VHN dry) and after 24 hours of storage in ethanol (VHN EtOH), and flexural strength (in MPa) and flexural modulus (in GPa) using a three-point bend test. Each composite layer and an uncured layer were also stored for one week in a standard cell growth medium to generate conditioned media. Human dental pulp cells were then cultured for 24 hours with the latter and cell viability was measured using an MTS assay. A similar experiment was repeated with conditioned media produced in contact with uncured composites, with and without the addition of 4 mM NAC. The data were subjected to a Shapiro-Wilk test, then one-way ANOVA or Kruskal-Wallis test, followed either by Tukey's test (inter-material comparison) or by Dunnett's or Dunn's test (comparison between layers relative to the upper one). The level of statistical significance was set at 0.05. Some materials (EverX, X-traF, VenusBF, X-traB) did not show any significant differences (p>0.05) for any of the properties considered between the intermediate layers compared to the upper one (considered as reference). Others displayed significant differences, at least for some properties, highlighting the value of combining various key mechanical and biological characterization methods when investigating the quality of cure in depth. Significant inter-material differences (p<0.05) were observed when comparing the properties of their upper layer, considered as "optimally" polymerized. Hence, one needs to consider the absolute property values, not only their relative evolution concerning layer thickness. Finally, the use of NAC appeared as beneficial to reduce the risk of harmful effects to dental pulp cells, especially in case of excessive thickness use, and may therefore be of potential interest as an additive to composites in the future.
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Affiliation(s)
- M Gilli
- *Matthieu Gilli, Adult and Child Dentistry, Cliniques Universitaires Saint-Luc, Brussels, Belgium; DRIM Research Group & Advanced Drug Delivery and Biomaterials, Louvain Drug Research Institute, UCLouvain, Brussels, Belgium
| | - T G Hollaert
- Thibaut G Hollaert, Adult and Child Dentistry, Cliniques Universitaires Saint-Luc, Brussels, Belgium; DRIM Research Group & Advanced Drug Delivery and Biomaterials, Louvain Drug Research Institute, UCLouvain, Brussels, Belgium
| | - H M Setbon
- Hugo M Setbon, private practice; DRIM Research Group & Advanced Drug Delivery and Biomaterials, Louvain Drug Research Institute, UCLouvain, Brussels, Belgium
| | - A des Rieux
- Anne des Rieux, DRIM Research Group & Advanced Drug Delivery and Biomaterials, Louvain Drug Research Institute, UCLouvain, Brussels, Belgium
| | - J G Leprince
- Julian G. Leprince, Adult and Child Dentistry, Cliniques Universitaires Saint-Luc, Brussels, Belgium; DRIM Research Group & Advanced Drug Delivery and Biomaterials, Louvain Drug Research Institute, UCLouvain, Brussels, Belgium
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Fidalgo-Pereira R, Carpio D, Torres O, Carvalho O, Silva F, Henriques B, Özcan M, Souza JCM. The influence of inorganic fillers on the light transmission through resin-matrix composites during the light-curing procedure: an integrative review. Clin Oral Investig 2022; 26:5575-5594. [PMID: 35767045 DOI: 10.1007/s00784-022-04589-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 06/19/2022] [Indexed: 11/26/2022]
Abstract
PURPOSE The objective of this study was to perform an integrative review on the effect the inorganic fillers on the light transmission through the resin-matrix composites during the light-curing procedure. METHOD A bibliographic review was performed on PubMed using the following search terms: "fillers" OR "particle" AND "light curing" OR "polymerization" AND "light transmission" OR "light absorption" OR "light irradiance" OR "light attenuation" OR "light diffusion" AND "resin composite." The search involved articles published in English language in the last 10 years. RESULTS Selected studies reported a decrease in biaxial strength and hardness in traditional resin-matrix composites in function of the depth of polymerization. However, there were no significant differences in biaxial strength and hardness recorded along the polymerization depth of Bulk-Fill™ composites. Strength and hardness were enhanced by increasing the size and content of inorganic fillers although some studies revealed a progressive decrease in the degree of conversion on increasing silica particle size. The translucency of glass-ceramic spherical fillers promoted light diffusion mainly in critical situations such as in the case of deep proximal regions of resin-matrix composites. CONCLUSIONS The amount of light transmitted through the resin-matrix composites is influenced by the size, content, microstructure, and shape of the inorganic filler particles. The decrease of the degree of conversion affects negatively the physical and mechanical properties of the resin-matrix composites. CLINICAL RELEVANCE The type and content of inorganic fillers in the chemical composition of resin-matrix composites do affect their polymerization. As a consequence, the clinical performance of resin-matrix composites can be compromised leading to variable physical properties and degradation. The polymerization mode of resin-matrix composites can be improved according to the type of inorganic fillers in their chemical composition.
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Affiliation(s)
- Rita Fidalgo-Pereira
- University Institute of Health Sciences (IUCS), CESPU, 4585-116, Gandra, PRD, Portugal
| | - Daniela Carpio
- University Institute of Health Sciences (IUCS), CESPU, 4585-116, Gandra, PRD, Portugal
| | - Orlanda Torres
- University Institute of Health Sciences (IUCS), CESPU, 4585-116, Gandra, PRD, Portugal
| | - Oscar Carvalho
- Center for Microelectromechanical Systems (CMEMS-UMINHO), University of Minho, Campus Azurém, 4800-058, Guimarães, Portugal
- Associate Laboratory (LABBELS), University of Minho, 4710-057, Guimarães, Braga, Portugal
| | - Filipe Silva
- Center for Microelectromechanical Systems (CMEMS-UMINHO), University of Minho, Campus Azurém, 4800-058, Guimarães, Portugal
- Associate Laboratory (LABBELS), University of Minho, 4710-057, Guimarães, Braga, Portugal
| | - Bruno Henriques
- Center for Microelectromechanical Systems (CMEMS-UMINHO), University of Minho, Campus Azurém, 4800-058, Guimarães, Portugal
- Associate Laboratory (LABBELS), University of Minho, 4710-057, Guimarães, Braga, Portugal
- Ceramic and Composite Materials Research Group (CERMAT), Federal University of Santa Catarina (UFSC), Campus Trindade, Florianópolis, SC, 88040-900, Brazil
| | - Mutlu Özcan
- Dental Materials Unit, Center of Dental Medicine, Clinic of Reconstructive Dentistry, University of Zurich, 8032, Zurich, Switzerland
| | - Júlio C M Souza
- University Institute of Health Sciences (IUCS), CESPU, 4585-116, Gandra, PRD, Portugal.
- Center for Microelectromechanical Systems (CMEMS-UMINHO), University of Minho, Campus Azurém, 4800-058, Guimarães, Portugal.
- Associate Laboratory (LABBELS), University of Minho, 4710-057, Guimarães, Braga, Portugal.
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Wang Z, Zhang X, Yao S, Zhao J, Zhou C, Wu J. Development of low-shrinkage dental adhesives via blending with spiroorthocarbonate expanding monomer and unsaturated epoxy resin monomer. J Mech Behav Biomed Mater 2022; 133:105308. [PMID: 35709601 DOI: 10.1016/j.jmbbm.2022.105308] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2022] [Revised: 06/01/2022] [Accepted: 06/02/2022] [Indexed: 11/24/2022]
Abstract
Polymerization shrinkage is one of the main drawbacks of dental resin adhesives. In this study, spiroorthocarbonate expanding monomer 3,9-diethyl-3,9-dimethylol -1,5,7,11-tetraoxaspiro-[5,5] undecane (DDTU) and unsaturated epoxy resin monomer Diallyl bisphenol A diglycidyl ether (DBDE) were synthesized and utilized as anti-shrinkage-coupling additive of methacrylate-based adhesives. Polymerization process and physicochemical properties including double bond conversion, polymerization shrinkage, compatibility, mechanical performance, thermal stability, contact angle, shear bond strength and cytotoxicity were characterized. Results indicated that adhesives containing anti-shrinkage-coupling additive had reduced volume shrinkage, improved compatibility and enhanced shear bond strength. When the amount of additive was 20 wt%, the volume shrinkage was decreased by 45.8% (4.17 ± 0.32%) and the shear bond strength was increased by 49.6% (19.64 ± 0.99 MPa). The results also showed that the use of additive had no adversely affect on double bond conversion and cytotoxicity. Therefore, novel low-shrinkage resin adhesives were prepared via blending with spiroorthocarbonate expanding monomer and unsaturated epoxy resin monomer.
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Affiliation(s)
- Zonghua Wang
- Department of Prosthodontics, School and Hospital of Stomatology, Cheeloo College of Medicine, Shandong University & Shandong Key Laboratory of Oral Tissue Regeneration & Shandong Engineering Laboratory for Dental Materials and Oral Tissue Regeneration, Jinan, 250012, China
| | - Xiaoran Zhang
- Department of Prosthodontics, School and Hospital of Stomatology, Cheeloo College of Medicine, Shandong University & Shandong Key Laboratory of Oral Tissue Regeneration & Shandong Engineering Laboratory for Dental Materials and Oral Tissue Regeneration, Jinan, 250012, China
| | - Shuo Yao
- Department of Prosthodontics, School and Hospital of Stomatology, Cheeloo College of Medicine, Shandong University & Shandong Key Laboratory of Oral Tissue Regeneration & Shandong Engineering Laboratory for Dental Materials and Oral Tissue Regeneration, Jinan, 250012, China
| | - Jiaxin Zhao
- Research Institute of Polymer Materials, School of Materials Science and Engineering, Shandong University, Jinan, 250061, China
| | - Chuanjian Zhou
- Research Institute of Polymer Materials, School of Materials Science and Engineering, Shandong University, Jinan, 250061, China
| | - Junling Wu
- Department of Prosthodontics, School and Hospital of Stomatology, Cheeloo College of Medicine, Shandong University & Shandong Key Laboratory of Oral Tissue Regeneration & Shandong Engineering Laboratory for Dental Materials and Oral Tissue Regeneration, Jinan, 250012, China.
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Grohmann CVS, Sinhoreti MAC, Soares EF, Oliveira RFD, Souza-Júnior EJDC, Geraldeli S. Effect of a polymerization inhibitor on the chemomechanical properties and consistency of experimental resin composites. Braz Dent J 2022; 33:92-98. [PMID: 35766722 DOI: 10.1590/0103-6440202204242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 05/21/2021] [Indexed: 11/21/2022] Open
Abstract
This study investigated the effect of butylated hydroxytoluene (BHT) inhibitor on degree of conversion (DC), flexural strength (FS), flexural modulus (FM), Knoop microhardness (KH), microhardness reduction (HR), and consistency of experimental resin composites at different BHT concentrations: C0 (control-0%); C0.01 (0.01%); C0.025 (0.025%); C0.05 (0.05%); C0.1 (0.1%); and C0.5 (0.5%). For the consistency, the composites were tested immediately after being exposed to a dental chair headlight (0, 20, 40 and 60 s). Data concerning DC, FS, FM, KH, and HR were submitted to one-way ANOVA, while the consistency data was submitted to 2-way ANOVA; mean values were then compared (Tukey's test; α=0.05). The KH, FS and FM analyses showed no significant difference among the composites tested. For DC, C0 showed the highest mean value (74.2%) and differed only from C0.5 (67.2%). For HR, C0.5 showed the lowest mean (13.09%) value and differed from C0 (26.4%) and C0.01 (24.87). The consistency analysis showed no difference among C0.05, C0.1 and C0.5, considering 0 and 20 s of light exposure, while C0 (14.07 mm), C0.01 (13.97 mm), and C0.025 (14.18 mm) showed higher mean values at 0 s when compared to 20 s (12.67, 12.77 and 13.05 mm, respectivelly). Polymerization occurred within 40 s of light exposure for C0, C0.01, C0.025, and C0.05 and within 60 s for C0.1. In conclusion, the BHT concentrations had no significant influence on FS, FM and KH. The higher the BHT concentration, the longer was its handling time under light, with a significant improvement in the HR, but a decrease in DC. Therefore, BHT at 0.1% showed the best outcomes concerning all the BHT concentrations tested.
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Affiliation(s)
- Caio Vinícius Signorelli Grohmann
- Department of Restorative Dentistry, Dental Materials Division, Piracicaba Dental School, University of Campinas, Piracicaba, SP, Brazil
| | - Mário Alexandre Coelho Sinhoreti
- Department of Restorative Dentistry, Dental Materials Division, Piracicaba Dental School, University of Campinas, Piracicaba, SP, Brazil
| | - Eveline Freitas Soares
- Department of Restorative Dentistry, Dental Materials Division, Piracicaba Dental School, University of Campinas, Piracicaba, SP, Brazil
| | - Robson Ferraz de Oliveira
- Department of Restorative Dentistry, Dental Materials Division, Piracicaba Dental School, University of Campinas, Piracicaba, SP, Brazil
| | | | - Saulo Geraldeli
- Division of Biomedical Materials, School of Dental Medicine, East Carolina University, Greenville, NC, USA
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Is the radiopacity of CAD/CAM aesthetic materials sufficient? Dent Mater 2022; 38:1072-1081. [DOI: 10.1016/j.dental.2022.04.025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 04/27/2022] [Indexed: 11/21/2022]
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El-Askary F, Hassanein A, Aboalazm E, Al-Haj Husain N, Özcan M. A Comparison of Microtensile Bond Strength, Film Thickness, and Microhardness of Photo-Polymerized Luting Composites. MATERIALS 2022; 15:ma15093050. [PMID: 35591383 PMCID: PMC9102044 DOI: 10.3390/ma15093050] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 04/07/2022] [Accepted: 04/20/2022] [Indexed: 02/04/2023]
Abstract
The aim of this study was to evaluate the effect of CAD/CAM composite thickness on micro-tensile bond strength (µTBS), microhardness (HV), and film thickness (FT) of different luting composites. Composite blocks (6.8 mm × 6.8 mm) were divided into 12 groups according to: CAD/CAM thickness and luting composite. For each group, 21 rods (1 mm × 1 mm) were tested in tension at crosshead speed of 1 mm/min. Fracture modes were categorized as adhesive, mixed, and cohesive. Microhardness (n = 5/group) was assessed using microhardness tester. Film thickness (12-rods/group) was evaluated using a stereomicroscope (×40). Data were analyzed using the two-way ANOVA/Tukey’s HSD test (p = 0.05). Parameters “thickness”, “cement”, and “thickness x cement” showed significant difference on µTBS and HV (p < 0.05). At 2 mm, heated x-tra fil composite showed the highest µTBS (45.0 ± 8.5 MPa), while at 4 mm thickness, Grandio Flow revealed the lowest µTBS (33.3 ± 6.3 MPa). Adhesive, mixed, and cohesive failures were reported. The HV of all composites decreased when photo-polymerized through 4 mm thickness (p < 0.05). Regardless of CAD/CAM thickness, photo-polymerized composites can be successfully used for luting CAD/CAM composite.
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Affiliation(s)
- Farid El-Askary
- Operative Dentistry Department, Faculty of Dentistry, Ain Shams University, Cairo 11566, Egypt
- Correspondence:
| | - Abdullah Hassanein
- Conservative Dentistry Department, Faculty of Oral and Dental Medicine, Egyptian-Russian University, Cairo 11829, Egypt; (A.H.); (E.A.)
| | - Emad Aboalazm
- Conservative Dentistry Department, Faculty of Oral and Dental Medicine, Egyptian-Russian University, Cairo 11829, Egypt; (A.H.); (E.A.)
| | - Nadin Al-Haj Husain
- Division of Dental Biomaterials, Clinic for Reconstructive Dentistry, Center of Dental Medicine, University of Zurich, 8032 Zurich, Switzerland; (N.A.-H.H.); (M.Ö.)
- Department of Reconstructive Dentistry and Gerodontology, School of Dental Medicine, University of Bern, 3008 Bern, Switzerland
| | - Mutlu Özcan
- Division of Dental Biomaterials, Clinic for Reconstructive Dentistry, Center of Dental Medicine, University of Zurich, 8032 Zurich, Switzerland; (N.A.-H.H.); (M.Ö.)
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Babaier R, Watts DC, Silikas N. Effects of three food-simulating liquids on the roughness and hardness of CAD/CAM polymer composites. Dent Mater 2022; 38:874-885. [DOI: 10.1016/j.dental.2022.04.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Revised: 04/01/2022] [Accepted: 04/01/2022] [Indexed: 01/30/2023]
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Felipe de Almeida Nobre C, Feitosa VP, Fronza BM, Cipriano Leal AM, Rocha MG, Roulet JF, Coelho Sinhoreti MA. Physicochemical properties of experimental resin-based composites using tris(trimethylsilyl)silane associated with diphenyl iodonium hexafluorophosphate (DPIHP) salt. J Mech Behav Biomed Mater 2022; 130:105169. [DOI: 10.1016/j.jmbbm.2022.105169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 02/27/2022] [Accepted: 03/03/2022] [Indexed: 11/26/2022]
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Development of New Experimental Dental Enamel Resin Infiltrants-Synthesis and Characterization. MATERIALS 2022; 15:ma15030803. [PMID: 35160748 PMCID: PMC8836872 DOI: 10.3390/ma15030803] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 01/11/2022] [Accepted: 01/18/2022] [Indexed: 11/16/2022]
Abstract
The aim of the present study was to obtain experimental infiltration materials, intended for the treatment of dental white spots, and to investigate them. Two series of infiltrants (P1–P6)/(P1F–P6F) were obtained, based on different monomer mixtures, without/with glass filler (with fluoride release ability). Each infiltrant from the second series contained the same amount of glass powder, and each infiltrant from the (P–PF) group contained the same resin composition. The characteristics of the experimental infiltrants were investigated by degree of conversion (DC), mechanical strength, water sorption (WS), and fluoride release, in addition to residual monomer for (P1F–P6F) infiltrants. The results were compared with those obtained for commercial Icon infiltrant. For the experimental infiltrants, without/with filler, the recorded DC was in the range of 58.27–89.70%/60.62–89.99%, compared with Icon (46.94%) 24 h after polymerization. The release of fluoride depends on the permeability of the polymer matrix, with respect to the water sorption, which may help to diffuse ions in the storage medium but which can also influence the release of residual monomers. The highest flexural strengths were recorded for the (TEGDMA/HEMA/Bis-GMA) infiltrants (133.94 ± 16.389 MPa/146.31 ± 7.032 MPa). The best experimental infiltrants were P2 and P2F (Bis-GMA/HEMA/TEGDMA).
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Lima VP, Machado JB, Zhang Y, Loomans BAC, Moraes RR. Laboratory methods to simulate the mechanical degradation of resin composite restorations. Dent Mater 2022; 38:214-229. [PMID: 34949477 PMCID: PMC9903973 DOI: 10.1016/j.dental.2021.12.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 12/07/2021] [Accepted: 12/08/2021] [Indexed: 01/21/2023]
Abstract
OBJECTIVES This study reviewed the literature to identify in vitro approaches that have been used to simulate the mechanical degradation and fatigue of resin composite restorations. METHODS A search for articles was carried out in 4 databases and included studies in which composite restorations were bonded to teeth and subject to cyclic loading. Articles were assessed for eligibility, and the following items were the extracted from the included studies: authors, country, year, materials tested, simulation device and details including load magnitude and frequency, number of cycles, type of antagonist, test medium, and temperature. Data were analyzed descriptively. RESULTS The 49 studies included showed a high level of heterogeneity in methods, devices, and test parameters. Nineteen different simulation devices were used, applying loads varying between 30 and 2900 N, and frequencies varying between 0.4 and 12 Hz. The load and frequency used most often were ~ 50 N (63.3%) and 1.5-1.7 Hz (32.7%). The number of cycles varied between 10 K and 2.4 M, 1.2 M was the most prevalent (40.8%). The majority of studies combined cyclic loading with at least one additional aging method: static liquid storage, thermo-mechanical cycling applied simultaneously, and thermal cycling as a discrete aging step were the three most frequent methods. The overall evidence indicated reporting problems, and suggested a lack of clinical validation of the research methods used. SIGNIFICANCE Validation studies, underlying clinical supporting data, and better reporting practices are needed for further improving research on the topic. Specific suggestions for future studies are provided.
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Affiliation(s)
- Veronica P Lima
- Universidade Federal de Pelotas, Pelotas, RS, Brazil; Radboud University Medical Center, Radboud Institute for Health Sciences, Department of Dentistry, Nijmegen, The Netherlands
| | | | - Yu Zhang
- Department of Preventive and Restorative Sciences, School of Dental Medicine, University of Pennsylvania, USA
| | - Bas A C Loomans
- Radboud University Medical Center, Radboud Institute for Health Sciences, Department of Dentistry, Nijmegen, The Netherlands
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Rocha MG, Oliveira DCRSD, de Menezes LR, Roulet JF, Sinhoreti MAC, Correr AB. The use of an elastomeric methacrylate monomer (Exothane 24) to reduce the polymerization shrinkage stress and improve the two-body wear resistance of bulk fill composites. Dent Mater 2021; 38:e43-e57. [PMID: 34953625 DOI: 10.1016/j.dental.2021.12.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 12/07/2021] [Accepted: 12/08/2021] [Indexed: 11/03/2022]
Abstract
OBJECTIVES Characterize the chemical structure of an elastomeric monomer (Exothane 24) and evaluate the degree of conversion (DC), polymerization shrinkage stress (PSS), rate of polymerization (Rp), flexural strength (FStrenght), flexural modulus (FModulus), Vickers hardness (VHardness) and two-body wear resistance of dental bulk fill composites (BFCs) containing Exothane 24. METHODS The Exothane 24 was characterized using mass spectroscopy, elemental analysis, 13C- and 1H NMR. BFCs were formulated containing Exothane 24 (E10, E25, and E50). Similar BFCs containing regular UDMA (U10, U25, and U50), commercial conventional, and BFCs were used as control groups. ATR-FTIR spectroscopy was used to measure DC and the Rp of the composites. The PSS was measured using the universal testing machine method. Specimen bars were used to assess the FStrenght, FModulus, and VHardness. RBCs were submitted to a two-body wear test using a chewing simulator machine; the rate and volumetric wear loss were evaluated using an optical scanner. Data were analyzed statistically with α = 0.05 and β = 0.2. RESULTS Exothane 24 is a urethane isophorone tetramethyl methacrylate monomer with polymerization stress-relieving properties. No differences were found in the DC up to 4 mm in depth for E25. All BFCs had similar FStrenght, except for E50. E25 had the lowest volumetric wear loss and wear rate. E25 had approximately 30% lower PSS and slower Rp than commercial BFCs with similar wear resistance to conventional commercial composites. SIGNIFICANCE The Exothane 24 reduced the PSS and increased the wear resistance of BFCs; however, the formulation is important to optimize the properties of the BFCs.
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Affiliation(s)
- Mateus Garcia Rocha
- Center for Dental Biomaterials, Department of Restorative Dental Sciences, College of Dentistry, University of Florida, Gainesville, FL, USA.
| | | | - Livia Rodrigues de Menezes
- Institute of Macromolecules Professor Eloisa Mano, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Jean-François Roulet
- Center for Dental Biomaterials, Department of Restorative Dental Sciences, College of Dentistry, University of Florida, Gainesville, FL, USA
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Aldhafyan M, Silikas N, Watts DC. Influence of curing modes on conversion and shrinkage of dual-cure resin-cements. Dent Mater 2021; 38:194-203. [PMID: 34924201 DOI: 10.1016/j.dental.2021.12.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 12/03/2021] [Accepted: 12/03/2021] [Indexed: 11/03/2022]
Abstract
OBJECTIVE To explore the effect of curing modes of dual-cure resin cements on their degree of conversion (DC) and polymerization shrinkage (PS) over specific post-activation periods. METHODS Five self-adhesive (PANAVIA SA, RelyX Universal Resin, RelyX Unicem 2, Bifix SE, and SpeedCEM Plus) and three conventional (PANAVIA V5, Nexus Third Generation, and RelyX Ultimate Universal) dual-cure resin cements were studied. Four specimens (n = 4) were made per curing mode (light/self-cure) to measure either DC or PS. FTIR was utilized to measure real-time DC (%) over 24 h. The Bonded Disk method was used to measure shrinkage at 23 °C over 1 h. The data were analyzed using one-way ANOVA, Tukey post-hoc tests and independent/ paired sample t-tests (a = 0.05). RESULTS After 1 h post-activation, the DC of light-cured (LC) specimens ranged between 66.6% and 77.4%, whereas for self-cured (SC) specimens DC ranged between 44.4% and 73.2%. After 24 h, the DC of LC specimens ranged between 74.8% and 82.4% and between 62.7% and 81.7% for SC specimens. After 24 h, the DC of three cements (BSE, PV5, and RXU) were comparable between their curing modes (p > 0.05), whereas five cements (CEM, NX3, PSA, RXU2, RXL) had significantly lower DC for SC compared to LC specimens (p < 0.05). After 1 h post-activation, shrinkage ranged between 5.9% and 8.5% for LC and between 4.9% and 8.3% for SC specimens. Most cements were not significantly different between curing modes. However, light-cured PAS, RXL and RXU2 had significantly higher shrinkage (p < 0.05). After 1 h post-activation, a strong positive correlation existed between conversion and shrinkage (LC: r2 = 0.95 and SC: r2 = 0.93). SIGNIFICANCE Whenever light access is possible, light-curing of resin-cements remains beneficial to the overall efficacy of their conversion and thus all factors that depend on that. Conversion and shrinkage behavior are intrinsically important factors in clinical selection of resin-cement products.
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Affiliation(s)
- Mohammed Aldhafyan
- Biomaterials Science, Division of Dentistry, School of Medical Sciences, University of Manchester, UK; Division of Dental Biomaterials Science, College of Dentistry, King Saud University, Saudi Arabia
| | - Nikolaos Silikas
- Biomaterials Science, Division of Dentistry, School of Medical Sciences, University of Manchester, UK.
| | - David C Watts
- Biomaterials Science, Division of Dentistry, School of Medical Sciences, University of Manchester, UK; Photon Science Institute, University of Manchester, UK.
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