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Kim RJY, Kim DH, Seo DG. Post-polymerization of three-dimensional printing resin using a dental light curing unit. J Dent Sci 2024; 19:945-951. [PMID: 38618100 PMCID: PMC11010625 DOI: 10.1016/j.jds.2023.07.028] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 07/24/2023] [Indexed: 04/16/2024] Open
Abstract
Background/Purpose In vat photopolymerization, post-polymerization of the three-dimensional (3D) printing resin is necessary to ensure the optimum physical properties of the printed objects. This study aimed to evaluate the potential use of a handheld polywave light-emitting diode (LED) dental light-curing unit (LCU) for post-polymerizing 3D printed resins by measuring the microhardness and biaxial flexural strength of the post-polymerized resin. Material and methods 3D printed 1- and 2-mm-thick disks were irradiated with a dental LCU at 3200 mW/cm2. Post-polymerization was repeated either on one side from the top surface: two cycles (T2), four cycles (T4), and eight cycles (T8), or on both sides from the top and bottom surfaces: one cycle (T1B1), two cycles (T2B2), and four cycles (T4B4) for each side. The microhardness and biaxial strength of the disks were compared to those post-polymerized by a conventional desktop polymerizing unit (PC) and those without post-polymerization (NC). Results Microhardness of the disks varied between the top and bottom surfaces of the 1-mm and 2-mm-thick disks, depending on the post-polymerization methods. T8 and T4B4 produced comparable microhardness on the top surface to PC for both thicknesses. In contrast, PC, T2B2, and T4B4 exhibited the highest microhardness on the bottom surface. Except for NC, the 1-mm-thick disks had a higher biaxial flexural strength than the 2-mm-thick disks. T4B4 resulted in the highest biaxial flexural strength for both thicknesses, which was comparable to that of the desktop polymerizing unit. Conclusion The microhardness and biaxial flexural strengths of the post-polymerized 3D-printed disks increase with polymerization time. With sufficient polymerization from both sides, the polywave LCU has the potential to be a viable alternative to desktop polymerization units.
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Affiliation(s)
- Ryan Jin Young Kim
- Department of Dental Science, Dental Research Institute, Seoul National University School of Dentistry, Seoul, Republic of Korea
| | - Dong-Hwan Kim
- Seoul Gospel Dental Clinic, Seoul, Republic of Korea
| | - Deog-Gyu Seo
- Department of Conservative Dentistry, Dental Research Institute, Seoul National University School of Dentistry, Seoul, Republic of Korea
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Abdollahpour S, Estedlal T, Chiniforush N, Rafeie N, Nikparto N, Abbasi M, Ranjbar Omrani L. Effect of Different Bleaching Methods on Monomer Release from Aged Microhybrid and Nanohybrid Resin Composites. Int J Dent 2023; 2023:2773879. [PMID: 37216177 PMCID: PMC10198759 DOI: 10.1155/2023/2773879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 04/09/2023] [Accepted: 04/11/2023] [Indexed: 05/24/2023] Open
Abstract
Introduction Recently, the application of laser-assisted bleaching has increased in dental practice. This method might affect the physical and chemical properties of resin composite and its monomer release. This study aimed to evaluate the effect of in-office, at-home, and laser-assisted bleaching on the monomer release (bisphenol A diglycidyl dimethacrylate (BisGMA), triethylene glycol dimethacrylate (TEGDMA), and urethane dimethacrylate (UDMA)) from aged nanohybrid (Grandio, Voco) and microhybrid (Clearfil AP-X Esthetics, Kuraray) resin composites. Methods Thirty-two samples of each composite were prepared. The samples underwent aging procedure with UV light at 65°C for 100 hr. The samples were divided into 4 groups: OB: conventional in-office bleaching with Opalescence Boost PF 40% gel; HB: home bleaching with Opalescence PF 15% gel; LB: bleaching with JW Power bleaching gel followed by diode laser application; and C: control group without bleaching. Then, the samples were immersed in a solution containing 75% ethanol + 25% distilled water. The medium was renewed after 8, 16, 24 hr, and 7 days and was analyzed using high-performance liquid chromatography method to evaluate the monomer release. The data were analyzed using Two-way ANOVA and Post hoc Tukey test. Results The bleaching method had no effect on TEGDMA and BisGMA release in both composites while it affected UDMA release in nanohybrid composite; UDMA release was significantly higher in LB compared to control and also higher in OB and LB compared to HB. No difference was observed in the microhybrid composite in this regard. Conclusion Laser-assisted bleaching did not affect monomer release from microhybrid composite while it increased UDMA release from nanohybrid composite. The bleaching method had no effect on TEGDMA and BisGMA release.
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Affiliation(s)
- Siavash Abdollahpour
- Department of Operative Dentistry, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran
| | - Tarane Estedlal
- Department of Operative Dentistry, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran
| | - Nasim Chiniforush
- Department of Surgical Science and Integrated Diagnosis, University of Genoa, Genoa, Italy
| | - Niyousha Rafeie
- Dental Research Center, Dentistry Research Institute, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran
| | - Nariman Nikparto
- Department of Oral and Maxillofacial Surgery, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran
| | - Mahdi Abbasi
- Restorative Dentistry Department, Dental Research Center, Dentistry Research Institute, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran
| | - Ladan Ranjbar Omrani
- Restorative Dentistry Department, Dental Research Center, Dentistry Research Institute, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran
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Odum NC, Ross JT, Citrin NS, Tantbirojn D, Versluis A. Fast Curing with High-power Curing Lights Affects Depth of Cure and Post-gel Shrinkage and Increases Temperature in Bulk-fill Composites. Oper Dent 2023; 48:98-107. [PMID: 36445972 DOI: 10.2341/21-160-l] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/18/2022] [Indexed: 12/02/2022]
Abstract
OBJECTIVES High-power LED curing lights and bulk-fill resin composites are intended to reduce chair time. This study investigated depth of cure, post-gel shrinkage (responsible for shrinkage stress), and heat generation in bulk-fill composites when cured according to minimum curing times recommended by manufacturers of curing lights and composites. METHODS A regular LED curing light (Demi Ultra, 1350 mW/cm2, Kerr Dental) and two LED curing lights with high-power modes (VALO Grand, 3117 mW/cm2 Xtra Power, Ultradent; and Bluephase PowerCure, 2435 mW/cm2 Turbo and 3344 mW/cm2 3sCure, Ivoclar Vivadent) were tested on three bulk-fill composites (Filtek One Bulk Fill, 3M Oral Care Solutions; Tetric EvoCeram Bulk Fill, Ivoclar Vivadent; Tetric Powerfill, Ivoclar Vivadent). Using minimum times recommended by manufacturers (3, 5, 6, 10, or 20 seconds), depth of cure was determined by Vickers hardness of specimens cured in a slot (n=10). Post-gel polymerization shrinkage was measured using a strain gauge (n=10) and temperature with a thermocouple (n=5). Results were analyzed using two- and one-way analysis of variance (ANOVA) followed by pairwise comparisons or Student-Newman-Keuls post hoc tests (α=0.05). RESULTS Curing lights and curing protocols significantly affected depth of cure, post-gel shrinkage, and temperature rise (p<0.001). Cure decreased with depth whereby best overall curing performance was achieved by the 20 second exposure at lowest irradiance (Demi Ultra). Fast curing (3-5 seconds) at high irradiance resulted in lesser depth-of-cure performance, except for the BluePhase-Tetric PowerFill combination. Post-gel shrinkage was higher in all composites when cured at high irradiance (p<0.001), while heat generated also tended to be higher. CONCLUSIONS Although the high-power LED curing lights advertise time savings, not all manufacturer recommended minimum curing times cured bulk-fill materials to the same extent. Moreover, these time savings came at a cost of higher post-gel shrinkage and generated more heat in the bulk-fill composites than the lower irradiance curing protocol.
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Affiliation(s)
- N C Odum
- Nicholas C Odum, BS, College of Dentistry, University of Tennessee Health Science Center, Memphis, TN, USA
| | - J T Ross
- Jason T Ross, BS, College of Dentistry, University of Tennessee Health Science Center, Memphis, TN, USA
| | - N S Citrin
- Nechama S Citrin, DMD, MS, Department of General Dentistry, College of Dentistry, University of Tennessee Health Science Center, Memphis, TN, USA
| | - D Tantbirojn
- Daranee Tantbirojn, DDS, MS, PhD, Department of General Dentistry, College of Dentistry, University of Tennessee Health Science Center, Memphis, TN, USA
| | - A Versluis
- *Antheunis Versluis, PhD, Department of Bioscience Research, College of Dentistry, University of Tennessee Health Science Center, Memphis, TN, USA
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4
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Dual-cure dental composites: can light curing interfere with conversion? J Mech Behav Biomed Mater 2022; 132:105289. [DOI: 10.1016/j.jmbbm.2022.105289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 05/17/2022] [Accepted: 05/19/2022] [Indexed: 11/21/2022]
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The effect of preheating of nano-filler composite resins on their degree of conversion and microfiltration in dental fillings. Polym Bull (Berl) 2022. [DOI: 10.1007/s00289-021-03880-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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6
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Favarão J, Oliveira D, Zanini MM, Rocha MG, Correr-Sobrinho L, Sinhoreti M. Effect of curing-light attenuation on color stability and physical and chemical properties of resin cements containing different photoinitiators. J Mech Behav Biomed Mater 2020; 113:104110. [PMID: 33032012 DOI: 10.1016/j.jmbbm.2020.104110] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 09/18/2020] [Accepted: 09/21/2020] [Indexed: 10/23/2022]
Abstract
This study aimed to evaluate the effect of light attenuation by ceramic veneers on the degree of conversion (DC), flexural strength (FS) and color change (CC) of resin cements containing different photoinitiators. Thus, samples included resin cements containing different photoinitiators: (a) camphorquinone (CQ)/ethyl 4-(dimethylamino)benzoate (EDMAB); (b) CQ/4-(N,N-dimethylamino) phenethyl alcohol (DMPOH); (c) CQ/2(dimethylamino) ethyl methacrylate (DMAEMA); (d) CQ/ethyl 4-(dimethylamino)benzoate (EDMAB) + diphenyl(2,4,6-trimethylbenzoyl)-phosphine oxide (TPO); (e) TPO; and (f) phenylbis(2.4.6-trimethylbenzoyl)phosphine oxide (BAPO). Ceramic veneers (10 × 10 mm) were 0.4 mm, 0.7 mm, 1.0 mm or 1.5 mm thick. The light irradiance of a multiple-peak LED through ceramic veneers was measured (n = 5) using a spectrometer. DC (micro-Raman spectrometer) and FS (Bar-shaped specimens) were tested in cements with and without the veneers. Color change was evaluated before and after UV artificial aging. Data were submitted to ANOVA and Tukey's test (α = 0.05). The violet spectrum showed the lowest irradiance values through the veneer, considering all thicknesses. BAPO had the highest DC values for all veneers. CQ/EDMAB + TPO, CQ + EDMAB, and CQ + DMPOH showed similar DC values concerning all thicknesses. TPO (1.0 mm) showed the lowest DC and FS values. CQ + TPO and CQ/amines showed similar FS values. CQ + EDMAB and CQ + DMAEMA showed the highest color change values while TPO showed the lowest. It was concluded that the physical and chemical properties of the resin cement were improved with BAPO. CQ/EDMAB + TPO showed the greatest color stability, considering all veneer groups and control, without affecting the other properties assessed.
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Affiliation(s)
- J Favarão
- Dental School, Centro Universitário Dinâmica das Cataratas, Paraná Avenue, 5661, Vila A, Foz do Iguaçu, 85868-030, Brazil.
| | - Dcrs Oliveira
- Department of Restorative Dental Sciences, Operative Dentistry Division, College of Dentistry, University of Florida, 1395 Center Drive, Gainesville, FL, 32610, USA.
| | - M M Zanini
- Dental School, Centro Universitário Dinâmica das Cataratas, Paraná Avenue, 5661, Vila A, Foz do Iguaçu, 85868-030, Brazil.
| | - M G Rocha
- Department of Restorative Dental Sciences, Operative Dentistry Division, College of Dentistry, University of Florida, 1395 Center Drive, Gainesville, FL, 32610, USA.
| | - L Correr-Sobrinho
- Department of Restorative Dentistry, Dental Materials Division, Piracicaba Dental School, University of Campinas, Limeira Avenue, 901, Vila Rezende, Areiao, Piracicaba, São Paulo, 13414-903, Brazil.
| | - Mac Sinhoreti
- Department of Restorative Dentistry, Dental Materials Division, Piracicaba Dental School, University of Campinas, Limeira Avenue, 901, Vila Rezende, Areiao, Piracicaba, São Paulo, 13414-903, Brazil.
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Aung SZ, Takagaki T, Ikeda M, Nozaki K, Burrow MF, Abdou A, Nikaido T, Tagami J. The effect of different light curing units on Vickers microhardness and degree of conversion of flowable resin composites. Dent Mater J 2020; 40:44-51. [PMID: 32848103 DOI: 10.4012/dmj.2019-353] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
This study aimed to assess the influence of different light curing units (LCUs) on the polymerization of various flowable resin composites. Three LCUs (Optilux 501, Elipar™ DeepCure-L LED and Bluephase®20i) and eight flowable resin composites: MI FIL Flow, Estelite Flow Quick, Estelite Universal Flow (medium), Estelite Universal Flow (super low), Beautifil Flow Plus, Clearfil Majesty ES Flow, Filtek Supreme Ultra flowable and TetricEvo Flow were tested. For Vickers microhardness (VHN) test and degree of conversion (DC), specimens were prepared and polymerized for 20 s. VHN test was performed at top surfaces (3 indentations) and DC for each specimen was measured using Fourier transform infrared (FT-IR) spectroscopy after 24 h dry storage in dark at 37˚C. The data were analyzed with 2-way ANOVA and t-test with Bonferroni correction. DC and hardness values showed a relationship between materials and LCUs. The curing efficacy of LCU type may depend on the material composition.
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Affiliation(s)
- Swe Zin Aung
- Cariology and Operative Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University
| | - Tomohiro Takagaki
- Cariology and Operative Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University.,Department of Operative Dentistry, Division of Oral Functional Sciences and Rehabilitation, School of Dentistry, Asahi University
| | - Masaomi Ikeda
- Oral Prosthetic Engineering, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University
| | - Kosuke Nozaki
- Department of Biofunction Research, Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental Universit
| | - Michael F Burrow
- Faculty of Dentistry, The University of Hong Kong, Prince Philip Dental Hospital
| | - Ahmed Abdou
- Cariology and Operative Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University
| | - Toru Nikaido
- Cariology and Operative Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University.,Department of Operative Dentistry, Division of Oral Functional Sciences and Rehabilitation, School of Dentistry, Asahi University
| | - Junji Tagami
- Cariology and Operative Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University
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Evaluation of Two Resin Composites Having Different Matrix Compositions. Dent J (Basel) 2020; 8:dj8030076. [PMID: 32709056 PMCID: PMC7559380 DOI: 10.3390/dj8030076] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 07/14/2020] [Accepted: 07/15/2020] [Indexed: 11/16/2022] Open
Abstract
This study compared two resin composites with similar filler systems and different matrix compositions. The depth of cure (DoC), polymerization shrinkage, and marginal leakage were evaluated. A Filtek Bulk Fill resin composite (FB) and a Filtek Supreme resin composite (FS) were used. For the DoC and polymerization shrinkage, cylindrical specimens with different thicknesses were prepared. The DoC was attributed to the bottom/top ratios of Vickers microhardness numbers. For polymerization shrinkage, each specimen was firstly scanned using micro-computed tomography (µCT) then cured for 20 s, then for 10 s, and then for 10 s, and they were rescanned between each curing time. Data were processed using the Mimics software. For marginal leakage, standardized 5 mm cavities were prepared in 90 molars. After etching and bonding, materials were packed according to groups: FB-bulk, FB-incremental, and FS-incremental, which were cured for 20, 30, and 40 s, respectively. After thermo-cycling, teeth were stored in 1% methylene blue dye for 24 h and then sectioned and observed for dye penetration. The results showed insignificant differences in the shrinkage and leakage between the different packing techniques and curing times of both materials. In conclusion, the introduction of a novel matrix into resin composite composition enabled bulk-filling in one layer up to 5 mm deep while keeping a tolerable polymerization shrinkage.
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9
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Pirmoradian M, Hooshmand T, Jafari-Semnani S, Fadavi F. Degree of conversion and microhardness of bulk-fill dental composites polymerized by LED and QTH light curing units. J Oral Biosci 2020; 62:107-113. [DOI: 10.1016/j.job.2019.12.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 12/05/2019] [Accepted: 12/10/2019] [Indexed: 10/25/2022]
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10
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Durner J, Schrickel K, Watts DC, Becker M, Hickel R, Draenert ME. An alternate methodology for studying diffusion and elution kinetics of dimethacrylate monomers through dentinal tubules. Dent Mater 2020; 36:479-490. [PMID: 32093972 DOI: 10.1016/j.dental.2020.02.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2019] [Revised: 02/12/2020] [Accepted: 02/12/2020] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Ethoxylated bisphenol A dimethacrylate (bisEMA) is a base monomer in several dental resin composites. It was the main aim of the present study to determine if bisEMA can reach the dental pulp by generally passive diffusion through the coronal dentinal tubules stimulated via eluent liquids surrounding the root structures only. METHODS In 20 human third molar teeth, standard Class-I occlusal cavities were prepared and provided either with an adhesive system alone or additionally with a composite restoration, according to the instructions of the manufacturer. The teeth were placed in an elution chamber such that the elution media only came into contact with the tooth root/tooth base where they were incubated at 37 °C for up to 7 d. Samples were taken after 1, 2, 4 and 7 d. Gas chromatography/mass spectrometry was used to identify bisEMA and other monomers in ethanol/water (3:1) and aqueous eluates. RESULTS bisEMA was only found in ethanol/water eluates, where the teeth had received a composite restoration. Traces of bisEMA with up to three ethylene oxide units could be detected in these eluates. Depending on the dentin thickness, different elution kinetics of bisEMA were determined. Regardless of the treatment of teeth, triethylene glycol dimethacrylate (TEGDMA) and tetraethylene glycol dimethacrylate (TEEGDMA) were found in ethanolic/aqueous eluates in equal amounts. Most TEGDMA and TEEGDMA diffused through the dentin within the first 24 h. SIGNIFICANCE Depending on the dentin layer thickness, bisEMA was released for varied time periods, resulting in varied concentrations and exposure times for the different cells of the dental pulp. The concentrations of TEGDMA and TEEGDMA were greatest for cells of the dental pulp within the first 24 h.
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Affiliation(s)
- Jürgen Durner
- Department of Conservative Dentistry and Periodontology, University Hospital, LMU Munich Ludwig-Maximilians-University of Munich, Goethestr. 70, 80336 Munich, Germany; Laboratory Becker and Colleagues, Führichstr. 70, 81671 München, Germany.
| | - Klaus Schrickel
- Thermo Fisher Scientific, Im Steingrund 4-6, 63303 Dreieich, Germany
| | - David C Watts
- School of Medical Sciences and Photon Science Institute, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Marc Becker
- Department of Conservative Dentistry and Periodontology, University Hospital, LMU Munich Ludwig-Maximilians-University of Munich, Goethestr. 70, 80336 Munich, Germany; Laboratory Becker and Colleagues, Führichstr. 70, 81671 München, Germany
| | - Reinhard Hickel
- Department of Conservative Dentistry and Periodontology, University Hospital, LMU Munich Ludwig-Maximilians-University of Munich, Goethestr. 70, 80336 Munich, Germany
| | - Miriam E Draenert
- Department of Conservative Dentistry and Periodontology, University Hospital, LMU Munich Ludwig-Maximilians-University of Munich, Goethestr. 70, 80336 Munich, Germany
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11
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Hasslen JA, Barkmeier WW, Shaddy RS, Little JR. Depth of cure of high-viscosity bulk-fill and conventional resin composites using varying irradiance exposures with a light-emitting diode curing unit. J Oral Sci 2019; 61:425-430. [PMID: 31341121 DOI: 10.2334/josnusd.18-0245] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
The purpose of this study was to determine the depth of cure (DOC) of three resin-based composites (RBCs) using varying irradiance exposures with a corded light-emitting diode curing unit. DOCs for Filtek Z250, TPH Spectra, and Tetric EvoCeram Bulk Fill were determined using the International Organization for Standardization (ISO) Standard 4049. The RBCs were light-polymerized using three different power modes and manufacturer-recommended curing times. Irradiance was determined using a spectrometer sensor and the total energy density was calculated for each power mode and concomitant polymerization time. The DOC data were analyzed with a two-way analysis of variance and Tukey's post hoc test. Tetric EvoCeram Bulk Fill produced significantly greater DOCs than TPH and Z250 (P < 0.05) for all three power mode settings. Overall, the DOC of Tetric EvoCeram Bulk Fill was greater than those of TPH and Z250 at all power settings, but the individual RBCs did not show a significant DOC difference among the three power settings (P > 0.05).
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Affiliation(s)
- Jennifer A Hasslen
- Department of General Dentistry, Creighton University School of Dentistry
| | - Wayne W Barkmeier
- Department of General Dentistry, Creighton University School of Dentistry
| | - Raymond S Shaddy
- Department of General Dentistry, Creighton University School of Dentistry
| | - Jared R Little
- Department of General Dentistry, Creighton University School of Dentistry
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12
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Effect of indirect restorative material and thickness on light transmission at different wavelengths. J Prosthodont Res 2019; 63:232-238. [DOI: 10.1016/j.jpor.2018.12.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Revised: 11/22/2018] [Accepted: 12/06/2018] [Indexed: 11/18/2022]
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13
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Bacchi A, Caldas RA, Cesar PF, Pfeifer CS. Optical properties and colorimetric evaluation of resin cements formulated with thio-urethane oligomers. J ESTHET RESTOR DENT 2018; 31:153-159. [PMID: 30394660 DOI: 10.1111/jerd.12437] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 09/07/2018] [Accepted: 09/25/2018] [Indexed: 11/28/2022]
Abstract
OBJECTIVE The aim of this study was to evaluate the color parameters and optical properties of resin cements (RCs) formulated with thio-urethanes (TUs). MATERIALS AND METHODS Six TUs were synthesized by combining thiols (pentaerythritol tetra-3-mercaptopropionate [PETMP] or trimethylol-tris-3-mercaptopropionate [TMP]) with di-functional isocyanates (1,6-Hexanediol-diissocyante [HDDI] [aliphatic-AL] or 1,3-bis(1-isocyanato-1-methylethyl) benzene [BDI] [aromatic-AR] or Dicyclohexylmethane 4,4'-Diisocyanate [HMDI] [cyclic-CC]). TUs (20 wt%) were added to a BisGMA/UDMA/TEGDMA matrix. Filler was introduced at 60 wt%. Fluorescence was evaluated through an UV-light emitting equipment. Coordinates L*, a*, and b* were obtained in the black and white reflectance to evaluate the contrast ratio (CR) and translucency parameter (TP00 ). The coordinates obtained from transmittance were used to evaluate lightness (L*), chroma (C*), color difference (ΔE00 ) after 6 month, and whiteness index for Dentistry (WID ). RESULTS RCs formulated with TUs presented significantly higher CR, and fluorescence (with T_AR). Significantly lower C*, L*, and TP00 (except for P_AR and T_AL) were also observed in RCs containing TUs. ΔE00 were not significant among the materials. WID was not influenced. CONCLUSION RCs composed by TU oligomers present higher CR and lower translucency. The material also present higher fluorescence depending on the oligomer used. CLINICAL SIGNIFICANCE The use of thio-urethanes to formulate resin cements can ensure a luting material with improved potential to mask colored substrates due to the higher contrast ratio and lower translucency obtained. A final higher fluorescence of restoration is also expected with the use of specific oligomer.
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Affiliation(s)
- Atais Bacchi
- Department of Biomaterials and Oral Biology, University of São Paulo-USP, São Paulo, Brazil.,Department of Prosthodontics and Dental Materials, Meridional Faculty-IMED, Passo Fundo, Brazil
| | - Ricardo Armini Caldas
- Department of Prosthodontics and Periodontics, Piracicaba Dental School, Campinas State University, Piracicaba, Brazil
| | - Paulo Francisco Cesar
- Department of Biomaterials and Oral Biology, University of São Paulo-USP, São Paulo, Brazil
| | - Carmem Silvia Pfeifer
- Department of Biomaterials and Biomechanics, Oregon Health & Science University, Portland, Oregon
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14
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Zhao J, Zeng H, Kalia S, Lui H. Using Raman Spectroscopy to Detect and Diagnose Skin Cancer In Vivo. Dermatol Clin 2017; 35:495-504. [PMID: 28886805 DOI: 10.1016/j.det.2017.06.010] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Raman spectroscopy provides a noninvasive bedside tool that captures unique optical signals via molecular vibrations in tissue samples. Raman theory was discovered at the beginning of the twentieth century, but it was not until the past few decades that it has been used to differentiate skin neoplasms. We provide a brief description of Raman spectroscopy for in vivo skin cancer diagnosis, including the physical principles underlying Raman spectroscopy, its advantages, typical spectra of skin pathologies, and its clinical application for aiding skin cancer diagnosis.
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Affiliation(s)
- Jianhua Zhao
- Photomedicine Institute, Department of Dermatology and Skin Science, Vancouver Coastal Health Research Institute, The University of British Columbia, 835 West 10th Avenue, Vancouver, British Columbia V5Z 4E8, Canada; Imaging Unit, Integrative Oncology Department, The BC Cancer Agency Research Center, 675 West 10th Avenue, Vancouver, British Columbia V5Z 1L3, Canada
| | - Haishan Zeng
- Photomedicine Institute, Department of Dermatology and Skin Science, Vancouver Coastal Health Research Institute, The University of British Columbia, 835 West 10th Avenue, Vancouver, British Columbia V5Z 4E8, Canada; Imaging Unit, Integrative Oncology Department, The BC Cancer Agency Research Center, 675 West 10th Avenue, Vancouver, British Columbia V5Z 1L3, Canada
| | - Sunil Kalia
- Photomedicine Institute, Department of Dermatology and Skin Science, Vancouver Coastal Health Research Institute, The University of British Columbia, 835 West 10th Avenue, Vancouver, British Columbia V5Z 4E8, Canada; Imaging Unit, Integrative Oncology Department, The BC Cancer Agency Research Center, 675 West 10th Avenue, Vancouver, British Columbia V5Z 1L3, Canada
| | - Harvey Lui
- Photomedicine Institute, Department of Dermatology and Skin Science, Vancouver Coastal Health Research Institute, The University of British Columbia, 835 West 10th Avenue, Vancouver, British Columbia V5Z 4E8, Canada; Imaging Unit, Integrative Oncology Department, The BC Cancer Agency Research Center, 675 West 10th Avenue, Vancouver, British Columbia V5Z 1L3, Canada.
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Tiwari A, Shyagali T, Kohli S, Joshi R, Gupta A, Tiwari R. Effect of Dental Chair Light on Enamel Bonding of Orthodontic Brackets Using Light Cure Based Adhesive System: An In-Vitro Study. Acta Inform Med 2017; 24:317-321. [PMID: 28077886 PMCID: PMC5203735 DOI: 10.5455/aim.2016.24.317-321] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Accepted: 10/10/2016] [Indexed: 11/03/2022] Open
Abstract
AIM The aim of this in vitro study was to evaluate the influence of the Dental chair light on the bond strength of light cured composite resin. MATERIALS AND METHODS Sixty therapeutically extracted human premolar teeth were randomly allocated to two groups of 30 specimens each. In both groups light cured composite resin (Transbond XT) and MBT premolar metal brackets (3M Unitek) was used to bond brackets. In group I and II light curing was done using Light-emitting diode light curing units without and with the dental chair light respectively. After bonding, all samples were stored in distilled water at room temperature for 24 hours and subsequently tested for shear bond strength and Adhesive Remnant Index (ARI) scores. Data was subjected to Mann Whitney U statistical test. RESULTS Results indicated that there was significantly higher shear bond strength (7.71 ± 1.90) for the Group II (composite cured with LED and dental chair light) compared with Group I (composite cured with LED LCU only) (5.74 ± 1.13).the obtained difference was statistically significant. There was no statistical significant difference between ARI scores in between the groups. CONCLUSIONS light cure bonding with dental chair light switched on will produce greater bond strength than the conventional bonding. However, the ARI score were similar to both the groups. It is advised that the inexperienced orthodontist should always switch off the dental chair light while bonding for enough working time during the bracket placement.
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Affiliation(s)
- Anil Tiwari
- Department of Orthodontics and Dentofacial Orthopedics, Hitkarini Dental College and Hospital, Jabalpur, MP, India
| | - Tarulatha Shyagali
- Department of Orthodontics and Dentofacial Orthopedics, Hitkarini Dental College and Hospital, Jabalpur, MP, India
| | - Sarvraj Kohli
- Department of Orthodontics and Dentofacial Orthopedics, Hitkarini Dental College and Hospital, Jabalpur, MP, India
| | - Rishi Joshi
- Department of Orthodontics and Dentofacial Orthopedics, Hitkarini Dental College and Hospital, Jabalpur, MP, India
| | - Abhishek Gupta
- Department of Orthodontics and Dentofacial Orthopedics, Hitkarini Dental College and Hospital, Jabalpur, MP, India
| | - Rana Tiwari
- Department of Orthodontics and Dentofacial Orthopedics, Hitkarini Dental College and Hospital, Jabalpur, MP, India
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Monterubbianesi R, Orsini G, Tosi G, Conti C, Librando V, Procaccini M, Putignano A. Spectroscopic and Mechanical Properties of a New Generation of Bulk Fill Composites. Front Physiol 2016; 7:652. [PMID: 28082918 PMCID: PMC5186780 DOI: 10.3389/fphys.2016.00652] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2016] [Accepted: 12/12/2016] [Indexed: 12/03/2022] Open
Abstract
Objectives: The aims of this study were to in vitro evaluate the degree of conversion and the microhardness properties of five bulk fill resin composites; in addition, the performance of two curing lamps, used for composites polymerization, was also analyzed. Materials and Methods: The following five resin-based bulk fill composites were tested: SureFil SDR®, Fill Up!™, Filtek™, SonicFill™, and SonicFill2™. Samples of 4 mm in thickness were prepared using Teflon molds filled in one increment and light-polymerized using two LED power units. Ten samples for each composite were cured using Elipar S10 and 10 using Demi Ultra. Additional samples of SonicFill2, (3 and 5 mm-thick) were also tested. The degree of conversion (DC) was determined by Raman spectroscopy, while the Vickers microhardness (VMH) was evaluated using a microhardness tester. The experimental evaluation was carried out on top and bottom sides, immediately after curing (t0), and, on bottom, after 24 h (t24). Two-ways analysis of variance was applied to evaluate DC and VMH-values. In all analyses, the level of significance was set at p < 0.05. Results: All bulk fill resin composites recorded satisfactory DCs on top and bottom sides. At t0, the top of SDR and SonicFill2 showed the highest DCs-values (85.56 ± 9.52 and 85.47 ± 1.90, respectively), when cured using Elipar S10; using Demi Ultra, SonicFill2 showed the highest DCs-values (90.53 ± 2.18). At t0, the highest DCs-values of bottom sides were recorded by SDR (84.64 ± 11.68), when cured using Elipar S10, and Filtek (81.52 ± 4.14), using Demi Ultra. On top sides, Demi Ultra lamp showed significant higher DCs compared to the Elipar S10 (p < 0.05). SonicFill2 reached suitable DCs also on bottom of 5 mm-thick samples. At t0, VMH-values ranged between 24.4 and 69.18 for Elipar S10, and between 26.5 and 67.3 for Demi Ultra. Using both lamps, the lowest VMH-values were shown by SDR, while the highest values by SonicFill2. At t24, all DC and VMH values significantly increased. Conclusions: Differences in DC and VMH among materials are suggested to be material and curing lamp dependent. Even at t0, the three high viscosity bulk composites showed higher VMH than the flowable or dual curing composites.
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Affiliation(s)
| | - Giovanna Orsini
- Department of Clinical Sciences and Stomatology, Polytechnic University of Marche Ancona, Italy
| | - Giorgio Tosi
- Department of Materials, Environmental Science and Urban Planning, Polytechnic University of Marche Ancona, Italy
| | - Carla Conti
- Department of Materials, Environmental Science and Urban Planning, Polytechnic University of Marche Ancona, Italy
| | - Vito Librando
- Department of Chemical Sciences, University of Catania Catania, Italy
| | - Maurizio Procaccini
- Department of Clinical Sciences and Stomatology, Polytechnic University of Marche Ancona, Italy
| | - Angelo Putignano
- Department of Clinical Sciences and Stomatology, Polytechnic University of Marche Ancona, Italy
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Dsouza R, Subhash H, Neuhaus K, Kantamneni R, McNamara PM, Hogan J, Wilson C, Leahy M. Assessment of curing behavior of light-activated dental composites using intensity correlation based multiple reference optical coherence tomography. Lasers Surg Med 2015; 48:77-82. [PMID: 26612183 DOI: 10.1002/lsm.22447] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/09/2015] [Indexed: 11/08/2022]
Abstract
BACKGROUND AND OBJECTIVES Monitoring the curing kinetics of light-activated resin is a key area of research. These resins are used in restorative applications and particularly in dental applications. They can undergo volumetric shrinkage due to poor control of the depth dependent curing process, modulated by the intensity and duration of the curing light source. This often results in the formation of marginal gaps, causing pain and damage to the restoration site. In this study, we demonstrate the capabilities of a correlation method applied using a multiple references optical coherence tomography (MR-OCT) architecture to monitor the curing of the resin. STUDY DESIGN/MATERIALS AND METHODS A MR-OCT system is used in this study to monitor the curing of the resin. The system operates at the center wavelength of 1310 nm with an A-scan rate of 1200 A-scans per second. The axial and lateral resolution of the system is ∼13 μm and ∼27 μm. The method to determine the intensity correlation between adjacent B-frames is based on the Pearson correlation coefficient for a region of interest. Calculating the correlation coefficient for multiple B-frames related to the first B-frame at regular spaced time points, shows for a noncured resin a reduction of the correlation coefficient over time due to Brownian motion. The time constant of the reduction of the correlation value is a measure for the progress of the polymerization during LED light irradiation of the resin. The proposed approach is potentially a low-cost, powerful and unique optical imaging modality for measuring the curing behavior of dental resin and other resins, coatings, and adhesives in medical and industrial applications. RESULTS To demonstrate the proposed method to monitor the curing process, a light-activated resin composite from GRADIA DIRECT ANTERIOR (GC Corporation, Japan) is studied. The curing time of resin was measured and monitored as a function of depth. The correlation coefficient method is highly sensitive to Brownian motion. The process of curing results in a change in intensity as measured by the MR-OCT signal and hence can be monitored using this method. CONCLUSIONS These results show that MR-OCT has the potential to measure the curing time and monitor the curing process as a function of depth. Moreover, MR-OCT as a product has potential to be compact, low-cost and to fit into a smartphone. Using such a device for monitoring the curing of the resin will be suitable for dentists in stationary and mobile clinical settings.
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Affiliation(s)
- Roshan Dsouza
- Tissue Optics and Microcirculation Imaging Group, School of Physics, National University of Ireland, Galway, Ireland
| | - Hrebesh Subhash
- Tissue Optics and Microcirculation Imaging Group, School of Physics, National University of Ireland, Galway, Ireland
| | - Kai Neuhaus
- Tissue Optics and Microcirculation Imaging Group, School of Physics, National University of Ireland, Galway, Ireland
| | | | - Paul M McNamara
- Tissue Optics and Microcirculation Imaging Group, School of Physics, National University of Ireland, Galway, Ireland.,Compact Imaging Ireland Ltd., Galway, Ireland
| | - Josh Hogan
- Compact Imaging, Inc., 897 Independence Ave., Suite 5B, Mountain View, California, 94043
| | - Carol Wilson
- Compact Imaging, Inc., 897 Independence Ave., Suite 5B, Mountain View, California, 94043
| | - Martin Leahy
- Tissue Optics and Microcirculation Imaging Group, School of Physics, National University of Ireland, Galway, Ireland.,Royal College of Surgeons (RCSI), Dublin, Ireland
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18
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Degree of conversion and surface hardness of bulk-fill composite versus incremental-fill composite. ACTA ACUST UNITED AC 2015. [DOI: 10.1016/j.tdj.2015.01.003] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Kitchens B, Wells M, Tantbirojn D, Versluis A. Depth of cure of sealants polymerized with high-power light emitting diode curing lights. Int J Paediatr Dent 2015; 25:79-86. [PMID: 24628863 DOI: 10.1111/ipd.12102] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
OBJECTIVE To determine whether recommended short curing times of three high-power light emitting diode (LED) curing lights are sufficient to polymerize sealant materials. METHODS Opaque-unfilled sealant (Delton LC Opaque), opaque-filled sealant (UltraSeal XT plus), and clear-filled sealant (FluroShield) were light cured in a covered slot-mold using the manufacturers' shortest recommended curing times with three high-power LED lights (3-s VALO, 5-s Fusion, 10-s Smartlite). A 40-s cure with a quartz-tungsten halogen (QTH) light was used as control. Vickers hardness was measured 24 h after curing at the sealant surface and through the depth (0.5 mm increments) (N = 10). Results were analyzed with two-way anova (pair-wise multiple comparisons, significance level 0.05). RESULTS The high-power LEDs did not cure the sealants as deep as the QTH. Delton LC Opaque showed the least depth of cure as hardness values beyond a depth of 0.5 mm were not measurable regardless of the curing light. Even for UltraSeal XT plus, when surface hardness was about the same with all lights, hardness decreased more rapidly with depth for the LEDs. FluroShield showed the slowest decline in hardness through the depth for all lights. CONCLUSIONS Manufacturers' recommendations for shortest possible curing time with high-power LEDs were not sufficient for adequate polymerization of the tested sealants.
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Affiliation(s)
- Brandon Kitchens
- Department of Pediatric Dentistry, College of Dentistry, University of Tennessee Health Science Center, Memphis, TN, USA
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Amato PAF, Martins RP, dos Santos Cruz CA, Capella MV, Martins LP. Time reduction of light curing: Influence on conversion degree and microhardness of orthodontic composites. Am J Orthod Dentofacial Orthop 2014; 146:40-6. [PMID: 24974997 DOI: 10.1016/j.ajodo.2014.03.022] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Revised: 03/01/2014] [Accepted: 03/01/2014] [Indexed: 11/30/2022]
Abstract
INTRODUCTION The aim of this study was to assess the influence of curing time and power on the degree of conversion and surface microhardness of 3 orthodontic composites. METHODS One hundred eighty discs, 6 mm in diameter, were divided into 3 groups of 60 samples according to the composite used-Transbond XT (3M Unitek, Monrovia, Calif), Opal Bond MV (Ultradent, South Jordan, Utah), and Transbond Plus Color Change (3M Unitek)- and each group was further divided into 3 subgroups (n = 20). Five samples were used to measure conversion, and 15 were used to measure microhardness. A light-emitting diode curing unit with multiwavelength emission of broad light was used for curing at 3 power levels (530, 760, and 1520 mW) and 3 times (8.5, 6, and 3 seconds), always totaling 4.56 joules. Five specimens from each subgroup were ground and mixed with potassium bromide to produce 8-mm tablets to be compared with 5 others made similarly with the respective noncured composite. These were placed into a spectrometer, and software was used for analysis. A microhardness tester was used to take Knoop hardness (KHN) measurements in 15 discs of each subgroup. The data were analyzed with 2 analysis of variance tests at 2 levels. RESULTS Differences were found in the conversion degree of the composites cured at different times and powers (P <0.01). The composites showed similar degrees of conversion when light cured at 8.5 seconds (80.7%) and 6 seconds (79.0%), but not at 3 seconds (75.0%). The conversion degrees of the composites were different, with group 3 (87.2%) higher than group 2 (83.5%), which was higher than group 1 (64.0%). Differences in microhardness were also found (P <0.01), with lower microhardness at 8.5 seconds (35.2 KHN), but no difference was observed between 6 seconds (41.6 KHN) and 3 seconds (42.8 KHN). Group 3 had the highest surface microhardness (35.9 KHN) compared with group 2 (33.7 KHN) and group 1 (30.0 KHN). CONCLUSIONS Curing time can be reduced up to 6 seconds by increasing the power, with a slight decrease in the degree of conversion at 3 seconds; the decrease has a positive effect on the surface microhardness.
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Affiliation(s)
| | - Renato Parsekian Martins
- Invited professor, Orthodontic Program, Araraquara School of Dentistry, São Paulo State University, Araraquara, São Paulo, Brazil; private practice, Araraquara, São Paulo, Brazil.
| | - Carlos Alberto dos Santos Cruz
- Associate professor, Department of Dental Materials and Prosthodontics, Araraquara School of Dentistry, São Paulo State University, Araraquara, São Paulo, Brazil
| | - Marisa Veiga Capella
- Assistant professor, Department of Physical Chemistry, Araraquara Institute of Chemistry, São Paulo State University, Araraquara, São Paulo, Brazil
| | - Lídia Parsekian Martins
- Chairman, Department of Orthodontics, Araraquara School of Dentistry, São Paulo State University, Araraquara, São Paulo, Brazil
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Sabatini C. Comparative study of surface microhardness of methacrylate-based composite resins polymerized with light-emitting diodes and halogen. Eur J Dent 2014; 7:327-335. [PMID: 24926213 PMCID: PMC4053622 DOI: 10.4103/1305-7456.115417] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Objective: The aim of this study was to evaluate the effect of polymerization with quartz-tungsten-halogen (QTH) and light-emitting diodes (LED) on the surface microhardness of eight commercially available light-polymerized, methacrylate-based composite resins, with different filler particle composition (microfill, minifill, nanohybrids, and microhybrids) immediately after polymerization, after 24 hours, and after three months of storage. Materials and Methods: Eighty disk-shaped specimens were prepared using a split Teflon mold (6 × 2 mm) and were irradiated with either the QTH (Elipar 2500; 600 mW/cm2) for 20 seconds or an LED (Bluephase G2; 1,200 mW/cm2) for 40 seconds. The microhardness values were recorded using a Vickers hardness tester at a 300 g load for 15 seconds, immediately after polymerization, after 24 hours, and after three months of dark aging in distilled water at 37°C. Statistical analysis was performed using a two-way analysis of variance (ANOVA) and the Tukey's test. Results: The baseline values demonstrated a significant effect of the composite and the interaction composite-LCU on the microhardness (P < 0.05). At 24 hours, only the composite variable showed a significant effect on the hardness values (P < 0.05). After three months, the composite, LCU, and the interaction composite-LCU all demonstrated a significant effect on the microhardness (P < 0.05). Conclusions: The effectiveness of polymerization, measured in terms of surface hardness, was shown to be dependent not only on the type of light curing unit, but also on the type of composite. Moreover, the choice of composite was shown to affect the performance of the light curing unit.
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Affiliation(s)
- Camila Sabatini
- Department of Restorative Dentistry, School of Dental Medicine, SUNY at Buffalo, Buffalo, NY, USA
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22
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Orçun Zorba Y, Bayındır YZ, Turgut H, Yıldız M. Quality of curing in relation to different light sources by measuring hardness, degree of conversion and depth of cure. ACTA ACUST UNITED AC 2013. [DOI: 10.1179/143289109x12494867167521] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Affiliation(s)
- Y. Orçun Zorba
- Department of EndodonticsDentistry Faculty, Kırıkkale University, Kırıkkale, Turkey
| | - Y. Z. Bayındır
- Department of Restorative DentistryDentistry Faculty, Atatürk University, Erzurum, Turkey
| | - H. Turgut
- Department of Restorative DentistryDentistry Faculty, Atatürk University, Erzurum, Turkey
| | - M. Yıldız
- Department of Restorative DentistryDentistry Faculty, Atatürk University, Erzurum, Turkey
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Cekic-Nagas I, Egilmez F, Ergun G, Kaya BM. Light transmittance of zirconia as a function of thickness and microhardness of resin cements under different thicknesses of zirconia. Med Oral Patol Oral Cir Bucal 2013; 18:e212-8. [PMID: 23385497 PMCID: PMC3613872 DOI: 10.4317/medoral.18181] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2012] [Accepted: 08/05/2012] [Indexed: 02/04/2023] Open
Abstract
OBJECTIVE The objective of this study was to compare microhardness of resin cements under different thicknesses of zirconia and the light transmittance of zirconia as a function of thickness. STUDY DESIGN A total of 126 disc-shaped specimens (2 mm in height and 5 mm in diameter) were prepared from dual-cured resin cements (RelyX Unicem, Panavia F and Clearfil SA cement). Photoactivation was performed by using quartz tungsten halogen and light emitting diode light curing units under different thicknesses of zirconia. Then the specimens (n=7/per group) were stored in dry conditions in total dark at 37°C for 24 h. The Vicker's hardness test was performed on the resin cement layer with a microhardness tester. Statistical significance was determined using multifactorial analysis of variance (ANOVA) (alpha=.05). Light transmittance of different thicknesses of zirconia (0.3, 0.5 and 0.8 mm) was measured using a hand-held radiometer (Demetron, Kerr). Data were analyzed using one-way ANOVA test (alpha=.05). RESULTS ANOVA revealed that resin cement and light curing unit had significant effects on microhardness (p < 0.001). Additionally, greater zirconia thickness resulted in lower transmittance. There was no correlation between the amount of light transmitted and microhardness of dual-cured resin cements (r = 0.073, p = 0.295). CONCLUSION Although different zirconia thicknesses might result in insufficient light transmission, dual-cured resin cements under zirconia restorations could have adequate microhardness.
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Affiliation(s)
- Isil Cekic-Nagas
- Gazi University, Faculty of Dentistry, Department of Prosthodontics, Ankara, Turkey.
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Brokos I, Turner S, Santini A. The effect of disposable infection control sleeves on the total energy delivered by dental LCUs. Prim Dent J 2012; 1:11-16. [PMID: 23720909 DOI: 10.1308/205016812803838438] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
AIM This study compared the effect of seven different disposable cross-infection control sleeves on the total energy delivered (J/cm2) by four different dental light-curing units (LCUs). METHODS Four LCUs and seven disposable sleeves (six proprietary brands and a general-purpose cellophane wrap) were used. Anterior and posterior tooth position was included as a third factor. Total energy delivered was measured for each LCU without a sleeve (control) and with each sleeve and for each tooth position. Curing time was 10 seconds, as recommended by the LCU manufacturers. Measurements were taken 10 times for each sleeve/LCU/tooth position and means (SD) calculated. Data were analysed using three-way analysis of variance (ANOVA). The null hypothesis was that none of the sleeves would, at a 0.1% level, significantly affect the total energy delivered. RESULTS All sleeves significantly reduced the total energy delivered (P < 0.001). Cellophane wrap (cling film) had the smallest effect on total energy. Total energy delivered was most strongly influenced by tooth position and LCU model. CONCLUSIONS Sleeves significantly reduce the total energy delivered compared to unsleeved LCUs, but to a degree that may not be clinically important. Cling film reduced total energy delivered to a significantly lesser extent than did proprietary bands of sleeve. In order to determine adequacy of delivered total energy, sleeved LCUs should be tested prior to clinical use.
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Miao X, Li Y, Zhang Q, Zhu M, Wang H. Low shrinkage light curable dental nanocomposites using SiO2 microspheres as fillers. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2012; 32:2115-2121. [DOI: 10.1016/j.msec.2012.05.053] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2011] [Revised: 05/27/2012] [Accepted: 05/31/2012] [Indexed: 10/28/2022]
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Degree of conversion and microhardness of TPO-containing resin-based composites cured by polywave and monowave LED units. J Dent 2012; 40:577-84. [DOI: 10.1016/j.jdent.2012.03.007] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2012] [Revised: 03/19/2012] [Accepted: 03/20/2012] [Indexed: 11/21/2022] Open
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Baek DM, Park JK, Son SA, Ko CC, Garcia-Godoy F, Kim HI, Kwon YH. Mechanical properties of composite resins light-cured using a blue DPSS laser. Lasers Med Sci 2012; 28:597-604. [PMID: 22585380 DOI: 10.1007/s10103-012-1117-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2012] [Accepted: 05/01/2012] [Indexed: 12/31/2022]
Abstract
Lasers have many favorable features as a light source owing to their monochromaticity and coherence. This study examined the mechanical properties of composite resins that were light-cured using a diode-pumped solid state (DPSS) laser. Eight composite resins were light-cured using four different light sources (one quartz-tungsten-halogen (QTH), two light-emitting diodes (LEDs), and one DPSS laser with a wavelength of 473 nm). The light intensity of the DPSS laser and remaining light-curing units were approximately 500 and 900 mW/cm(2), respectively. The microhardness, flexural properties, and compressive properties were evaluated using the Vickers hardness test, three-point bending test, and compression test, respectively. In most cases, the microhardness, flexural properties, and compressive properties of the specimens light-cured using the DPSS laser were similar to those obtained using the other light-curing units. Within the limits of the study, the microhardness, flexural modulus, and compressive strength were linearly correlated with the filler content (in weight percent). The flexural modulus and compressive modulus were also linearly correlated with the microhardness. Even with a much lower light intensity, the DPSS laser with a wavelength of 473 nm can polymerize composite resins and give comparable mechanical properties to those obtained using the other light-curing units.
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Affiliation(s)
- Du-Man Baek
- Department of Dental Materials, School of Dentistry, Pusan National University, Yangsan, 626-870, South Korea
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Santini A, Miletic V, Koutsaki D. Degree of conversion of three fissure sealants cured by different light curing units using micro-Raman spectroscopy. J Dent Sci 2012. [DOI: 10.1016/j.jds.2012.01.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Contraction behaviors of dental composite restorations — Finite element investigation with DIC validation. J Mech Behav Biomed Mater 2011; 4:2138-49. [DOI: 10.1016/j.jmbbm.2011.07.014] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2011] [Revised: 07/16/2011] [Accepted: 07/25/2011] [Indexed: 11/20/2022]
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Cuspal deflection and depth of cure in resin-based composite restorations filled by using bulk, incremental and transtooth-illumination techniques. J Am Dent Assoc 2011; 142:1176-82. [DOI: 10.14219/jada.archive.2011.0087] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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General dental practitioners' knowledge of polymerisation of resin-based composite restorations and light curing unit technology. Br Dent J 2011; 211:E13. [PMID: 21941302 DOI: 10.1038/sj.bdj.2011.768] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/21/2011] [Indexed: 11/08/2022]
Abstract
OBJECTIVE Clinical successful use of resin-based composite restorations (RBCs) depends on knowledge of material and light curing unit (LCU) related factors. The purpose of this study was to evaluate general dental practitioners' knowledge of polymerisation of RBCs and LCU technology. METHODS Members of the Active Research Group of the Faculty of General Dental Practice (UK) in England, Scotland and Wales engaged in primary dental care were sent a letter introducing the study and asking for their cooperation, followed by an email containing a link to the online survey questionnaire, hosted on Surveymonkey.com. The questionnaire enquired about current LCUs, and asked a series of questions on material science. RESULTS Sixty-six percent of the 274 members contacted responded. Fifty-seven percent used LED units, 25% quartz tungsten halogen (QTH), and 1% plasma arc (missing: 17%). Thirty percent reported having access to a radiometer. Appropriate responses regarding the degree of conversion of composite and adhesive materials were given by 32% and 23% respectively, and 22% agreed that LED and QTH LCUs had comparable efficiency in polymerising composites. Thirty-three percent were aware that RBCs eluted substances that may have adverse local or systemic consequences. Fifty-eight percent stated that if polymerisation of RBC is slowed down, polymerisation stress will be lower, and 43% said that polymerisation shrinkage will be reduced if the degree of conversion is reduced. Knowledge (measured by appropriate responses to these questions) was not related to years since qualification (r=-0.05, n=168, p=0.53). CONCLUSION The study suggests that dentists' knowledge of curing RBC restorations and LCUs is poor. This indicates that there is a need for training and guidance in this aspect of primary dental care.
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Zhu S, Platt J. Curing Efficiency of Three Different Curing Modes at Different Distances for Four Composites. Oper Dent 2011; 36:362-71. [DOI: 10.2341/09-245-l] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Clinical Relevance
Doubling the exposure time of a high-intensity light-emitting diode curing light with a turbo tip and autofocus capability does not predictably compensate for distance in deep cavities.
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Durner J, Stojanovic M, Urcan E, Spahl W, Haertel U, Hickel R, Reichl FX. Effect of hydrogen peroxide on the three-dimensional polymer network in composites. Dent Mater 2011; 27:573-80. [DOI: 10.1016/j.dental.2011.02.013] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2010] [Revised: 10/08/2010] [Accepted: 02/24/2011] [Indexed: 10/18/2022]
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da Silva MAB, de Oliveira GJPL, Tonholo J, Júnior JGDS, Santos LDM, Dos Reis JIL. Effect of the insertion and polymerization technique in composite resin restorations: analysis of marginal gap by atomic force microscopy. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2010; 16:779-784. [PMID: 20920378 DOI: 10.1017/s1431927610093931] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
This in vitro study evaluated the marginal gap at the composite tooth/resin interface in class V cavities under the influence of two insertion techniques and a curing system by means of atomic force microscopy (AFM). Forty enamel and dentin cavities were prepared on the buccal surface in bovine teeth with quadratic forms measuring 2 mm × 2 mm and depth of 1.5 mm. The teeth were then divided into four groups: group A, 10 cavities were restored in one increment, light cured by halogen light; group B, 10 cavities filled with bulk filling, light cured by the light emitting diodes (LED); group C, 10 cavities were restored by the incremental technique, light cured by halogen light; group D, 10 cavities were restored by the incremental technique, light cured by the LED. The teeth underwent the polishing procedure and were analyzed by AFM for tooth/restoration interface evaluation. The data were compared between groups using the nonparametric Kruskall-Wallis and Mann-Whitney tests (p < 0.05). The results showed a statistically significant difference between groups A and B and groups A and C. It was concluded that no insertion and polymerization technique was able to completely seal the cavity.
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Affiliation(s)
- Marcos Aurélio Bomfim da Silva
- Departamento de Odontologia Restauradora, Faculdade de Odontologia de Piracicaba, Universidade Estadual de Campinas, 13414-903, Piracicaba-SP, Brazil
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Rahiotis C, Patsouri K, Silikas N, Kakaboura A. Curing efficiency of high-intensity light-emitting diode (LED) devices. J Oral Sci 2010; 52:187-95. [PMID: 20587941 DOI: 10.2334/josnusd.52.187] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
We evaluated the curing efficiency of 4 high-intensity light-emitting diode (LED) devices by assessing percentage of residual C=C (%RDB), surface microhardness (SM), depth of cure (DC), percentage of linear shrinkage-strain (%LS), and percentage of wall-to-wall contraction (%WWC). The light-curing units tested were a QTH light, the Elipar TriLight (3M/ESPE), and 4 LED devices - the Allegro (Denmat), the Bluephase (Ivoclar/Vivadent), the FreeLight2 (3M/ESPE), and The Cure TC-01 (Spring Health Products). The %RDB was measured by microFTIR spectroscopy. Microhardness measurements (Vickers) were performed at the surface (H0) and at depths of 3 mm (H3) and 5 mm (H5) of cylindrical specimens. Depth of cure was expressed as the ratio of microhardness at each depth, relative to the corresponding surface value (H3/H0 and H5/H0). The bonded disc method was used to evaluate %LS. For the %WWC evaluation, cylindrical resin restorations were imaged by high resolution micro-CT and the %WWC was calculated at depths of 0 mm and 2 mm. There were no statistical differences among the LEDs in %RDB or %LS. The Bluephase and Allegro had the highest SM values. As compared with the other LEDs, the Bluephase and The Cure TC-01 had lower values for depth of cure at depths of 3 mm and 5 mm. There were no significant differences in %WWC among the LEDs at either depth, and the QTH had the lowest %WWC at both depths.
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Affiliation(s)
- Christos Rahiotis
- Department of Oral Biology, Faculty of Dentistry, University of Athens, Goudi, Greece.
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Lohbauer U, Pelka M, Belli R, Schmitt J, Mocker E, Jandt KD, Müller FA. Degree of Conversion of Luting Resins Around Ceramic Inlays in Natural Deep Cavities: A Micro-Raman Spectroscopy Analysis. Oper Dent 2010; 35:579-86. [PMID: 20945750 DOI: 10.2341/10-012-l] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Clinical Relevance
Contrary to previous evidence, the degrees of conversion of resin luting materials have been shown to reach statistically similar values in three different depths around ceramic inlays luted to natural cavities. Both dual-cure and light-cure materials have presented conversion homogeneity, although they have been shown to be material-dependent.
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Affiliation(s)
- Ulrich Lohbauer
- Dental Clinic 1, Dental Materials Lab, Friedrich-Alexander-University of Erlangen, Erlangen, Germany.
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Contraction stress related to composite inorganic content. Dent Mater 2010; 26:704-9. [DOI: 10.1016/j.dental.2010.03.015] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2009] [Revised: 12/11/2009] [Accepted: 03/09/2010] [Indexed: 11/21/2022]
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Pollington S, Kahakachchi N, van Noort R. The Influence of Plastic Light Cure Sheaths on the Hardness of Resin Composite. Oper Dent 2009; 34:741-5. [DOI: 10.2341/09-024-l] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Clinical Relevance
Disposable sheaths are now recommended as a method of cross infection control when light curing resin composite. However, these sheaths may affect the depth of cure of the resin composite, resulting in a compromise of the mechanical properties of the restorative material.
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dos Santos GB, Alto RVM, Filho HRS, da Silva EM, Fellows CE. Light transmission on dental resin composites. Dent Mater 2008; 24:571-6. [PMID: 17689605 DOI: 10.1016/j.dental.2007.06.015] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2006] [Accepted: 06/06/2007] [Indexed: 10/23/2022]
Abstract
OBJECTIVES The purposes of this study was: (1) to examine the light transmittance characteristics of two light-cured resin composites, for different thickness, (2) to correlate the light transmittance through the resin composites and the filler contents, and (3) to determine the penetration depth of the light as a function of the wavelength. METHODS Two resin composites (Filtek Z250, shade A2 and Filtek Supreme XT, shade A2E) were used. Specimens of six different thicknesses (0.15, 0.25, 0.30, 0.36, 0.47 and 0.75 mm) were prepared (n=3). The transmittance at wavelengths from 400 to 800 nm was measured using a UV-visible spectrophotometer, before and after light polymerization. RESULTS AND SIGNIFICANCE Significant differences were found in the wavelength dependence of transmittance between the two materials, and between the unpolymerized and polymerized stages of each resin composite. At lower wavelengths, the light transmittance of the Filtek Supreme XT resin composite was lower than the Filtek Z250. At the higher wavelengths, however, Filtek Supreme XT presented higher light transmittance. For both resin composites, the penetration depth was higher after polymerization. However, Filtek Supreme XT showed a higher gain in transmittance at the 0.15 mm thickness. The difference in light transmittance characteristics of the resin composites may affect their depth of polymerization.
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Affiliation(s)
- G B dos Santos
- Faculdade de Odontologia, Universidade do Estado do Rio de Janeiro, Boulevard 28 de Setembro, 157, Vila Isabel, Rio de Janeiro 20.0000, Brazil
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