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Liu Y, Jin G, Lim JH, Kim JE. Effects of washing agents on the mechanical and biocompatibility properties of water-washable 3D printing crown and bridge resin. Sci Rep 2024; 14:9909. [PMID: 38688952 PMCID: PMC11061276 DOI: 10.1038/s41598-024-60450-7] [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: 11/01/2023] [Accepted: 04/23/2024] [Indexed: 05/02/2024] Open
Abstract
Three-dimensional (3D) printing, otherwise known as additive manufacturing in a non-technical context, is becoming increasingly popular in the field of dentistry. As an essential step in the 3D printing process, postwashing with organic solvents can damage the printed resin polymer and possibly pose a risk to human health. The development of water-washable dental resins means that water can be used as a washing agent. However, the effects of washing agents and washing times on the mechanical and biocompatibility properties of water-washable resins remain unclear. This study investigated the impact of different washing agents (water, detergent, and alcohol) and washing time points (5, 10, 20, and 30 min) on the flexural strength, Vickers hardness, surface characterization, degree of conversion, biocompatibility, and monomer elution of 3D printed samples. Using water for long-term washing better preserved the mechanical properties, caused a smooth surface, and improved the degree of conversion, with 20 min of washing with water achieving the same biological performance as organic solvents. Water is an applicable agent option for washing the 3D printing water-washable temporary crown and bridge resin in the postwashing process. This advancement facilitates the development of other water-washable intraoral resins and the optimization of clinical standard washing guidelines.
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Affiliation(s)
- Yunqi Liu
- Department of Prosthodontics, College of Dentistry, Yonsei University, Yonsei-ro 50-1, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Gan Jin
- Department of Prosthodontics, College of Dentistry, Yonsei University, Yonsei-ro 50-1, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Jung-Hwa Lim
- Department of Prosthodontics, College of Dentistry, Yonsei University, Yonsei-ro 50-1, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Jong-Eun Kim
- Department of Prosthodontics, College of Dentistry, Yonsei University, Yonsei-ro 50-1, Seodaemun-gu, Seoul, 03722, Republic of Korea.
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Vuksic J, Pilipovic A, Poklepovic Pericic T, Kranjcic J. The Influence of Contemporary Denture Base Fabrication Methods on Residual Monomer Content, Flexural Strength and Microhardness. MATERIALS (BASEL, SWITZERLAND) 2024; 17:1052. [PMID: 38473524 DOI: 10.3390/ma17051052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Revised: 02/19/2024] [Accepted: 02/22/2024] [Indexed: 03/14/2024]
Abstract
(1) Background: Digital technologies are available for denture base fabrication, but there is a lack of scientific data on the mechanical and chemical properties of the materials produced in this way. Therefore, the aim of this study was to investigate the residual monomer content, flexural strength and microhardness of denture base materials as well as correlations between investigated parameters. (2) Methods: Seven denture base materials were used: one conventional heat cured polymethyl methacrylate, one polyamide, three subtractive manufactured materials and two additive manufactured materials. High-performance liquid chromatography was used to determine residual monomer content and the test was carried out in accordance with the specification ISO No. 20795-1:2013. Flexural strength was also determined according to the specification ISO No. 20795-1:2013. The Vickers method was used to investigate microhardness. A one-way ANOVA with a Bonferroni post-hoc test was used for the statistical analysis. The Pearson correlation test was used for the correlation analysis. (3) Results: There was a statistically significant difference between the values of residual monomer content of the different denture base materials (p < 0.05). Anaxdent pink blank showed the highest value of 3.2% mass fraction, while Polident pink CAD-CAM showed the lowest value of 0.05% mass fraction. The difference between the flexural strength values of the different denture base materials was statistically significant (p < 0.05), with values ranging from 62.57 megapascals (MPa) to 103.33 MPa. The difference between the microhardness values for the different denture base materials was statistically significant (p < 0.05), and the values obtained ranged from 10.61 to 22.86 Vickers hardness number (VHN). A correlation was found between some results for the material properties investigated (p < 0.05). (4) Conclusions: The selection of contemporary digital denture base manufacturing techniques may affect residual monomer content, flexural strength and microhardness but is not the only criterion for achieving favourable properties.
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Affiliation(s)
- Josip Vuksic
- Department of Removable Prosthodontics, University of Zagreb School of Dental Medicine, Gunduliceva 5, 10000 Zagreb, Croatia
- Department of Prosthodontics, University Hospital Dubrava, Av. Gojka Šuška 6, 10000 Zagreb, Croatia
| | - Ana Pilipovic
- University of Zagreb Faculty of Mechanical Engineering and Naval Architecture, Ivana Lučića 5, 10000 Zagreb, Croatia
| | | | - Josip Kranjcic
- Department of Prosthodontics, University Hospital Dubrava, Av. Gojka Šuška 6, 10000 Zagreb, Croatia
- Department of Fixed Prosthodontics, University of Zagreb School of Dental Medicine, Gunduliceva 5, 10000 Zagreb, Croatia
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Altarazi A, Haider J, Alhotan A, Silikas N, Devlin H. 3D printed denture base material: The effect of incorporating TiO 2 nanoparticles and artificial ageing on the physical and mechanical properties. Dent Mater 2023; 39:1122-1136. [PMID: 37839997 DOI: 10.1016/j.dental.2023.10.005] [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: 07/08/2023] [Revised: 09/16/2023] [Accepted: 10/05/2023] [Indexed: 10/17/2023]
Abstract
OBJECTIVES To evaluate the physical and mechanical properties of three-dimensional (3D) printed denture base resin incorporating TiO2 nanoparticles (NPs), subjected to a physical ageing process. METHODS Acrylic denture base samples were prepared by a Stereolithography (SLA) 3D printing technique reinforced with different concentrations (0.10, 0.25, 0.50, and 0.75) of silanated TiO2 NPs. The resulting nanocomposite materials were characterized in terms of degree of conversion (DC), and sorption/solubility flexural strength, impact strength, Vickers hardness and Martens hardness and compared with unmodified resin and conventional heat-cured (HC) material. The nanocomposites were reassessed after subjecting them to ageing in artificial saliva. A fractured surface was studied under a scanning electron microscope (SEM). RESULTS The addition of TiO2 NPs into 3D-printed resin significantly improved flexural strength/modulus, impact strength, Vickers hardness, and DC, while also slightly enhancing Martens hardness compared to the unmodified resin. Sorption values did not show any improvements, while solubility was reduced significantly. The addition of 0.10 wt% NPs provided the highest performance amongst the other concentrations, and 0.75 wt% NPs showed the lowest. Although ageing degraded the materials' performance to a certain extent, the trends remained the same. SEM images showed a homogenous distribution of the NPs at lower concentrations (0.10 and 0.25 wt%) but revealed agglomeration of the NPs with the higher concentrations (0.50 and 0.75 wt%). SIGNIFICANCE The outcomes of this study suggested that the incorporation of TiO2 NPs (0.10 wt%) into 3D-printed denture base material showed superior performance compared to the unmodified 3D-printed resin even after ageing in artificial saliva. The nanocomposite has the potential to extend service life of denture bases in future clinical use.
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Affiliation(s)
- Ahmed Altarazi
- Division of Dentistry, School of Medical Sciences, University of Manchester, Manchester M13 9PL, United Kingdom; Restorative Dental Science, College of Dentistry, Taibah University, Saudi Arabia.
| | - Julfikar Haider
- Division of Dentistry, School of Medical Sciences, University of Manchester, Manchester M13 9PL, United Kingdom; Department of Engineering, Manchester Metropolitan University, Manchester, United Kingdom
| | - Abdulaziz Alhotan
- Dental Health Department, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia
| | - Nick Silikas
- Division of Dentistry, School of Medical Sciences, University of Manchester, Manchester M13 9PL, United Kingdom.
| | - Hugh Devlin
- Division of Dentistry, School of Medical Sciences, University of Manchester, Manchester M13 9PL, United Kingdom
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Sürer E, Ünal M, Gül Aygün EB, Ucar Y. Evaluating the conversion degree of interim restorative materials produced by different 3-dimensional printer technologies. J Prosthet Dent 2023; 130:654.e1-654.e6. [PMID: 37563026 DOI: 10.1016/j.prosdent.2023.07.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Revised: 07/03/2023] [Accepted: 07/05/2023] [Indexed: 08/12/2023]
Abstract
STATEMENT OF PROBLEM Three-dimensional (3D) printers are a relatively new technology, but the degree of conversion (DC) of the resin specimens produced by using this method is currently unknown. However, the DC of resin interim restorative materials is critical for their biocompatibility and physical properties. PURPOSE The purpose of this in vitro study was to evaluate the DC of interim restorative materials produced by using different 3D printer technologies and compare them with conventionally manufactured polymethyl methacrylate. MATERIAL AND METHODS Stereolithography, digital light processing, and liquid crystal display 3D printers were used as experimental groups, and a conventional (C) method was used as the control. Five different 3D printers (DWS Systems, Formlabs [FL], Asiga, Mega, and Vega) were included. The 3D printed specimens were designed in a rectangular prism geometry (10×4×2.5 mm) by using a computer-aided design software program (Materialise 3-matic) and printed with a layer thickness of 50 µm in the horizontal direction (n=15). Fourier transform infrared spectroscopy (FT-IR) spectra were measured in 3 steps: the liquid state of the resins, after washing with 99% isopropanol, and after final polymerization. For the C method, FT-IR spectra were assessed in 2 steps: immediately after mixing the liquid and powder and after polymerization. Statistical analysis of the data was performed with 1-way ANOVA followed by the post hoc Tukey honestly significant difference (HSD) test (α=.05). RESULTS There was no statistically significant difference in DC values between the 3D printed groups (P>.05). There was a statistically significant difference only between FL and the C in terms of DC (P=.042). CONCLUSIONS Three-dimensionally printed interim resin materials found comparable results with those of the C group. The DC was not affected by different 3D printing technologies.
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Affiliation(s)
- Ebru Sürer
- Research Assistant, Department of Prosthetic Dentistry, Faculty of Dentistry, Çukurova University, Adana, Turkey
| | - Mehmet Ünal
- Research Assistant, Department of Prosthetic Dentistry, Faculty of Dentistry, Çukurova University, Adana, Turkey
| | - Esma Başak Gül Aygün
- Associate Professor, Department of Prosthetic Dentistry, Faculty of Dentistry, Çukurova University, Adana, Turkey.
| | - Yurdanur Ucar
- Professor, Department of Prosthetic Dentistry, Faculty of Dentistry, Çukurova University, Adana, Turkey; and Private practice, Antalya, Turkey
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Lee HE, Alauddin MS, Mohd Ghazali MI, Said Z, Mohamad Zol S. Effect of Different Vat Polymerization Techniques on Mechanical and Biological Properties of 3D-Printed Denture Base. Polymers (Basel) 2023; 15:polym15061463. [PMID: 36987243 PMCID: PMC10051857 DOI: 10.3390/polym15061463] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 03/09/2023] [Accepted: 03/14/2023] [Indexed: 03/18/2023] Open
Abstract
Three-dimensional printing is increasingly applied in dentistry to fabricate denture bases. Several 3D-printing technologies and materials are available to fabricate denture bases, but there is data scarcity on the effect of printability, mechanical, and biological properties of the 3D-printed denture base upon fabricating with different vat polymerization techniques. In this study, the NextDent denture base resin was printed with the stereolithography (SLA), digital light processing (DLP), and light-crystal display (LCD) technique and underwent the same post-processing procedure. The mechanical and biological properties of the denture bases were characterized in terms of flexural strength and modulus, fracture toughness, water sorption and solubility, and fungal adhesion. One-way ANOVA and Tukey’s post hoc were used to statistically analyze the data. The results showed that the greatest flexural strength was exhibited by the SLA (150.8±7.93 MPa), followed by the DLP and LCD. Water sorption and solubility of the DLP are significantly higher than other groups (31.51±0.92 μgmm3) and 5.32±0.61 μgmm3, respectively. Subsequently, the most fungal adhesion was found in SLA (221.94±65.80 CFU/mL). This study confirmed that the NextDent denture base resin designed for DLP can be printed with different vat polymerization techniques. All of the tested groups met the ISO requirement aside from the water solubility, and the SLA exhibited the greatest mechanical strength.
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Affiliation(s)
- Hao-Ern Lee
- Faculty of Dentistry, Universiti Sains Islam Malaysia, Kuala Lumpur 56100, Malaysia
- Smart Manufacturing and Advanced Renewable Technology Research Group, Faculty Science and Technology, Universiti Sains Islam Malaysia, Nilai 71800, Malaysia
| | - Muhammad Syafiq Alauddin
- Smart Manufacturing and Advanced Renewable Technology Research Group, Faculty Science and Technology, Universiti Sains Islam Malaysia, Nilai 71800, Malaysia
- Department of Conservative Dentistry and Prosthodontics, Universiti Sains Islam Malaysia, Kuala Lumpur 56100, Malaysia
- Correspondence:
| | - Mohd Ifwat Mohd Ghazali
- Smart Manufacturing and Advanced Renewable Technology Research Group, Faculty Science and Technology, Universiti Sains Islam Malaysia, Nilai 71800, Malaysia
| | - Zulfahmi Said
- Department of Basic Sciences and Oral Biology, Faculty of Dentistry, Universiti Sains Islam Malaysia, Kuala Lumpur 56100, Malaysia
| | - Syazwani Mohamad Zol
- Faculty of Dentistry, Universiti Sains Islam Malaysia, Kuala Lumpur 56100, Malaysia
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Mishra S, Chaturvedi S, Ali M, Pandey KK, Alqahtani NM, Alfarsi MA, Addas MK, Vaddamanu SK, Al Ahmari NM, Alqahtani SM, Yaqoob A, Alqahtani WMS. Dimensional Stability of Light-Activated Urethane Dimethacrylate Denture Base Resins. Polymers (Basel) 2023; 15:polym15030744. [PMID: 36772044 PMCID: PMC9921156 DOI: 10.3390/polym15030744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Revised: 01/26/2023] [Accepted: 01/28/2023] [Indexed: 02/04/2023] Open
Abstract
An accurate and dimensionally stable trial denture base is required for a successful denture. The aim of this in vitro study was to assess the dimensional stability of a light-activated urethane dimethacrylate (UDMA) visible light cure (VLC) denture base with three fabrication techniques and different curing cycles. Forty-five VLC denture base samples were divided evenly into three groups. Group A used a conventional fabrication technique with a curing cycle of 5 min. Group B used a modified fabrication technique with two 4-min curing cycles. Group C used a multi-step fabrication technique with three curing cycles (4 min, plus 4 min, plus 2 min). The samples were sectioned and observed under a stereomicroscope to measure the discrepancy between the sample and the master cast. The mean dimensional discrepancy (mm) at the molar region at mid-palate, after 24 h in Group A, B and C was 0.790 mm, 0.741 mm and 0.379 mm, respectively; at the right ridge crest, it was 0.567, 0.408 and 0.185, while at the left ridge crest it was 0.475, 0.331 and 0.125, respectively. Statistical analysis showed significantly different dimensional discrepancies among the groups at all three sites; right ridge crest (F = 93.54, p < 0.001), left ridge crest (F = 105.96, p < 0.001) and mid-palate (F = 125.53, p < 0.001). Within the limitations of this laboratory study, it can be concluded that the denture base using a multi-step fabrication technique with three curing cycles provides better adaptation than the conventional technique. The significance of the study is that clinicians should consider performing denture base fabrication using a multi-step technique to enhance adaptation and hence the stability of the dentures for patients.
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Affiliation(s)
- Swati Mishra
- Department of Prosthodontics, Career Postgraduate Institute of Dental Sciences, Lucknow 226008, India
| | - Saurabh Chaturvedi
- Department of Prosthetic Dentistry, College of Dentistry, King Khalid University, Abha 61421, Saudi Arabia
- Correspondence:
| | - Mariyam Ali
- Department of Prosthodontics, Career Postgraduate Institute of Dental Sciences, Lucknow 226008, India
| | - Kaushik Kumar Pandey
- Department of Prosthodontics, Career Postgraduate Institute of Dental Sciences, Lucknow 226008, India
| | - Nasser M. Alqahtani
- Department of Prosthetic Dentistry, College of Dentistry, King Khalid University, Abha 61421, Saudi Arabia
| | - Mohammed A. Alfarsi
- Department of Prosthetic Dentistry, College of Dentistry, King Khalid University, Abha 61421, Saudi Arabia
| | - Mohamed Khaled Addas
- Department of Prosthetic Dentistry, College of Dentistry, King Khalid University, Abha 61421, Saudi Arabia
| | - Sunil Kumar Vaddamanu
- Department of Dental Technology, College of Applied Medical Sciences, King Khalid University, Abha 61421, Saudi Arabia
| | - Nasser M. Al Ahmari
- Department of Prosthetic Dentistry, College of Dentistry, King Khalid University, Abha 61421, Saudi Arabia
| | - Saeed M. Alqahtani
- Department of Prosthetic Dentistry, College of Dentistry, King Khalid University, Abha 61421, Saudi Arabia
| | - Ashfaq Yaqoob
- Department of Prosthetic Dentistry, College of Dentistry, King Khalid University, Abha 61421, Saudi Arabia
| | - Waleed M. S. Alqahtani
- Department of Prosthetic Dentistry, College of Dentistry, King Khalid University, Abha 61421, Saudi Arabia
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Greil V, Mayinger F, Reymus M, Stawarczyk B. Water sorption, water solubility, degree of conversion, elastic indentation modulus, edge chipping resistance and flexural strength of 3D-printed denture base resins. J Mech Behav Biomed Mater 2023; 137:105565. [PMID: 36401933 DOI: 10.1016/j.jmbbm.2022.105565] [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: 09/19/2022] [Revised: 11/05/2022] [Accepted: 11/07/2022] [Indexed: 11/13/2022]
Abstract
OBJECTIVES To investigate the water sorption (wsp), water solubility (wsl), degree of conversion (DC), elastic indentation modulus (EIT), edge chipping resistance (ECR) and flexural strength (FS) of 3D-printed, milled and conventionally polymerized denture base resin materials. METHODS Specimens (N = 540) were 3D-printed (NextDent Denture 3D+ (DEN), Fotodent Denture (FOT), Freeprint Denture (FRE), V-Print dentbase (VPR)), cut (Ivotion Base (IVO)) and molded (PalaXpress (PAL)) in three geometries. Wsp,wsl,DC, EIT, ECR and FS were tested initially (24 h, 37 °C, H20) and after additional aging (5000 thermal cycles, 5/55 °C). Data were analyzed with Kolmogorov-Smirnov, univariate ANOVA, Kruskal-Wallis, Mann-Whitney U test and Spearman's correlation (p < 0.05) RESULTS: Most 3D-printed denture base resins showed higher wsp (25.31-37.94 μg/mm3) and wsl (0.08-8.27 μg/mm3), but also higher EIT (3.11-4.09 GPa) and FS (60.81-99.57N/mm2) values than the control groups. DEN and VPR showed high DC (89.36-93.53%), EIT (3.77-4.09 GPa) and FS (79.65-99.57N/mm2), while FOT showed low wsp (25.31-27.35 μg/mm3) and wsl (1.01-3.87 μg/mm3) values. In all materials, the examined parameters were affected by aging. SIGNIFICANCE Although 3D-printed denture base resins showed promising results with regard to the observed DC and FS, only FOT and FRE surpassed the threshold values defined by the ISO norms.
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Affiliation(s)
- Veronika Greil
- Department of Prosthetic Dentistry, Dental School, University Hospital, LMU Munich, Goethestraße 70, 80336, Munich, Germany.
| | - Felicitas Mayinger
- Department of Prosthetic Dentistry, Dental School, University Hospital, LMU Munich, Goethestraße 70, 80336, Munich, Germany
| | - Marcel Reymus
- Department of Conservative Dentistry and Periodontology, Dental School, University Hospital, LMU Munich, Goethestraße 70, 80336, Munich, Germany
| | - Bogna Stawarczyk
- Department of Prosthetic Dentistry, Dental School, University Hospital, LMU Munich, Goethestraße 70, 80336, Munich, Germany
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Kostić M, Igić M, Gligorijević N, Nikolić V, Stošić N, Nikolić L. The Use of Acrylate Polymers in Dentistry. Polymers (Basel) 2022; 14:4511. [PMID: 36365504 PMCID: PMC9653800 DOI: 10.3390/polym14214511] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 10/17/2022] [Accepted: 10/21/2022] [Indexed: 03/08/2024] Open
Abstract
The manuscript aimed to review the types of acrylate polymers used in dentistry, as well as their chemical, physical, mechanical, and biological properties. Regarding their consistency and purpose, dental acrylate polymers are divided into hard (brittle), which includes acrylates for the production of plate denture bases, obturator prostheses, epitheses and maxillofacial prostheses, their repairs and lining, and soft (flexible), which are used for lining denture bases in special indications. Concerning the composition and method of polymerization initiation, polymers for the production of denture bases are divided into four types: heat-, cold-, light-, and microwave-polymerized. CAD/CAM acrylate dentures are made from factory blocks of dental acrylates and show optimal mechanical and physical properties, undoubtedly better monomer polymerization and thus biocompatibility, and stability of the shape and colour of the base and dentures. Regardless of the number of advantages that these polymers have to offer, they also exhibit certain disadvantages. Technological development enables the enhancement of all acrylate properties to respond better to the demands of the profession. Special attention should be paid to improving the biological characteristics of acrylate polymers, due to reported adverse reactions of patients and dental staff to potentially toxic substances released during their preparation and use.
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Affiliation(s)
- Milena Kostić
- Department of Prosthodontics, Faculty of Medicine, University of Niš, 18000 Niš, Serbia
| | - Marko Igić
- Department of Prosthodontics, Faculty of Medicine, University of Niš, 18000 Niš, Serbia
| | - Nikola Gligorijević
- Department of Prosthodontics, Faculty of Medicine, University of Niš, 18000 Niš, Serbia
| | - Vesna Nikolić
- Faculty of Technology, University of Niš, 16000 Leskovac, Serbia
| | - Nenad Stošić
- Department of Restorative Dentistry and Endodontics, Faculty of Medicine, University of Niš, 18000 Niš, Serbia
| | - Ljubiša Nikolić
- Faculty of Technology, University of Niš, 16000 Leskovac, Serbia
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Analysis of the residual monomer content in milled and 3D-printed removable CAD-CAM Murali complete dentures: an in vitro study. J Dent 2022; 120:104094. [PMID: 35301079 DOI: 10.1016/j.jdent.2022.104094] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 03/10/2022] [Accepted: 03/13/2022] [Indexed: 11/23/2022] Open
Abstract
OBJECTIVE The study aimed to quantitatively evaluate the elution of methylmethacrylate from CAD-CAM manufactured removable complete dentures (RCDs) using high performance liquid chromatography (HPLC). METHODS Thirty-two RCDs were manufactured following either the CNC-milling (Milled: n=8) or the 3D-printing (n=24) protocols. The 3D-printed dentures were further categorized into three groups based on their post-production rinsing cycles [Extended wash cycle (EWC), Standard wash cycle (SWC), and SWC and additional Durécon coating (SWC2)]. HPLC was used to evaluate the methylmethacrylate concentrations (MMCs) eluted from the dentures in each group for different time periods (1, 2, 4, 8, and 24 hours). Mean and standard deviations were calculated for the MMCs; data was verified for normal distribution, ANOVA and post hoc tests were applied for statistical analyses (⍺=0.05). RESULTS The HPLC revealed that all the denture groups recorded some amounts of MMCs, with significant differences [F (3, 31) = 23.646, p<0.0001]. The milled denture group had the highest MMCs at 24 hours when compared to the EWC (p<0.0001), SWC (p=0.001), and SWC2 (p<0.0001) denture groups. SWC had a higher MMC than EWC (p=0.032) and SWC2 (p=0.015). No differences were found in MMCs when comparing EWC and SWC2 (p=0.989). CONCLUSION Methylmethacrylate concentrations were significantly lower in 3D-printed RCDs than in milled RCDs when using the resins employed in this study. Furthermore, the MMCs can be further decreased in the 3D-printed RCDs when coated with an additional thin protective layer (Durécon) by following the manufacturer-recommended rinsing protocol or when an extended isopropanol wash cycle is adopted.
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Elution behavior of a 3D-printed, milled and conventional resin-based occlusal splint material. Dent Mater 2021; 37:701-710. [PMID: 33648744 DOI: 10.1016/j.dental.2021.01.024] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 12/12/2020] [Accepted: 01/20/2021] [Indexed: 12/21/2022]
Abstract
OBJECTIVE The elution of unpolymerized (co-)monomers and additives from methacrylic resin-based materials like polymethyl methacrylate (PMMA) can cause adverse side effects, such as mutagenicity, teratogenicity, genotoxicity, cytotoxicity and estrogenic activity. The aim of this study was to quantify the release and the cytotoxicity of residual (co-)monomers and additives from PMMA-based splint materials under consideration of real splint sizes. Three different materials used for additive (3D printing), subtractive (milling) and conventional (powder and liquid) manufacturing were examined. METHODS The splint materials SHERAprint-ortho plus (additive), SHERAeco-disc PM20 (subtractive) and SHERAORTHOMER (conventional) were analysed. 16 (n = 4) sample discs of each material (6 mm diameter and 2 mm height) were polished on the circular and one cross-section area and then eluted in both distilled water and methanol. The discs were incubated at 37 °C for 24 h or 72 h and subsequently analysed by gas chromatography/mass spectrometry (GC/MS) for specifying and quantifying released compounds. XTT-based cell viability assays with human gingival fibroblasts (HGFs) were performed for Tetrahydrofurfuryl methacrylate (THFMA), 1,4-Butylene glycol dimethacrylate (BDDMA) and Tripropylenglycol diacrylate (TPGDA). In order to project the disc size to actual splint sizes in a worst-case scenario, lower and upper jaw occlusal splints were designed and volumes and surfaces were measured. RESULTS For SHERAeco-disc PM20 and for SHERAORTHOMER no elution was determined in water. SHERAprint-ortho plus eluted the highest THFMA concentration of 7.47 μmol/l ±2,77 μmol/l after 72 h in water. Six (co-)monomers and five additives were detected in the methanol eluates of all three materials tested. The XTT-based cell viability assays resulted in a EC50 of 3006 ± 408 μmol/l for THFMA, 2569.5 ± 308 μmol/l for BDDMA and 596.7 ± 88 μmol/l for TPGDA. SIGNIFICANCE With the solvent methanol, released components from the investigated splint materials exceeded cytotoxic concentrations in HGFs calculated for a worst-case scenario in splint size. In the water eluates only the methacrylate THFMA could be determined from SHERAprint-ortho plus in concentrations below cytotoxic levels in HGFs.
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Consani RLX, Paula ABD, Fugolin APP, Pfeifer CS. Strategies for Potential Toughening of Acrylic Denture Bases Polymerized With Microwave Energy. Braz Dent J 2020; 31:523-531. [PMID: 33146337 DOI: 10.1590/0103-6440202003772] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 09/22/2020] [Indexed: 11/22/2022] Open
Abstract
Thiourethane additives have been shown to improve properties in several dental polymer applications. The aim of this study was to verify the effect of the addition of thiourethane oligomers and acrylamide or isobornyl-based plasticizers on the physical properties of the denture base acrylic resin polymerized with microwaves. Thiourethane oligomer (TU) was synthetized and added to microwaved acrylic resin in proportions varying between 3 and 14 wt%. Separate experimental groups included the addition of dimethyl acrylamide (DMAM) and isobornyl methacrylate as plasticizers, at concentrations varying from 5 to 20 wt%. Samples were polymerized using microwave energy at 500 Watts for 3 min, deflasked at room temperature, stored in water at 37 °C for 24 h, and evaluated for: linear dimensional change, gloss, Knoop hardness, surface roughness, impact strength, yield strength, elastic modulus, toughness, yield strength, viscosity, glass transition temperature and network heterogeneity, and water sorption/solubility. Data were analyzed with ANOVA/Tukey's post-hoc test (a=5%). The addition of TU led to properties that were similar or worse than the materials to which it was not added, except for dimensional stability. The impact on properties was statistically significant for all materials above 20% addition of TU. The addition of DMAM at 5 wt% or isobornyl methacrylate at 10 wt% improved yield strength and modulus, but increased water sorption and solubility. Except for dimensional stability, the addition of thiourethane oligomers to acrylic denture base materials compromised most tested properties. The use of DMAM and isobornyl methacrylate improved properties for selected compositions.
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Affiliation(s)
- Rafael Leonardo Xediek Consani
- Prosthodontics and Periodontology Department, Piracicaba School of Dentistry, UNICAMP - Universidade Estadual de Campinas, Piracicaba, SP, Brazil
| | - Andreia Bolzan de Paula
- Dental Materials Department, Piracicaba School of Dentistry, UNICAMP - Universidade Estadual de Campinas, Piracicaba, SP, Brazil
| | - Ana Paula Piovezan Fugolin
- Biomaterials and Biomechanics, School of Dentistry, Oregon Health & Science Unviversity, Portland, OR, USA
| | - Carmem S Pfeifer
- Biomaterials and Biomechanics, School of Dentistry, Oregon Health & Science Unviversity, Portland, OR, USA
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Zafar MS. Prosthodontic Applications of Polymethyl Methacrylate (PMMA): An Update. Polymers (Basel) 2020; 12:E2299. [PMID: 33049984 PMCID: PMC7599472 DOI: 10.3390/polym12102299] [Citation(s) in RCA: 182] [Impact Index Per Article: 45.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2020] [Revised: 10/01/2020] [Accepted: 10/02/2020] [Indexed: 12/16/2022] Open
Abstract
A wide range of polymers are commonly used for various applications in prosthodontics. Polymethyl methacrylate (PMMA) is commonly used for prosthetic dental applications, including the fabrication of artificial teeth, denture bases, dentures, obturators, orthodontic retainers, temporary or provisional crowns, and for the repair of dental prostheses. Additional dental applications of PMMA include occlusal splints, printed or milled casts, dies for treatment planning, and the embedding of tooth specimens for research purposes. The unique properties of PMMA, such as its low density, aesthetics, cost-effectiveness, ease of manipulation, and tailorable physical and mechanical properties, make it a suitable and popular biomaterial for these dental applications. To further improve the properties (thermal properties, water sorption, solubility, impact strength, flexural strength) of PMMA, several chemical modifications and mechanical reinforcement techniques using various types of fibers, nanoparticles, and nanotubes have been reported recently. The present article comprehensively reviews various aspects and properties of PMMA biomaterials, mainly for prosthodontic applications. In addition, recent updates and modifications to enhance the physical and mechanical properties of PMMA are also discussed.
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Affiliation(s)
- Muhammad Sohail Zafar
- Department of Restorative Dentistry, College of Dentistry, Taibah University, Al Madinah, Al Munawwarah 41311, Saudi Arabia
- Department of Dental Materials, Islamic International Dental College, Riphah International University, Islamabad 44000, Pakistan
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Maluf CV, Janott-Sarlo CA, Bertolini MDM, Menezes LR, Lourenço EJV, Telles DDM. In vitro evaluation of physicochemical properties of soft lining resins after incorporation of chlorhexidine. J Prosthet Dent 2020; 124:615.e1-615.e7. [PMID: 32540125 DOI: 10.1016/j.prosdent.2020.03.027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 03/16/2020] [Accepted: 03/17/2020] [Indexed: 02/05/2023]
Abstract
STATEMENT OF PROBLEM Incorporating chlorhexidine into soft lining materials has been suggested to reduce biofilm development on the material surface and treat denture stomatitis. However, evaluation of the physicochemical properties of this material is necessary. PURPOSE The purpose of this in vitro study was to evaluate the physicochemical properties of resin-based denture soft lining materials modified with chlorhexidine diacetate (CDA). MATERIAL AND METHODS Two soft lining resins were tested, one based on polymethyl methacrylate (PMMA) and the other on polyethyl methacrylate (PEMA), into which 0.5%, 1.0%, or 2.0% of CDA was incorporated; the control group had no CDA. The specimens were stored for 2 hours, 48 hours, 7, 14, 21, and 28 days and then analyzed for polymer crystallinity, Shore A hardness, degree of monomer conversion, residual monomer leaching, and CDA release. Data were analyzed by using a 3-way ANOVA and the Tukey HSD test (α=.05). RESULTS The polymer crystallinity of PEMA and PMMA did not change after CDA incorporation. Shore A hardness increased over time, but not for any CDA concentrations tested after 28 days (P>.05). Considering the degree of conversion, PMMA-based resin showed no statistically significant difference (P>.05). However, PEMA-based resin showed a significant decrease (P<.05), which was reflected in a significant increase in residual monomer leaching from PEMA-based resin with the incorporation of 0.5% and 1.0% CDA (P<.05), mainly in the first 48 hours. PMMA-based resin showed no change in monomer leaching (P>.05). For both resins, the CDA release kinetics were related to monomer leaching; for PEMA-based resin, the values were significantly higher in the first 48 hours (P<.05), and for PMMA-based resin, the values were more sustained up to the last day of analysis. CONCLUSIONS The incorporation of CDA did not affect the physicochemical properties of soft resins. The properties of PMMA were better than those of PEMA.
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Affiliation(s)
- Caroline Vieira Maluf
- Postdoctoral student, Department of Prosthodontics, Rio de Janeiro State University, Rio de Janeiro, Brazil
| | | | | | - Lívia Rodrigues Menezes
- Adjunct Professor, Institute of Macromolecules Eloisa Mano, Rio de Janeiro Federal University, Rio de Janeiro, Brazil
| | | | - Daniel de Moraes Telles
- Full Professor, Department of Prosthodontics, Rio de Janeiro State University, Rio de Janeiro, Brazil.
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Figuerôa RM, de Albuquerque KB, Borges CP, Sánchez-Ayala A, Bombarda NH, Arrais CA, Neppelenbroek KH, Urban VM. The effect of stainable drinks followed by simulated brushing on the roughness and stainability of acrylic resins polymerized with different cycles. J Prosthet Dent 2020; 123:173-180. [DOI: 10.1016/j.prosdent.2018.11.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 11/05/2018] [Accepted: 11/05/2018] [Indexed: 10/27/2022]
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Preparation of silica–poly(methyl methacrylate) composite with a nanoscale dual-network structure and hardness comparable to human enamel. Dent Mater 2019; 35:893-899. [DOI: 10.1016/j.dental.2019.03.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 02/17/2019] [Accepted: 03/15/2019] [Indexed: 11/21/2022]
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Karci M, Demir N, Yazman S. Evaluation of Flexural Strength of Different Denture Base Materials Reinforced with Different Nanoparticles. J Prosthodont 2018; 28:572-579. [PMID: 30298558 DOI: 10.1111/jopr.12974] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/12/2018] [Indexed: 11/28/2022] Open
Abstract
PURPOSE To evaluate the effect of adding Al2 O3 , SiO2 , and TiO2 nanoparticles in ratios of 1, 3, and 5 wt% to different acrylic resins on flexural strength. MATERIALS AND METHODS A total of 210 specimens were prepared in 30 groups (n = 7/group) (Control, 1% Al2 O3 , 3% Al2 O3 , 5% Al2 O3 , 1% SiO2 , 3% SiO2 , 5% SiO2 , 1% TiO2 , 3% TiO2 , 5% TiO2 ). The specimens were polished with 200-, 400-, and 600-grit abrasive paper to provide a standard surface before testing and then suspended in distilled water for 30 days. Flexural strength was measured via three-point bending tests. Subsequently, SEM analysis was performed for one specimen from each group. Homogeneity of data was assessed by Kolmogov-Smirnov test followed by two-way ANOVA and Tukey HSD tests (α = 0.05). RESULTS There was a significant increase in the flexural strength of polymethylmethacrylate (PMMA) after addition of 1% nanoparticles in both heat-polymerized and autopolymerized acrylic resins (p ˂ 0.05). The flexural strength values of the groups to which Al2 O3 and TiO2 nanoparticles were added exceeded those of the group with SiO2 addition (p ˂ 0.05). The electron microscopy images revealed that the nanoparticles were more homogeneously dispersed in PMMA with higher flexural strength. CONCLUSIONS The mechanical properties of PMMA can be improved by the addition of nanoparticles to PMMA; however, the flexural strength values of PMMA decrease with the addition of nanoparticles at higher percentages (3-5%). Hence, the ideal filler ratio corresponds to 1%.
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Affiliation(s)
- Muhammet Karci
- Department of Prosthodontics, Selcuk University, Faculty of Dentistry, Konya, Turkey
| | - Necla Demir
- Department of Prosthodontics, Selcuk University, Faculty of Dentistry, Konya, Turkey
| | - Sakir Yazman
- Ilgın Technical Collage, Selçuk University, Konya, Turkey
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Effect of Pressure, Post-Pressing Time, and Polymerization Cycle on the Degree of Conversion of Thermoactivated Acrylic Resin. Int J Dent 2018; 2018:5743840. [PMID: 30186326 PMCID: PMC6114067 DOI: 10.1155/2018/5743840] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 06/29/2018] [Accepted: 07/18/2018] [Indexed: 11/17/2022] Open
Abstract
Herein, the effect of different post-pressing times and pressure in two cycles of polymerization on the degree of conversion (DC) of thermally activated acrylic resin (TRRA) is analyzed to optimize the polymerization of this material. After post-pressing for 0, 6, or 12 h, polymerization was performed with or without a pressure of 60 psi (0.41 MPa) in a short (4 h) or a long (11 h) cycle, totaling 12 groups. To determine the DC, PMMA specimens were analyzed by Fourier transform infrared spectroscopy. The influence of each factor alone on the DC was studied by experimental planning. The statistical tests used were three-way ANOVA, t-test, Tukey's test, and Levene's test, with a margin of error of 5%. Two groups prepared with post-pressing times of 12 h had the lowest DC (p < 0.001). Post-pressing times of 0 and 6 h did not yield statistically different results. Pressure increased the DC in only one group (long cycle +12 h, p=0.001). The short cycle resulted in a higher DC than the long cycle in 2 groups (with pressure +0 h, p=0.002; without pressure +6 h, p=0.015), while the long cycle yielded a statistically higher DC in only one group (with pressure +12 h, p < 0.001). The polymerization showed satisfactory DC in all 12 groups. Small differences found among the specimens indicate that the pressure, post-pressing time, and polymerization cycles herein were not influential factors for the DC of PMMA.
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Steinmassl PA, Wiedemair V, Huck C, Klaunzer F, Steinmassl O, Grunert I, Dumfahrt H. Do CAD/CAM dentures really release less monomer than conventional dentures? Clin Oral Investig 2016; 21:1697-1705. [PMID: 27704295 PMCID: PMC5442236 DOI: 10.1007/s00784-016-1961-6] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Accepted: 09/14/2016] [Indexed: 11/29/2022]
Abstract
Objectives Computer-aided design (CAD)/computer-aided manufacturing (CAM) dentures are assumed to have more favourable material properties than conventionally fabricated dentures, among them a lower methacrylate monomer release. The aim of this study was to test this hypothesis. Materials and methods CAD/CAM dentures were generated from ten different master casts by using four different CAD/CAM systems. Conventional, heat-polymerised dentures served as control group. Denture weight and volume were measured; the density was calculated, and the denture surface area was assessed digitally. The monomer release after 7 days of water storage was measured by high-performance liquid chromatography. Results Whole You Nexteeth and Wieland Digital Dentures had significantly lower mean volume and weight than conventional dentures. Baltic Denture System and Whole You Nexteeth had a significantly increased density. Baltic Denture System had a significantly smaller surface area. None of the CAD/CAM dentures released significantly less monomer than the control group. Conclusions All tested dentures released very low amounts of methacrylate monomer, but not significantly less than conventional dentures. A statistically significant difference might nevertheless exist in comparison to other, less recommendable denture base materials, such as the frequently used autopolymerising resins. Clinical relevance CAD/CAM denture fabrication has numerous advantages. It enables the fabrication of dentures with lower resin volume and lower denture weight. Both could increase the patient comfort. Dentures with higher density might exhibit more favourable mechanical properties. The hypothesis that CAD/CAM dentures release less monomer than conventional dentures could, however, not be verified.
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Affiliation(s)
- Patricia-Anca Steinmassl
- University Hospital for Dental Prosthetics and Restorative Dentistry, Medical University of Innsbruck, MZA, Anichstr. 35, A-6020, Innsbruck, Austria
| | - Verena Wiedemair
- Institute of Analytical Chemistry and Radiochemistry, University of Innsbruck, CCB, Innrain 80, A-6020, Innsbruck, Austria
| | - Christian Huck
- Institute of Analytical Chemistry and Radiochemistry, University of Innsbruck, CCB, Innrain 80, A-6020, Innsbruck, Austria
| | - Florian Klaunzer
- University Hospital for Dental Prosthetics and Restorative Dentistry, Medical University of Innsbruck, MZA, Anichstr. 35, A-6020, Innsbruck, Austria
| | - Otto Steinmassl
- University Hospital for Cranio-Maxillofacial and Oral Surgery, Medical University of Innsbruck, MZA, Anichstr. 35, A-6020, Innsbruck, Austria.
| | - Ingrid Grunert
- University Hospital for Dental Prosthetics and Restorative Dentistry, Medical University of Innsbruck, MZA, Anichstr. 35, A-6020, Innsbruck, Austria
| | - Herbert Dumfahrt
- University Hospital for Dental Prosthetics and Restorative Dentistry, Medical University of Innsbruck, MZA, Anichstr. 35, A-6020, Innsbruck, Austria
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Rashid H, Sheikh Z, Vohra F. Allergic effects of the residual monomer used in denture base acrylic resins. Eur J Dent 2016; 9:614-619. [PMID: 26929705 PMCID: PMC4745248 DOI: 10.4103/1305-7456.172621] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Denture base resins are extensively used in dentistry for a variety of purposes. These materials can be classified as chemical, heat, light, and microwave polymerization materials depending upon the factor which starts the polymerization reaction. Their applications include use during denture base construction, relining existing dentures, and for fabrication of orthodontic removable appliances. There have been increased concerns regarding the safe clinical application of these materials as their biodegradation in the oral environment leads to harmful effects. Along with local side effects, the materials have certain occupational hazards, and numerous studies can be found in the literature mentioning those. The purpose of this article is to outline the cytotoxic consequences of denture base acrylic resins and clinical recommendations for their use.
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Affiliation(s)
- Haroon Rashid
- Department of Prosthodontics, College of Dentistry, Ziauddin University, Karachi, Pakistan
| | - Zeeshan Sheikh
- Matrix Dynamics Group, Faculty of Dentistry, University of Toronto, Ontario, Canada
| | - Fahim Vohra
- Department of Prosthodontics, College of Dentistry, King Saud University, Riyadh, Saudi Arabia
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Yerro O, Radojevic V, Radovic I, Petrovic M, Uskokovic P, Stojanovic D, Aleksic R. Thermoplastic acrylic resin with self-healing properties. POLYM ENG SCI 2015. [DOI: 10.1002/pen.24244] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- O. Yerro
- University of Belgrade, Faculty of Technology and Metallurgy; Belgrade 11 000 Serbia
| | - V. Radojevic
- University of Belgrade, Faculty of Technology and Metallurgy; Belgrade 11 000 Serbia
| | - I. Radovic
- University of Belgrade, Faculty of Technology and Metallurgy; Belgrade 11 000 Serbia
| | - M. Petrovic
- University of Belgrade, Faculty of Technology and Metallurgy; Belgrade 11 000 Serbia
| | - P.S. Uskokovic
- University of Belgrade, Faculty of Technology and Metallurgy; Belgrade 11 000 Serbia
| | - D.B. Stojanovic
- University of Belgrade, Faculty of Technology and Metallurgy; Belgrade 11 000 Serbia
| | - R. Aleksic
- University of Belgrade, Faculty of Technology and Metallurgy; Belgrade 11 000 Serbia
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dos Santos RL, Pithon MM, Carvalho FG, Ramos AADS, Romanos MTV. Mechanical and biological properties of acrylic resins manipulated and polished by different methods. Braz Dent J 2015; 24:492-7. [PMID: 24474291 DOI: 10.1590/0103-6440201302293] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2013] [Accepted: 09/03/2013] [Indexed: 11/21/2022] Open
Abstract
This study evaluated the influence of the manipulation technique and polishing method on the flexural strength and cytotoxicity of acrylic resins. Two manipulation techniques and three polishing methods were used in the fabrication of acrylic plates that were divided into 6 groups (n=10). Groups MM, MC and MW: mass technique with mechanical polishing, chemical polishing and without polishing, respectively; and Groups SM, SC and SW: Saturation technique with mechanical polishing, chemical polishing and without polishing, respectively). Flexural strength was tested in a universal testing machine and the cytotoxicity assay used cell cultures (L-929) for periods of 24 h to 168 h. Flexural strength and cytotoxicity data were assessed using two-way and three-way ANOVA, respectively (α=0.05), followed by post hoc Bonferroni test for multiple comparisons. The effect of combinations of manipulation techniques and polishing methods on flexural strength showed significant differences only between Group SC and Groups MW, MM and MC (p<0.01). Cell viability ranged from 51% (3.9%) to 87,6% (3.2) in the 24-h time interval, and from 87.8% (5.0) to 95.7% (3.1%) in the 168-h time interval. With the increase of cell viability, from the third day (72 h), there was no significant difference among the groups, except between MM and SC (p<0.01) at 72 h. In conclusion, the manipulation technique and polishing method had more influence on the cytotoxicity than on flexural strength.
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Affiliation(s)
- Rogério Lacerda dos Santos
- Department of Orthodontics and Pediatric Dentistry, UFCG - Federal University of Campina Grande, PatosPB, Brazil
| | - Matheus Melo Pithon
- Department of Orthodontics, UESB - State University of Southwest Bahia, JequiéBA, Brazil
| | - Fabiola Galbiatti Carvalho
- Department of Orthodontics and Pediatric Dentistry, UFCG - Federal University of Campina Grande, PatosPB, Brazil
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Sahin O, Ozdemir AK, Turgut M, Boztug A, Sumer Z. Investigation of flexural strength and cytotoxicity of acrylic resin copolymers by using different polymerization methods. J Adv Prosthodont 2015; 7:98-107. [PMID: 25932307 PMCID: PMC4414953 DOI: 10.4047/jap.2015.7.2.98] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Revised: 11/24/2014] [Accepted: 02/05/2015] [Indexed: 11/25/2022] Open
Abstract
PURPOSE The aim of this study was to appraise the some mechanical properties of polymethyl methacrylate based denture base resin polymerized by copolymerization mechanism, and to investigate the cytotoxic effect of these copolymer resins. MATERIALS AND METHODS 2-hydroxyethyl methacrylate (HEMA) and isobutyl methacrylate (IBMA) were added to monomers of conventional heat polymerized and injection-molded poly methyl methacrylate (PMMA) resin contents of 2%, 3%, and 5% by volume and polymerization was carried out. Three-point bending test was performed to detect flexural strength and the elasticity modulus of the resins. To determine the statistical differences between the study groups, the Kruskall-Wallis test was performed. Then pairwise comparisons were performed between significant groups by Mann-Whitney U test. Agar-overlay test was performed to determine cytotoxic effect of copolymer resins. Chemical analysis was determined by FTIR spectrum. RESULTS Synthesis of the copolymer was approved by FTIR spectroscopy. Within the conventional heat-polymerized group maximum transverse strength had been seen in the HEMA 2% concentration; however, when the concentration ratio increased, the strength decreased. In the injection-molded group, maximum transverse strength had been seen in the IBMA 2% concentration; also as the concentration ratio increased, the strength decreased. Only IBMA showed no cytotoxic effect at low concentrations when both two polymerization methods applied while HEMA showed cytotoxic effect in the injection-molded resins. CONCLUSION Within the limitations of this study, it may be concluded that IBMA and HEMA may be used in low concentration and at high temperature to obtain non-cytotoxic and durable copolymer structure.
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Affiliation(s)
- Onur Sahin
- Department of Prosthodontics, Faculty of Dentistry, Bülent Ecevit University, Zonguldak, Turkey
| | - Ali Kemal Ozdemir
- Department of Prosthodontics, Faculty of Dentistry, Cumhuriyet University, Sivas, Turkey
| | - Mehmet Turgut
- Department of Prosthodontics, Dentaforum Dental Clinic, Kayseri, Turkey
| | - Ali Boztug
- Department of Chemistry, Tunceli University, Tunceli, Turkey
| | - Zeynep Sumer
- Department of Microbiology Faculty of Medical, Cumhuriyet University, Sivas, Turkey
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SPARTALIS GK, CAPPELLETTI LK, SCHOEFFEL AC, MICHÉL MD, PEGORARO TA, ARRAIS CAG, NEPPELENBROEK KH, URBAN VM. Effect of conventional water-bath and experimental microwave polymerization cycles on the flexural properties of denture base acrylic resins. Dent Mater J 2015; 34:623-8. [DOI: 10.4012/dmj.2015-047] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Comparative effect of different polymerization techniques on residual monomer and hardness properties of PMMA-based denture resins. J Appl Biomater Funct Mater 2014; 12:228-33. [PMID: 25199069 DOI: 10.5301/jabfm.5000199] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/23/2013] [Indexed: 11/20/2022] Open
Abstract
PURPOSE The aim of this study was to compare the residual monomer and microhardness of poly(methyl methacrylate) (PMMA)-based denture resins processed by using autoclave and conventional water bath techniques. METHODS To determine the amount of residual methyl methacrylate (MMA) monomer, disk-shaped specimens (n=5) were prepared from 3 different acrylic resins (Meliodent, Paladent and Qc-20). Control groups were polymerized in water bath for 30 minutes at 100°C. The study groups were prepared in an autoclave device for 60°C/30 min followed 130°C/10 min and the other group for 60°C/30 min followed by 130°C/20 min. According to standard calibration curves, ultraviolet spectrophotometry at 230 nm was used to determine the residual monomer. For the Vickers hardness measurements, disk-shaped specimens (n=5) were prepared for each test group. Hardness measurements were performed with a Vickers hardness tester under a 4.91-N press load for a 30 seconds, after immersion in distilled water at 37ºC for 48 hours. The data were analyzed by ANOVA and Tukey HSD test (p<0.05). RESULTS Autoclave polymerization produced a significant decrease in the amount of residual monomers for all resin groups (p<0.05). This procedure also showed a significant increase in hardness for all resin groups (p<0.05). For the 3 resin groups, no significant differences were found between autoclave polymerization for 10 minutes and for 20 minutes (p>0.05). CONCLUSIONS The autoclave polymerization technique exhibited significantly lower residual monomer content and greater hardness than conventional heat polymerization.
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Nik TH, Shahroudi AS, Eraghihzadeh Z, Aghajani F. Comparison of residual monomer loss from cold-cure orthodontic acrylic resins processed by different polymerization techniques. J Orthod 2014; 41:30-7. [DOI: 10.1179/1465313313y.0000000078] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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Iça RB, Öztürk F, Ates B, Malkoc MA, Kelestemur Ü. Level of residual monomer released from orthodontic acrylic materials. Angle Orthod 2014; 84:862-7. [DOI: 10.2319/060713-435.1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Affiliation(s)
- R. Betul Iça
- Research Assistant, Inonu University, Faculty of Dentistry, Department of Orthodontics, Malatya, Turkey
| | - Fırat Öztürk
- Associate Professor, Pamukkale University, Faculty of Dentistry, Department of Orthodontics, Denizli, Turkey
| | - Burhan Ates
- Associate Professor, Inonu University, Faculty of Science and Art, Department of Chemistry, Malatya, Turkey
| | - Meral Arslan Malkoc
- Assistant Professor, Inonu University, Faculty of Dentistry, Department of Prosthodontics, Malatya, Turkey
| | - Ünzile Kelestemur
- Research Assistant, Inonu University, Faculty of Science and Art, Department of Chemistry, Malatya, Turkey
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Kostić M, Najman S, Najdanović J, Krunić N, Kostić I. PRIMENA TESTA DIREKTNOG KONTAKTA U ISPITIVANJU CITOTOKSIČNOSTI STOMATOPROTETSKIH AKRILATA. ACTA MEDICA MEDIANAE 2013. [DOI: 10.5633/amm.2012.0112s] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Köroǧlu A, Özdemir T, Duru Pamir A, Usanmaz A. Residual acrylic monomer content of denture base resins with different fiber systems. J Appl Polym Sci 2012. [DOI: 10.1002/app.35671] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Trubiani O, Toniato E, Di Iorio D, Diomede F, Merciaro I, D'Arcangelo C, Caputi S, Oriana T. Morphological Analysis and Interleukin Release in Human Gingival Fibroblasts Seeded on Different Denture Base Acrylic Resins. Int J Immunopathol Pharmacol 2012; 25:637-43. [DOI: 10.1177/039463201202500310] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The development of different types of materials with application in practice dentistry is an area of intense growth and research due to its importance in oral health. Among the diverse materials currently used in restoration or in dentures, the acrylic based resins have been widely employed. The release of toxic components and the changes on their physical and mechanical properties actually represent a goal of intensive research. In vivo analysis showed that the surface roughness of the acrylic resin represents a factor that could stimulate bacteria colonization and soft tissue inflammation. For this purpose, in this work, we have analyzed the cell response to acrylic based resins Ivoclar, Tokuso and Coldpack in basal conditions, unpolished, and after the polished procedure performed to reduce the surface roughness. Our in vitro results using human gingival fibroblasts (HGFs) showed a decrease of cell growth, evaluated by MTT assay starting at 24 h of incubation, in samples seeded on resins in basal conditions and after the polished procedure. This cell growth reduction was associated to evident morphological changes in unpolished materials. After 24 h of culture in presence of polished and unpolished resins a spontaneous release was present of pro-inflammatory cytokines such as Interleukin-6 (IL-6) and −8 (IL-8), which was higher in unpolished resins, indicating that the polished procedure, minimizing the cytotoxicity process, could contribute to reduce the gingival inflammation processes.
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Affiliation(s)
- O. Trubiani
- Department of Medical, Oral and Biotechnological Sciences. University “G. D'Annunzio” Chieti-Pescara, Chieti, Italy
| | - E. Toniato
- Department of Medical, Oral and Biotechnological Sciences. University “G. D'Annunzio” Chieti-Pescara, Chieti, Italy
| | - D. Di Iorio
- Department of Medical, Oral and Biotechnological Sciences. University “G. D'Annunzio” Chieti-Pescara, Chieti, Italy
| | - F. Diomede
- Department of Medical, Oral and Biotechnological Sciences. University “G. D'Annunzio” Chieti-Pescara, Chieti, Italy
| | - I. Merciaro
- Department of Medical, Oral and Biotechnological Sciences. University “G. D'Annunzio” Chieti-Pescara, Chieti, Italy
| | - C. D'Arcangelo
- Department of Medical, Oral and Biotechnological Sciences. University “G. D'Annunzio” Chieti-Pescara, Chieti, Italy
| | - S. Caputi
- Department of Medical, Oral and Biotechnological Sciences. University “G. D'Annunzio” Chieti-Pescara, Chieti, Italy
| | - T. Oriana
- Department of Medical, Oral and Biotechnological Sciences. University “G. D'Annunzio” Chieti-Pescara, Chieti, Italy
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30
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The effect of N-acetylcysteine addition on the polymerization behavior of PMMA bone cement. Macromol Res 2012. [DOI: 10.1007/s13233-012-0132-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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31
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Kostić M, Najman S, Najdanović J, Krunić N, Kostić I. APPLICATION OF DIRECT CONTACT TEST IN EVALUATION OF CYTOTOXICITY OF ACRYLIC DENTURE BASE RESINS. ACTA MEDICA MEDIANAE 2012. [DOI: 10.5633/amm.2012.0112] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Kwon TY, Bagheri R, Kim YK, Kim KH, Burrow MF. Cure mechanisms in materials for use in esthetic dentistry. ACTA ACUST UNITED AC 2012; 3:3-16. [PMID: 22298515 DOI: 10.1111/j.2041-1626.2012.00114.x] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Affiliation(s)
- Tae-Yub Kwon
- Department of Dental Biomaterials, Kyungpook National University, Jung-gu, Daegu, Korea
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33
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Bural C, Aktaş E, Deniz G, Ünlüçerçi Y, Kızılcan N, Bayraktar G. Effect of post-polymerization heat-treatments on degree of conversion, leaching residual MMA and in vitro cytotoxicity of autopolymerizing acrylic repair resin. Dent Mater 2011; 27:1135-43. [DOI: 10.1016/j.dental.2011.08.007] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2011] [Revised: 07/11/2011] [Accepted: 08/19/2011] [Indexed: 11/28/2022]
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34
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Reis JMSN, Giampaolo ET, Pavarina AC, Machado AL, Erxleben J, Vergani CE. Exothermic behavior, degree of conversion, and viscoelastic properties of experimental and commercially available hard chairside reline resins. J Appl Polym Sci 2011. [DOI: 10.1002/app.34268] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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35
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Ha JY, Kim SH, Kim KH, Kwon TY. Influence of the volumes of bis-acryl and poly(methyl methacrylate) resins on their exothermic behavior during polymerization. Dent Mater J 2011; 30:336-42. [PMID: 21597212 DOI: 10.4012/dmj.2010-188] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
This study aimed to evaluate the influence of the volumes of a bis-acryl resin (Luxatemp) and a poly(methyl methacrylate) resin (Jet) on their exothermic behaviors during polymerization based on vinyl group conversion. The number of vinyl groups reacted and exotherm were determined based on weight percent of methacrylate groups using FTIR spectroscopy. Temperature changes during polymerization at 23°C were recorded for 20 minutes using a multiple cavity mold overlying a thermocouple. The number of vinyl groups reacted and exotherm of Luxatemp were consistently lower than those of Jet at each resin volume. Mean peak temperature rises of Luxatemp and Jet were in the range of 2.0-6.6°C and 4.2-11.6°C respectively, with Luxatemp and Jet taking 2 and 10 minutes respectively to reach their peak temperatures. As their resin volumes increased, their peak temperatures and total peak areas were also observed to increase significantly (p<0.01).
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Affiliation(s)
- Jung-Yun Ha
- Department of Medical and Biological Engineering, Kyungpook National University, Daegu, Korea
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36
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Testing of residual monomer content reduction possibility on acrilic resins quality. HEMIJSKA INDUSTRIJA 2011. [DOI: 10.2298/hemind101103008k] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Poly (methyl methacrylate) (PMMA) is material widely used in dentistry.
Despite the various methods used to initiate the polymerization of acrylic
resins, the conversion of monomer to polymer is not complete thus leaving
some unreacted methyl methacrylate (MMA), known as residual monomer (RM), in
denture structure. RM in dental acrylic resins has deleterious effects on
their mechanical properties and their biocompatibility. The objective of the
work was to test the residual monomer reduction possibility by applying the
appropriate postpolymerization treatment as well as to determine the effects
of this reduction on pressure yields stress and surface structure
characteristics of the acrylic resins. Postpolymerization treatments and
water storage induced reduction of RM amount in cold-polymerized acrylic
resins improved their mechanical properties and the homogenized surface
structure. After the polymerization of heat-polymerized acrylic resins the
post-polymerization treatments for improving the quality of this material
type are not necessary.
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37
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The influence of PMMA in 4-META/MMA-TBB resin on the degree of conversion and bonding durability to titanium. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2010. [DOI: 10.1016/j.msec.2009.10.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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38
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Ata SO, Yavuzyılmaz H. In vitro comparison of the cytotoxicity of acetal resin, heat-polymerized resin, and auto-polymerized resin as denture base materials. J Biomed Mater Res B Appl Biomater 2009; 91:905-909. [PMID: 19637373 DOI: 10.1002/jbm.b.31473] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
This in vitro study aims to evaluate three different base materials (acetal, heat-polymerized, and auto-polymerized resins) on L-929 mouse fibroblast cells over 1 h-, 1-, 3-, 5-, 7-day periods. The hypothesis was that acetal resin would show higher cytotoxic effect than heat-polymerized and auto-polymerized acrylic resins, as it seems possible that residual formaldehyde might be leaching from the material into the cell culture medium. The samples were produced according to the manufacturer's protocol. Then they were placed in Dulbecco's Modified Eagle Medium/Ham's F12 (DMEM/F12) for 1 h, 1, 3, 5, 7 days. After the incubation periods, cytotoxicity of the extracts to cultured fibroblasts (L-929) was measured by MTT assay. The degree of cytotoxicity of each sample was determined according to the reference value represented by the cells with a control. Statistical significance was determined by one-way ANOVA. Tukey and Tamhane tests were used as a post-hoc method to determine differences among the groups. Statistically significant difference was found among test groups at all time incubation periods (p = 0.000). The auto-polymerized resin performed higher cytotoxic effect than heat-polymerized resin and it was statistically significant at 1-day period (p < 0.05). The highest cytotoxic effect of acetal resin was observed at 5-day incubation period. In conclusion, the hypothesis was verified, since acetal resin showed more cytotoxic effect on the 3rd, 5th, and 7th days than heat- and auto-polymerized resins. Cell survival rates (% of control) of acetal resin were 58, 54, and 60%, respectively.
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Affiliation(s)
- Secil Ozkan Ata
- Research Assistant, Faculty of Dentistry, Department of Prosthodontics, Gazi University, Emek, Ankara, Turkey
| | - Hüsnü Yavuzyılmaz
- Professor, Faculty of Dentistry, Department of Prosthodontics, Gazi University, Emek, Ankara, Turkey
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[Residual monomer content determination in some acrylic denture base materials and possibilities of its reduction]. VOJNOSANIT PREGL 2009; 66:223-7. [PMID: 19341229 DOI: 10.2298/vsp0903223k] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND/AIM Polymethyl methacrylate is used for producing a denture basis. It is a material made by the polymerization process of methyl methacrylate. Despite of the polymerization type, there is a certain amount of free methyl methacrylate (residual monomer) incorporated in the denture, which can cause irritation of the oral mucosa. The aim of this study was to determine the amount of residual monomer in four different denture base acrylic resins by liquid chromatography and the possibility of its reduction. METHODS After the polymerization, a postpolymerization treatment was performed in three different ways: in boiling water for thirty minutes, with 500 W microwaves for three minutes and in steam bath at 22 degrees C for one to thirty days. RESULTS The obtained results showed that the amount of residual monomer is significantly higher in cold polymerizing acrylates (9.1-11%). The amount of residual monomer after hot polymerization was in the tolerance range (0.59-0.86%). CONCLUSION The obtained results denote a low content of residual monomer in the samples which have undergone postpolymerization treatment. A lower percent of residual monomer is established in samples undergone a hot polymerization.
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40
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Moraes LGP, Rocha RSF, Menegazzo LM, de Araújo EB, Yukimito K, Moraes JCS. Infrared spectroscopy: a tool for determination of the degree of conversion in dental composites. J Appl Oral Sci 2009; 16:145-9. [PMID: 19089207 PMCID: PMC4327635 DOI: 10.1590/s1678-77572008000200012] [Citation(s) in RCA: 112] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2007] [Accepted: 12/13/2007] [Indexed: 11/22/2022] Open
Abstract
Infrared spectroscopy is one of the most widely used techniques for measurement of conversion degree in dental composites. However, to obtain good quality spectra and quantitative analysis from spectral data, appropriate expertise and knowledge of the technique are mandatory. This paper presents important details to use infrared spectroscopy for determination of the conversion degree.
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41
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Effect of denture base resin extracts on HeLa cells growth in vitro. HEMIJSKA INDUSTRIJA 2008. [DOI: 10.2298/hemind0803217k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Growth of HeLa cell culture in vitro was examined, in different concentrations of four resin materials extracts which are used for denture base making. Cell growth was evaluated through density, invert microscope counting, after 48 hours of incubation and through metabolic MTT test after 3 days. Extract was taken by incubation of material sample on 37 ?C in physiological solution, for 72 hours. It is given weaker growth, reduction of adherent cells count and phenotypic changes of cells grown in presence of extracts from all examined materials. Extracts of examined materials increase number of phyllopodic extensions on dose dependent manner.
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42
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Rocha Filho R, Paula LVD, Costa VC, Seraidarian PI. Avaliação de monômero residual em resinas acrílicas de uso ortodôntico e protético: análise por espectroscopia. ACTA ACUST UNITED AC 2007. [DOI: 10.1590/s1415-54192007000200014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJETIVO: duas marcas comerciais de resinas acrílicas ativadas quimicamente (RAAQ), uma de uso ortodôntico (Orto Cril®) e outra de uso protético (Jet®), polimerizadas em presença e ausência de pressão, foram analisadas em relação ao conteúdo de monômero (MMA) residual liberado em solução, em diferentes intervalos de tempo (0,083; 0,25; 1; 1,25; 2,17; 5; 9; 14 e 21 dias). METODOLOGIA: a espectroscopia de absorção no ultravioleta foi utilizada na análise de soluções aquosas de MMA, com concentrações conhecidas, visando a determinação de uma curva de calibração. Soluções aquosas contendo corpos-de-prova, confeccionados com as citadas RAAQ, foram também submetidas à análise por espectroscopia de absorção no ultravioleta. RESULTADOS E CONCLUSÕES: os resultados foram comparados aos dados da curva de calibração, visando estabelecer a concentração de MMA residual das amostras. Eles permitiram concluir que o nível de MMA residual liberado em solução foi mais elevado durante as primeiras 24 horas, havendo uma tendência à estabilização a partir desse período e que a resina acrílica de uso ortodôntico apresentou níveis mais elevados de MMA em solução do que a de uso protético, em ambas as condições de polimerização empregadas, com presença e ausência de pressão. Além disso, a presença de pressão, durante a polimerização das duas resinas, elevou a concentração de MMA em solução, não havendo, entretanto, efeito da interação entre as marcas das resinas e a presença e ausência de pressão na concentração de MMA em solução, medida ao longo do tempo. Porém, todas as três variáveis (tempo, resina e pressão) foram significantes.
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43
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Jorge JH, Giampaolo ET, Vergani CE, Machado AL, Pavarina AC, Carlos IZ. Biocompatibility of denture base acrylic resins evaluated in culture of L929 cells. Effect of polymerisation cycle and post-polymerisation treatments. Gerodontology 2007; 24:52-7. [PMID: 17302932 DOI: 10.1111/j.1741-2358.2007.00146.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVE The purpose of this study was to evaluate the effect of two post-polymerisation treatments and different cycles of polymerisation on the cytotoxicity of two denture base resins. MATERIALS AND METHODS The resins tested were Lucitone 550 and QC 20. Discs of resins were fabricated following the manufacturer's instructions. Lucitone 550 was processed by long cycle or short cycle. The resin QC 20 was processed by reverse cycle or normal cycle. The specimens were divided into groups: (i) post-polymerised in microwave for 3 min at 500 W; (ii) post-polymerised in water-bath at 55 degrees C for 60 min and (iii) without post-polymerisation. Eluates were prepared by placing three discs into a sterile glass vial with 9 ml of Eagle's medium and incubated at 37 degrees C for 24 hours. L929 cells were seeded into 96 well culture plates and DNA synthesis was assessed by (3)H-thymidine incorporation assay. RESULTS The results were submitted to two-way anova and Tukey HSD test. QC 20 specimens polymerised by the normal cycle and submitted to microwave post-polymerisation were graded as moderately cytotoxic. Similar results were observed for Lucitone 550 processed by long cycle without post-polymerisation. The other experimental groups were graded as not cytotoxic. After water-bath post-polymerisation, specimens of Lucitone 550 processed by long cycle produced significantly lower inhibition of DNA synthesis than the other groups. CONCLUSION The long cycle increased the cytotoxicity of Lucitone 550 and water-bath post-polymerisation reduced the cytotoxicity of Lucitone 550 processed by long cycle.
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Affiliation(s)
- Janaina Habib Jorge
- Department of Dental Materials and Prosthodontics, Araraquara Dental School, São Paulo State University, São Paulo, Brazil.
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Neppelenbroek KH, Pavarina AC, Gomes MN, Machado AL, Vergani CE. Bond strength of hard chairside reline resins to a rapid polymerizing denture base resin before and after thermal cycling. J Appl Oral Sci 2006; 14:436-42. [PMID: 19089244 PMCID: PMC4327296 DOI: 10.1590/s1678-77572006000600009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2005] [Revised: 09/25/2006] [Accepted: 10/27/2006] [Indexed: 11/24/2022] Open
Abstract
PURPOSE This study assessed the shear bond strength of 4 hard chairside reline resins (Kooliner, Tokuso Rebase Fast, Duraliner II, Ufi Gel Hard) to a rapid polymerizing denture base resin (QC-20) processed using 2 polymerization cycles (A or B), before and after thermal cycling. MATERIALS AND METHODS Cylinders (3.5 mm x 5.0 mm) of the reline resins were bonded to cylinders of QC-20 polymerized using cycle A (boiling water-20 minutes) or B (boiling water; remove heat-20 minutes; boiling water-20 minutes). For each reline resin/polymerization cycle combination, 10 specimens (groups CAt e CBt) were thermally cycled (5 and 55 degrees C; dwell time 30 seconds; 2,000 cycles); the other 10 were tested without thermal cycling (groups CAwt ad CBwt). Shear bond tests (0.5 mm/min) were performed on the specimens and the failure mode was assessed. Data were analyzed by 3-way ANOVA and Newman-Keuls post-hoc test (alpha=.05). RESULTS QC-20 resin demonstrated the lowest bond strengths among the reline materials (P<.05) and mainly failed cohesively. Overall, the bond strength of the hard chairside reline resins were similar (10.09+/-1.40 to 15.17+/-1.73 MPa) and most of the failures were adhesive/cohesive (mixed mode). However, Ufi Gel Hard bonded to QC-20 polymerized using cycle A and not thermally cycled showed the highest bond strength (P<.001). When Tokuso Rebase Fast and Duraliner II were bonded to QC-20 resin polymerized using cycle A, the bond strength was increased (P=.043) after thermal cycling. CONCLUSIONS QC-20 displayed the lowest bond strength values in all groups. In general, the bond strengths of the hard chairside reline resins were comparable and not affected by polymerization cycle of QC-20 resin and thermal cycling.
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Affiliation(s)
- Karin Hermana Neppelenbroek
- DDS, MSc, PhD, Pos Doctor Researcher, Department of Dental Materiais and Prosthodontics, Araraquara Dental School, São Paulo State University, São Paulo, Brazil
| | - Ana Cláudia Pavarina
- DDS, MSc, PhD, Assistant Professor of Removable Prosthodontics, Department of Dental Materiais and Prosthodontics, Araraquara Dental School, São Paulo State University, São Paulo, Brazil
| | - Mauricio Neves Gomes
- DDS, MSc student, Department of Dental Materiais and Prosthodontics, Araraquara Dental School, São Paulo State University, São Paulo, Brazil
| | - Ana Lucia Machado
- DDS, MSc, PhD, Associate Professor of Removable Prosthodontics, Department of Dental Materiais and Prosthodontics, Araraquara Dental School, São Paulo State University, São Paulo, Brazil
| | - Carlos Eduardo Vergani
- DDS, MSc, PhD, Associate Professor of Removable Prosthodontics, Department of Dental Materiais and Prosthodontics, Araraquara Dental School, São Paulo State University, São Paulo, Brazil
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Urban VM, Cass QB, Oliveira RV, Giampaolo ET, Machado AL. Development and application of methods for determination of residual monomer in dental acrylic resins using high performance liquid chromatography. Biomed Chromatogr 2006; 20:369-76. [PMID: 16177959 DOI: 10.1002/bmc.575] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Two high-performance liquid chromatographic methods for determination of residual monomer in dental acrylic resins are described. Monomers were detected by their UV absorbance at 230 nm, on a Nucleosil C18 (5 microm particle size, 100 A pore size, 15 x 0.46 cm i.d.) column. The separation was performed using acetonitrile-water (55:45 v/v) containing 0.01% triethylamine (TEA) for methyl methacrylate and butyl methacrylate, and acetonitrile-water (60:40 v/v) containing 0.01% TEA for isobutyl methacrylate and 1,6-hexanediol dimethacrylate as mobile phases, at a flow rate of 0.8 mL/min. Good linear relationships were obtained in the concentration range 5.0-80.0 microg/mL for methyl methacrylate, 10.0-160.0 microg/mL for butyl methacrylate, 50.0-500.0 microg/mL for isobutyl methacrylate and 2.5-180.0 microg/mL for 1,6-hexanediol dimethacrylate. Adequate assay for intra- and inter-day precision and accuracy was observed during the validation process. An extraction procedure to remove residual monomer from the acrylic resins was also established. Residual monomer was obtained from broken specimens of acrylic disks using methanol as extraction solvent for 2 h in an ice-bath. The developed methods and the extraction procedure were applied to dental acrylic resins, tested with or without post-polymerization treatments, and proved to be accurate and precise for the determination of residual monomer content of the materials evaluated.
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Affiliation(s)
- V M Urban
- Department of Dental Materials and Prosthodontics, São Paulo State University, UNESP, Araraquara, São Paulo, Brazil
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46
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Bayraktar G, Guvener B, Bural C, Uresin Y. Influence of polymerization method, curing process, and length of time of storage in water on the residual methyl methacrylate content in dental acrylic resins. J Biomed Mater Res B Appl Biomater 2006; 76:340-5. [PMID: 16161124 DOI: 10.1002/jbm.b.30377] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
This study compared the influence of different polymerization methods (heat, auto-, and microwave energy), different curing processes (in the case of heat- and autopolymerized specimens), and length of storage of the polymerized specimens in distilled water at 37 degrees C on the residual methyl methacrylate (MMA) content in dental acrylic resin specimens. Residual MMA of 120 resin specimens were measured using high-performance liquid chromatography. For the heat-polymerized resins, the lowest residual MMA content was obtained when they were given a long-term terminal boil and then stored in the distilled water for at least 1 day. For the autopolymerized resins, the lowest residual MMA content was obtained when they were additionally cured in water at 60 degrees C and then stored in the distilled water at least 1 day. For the microwave-polymerized resins, the lowest residual MMA content was obtained when they were stored in the distilled water at least 1 month. The lowest overall residual MMA content was obtained from heat-polymerized specimens that were given a long-term terminal boil cure and then stored in the distilled water at least 1 day. Different polymerization methods and curing processes have different effects on residual MMA content. It is thus shown that storing a dental acrylic resin specimen in distilled water at 37 degrees C is a simple but effective method of reducing its residual MMA content.
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Affiliation(s)
- Gulsen Bayraktar
- Istanbul University, Faculty of Dentistry, Department of Removable Prosthodontics, Istanbul, Turkey.
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47
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Lung CYK, Darvell BW. Minimization of the inevitable residual monomer in denture base acrylic. Dent Mater 2005; 21:1119-28. [PMID: 16040111 DOI: 10.1016/j.dental.2005.03.003] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2004] [Accepted: 03/24/2005] [Indexed: 10/25/2022]
Abstract
OBJECTIVES Residual monomer ([MMA](R)) in denture base acrylic continues to be of concern. The response surface of concentration vs. time and temperature for the equilibration of methyl methacrylate (MMA) and its polymer (PMMA) allows a prediction of the time to the minimum at any temperature for a closed system. It was the purpose here to determine whether this prediction applies to normal denture base processing, and whether optimum conditions could be identified. METHODS Denture bases were processed following normal laboratory procedures, including pre-cure for 3 h at 70 degrees C for all tests. Commercial powder and liquid were used at either 95 or 100 degrees C, or a plain PMMA powder and the same liquid at 95 degrees C, for times ranging from 5 to 192 h. Residual MMA was determined by gas chromatography. RESULTS [MMA](R) decreased steadily from approximately 0.25% to as low as approximately 0.07% with increasing time at temperature, but did not approach equilibrium. The rate of diffusive loss of MMA appears to exceed the rate of depolymerization. SIGNIFICANCE Residual monomer is inevitable for all PMMA-based products no matter what the curing conditions are. However, extended time at high temperature can allow low values to be attained, and the time allowed can compensate for processing temperatures somewhat lower than the ordinarily recommended 100 degrees C. It is suggested that overnight processing at 95 degrees C should be adopted to minimize [MMA](R) and save energy. This result is of importance for work at high altitude.
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Affiliation(s)
- C Y K Lung
- Dental Materials Science, The University of Hong Kong, Prince Philip Dental Hospital, China
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Sofou A, Tsoupi I, Emmanouil J, Karayannis M. HPLC determination of residual monomers released from heat-cured acrylic resins. Anal Bioanal Chem 2005; 381:1336-46. [PMID: 15759139 DOI: 10.1007/s00216-005-3059-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2004] [Revised: 01/10/2005] [Accepted: 01/17/2005] [Indexed: 11/28/2022]
Abstract
HPLC was used to examine the leachability of three non-phthalic and four phthalic post-polymerized residual monomers from three commercially available heat-cured acrylic resins. Specimens of equal dimensions were constructed from each brand of material by following the standardized procedure and were stored under three different conditions, namely, distilled water, artificial saliva, and a binary mixture of ethanol/water. The resulting liquids provided samples for analysis by HPLC. Three different experiments were performed for each brand of acrylic and each storage condition in order to examine the effects of parameters, particularly time and temperature. The results obtained from this study suggest that a wide spectrum of residues diffuse out of the three examined acrylic resin materials. The non-phthalic compounds were leached at high concentrations, whereas all the phthalates examined exhibited different degrees of elusion commensurate with the storage condition, brand of material, and type of experiment. It seems that a significant quantity of non-phthalic and phthalic residues diffuse out of the acrylic resin materials examined. The main component extracted was methyl methacrylate, the level of which seems to be time-dependent and decreases for a period of up to 5 days when resins are stored in distilled water at room temperature.
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Affiliation(s)
- Afrodite Sofou
- Department of Removable Prosthodontics, School of Dentistry, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
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Botega DM, de Souza Machado T, de Mello JAN, Garcia RCMR, Del Bel Cury AA. Polymerization time for a microwave-cured acrylic resin with multiple flasks. Braz Oral Res 2004; 18:23-8. [PMID: 15273782 DOI: 10.1590/s1806-83242004000100005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
This study aimed at establishing the polymerization time of a microwave-cured acrylic resin (AcronTM MC), simultaneously processing 2, 4, and 6 flasks. Required time was measured according to the parameters: monomer release in water, Knoop hardness, and porosity. Samples were made with AcronTM MC in different shapes: rectangular (32 x 10 x 2.5 mm) for monomer release and porosity; and half-disc (30 mm in diameter x 4 mm in height) for Knoop hardness. There were four experimental groups (n = 24 per group): G1) one flask (control); G2) two flasks; G3) four flasks, and G4) six flasks. At first, polymerization protocol was similar for all groups (3 min/450 W). Time was then adjusted for G2, G3, and G4, based on monomer release evaluation in the control group, obtained by spectrophotometer Beckman DU-70, with emitting wave of 206 nm. Knoop hardness test was performed using a Shimadzu HMV 2000 hardness tester, and 10 indentations were performed on each specimen's surface. Porosity was assessed after specimens were immersed in black ink and the pores counted in a microscope. Results showed that the complete polymerization of the resin occurred in 4.5 min for two flasks (G2); 8.5 min for four flasks (G3); and 13 min for six flasks (G4), all with 450 W. Statistical analysis revealed that the number of flasks does not interfere with polymerization, Knoop hardness, and porosity of the resin. Results showed that polymerization of microwave-curing resin with more than one flask is a viable procedure, as long as polymerization time is adjusted.
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Affiliation(s)
- Daniela Maffei Botega
- Department of Prosthodontics and Periodontology, School of Dentistry of Piracicaba, University of Campinas
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Oliveira VMB, Léon BLT, Del Bel Cury AA, Consani S. Influence of number and position of flasks in the monomer release, Knoop hardness and porosity of a microwave-cured acrylic resin. J Oral Rehabil 2003; 30:1104-8. [PMID: 14641676 DOI: 10.1046/j.1365-2842.2003.01195.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Simultaneous irradiation of multiple flasks may have deleterious effects on the polymerization of microwave cured-acrylic resins. This study evaluated the effect of the number and position of flasks in the monomer release, Knoop hardness and porosity of a microwave-cured acrylic resin. Samples were made of Acron MC(R) (AMC, GC Dent. Ind. Corp.) processed at 500 W. The following associations of the number and position of the flasks were tested: one simple flask centrally placed on the turning plate (I, control); two flasks, one in the centre (IIa) and the other peripherally placed in the plate (IIb); two flasks centrally, one above (IIIa) and the other below (IIIb). The processing time varied according to the number of flasks: 3 or 4.5 min for one or two flasks, respectively. For monomer release, each specimen (n = 12) was put in an assay glass tube containing 6 mL of deionized water that was changed daily. Monomer levels were obtained by spectrophotometry at 206 nm. For hardness test (n = 10), 12 indentations were made in the surface of each specimen. Immersing the polished specimens in permanent ink and counting the porous in a stereo light microscope verified the porosity. Monomer release was significant before 24 h: GI = 263.1(153.3)a, GIIa = 236.9(180.2)a, GIIb = 441.5(446.2)a, GIIIa = 1216.6(857.9)b. Tukey test showed no statistically significant differences among the groups for porosity and hardness. Monomer release was affected by the position of the flask (P < 0.05).
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Affiliation(s)
- V M B Oliveira
- Piracicaba Dental School, University of Campinas, Piracicaba, São Paulo, Brazil
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