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Szczesio-Wlodarczyk A, Garoushi S, Vallittu P, Bociong K, Lassila L. Polymerization shrinkage of contemporary dental resin composites: Comparison of three measurement methods with correlation analysis. J Mech Behav Biomed Mater 2024; 152:106450. [PMID: 38325167 DOI: 10.1016/j.jmbbm.2024.106450] [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: 12/04/2023] [Revised: 01/18/2024] [Accepted: 01/30/2024] [Indexed: 02/09/2024]
Abstract
The aim of this study was to evaluate a novel approach for measuring the polymerization shrinkage of dental resin composites - measurement of sample depth variation. This new method was compared with two testing methodologies used for assessing the polymerization shrinkage (buoyancy and strain gauge methods). Eleven commercial resin composites were investigated (EverX Posterior; EverX Flow Bulk & Dentin; G-aenial Anterior, Posterior, A'chord & Universal Injectable; Filtek One Bulk Fill & Universal Restorative; SDR + Flow and Aura Bulk Fill). In addition, filler content (wt. %), flexural modulus, and the degree of conversion were evaluated. Shrinkage values, obtained by the buoyancy method, are greater than shrinkage evaluated by the strain gauge. There are significant differences in polymerization shrinkage among the tested resin composite materials. There is a strong correlation between the newly proposed method of shrinkage measurement and the buoyancy method (r2 = 0.8; p < 0.01). There is no correlation between volumetric shrinkage measurement (depth changes and buoyancy method) and linear strain measurement. Volumetric filler amount correlates with shrinkage values evaluated by all three methods. The degree of conversion for the tested resin composites ranges from 36 % to 52 %. There are some differences (around 10 %) between the filler content (wt. %) measured by the ashing-in-air method and the data given by the manufacturers. The highest flexural modulus is 14.8 GPa and the lowest 6.6 GPa. New formulations may introduce unknown relationships between the fundamental properties of dental resin composites.
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Affiliation(s)
- Agata Szczesio-Wlodarczyk
- University Laboratory of Materials Research, Medical University of Lodz, Pomorska 251, 92-213, Lodz, Poland.
| | - Sufyan Garoushi
- Department of Biomaterials Science and Turku Clinical Biomaterials Center-TCBC, Institute of Dentistry, University of Turku, Itäinen Pitkäkatu 4b, 20520, Turku, Finland
| | - Pekka Vallittu
- Department of Biomaterials Science and Turku Clinical Biomaterials Center-TCBC, Institute of Dentistry, University of Turku, Itäinen Pitkäkatu 4b, 20520, Turku, Finland; Wellbeing Services County of South-West Finland, Turku, Finland
| | - Kinga Bociong
- Department of General Dentistry, Medical University of Lodz, ul. Pomorska 251, 92-213, Lodz, Poland
| | - Lippo Lassila
- Department of Biomaterials Science and Turku Clinical Biomaterials Center-TCBC, Institute of Dentistry, University of Turku, Itäinen Pitkäkatu 4b, 20520, Turku, Finland
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SILVA JDS, FREITAS LASD, SILVA VASE, FIRMIANO TC, TANTBIROJN D, VERSLUIS A, VERÍSSIMO C. Using a professional DSLR camera to measure total shrinkage of resin composites. Braz Oral Res 2022; 36:e009. [DOI: 10.1590/1807-3107bor-2022.vol36.0009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 09/09/2021] [Indexed: 11/22/2022] Open
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Osiewicz MA, Werner A, Roeters FJM, Kleverlaan CJ. Wear of bulk-fill resin composites. Dent Mater 2021; 38:549-553. [PMID: 34972580 DOI: 10.1016/j.dental.2021.12.138] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 12/20/2021] [Indexed: 11/18/2022]
Abstract
OBJECTIVE Bulk-fill resin composites are a special group of restorative materials designed to reduce chair time needed to insert a direct composite restoration. However, other factors determine the clinical success of a restorative material. Clinically the major reasons for failure of direct restorations are secondary caries and fracture of the restoration or the tooth itself. In the long-term composite resin restorations in posterior teeth may be prone to wear. As bulk-fill materials have their own composition that will determine their mechanical properties, the wear resistance may be affected as well. The aim of this in vitro study was to evaluate the wear of bulk-fill composites in comparison with a conventional hybrid composite. The null hypothesis was that there are no differences between the four bulk-fill materials and one traditional highly filled nanohybrid composite for posterior use when subjected to a two-body wear rate test and hardness measurement. METHODS Four bulk-fill composites SDR Smart Dentin Replacement (SDR), X-tra base (XBA), FiltekBulk Fill (FUP), Dual-Curing Bulk Composite (FBFL) and conventional nanohybrid resin composite Grandio (GDO) subjected to a two-body wear test against a stainless steel (SS) antagonist wheel. Scanning Electron Microscopy analysis was performed to detect the surface alterations. Microhardness of all samples was tested (n = 5) with a Vickers diamond indenter (5 indentations in each specimen). One-way ANOVA and Tukey's post hoc test (P < 0.01) were used to analyze differences in wear values. The hardness data were submitted to one-way ANOVA test, followed by the Tukey post hoc test (α = 0.05). T-test was applied to compare wear rate in time interval between one day and one month. RESULTS The highest wear rate values were recorded for SDR and the lowest wear rate values were for GDO. Hardness was the highest for GDO and the lowest for FBFL. SIGNIFICANCE The bulk-fill composites have a higher wear rate and lower hardness than the conventional nanohybrid composite, making them less suitable for stress-bearing restorations.
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Affiliation(s)
- Magdalena A Osiewicz
- Department of Integrated Dentistry, Jagiellonian University, Krakow, Poland; Department of Dental Materials Science, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
| | - Arie Werner
- Department of Dental Materials Science, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Franciscus J M Roeters
- Department of Comprehensive Dentistry, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Cornelis J Kleverlaan
- Department of Dental Materials Science, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
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Peng X, Zhang J, Stachurski ZH, Banaszak Holl MM, Xiao P. Visible-Light-Sensitive Triazine-Coated Silica Nanoparticles: A Dual Role Approach to Polymer Nanocomposite Materials with Enhanced Properties. ACS APPLIED MATERIALS & INTERFACES 2021; 13:46033-46042. [PMID: 34530612 DOI: 10.1021/acsami.1c15420] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Nanocomposite materials are of great interest because of their superior properties. Besides the traditional synthesis methods that require high temperatures or toxic solvents, photopolymerization technology provides a simple, low-cost, and environmentally friendly route in preparing nanocomposites. In this research, the preparation of blue-light-sensitive triazine derivative-coated silica nanoparticles is presented. The resulting triazine-coated silica nanoparticles can play a dual role, i.e., acting as both photoinitiators to trigger photopolymerization reactions under the irradiation of LED@410 nm and fillers to endow the produced photopolymer nanocomposite materials with enhanced properties. Specifically, the triazine-coated silica nanoparticles can successfully induce free radical polymerization of trimethylolpropane triacrylate efficiently under the irradiation of LED@410 nm and demonstrate comparable photoinitiation ability to the triazine derivative-based photoinitiator. The effects of different loading amounts of triazine-coated silica nanoparticles toward the photopolymerization kinetics are also evaluated. By coating with the triazine derivative, the nanoparticles show good dispersion in the polymer matrix and significantly reduce the shrinkage of the samples during the photopolymerization. Moreover, the photocured nanocomposites exhibit enhanced migration stability and mechanical properties when an optimal amount of triazine-coated silica nanoparticles is added in the formulation.
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Affiliation(s)
- Xiaotong Peng
- Research School of Chemistry, Australian National University, Canberra, ACT 2601, Australia
| | - Jing Zhang
- Department of Chemical Engineering, Monash University, Clayton, Victoria 3800, Australia
| | - Zbigniew H Stachurski
- Research School of Engineering, Australian National University, Canberra, ACT 2601, Australia
| | - Mark M Banaszak Holl
- Department of Chemical Engineering, Monash University, Clayton, Victoria 3800, Australia
| | - Pu Xiao
- Research School of Chemistry, Australian National University, Canberra, ACT 2601, Australia
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Taylor R, Fuentealba R, Brackett WW, Roberts HW. 24 hour polymerization shrinkage of resin composite core materials. J ESTHET RESTOR DENT 2021; 33:775-785. [PMID: 34060198 DOI: 10.1111/jerd.12788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 04/20/2021] [Accepted: 05/06/2021] [Indexed: 12/01/2022]
Abstract
PURPOSE The study's purpose was to evaluate the 24-hour polymerization shrinkage of resin composite core materials. MATERIAL AND METHODS Eleven resin composite core material samples (n = 12) were evaluated using a non-contact imaging device with measurements obtained over 24 h. Shrinkage values were determined corresponding to proposed times involved with CAD/CAM same-day treatment and at 24 h. Shrinkage data was statistically compared using Friedman/Dunn's test for intragroup analysis and Kruskal Wallis/Dunn's test for intergroup analysis, all at a 95% level of confidence (α = 0.05). RESULTS Mean results identified a wide volumetric shrinkage range with considerable similarity overlap. Inconsistent shrinkage behavior was evident and all materials reached maximum values before 24 h. No significant difference was observed during proposed digital same day all ceramic crown procedures, but some differences were noted at 24 h. CONCLUSIONS Under this study's conditions results were material specific, at times inconsistent, with wide variation. Shrinkage consistently increased for all products and it is not known if the continued shrinkage magnitude may compromise the stability and fit of all-ceramic crowns at 24 h.
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Affiliation(s)
- Robert Taylor
- Division of Comprehensive Care, University of Kentucky College of Dentistry, Lexington, Kentucky, USA
| | - Rodrigo Fuentealba
- Division of Prosthodontics, University of Kentucky College of Dentistry, Lexington, Kentucky, USA
| | - William W Brackett
- Operative Dentistry and Fixed Prosthodontics, Department of Restorative Sciences, Dental College of Georgia, Augusta, Georgia, USA
| | - Howard W Roberts
- Director of Graduate Studies, University of Kentucky College of Dentistry, Lexington, Kentucky, USA.,Comprehensive Dentistry, Uniformed Services University of the Health Sciences Postgraduate Dental School, Bethesda, Maryland, USA
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Zhang J, Gao P, Wei Q, Yan M, Zhao Q, Xu T, Zhu S. Influence of water aging on surface hardness of low-shrinkage light-cured composite resins. J Oral Sci 2019; 61:89-94. [PMID: 30814389 DOI: 10.2334/josnusd.17-0492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
This study evaluated the microhardness of four types of low-shrinkage composite resins and two types of universal composite resins with either 12 or 16 J/cm2 light power energy. Three disks were made for each group (n = 3) for a total of 36 specimens. The specimens were prepared by condensing the composite resin into a circular copper mold (diameter: 6 mm; height: 2 mm) and polymerizing with 700 mW/cm2 light power density. The microhardness values of the resin specimens were measured using a Vickers hardness tester after different storage durations. Z250 and Clearfil Majesty Posterior composites showed softer subsurfaces when comparing the 24 h samples for all six types. Conversely, Kalore GC and Admira (AD) composites showed harder subsurfaces during the 24 h samples. All the composite resins showed significant differences (P < 0.05) in microhardness values at one of the aging times when they were polymerized with either 12 or 16 J/cm2 light power energy. Composite resin AD had a higher microhardness value after polymerization with 12 J/cm2 than with 16 J/cm2. The results indicated that low-shrinkage composite resins have better subsurface characteristics, and the light power energy of 16 J/cm2 is better for the polymerization of most composites.
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Affiliation(s)
- Jiahui Zhang
- School and Hospital of Stomatology, Jilin University
| | - Ping Gao
- School and Hospital of Stomatology, Jilin University
| | - Qianqian Wei
- School and Hospital of Stomatology, Jilin University
| | - Min Yan
- School and Hospital of Stomatology, Jilin University
| | - Qi Zhao
- School and Hospital of Stomatology, Jilin University
| | - Tong Xu
- School and Hospital of Stomatology, Jilin University
| | - Song Zhu
- School and Hospital of Stomatology, Jilin University
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Polymerisation Shrinkage Profiling of Dental Composites using Optical Fibre Sensing and their Correlation with Degree of Conversion and Curing Rate. Sci Rep 2019; 9:3162. [PMID: 30816275 PMCID: PMC6395615 DOI: 10.1038/s41598-019-40162-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Accepted: 02/08/2019] [Indexed: 11/25/2022] Open
Abstract
Traditional polymerisation shrinkage (PS) measurement systems measure average PS of dental composites, but the true local PS varies along the length and breadth of the composite. The PS depends on the curing light intensity distribution, resultant degree of conversion (DOC) and the curing rate. In this paper, optical fibre Bragg grating (FBG) sensing based technology is used to measure the linear post-gel PS at multiple locations within dental composite specimens, and is correlated with DOC and curing rate. A commercial dental composite is used, and its post-gel PS and DOC are mapped using embedded fibre Bragg grating sensors at different curing conditions. The distance between the curing lamp and the composite specimen is varied which resulted in different intensity distribution across the specimen. The effect of curing light intensity distribution on PS, curing rate and DOC are investigated for demonstrating a relationship among them. It is demonstrated that FBG sensing method is an effective method to accurately profiling post-gel PS across the specimen.
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Fallahzadeh F, Atai M, Ghasemi S, Mahdkhah A. Effect of rinsing time and surface contamination on the bond strength of silorane-based and dimethacrylate-based composites to enamel. J Clin Exp Dent 2019; 10:e1115-e1122. [PMID: 30607230 PMCID: PMC6311400 DOI: 10.4317/jced.55148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 09/02/2018] [Indexed: 11/16/2022] Open
Abstract
Background The aim of this study was to assess whether saliva contamination and rinsing time for 15, 30, and 60 seconds, affects the shear bond strength of silorane and methacrylate-based composites to enamel. Material and Methods Two light cure resin, P60 (3M ESPE) and Filtek LS Silorane were tested. 120 sound premolars were randomly divided into four groups of 30 teeth based on composite type with or without saliva contamination after etching and rinsing. Each group was further divided into three subgroups according to their rinsing time. Then a cylinder of the composite was bonded to the enamel and Shear bond strength was assessed. To determine the failure mode, the bonded surfaces were then observed under SEM. In addition, the DC of each group was measured at pH levels of 4 and 7 using FTIR spectroscopy. The data were analyzed with one-way ANOVA and post hoc analysis followed by Fisher’s least significant difference. Results The bond strength of the non-contaminated methacrylate group was significantly higher than the other groups (p< 0.0001). In addition, there was no significant deference between the methacrylate subgroups. In the silorane groups, the shear bond strength was higher in the rinsing time of 15 seconds. Failure pattern was mainly adhesive. The DC of the Methacrylates had no significant difference at pH 4 and pH 7, but was significantly higher than that of siloranes (p< 0.0001). While the DC of the siloranes at pH 4 was significantly higher than at pH 7 (p< 0.0001). Conclusions Saliva contamination in both composites reduces bond strength. Increasing rinsing time in Methacrylates proves ineffective. In non-contaminated siloranes, excessive rinsing time reduced bond strength. The best-recommended rinsing time for both composite is 15 seconds. Key words:Composite resins, silorane composite resin, methacrylates, shear strength.
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Affiliation(s)
- Farnoosh Fallahzadeh
- Assistant Professor of Operative Dentistry, Faculty of dentistry, Qazvin University of medical science, Qazvin, Iran
| | - Mohammad Atai
- Professor of Polymer Science, Iran Polymer and Petrochemical Institute (IPPI), Tehran, Iran
| | | | - Ailin Mahdkhah
- Post-graduate Student of Operative Dentistry, Faculty of Dentistry, Qazvin University of Medical Science, Qazvin, Iran
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Spajić J, Prskalo K, Šariri K, Par M, Pandurić V, Demoli N. Dimensional Changes of Glass Ionomers and a Giomer during the Setting Time. Acta Stomatol Croat 2018; 52:298-306. [PMID: 30666060 PMCID: PMC6336448 DOI: 10.15644/asc52/4/3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Objectives The aim of this study was to evaluate dimensional changes of conventional glass ionomer cements, resin-modified glass-ionomer cement, and a giomer during the setting time using digital laser interferometry. Additionally, the influence of different curing modes ("high", "soft", and "low") of a light-emitting diode (LED) curing unit on dimensional changes was evaluated. Materials and methods Linear curing shrinkage of conventional glass ionomer cements (CGICs): Fuji IX Extra (F9E), Fuji IX Fast (F9F), Ketac Molar Aplicap (KM), Ketac Molar Quick Aplicap (KMQ), resin-modified glass ionomer cement (RM GIC): Fuji II LC (F2LC) and giomer: Beautifil II (B2) was analyzed. All tested materials were of shade A3, while all of the GIC were encapsulated. Discoid specimens (n=10, d=10 mm, h=0.85 mm) were prepared for each tested material and each curing mode (for light-curable materials) according to the manufacturer's instructions. Light-curable specimens were cured with LED curing unit (Bluephase G2, Ivoclar-Vivadent, and Schaan, Liechtenstein). Dimensional changes during curing were recorded in real-time. The results were analyzed by ANOVA, and Tukey post hoc test was used for multiple comparisons (α˂ 1%). Results All tested materials showed an initial setting expansion and a subsequent setting shrinkage. KM and KMQ had significantly lower setting shrinkage than RM GIC polymerized using any of the three curing modes. B2 showed lower shrinkage compared to F2LC. Conclusions The extent of curing shrinkage in RM GIC measured in this study can affect longevity of restorations.
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Affiliation(s)
| | - Katica Prskalo
- Department of endodontics and restorative dental medicine School of Dental Medicine University of Zagreb, Gundulićeva 5, Zagreb
| | | | - Matej Par
- Department of endodontics and restorative dental medicine School of Dental Medicine University of Zagreb, Gundulićeva 5, Zagreb
| | - Vlatko Pandurić
- Department of endodontics and restorative dental medicine School of Dental Medicine University of Zagreb, Gundulićeva 5, Zagreb
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Ólafsson VG, Ritter AV, Swift EJ, Boushell LW, Ko CC, Jackson GR, Ahmed SN, Donovan TE. Effect of composite type and placement technique on cuspal strain. J ESTHET RESTOR DENT 2018; 30:30-38. [PMID: 29034597 PMCID: PMC5815887 DOI: 10.1111/jerd.12339] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To compare the cuspal strain in Class II restorations made with bulk-fill and conventional composite resins. MATERIALS AND METHODS Fifty extracted maxillary premolars were mounted into phenolic rings and divided into five groups (n = 10). Specimens received standardized MOD preparations. A two-step self-etch adhesive was applied and the preparations were restored using a custom matrix as follows: Filtek Supreme Ultra in eight 2-mm increments (FSUI); Filtek Supreme Ultra in bulk (FSUB); SonicFill in bulk (SF); SureFil SDR flow in bulk, covered with a 2-mm occlusal layer of Filtek Supreme Ultra (SDR/FSU); Tetric EvoCeram Bulk Fill in bulk (TEBF). Strain gages bonded to the buccal and lingual cusps recorded cuspal strain during restorations. End strain values were determined and data were subjected to Kruskal-Wallis testing, followed by one-way ANOVA and Tukey´s post hoc test. RESULTS Combined strain values and standard deviations (in µɛ) were: FSUI: 723 ± 102.8, FSUB: 929.2 ± 571.9, SF: 519.1 ± 80.2, SDR-FSU: 497.4 ± 67.6 and TEBF: 604.5 ± 127.1. A significant difference was found between group FSUI and groups SF, SDR-FSU, and TEBF. Group FSUB showed significantly higher mean strain and greater standard deviation than all other groups due to cuspal fractures, and was thus excluded from the statistical analysis. CONCLUSIONS The tested bulk-fill composite resins exerted less strain onto tooth structure than the incrementally placed conventional composite resin, although the magnitude of generated strain was product-dependent. Bulk-filling with conventional composite resins is contraindicated. CLINICAL SIGNIFICANCE Bulk-fill composite resins exerted less strain onto adjacent tooth structure than a traditional composite, even when that composite is was placed incrementally. Bulk-filling with traditional composite resins is unpredictable and contraindicated.
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Affiliation(s)
- Vilhelm G. Ólafsson
- Department of Operative Dentistry and Cariology, Faculty of Odontology, University of Iceland, Vatnsmyrarvegur 16, 101, Reykjavik, Iceland
- Department of Operative Dentistry, School of Dentistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-7450
| | - André V. Ritter
- Department of Operative Dentistry, School of Dentistry, University of North Carolina at Chapel Hill, 440 Brauer Hall, CB #7450, Chapel Hill, North Carolina 27599-7450
| | - Edward J. Swift
- School of Dentistry, University of North Carolina at Chapel Hill, 1611 Koury Oral Health Sciences Building, CB #7450, Chapel Hill, North Carolina 27599-7450
| | - Lee W. Boushell
- Department of Operative Dentistry, School of Dentistry, University of North Carolina at Chapel Hill, 448 Brauer Hall, CB #7450, Chapel Hill, North Carolina 27599-7450
| | - Ching-Chang Ko
- Department of Orthodontics, School of Dentistry, University of North Carolina at Chapel Hill, 275 Brauer Hall, CB #7454, Chapel Hill, North Carolina 27599-7454
| | - Gabrielle R. Jackson
- Department of Prosthodontics, School of Dentistry, University of North Carolina at Chapel Hill, 330 Brauer Hall, CB #7450, Chapel Hill, North Carolina, 27599-7450
| | - Sumitha N. Ahmed
- Department of Operative Dentistry, School of Dentistry, University of North Carolina at Chapel Hill, 441 Brauer Hall, CB #7450, Chapel Hill, North Carolina 27599-7450
| | - Terence E. Donovan
- Department of Operative Dentistry, School of Dentistry, University of North Carolina at Chapel Hill, 437 Brauer Hall, CB #7450, Chapel Hill, North Carolina 27599-7450
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Soares CJ, Faria-E-Silva AL, Rodrigues MDP, Vilela ABF, Pfeifer CS, Tantbirojn D, Versluis A. Polymerization shrinkage stress of composite resins and resin cements - What do we need to know? Braz Oral Res 2017; 31:e62. [PMID: 28902242 DOI: 10.1590/1807-3107bor-2017.vol31.0062] [Citation(s) in RCA: 102] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2017] [Accepted: 05/22/2017] [Indexed: 11/22/2022] Open
Abstract
Polymerization shrinkage stress of resin-based materials have been related to several unwanted clinical consequences, such as enamel crack propagation, cusp deflection, marginal and internal gaps, and decreased bond strength. Despite the absence of strong evidence relating polymerization shrinkage to secondary caries or fracture of posterior teeth, shrinkage stress has been associated with post-operative sensitivity and marginal stain. The latter is often erroneously used as a criterion for replacement of composite restorations. Therefore, an indirect correlation can emerge between shrinkage stress and the longevity of composite restorations or resin-bonded ceramic restorations. The relationship between shrinkage and stress can be best studied in laboratory experiments and a combination of various methodologies. The objective of this review article is to discuss the concept and consequences of polymerization shrinkage and shrinkage stress of composite resins and resin cements. Literature relating to polymerization shrinkage and shrinkage stress generation, research methodologies, and contributing factors are selected and reviewed. Clinical techniques that could reduce shrinkage stress and new developments on low-shrink dental materials are also discussed.
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Affiliation(s)
- Carlos José Soares
- Universidade Federal de Uberlândia - UFU, Dental School, Department of Operative Dentistry and Dental Materials, Uberlândia, Minas Gerais, Brazil
| | - André Luis Faria-E-Silva
- Universidade Federal de Sergipe - UFS, Dental School, Department of Dentistry, Aracaju, Sergipe, Brazil
| | - Monise de Paula Rodrigues
- Universidade Federal de Uberlândia - UFU, Dental School, Department of Operative Dentistry and Dental Materials, Uberlândia, Minas Gerais, Brazil
| | - Andomar Bruno Fernandes Vilela
- Universidade Federal de Uberlândia - UFU, Dental School, Department of Operative Dentistry and Dental Materials, Uberlândia, Minas Gerais, Brazil
| | - Carmem Silvia Pfeifer
- Oregon Health and Science University - OHSU, School of Dentistry, Department of Restorative Dentistry, Portland, OR, United States of America
| | - Daranee Tantbirojn
- University of Tennessee Health Science Center, College of Dentistry, Department of Restorative Dentistry, Memphis, TN, United States of America
| | - Antheunis Versluis
- University of Tennessee Health Science Center, College of Dentistry, Department of Bioscience Research, TN, United States of America
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12
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Polymerization shrinkage assessment of dental resin composites: a literature review. Odontology 2016; 104:257-70. [DOI: 10.1007/s10266-016-0264-3] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Accepted: 07/15/2016] [Indexed: 10/21/2022]
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Son SA, Park JK, Seo DG, Ko CC, Kwon YH. How light attenuation and filler content affect the microhardness and polymerization shrinkage and translucency of bulk-fill composites? Clin Oral Investig 2016; 21:559-565. [PMID: 27475636 DOI: 10.1007/s00784-016-1920-2] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Accepted: 07/20/2016] [Indexed: 11/30/2022]
Abstract
OBJECTIVES The purpose of this study was to investigate the microhardness, polymerization shrinkage, and translucency of bulk-fill composites (BFCs) which have different light attenuation properties and filler contents. MATERIALS AND METHODS Five BFCs [Filtek Bulk Fill (FB), SureFil SDR (SS), Venus Bulk Fill (VB), SonicFill (SF), and Tetric N-Ceram Bulk Fill (TB)] and two resin-based composites (RBCs) [Tetric N-Ceram (TN) and Filtek Z350XT Flowable (ZF)] were chosen. Numbers of transmitted photons, refractive index, microhardness at different thicknesses, polymerization shrinkage, and translucency parameter (TP) were evaluated. RESULTS Attenuation coefficients (ACs) based on measured photons ranged from -0.88 to -1.90. BFCs, except SF, had lower AC values than TN or ZF, and BFCs, except TN, had smaller refractive index decreases between top and bottom surfaces. Regardless of an exponential decrease in photon counts, microhardness decreased linearly as specimen thickens. Moreover, microhardness of BFCs showed smaller top-to-bottom decreases (11.5-48.8 %) than TN or ZF (57.3 and 71.5 %, respectively). BFCs with low filler contents showed lower microhardness and higher polymerization shrinkage than those of high filler contents. Also, BFCs had significantly higher (p < 0.001) TP values than TN or ZF. CONCLUSION BFCs attenuated light less than RBCs. However, some BFCs had much lower top surface microhardness and higher polymerization shrinkage than tested RBCs. CLINICAL RELEVANCE Despite the convenience of bulk filling, careful selection of BFC is advised because some BFCs have worse microhardness and polymerization shrinkage than RBCs due to their lower filler contents.
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Affiliation(s)
- Sung-Ae Son
- Department of Conservative Dentistry, School of Dentistry, Pusan National University, Yangsan, 50612, South Korea
| | - Jeong-Kil Park
- Department of Conservative Dentistry, School of Dentistry, Pusan National University, Yangsan, 50612, South Korea
| | - Deog-Gyu Seo
- Department of Conservative Dentistry, School of Dentistry, Seoul National University, Seoul, 02707, South Korea
| | - Ching-Chang Ko
- Department of Orthodontics, School of Dentistry, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Yong Hoon Kwon
- Department of Dental Materials, School of Dentistry, Dental Research Institute, Pusan National University Dental Hospital, Pusan National University, Yangsan, 50612, South Korea.
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Tantbirojn D, Pfeifer CS, Amini AN, Versluis A. Simple optical method for measuring free shrinkage. Dent Mater 2015; 31:1271-8. [DOI: 10.1016/j.dental.2015.08.150] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Revised: 04/10/2015] [Accepted: 08/14/2015] [Indexed: 11/30/2022]
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15
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Ro JH, Son SA, Park JK, Jeon GR, Ko CC, Kwon YH. Effect of two lasers on the polymerization of composite resins: single vs combination. Lasers Med Sci 2015; 30:1497-503. [PMID: 25895056 DOI: 10.1007/s10103-015-1753-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Accepted: 04/02/2015] [Indexed: 01/14/2023]
Abstract
The selection of a light-curing unit for the curing composite resins is important to achieve best outcomes. The purpose of the present study was to test lasers of 457 and 473 nm alone or in combination under different light conditions with respect to the cure of composite resins. Four different composite resins were light cured using five different laser combinations (530 mW/cm(2) 457 nm only, 530 mW/cm(2) 473 nm only, 177 mW/cm(2) 457 + 177 mW/cm(2) 473 nm, 265 mW/cm(2) 457 + 265 mW/cm(2) 473 nm, and 354 mW/cm(2) 457 + 354 mW/cm(2) 473 nm). Microhardness and polymerization shrinkage were evaluated. A light-emitting diode (LED) unit was used for comparison purposes. On top surfaces, after aging for 24 h, microhardness achieved using the LED unit and the lasers with different conditions ranged 42.4-65.5 and 38.9-67.7 Hv, respectively, and on bottom surfaces, corresponding ranges were 25.2-56.1 and 18.5-55.7 Hv, respectively. Of the conditions used, 354 mW/cm(2) 457 nm + 354 mW/cm(2) 473 nm produced the highest bottom microhardness (33.8-55.6 Hv). On top and bottom surfaces, microhardness by the lowest total light intensity, 354 (177 × 2) mW/cm(2), ranged 39.0-60.5 and 18.5-52.8 Hv, respectively. Generally, 530 mW/cm(2) at 457 nm produced the lowest polymerization shrinkage. However, shrinkage values obtained using all five laser conditions were similar. The study shows the lasers of 457 and 473 nm are useful for curing composite resins alone or in combination at much lower light intensities than the LED unit.
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Affiliation(s)
- Jung-Hoon Ro
- Department of Biomedical Engineering, School of Medicine, Yangsan, 626-770, Korea
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16
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Kim TW, Lee JH, Jeong SH, Ko CC, Kim HI, Kwon YH. Mechanical properties and polymerization shrinkage of composite resins light-cured using two different lasers. Photomed Laser Surg 2015; 33:213-9. [PMID: 25763478 DOI: 10.1089/pho.2014.3849] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
OBJECTIVE The purpose of the present study was to investigate the usefulness of 457 and 473 nm lasers for the curing of composite resins during the restoration of damaged tooth cavity. BACKGROUND DATA Monochromaticity and coherence are attractive features of laser compared with most other light sources. Better polymerization of composite resins can be expected. MATERIALS AND METHODS Eight composite resins were light cured using these two lasers and a light-emitting diode (LED) light-curing unit (LCU). To evaluate the degrees of polymerization achieved, polymerization shrinkage and flexural and compressive properties were measured and compared. RESULTS Polymerization shrinkage values by 457 and 473 nm laser, and LED ranged from 10.9 to 26.8, from 13.2 to 26.1, and from 11.5 to 26.3 μm, respectively. The values by 457 nm laser was significantly different from those by 473 and LED LCU (p<0.05). However, there was no statistical difference between values by 473 and LED LCU. Before immersion in distilled water, flexural strength (FS) and compressive modulus (CM) of the specimens were inconsistently influenced by LCUs. On the other hand, flexural modulus (FM) and compressive strength (CS) were not significantly different for the three LCUs (p>0.05). For the tested LCUs, no specific LCU could consistently achieve highest strength and modulus from the specimens tested. CONCLUSIONS Two lasers (457 and 473 nm) can polymerize composite resins to the level that LED LCU can achieve despite inconsistent trends of polymerization shrinkage and flexural and compressive properties of the tested specimens.
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Affiliation(s)
- Tae-Wan Kim
- 1 Department of Dental Materials, School of Dentistry and Biomedical Research Institute, Pusan National University , Yangsan, Korea
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Schmidt C, Scherzer T. Monitoring of the shrinkage during the photopolymerization of acrylates using hyphenated photorheometry/near-infrared spectroscopy. ACTA ACUST UNITED AC 2015. [DOI: 10.1002/polb.23694] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Christian Schmidt
- Leibniz-Institut für Oberflächenmodifizierung (IOM); Chemische Abteilung, Permoserstr. 15 D-04318 Leipzig Germany
| | - Tom Scherzer
- Leibniz-Institut für Oberflächenmodifizierung (IOM); Chemische Abteilung, Permoserstr. 15 D-04318 Leipzig Germany
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Son SA, Park JK, Jung KH, Ko CC, Jeong CM, Kwon YH. Effect of 457 nm diode-pumped solid state laser on the polymerization composite resins: microhardness, cross-link density, and polymerization shrinkage. Photomed Laser Surg 2014; 33:3-8. [PMID: 25549163 DOI: 10.1089/pho.2014.3786] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
OBJECTIVE The purpose of the present study was to test the usefulness of 457 nm diode-pumped solid state (DPSS) laser as a light source to cure composite resins. MATERIALS AND METHODS Five different composite resins were light cured using three different light-curing units (LCUs): a DPSS 457 nm laser (LAS), a light-emitting diode (LED), and quartz-tungsten-halogen (QTH) units. The light intensity of LAS was 560 mW/cm(2), whereas LED and QTH LCUs was ∼900 mW/cm(2). The degree of polymerization was tested by evaluating microhardness, cross-link density, and polymerization shrinkage. RESULTS Before water immersion, the microhardness of laser-treated specimens ranged from 40.8 to 84.7 HV and from 31.7 to 79.0 HV on the top and bottom surfaces, respectively, and these values were 3.3-23.2% and 2.9-31.1% lower than the highest microhardness obtained using LED or QTH LCUs. Also, laser-treated specimens had lower top and bottom microhardnesses than the other LCUs treated specimens by 2.4-19.4% and 1.4-27.8%, respectively. After ethanol immersion for 24 h, the microhardness of laser-treated specimens ranged from 20.3 to 63.2 HV on top and bottom surfaces, but from 24.9 to 71.5 HV when specimens were cured using the other LCUs. Polymerization shrinkage was 9.8-14.7 μm for laser-treated specimens, and these were significantly similar or lower (10.2-16.0 μm) than those obtained using the other LCUs. CONCLUSIONS The results may suggest that the 457 nm DPSS laser can be used as a light source for light-curing dental resin composites.
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Affiliation(s)
- Sung-Ae Son
- 1 Department of Conservative Dentistry, School of Dentistry, Pusan National University , Yangsan, Korea
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Chandurkar AM, Metgud SS, Yakub SS, Kalburge VJ, Biradar BC. Comparative Evaluation of the Effects of Light Intensities and Curing Cycles of QTH, and LED Lights on Microleakage of Class V Composite Restorations. J Clin Diagn Res 2014; 8:221-4. [PMID: 24783142 DOI: 10.7860/jcdr/2014/7463.4167] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2013] [Accepted: 02/17/2014] [Indexed: 11/24/2022]
Abstract
BACKGROUND The purpose of this study was to evaluate the effects of light intensity and curing cycles of QTH and LED lights on the microleakage of Class V composite restorations. MATERIALS AND METHODS Eighty freshly extracted human maxillary premolars were used for this study. Standardized Class V cavities were prepared and they were restored with microhybrid resin composite. According to the curing protocol, the teeth were then divided into 4 groups (n=20): QTH curing (standard and soft start modes), and LED (standard and soft start modes) irradiations. Microleakage was evaluated by immersion of the samples in 50% silver nitrate solution. The samples were then sectioned, evaluated under a stereomicroscope, and scored for microleakage. RESULTS The results of the present in-vitro study showed mean dye leakage scores of 1.9, 1.2, 1.45 and 0.90 for Group I (QTH-Standard mode), Group II (QTH-Soft Start mode), Group III (LED-Standard mode) and Group IV (LED-Soft Start mode) respectively. CONCLUSION It was thus concluded that the soft start polymerization showed a highly significant difference as compared to the standard curing modes of QTH and LED lights, respectively.
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Affiliation(s)
- Anshu M Chandurkar
- Assistant Professor, Department of Conservative Dentistry and Endodontics, Rural Dental College , Pravara Medical Trust, India
| | - Sandeep S Metgud
- Professor, Department of Conservative Dentistry and Endodontics, Pacific Dental College , Udaipur, Rajasthan, India
| | - Shaikh Shoeb Yakub
- Professor, Department of Conservative Dentistry and Endodontics, Rural Dental College , Pravara Medical Trust, India
| | - Vaishali J Kalburge
- Assistant Professor, Department of Conservative Dentistry and Endodontics, Siddhpur Dental College and Research Centre , Siddhpur, India
| | - Basawaraj C Biradar
- Reader, Department of Conservative Dentistry and Endodontics, Rural Dental College , Pravara Medical Trust, India
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PARK JK, LEE GH, KIM JH, PARK MG, KO CC, KIM HI, KWON YH. Polymerization shrinkage, flexural and compression properties of low-shrinkage dental resin composites. Dent Mater J 2014; 33:104-10. [DOI: 10.4012/dmj.2013-126] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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21
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Spatio-temporal analysis of shrinkage vectors during photo-polymerization of composite. Dent Mater 2013; 29:1236-43. [DOI: 10.1016/j.dental.2013.09.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Revised: 07/31/2013] [Accepted: 09/17/2013] [Indexed: 11/19/2022]
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22
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Chang M, Dennison J, Yaman P. Physical Property Evaluation of Four Composite Materials. Oper Dent 2013; 38:E144-53. [DOI: 10.2341/12-203-l] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
SUMMARY
Purpose
The purpose of this study was to evaluate the physical properties of current formulations of composite resins for polymerization shrinkage, surface hardness, and flexural strength. In addition, a comparison of Knoop and Vickers hardness tests was made to determine if there was a correlation in the precision between the two tests.
Materials and Methods
Four composite resin materials were used: Filtek LS (3M-ESPE), Aelite LS (Bisco), Kalore (GC America), and Empress Direct (Ivoclar). Ten samples of each composite (shade Vita A2) were used. Polymerization shrinkage was measured with the Kaman linometer using 2-mm-thick samples, cured for 40 seconds and measured with digital calipers for sample thickness. Surface microhardness samples were prepared (2-mm thick × 12-mm diameter) and sequentially polished using 600-grit silicone carbide paper, 9 μm and 1 μm diamond polishing solutions. After 24 hours of dry storage, Knoop (200 g load, 15 seconds dwell time) and Vickers (500 g load, 15 seconds dwell time) hardness tests were conducted. Flexural strength test samples (25 × 2 × 2 mm) were stored in 100% relative humidity and analyzed using a three-point bending test with an Instron Universal Testing Machine (Instron 5565, Instron Corp) applied at a crosshead speed of 0.75 ± 0.25 mm/min. Maximum load at fracture was recorded. One-way analysis of variance and Tukey multiple comparison tests were used to determine significant differences in physical properties among materials.
Results
Filtek LS had significantly lower shrinkage (0.45 [0.39] vol%). Aelite LS demonstrated the greatest Knoop surface hardness (114.55 [8.67] KHN), followed by Filtek LS, Kalore, and Empress Direct (36.59 [1.75] KHN). Vickers surface hardness was significantly greater for Aelite LS (126.88 [6.58] VH), followed by Filtek LS, Kalore, and Empress Direct (44.14 [1.02] VH). Flexural strength (MPa) was significantly higher for Aelite LS and Filtek LS (135.75 [17.35]; 129.42 [9.48]) than for Kalore and Empress Direct (86.84 [9.04]; 92.96 [9.27]). There is a strong correlation between results obtained using Knoop and Vickers hardness tests (r=0.99), although Vickers values were significantly greater for each material.
Conclusion
Results suggest that Aelite LS possesses superior hardness and flexural strength, while Filtek LS has significantly less shrinkage compared with the other composites tested.
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Affiliation(s)
- M Chang
- Matthew Chang, DDS, MS, MA, FAGD, Lieutenant Commander, Dental Corps, US Navy
| | - J Dennison
- Joseph Dennison, DDS, MS, University of Michigan School of Dentistry, Cariology, Restorative Sciences and Endodontics, Ann Arbor, Michigan
| | - P Yaman
- Peter Yaman, DDS, MS, University of Michigan School of Dentistry, Cariology, Restorative Sciences and Endodontics, Ann Arbor, Michigan
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LEE SK, KIM TW, SON SA, PARK JK, KIM JH, KIM HI, KWON YH. Influence of light-curing units on the polymerization of low-shrinkage composite resins. Dent Mater J 2013; 32:688-94. [PMID: 24088822 DOI: 10.4012/dmj.2013-027] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Park MG, Ro JH, Park JK, Ko CC, Kwon YH. Effect of a DPSS laser on the shear bond strength of ceramic brackets with different base designs. Lasers Med Sci 2012; 28:1461-6. [PMID: 23135786 DOI: 10.1007/s10103-012-1227-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Accepted: 10/29/2012] [Indexed: 11/24/2022]
Abstract
This study evaluated the shear bond strength (SBS) and adhesive remnant index (ARI) of ceramic brackets with different base designs using a 473-nm diode-pumped solid-state (DPSS) laser to test its usefulness as a light source. A total of 180 caries-free human premolars were divided into four groups according to the base designs: microcrystalline, crystalline particle (CP), dovetail, and mesh. For each base design, teeth were divided into three different subgroups for light curing using three different light-curing units (LCUs) (quartz-tungsten-halogen unit, light-emitting diode unit, and a DPSS laser of 473 nm). Applied light intensities for the DPSS laser and the other LCUs were approximately 630 and 900 mW/cm(2), respectively. Stainless steel brackets with a mesh design served as controls. The failure modes of debonded brackets were scored using ARI. As a result, brackets bonded using the DPSS laser had the highest SBS values (16.5-27.3 MPa) among the LCUs regardless of base design. Regarding base designs, the CP groups showed the highest SBS values (22.9-27.3 MPa) regardless of LCU. Furthermore, stainless steel brackets with a mesh design had the lowest SBS values regardless of LCU. In many cases, brackets bonded using the DPSS laser had higher ARI scores and had more adhesive on their bases than on tooth surfaces. The study shows that the 473-nm DPSS laser has considerable potential for bonding ceramic brackets at lower light intensities than the other light-curing units examined.
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Affiliation(s)
- Mi-Gyoung Park
- Department of Dental Laboratory Science, College of Health Sciences, Catholic University of Pusan, Busan, 609-757, South Korea
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Bakhsh TA, Sadr A, Shimada Y, Mandurah MM, Hariri I, Alsayed EZ, Tagami J, Sumi Y. Concurrent evaluation of composite internal adaptation and bond strength in a class-I cavity. J Dent 2012; 41:60-70. [PMID: 23044389 DOI: 10.1016/j.jdent.2012.10.003] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2012] [Revised: 09/29/2012] [Accepted: 10/02/2012] [Indexed: 10/27/2022] Open
Abstract
OBJECTIVES This study investigated class-I cavity floor adaptation by swept-source optical coherence tomography (OCT) in combination with microtensile bond strength (MTBS) using different filling methods. METHODS Two adhesive systems; Tokuyama Bond Force and Tri-S Bond Plus were used in conjunction with a universal composite (Estelite Sigma Quick) placed either incrementally (oblique) or in bulk with or without a flowable composite lining (Palfique Estelite LV). Ten serial B-scan images were obtained throughout each cavity by OCT (center wavelength: 1319nm). In order to evaluate adaptation defined as the cavity floor percentage showing no gap, a significant increase in the signal intensity was considered as gap at the bonded interface of the cavity floor. The same specimens were then cut into beams to measure MTBS at the cavity floor. RESULTS Two-way ANOVA demonstrated that the interaction of adhesive systems and filling techniques was significantly affecting both adaptation and MTBS (p<0.05). There was a significant correlation between MTBS and adaptation at cavity floor (p<0.05). Cavity floor adaptation and MTBS were improved when incremental filling technique was applied, while the outcome of lining technique was variable. CONCLUSIONS Quantitative assessment by OCT can non-destructively provide information on the performance and effectiveness of dental composites and restoration techniques. There was a moderate correlation between floor adaptation and bond strength in class-I cavities. Incremental application of composite restoration showed the best performance in terms of bond strength and internal adaptation. CLINICAL SIGNIFICANCE Incremental application of composite restoration was the most advantageous placement technique in terms of bond strength and internal adaptation. The lack of placement pressure with flowable composites may affect their adaptation to all-in-one adhesives; therefore, the outcome of cavity lining by flowable composite was variable.
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Affiliation(s)
- Turki A Bakhsh
- Cariology and Operative Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia; Cariology and Operative Dentistry, Tokyo Medical and Dental University, Tokyo, Japan
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Singla M, Aggarwal V, Kumar N. Effect of chlorhexidine cavity disinfection on microleakage in cavities restored with composite using a self-etching single bottle adhesive. J Conserv Dent 2012; 14:374-7. [PMID: 22144806 PMCID: PMC3227284 DOI: 10.4103/0972-0707.87201] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2010] [Revised: 05/19/2011] [Accepted: 06/07/2011] [Indexed: 11/13/2022] Open
Abstract
Aims: This study evaluated the effect of 2% chlorhexidine cavity disinfectant on microleakage in class II cavities restored with light cured composites using a single bottle adhesive in an in vitro model. Materials and Methods: Proximal box cavities were prepared on mesial and distal surfaces of 40 non carious mandibular third molars, resulting in total of 80 cavities. Forty cavities on were rinsed with normal saline and 40 cavities were rinsed with 2% chlorhexidine cavity disinfectant. All cavities were restored with a single bottle adhesive and nano hybrid composite resin. Microleakage was evaluated at the gingival margin using methylene blue dye penetration method. Results and Conclusion: Chlorhexidine cavity disinfectants produced significantly higher microleakage while restoring the cavities using a self-etching single bottle adhesive.
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Affiliation(s)
- Mamta Singla
- Department of Conservative Dentistry and Endodontics, Institute of Dental Sciences and Technology, Modinagar, Currently working as Assistant Professor, Department of Conservative Dentistry and Endodontics, Faculty of Dentistry, Jamia Millia Islamia, New Delhi, India
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Lee IB, Min SH, Seo DG. A new method to measure the polymerization shrinkage kinetics of composites using a particle tracking method with computer vision. Dent Mater 2012; 28:212-8. [DOI: 10.1016/j.dental.2011.10.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2010] [Accepted: 10/04/2011] [Indexed: 10/15/2022]
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28
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Shrinkage Characteristics of Experimental Polymer Containing Composites under Controlled Light Curing Modes. Polymers (Basel) 2012. [DOI: 10.3390/polym4010256] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Tauböck TT, Bortolotto T, Buchalla W, Attin T, Krejci I. Influence of light-curing protocols on polymerization shrinkage and shrinkage force of a dual-cured core build-up resin composite. Eur J Oral Sci 2010; 118:423-9. [DOI: 10.1111/j.1600-0722.2010.00746.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Jung YH, Cho BH, Nah KS, Kim HI, Kwon YH. Effect of diode-pumped solid state laser on polymerization shrinkage and color change in composite resins. Lasers Med Sci 2010; 25:339-43. [PMID: 19205788 DOI: 10.1007/s10103-009-0644-9] [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] [Received: 05/23/2008] [Accepted: 01/10/2009] [Indexed: 11/25/2022]
Abstract
A diode-pumped solid state (DPSS) laser emitting at 473 nm was used to test its influence on the degree of polymerization of composite resins. Eight composite resins were chosen and light cured with three different light-curing systems [a quartz-tungsten-halogen (QTH) lamp-based unit, a light-emitting diode (LED) unit, and a DPSS laser]. Polymerization shrinkage and color change in specimens were measured. According to the statistical analysis, each light-curing system produced a significantly different value of maximum polymerization shrinkage. In most specimens, the DPSS laser induced the least polymerization shrinkage. After being immersed in distilled water for 10 days, specimens light-cured by the DPSS laser had undergone less color change than those cured by the other units. In conclusion, the DPSS laser induced better or similar polymerization in terms of polymerization shrinkage and color change in composite resins compared with those of the QTH lamp-based and LED units.
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Affiliation(s)
- Yun-Hoa Jung
- College of Dentistry and Medical Research Institute, Pusan National University, Busan, South Korea
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Lee IB, Min SH, Seo DG, Kim SY, Kwon Y. A new method to measure the linear polymerization shrinkage of composites using a particle tracking method with computer vision. ACTA ACUST UNITED AC 2010. [DOI: 10.5395/jkacd.2010.35.3.180] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- In-Bog Lee
- Department of Conservative Dentistry, School of Dentistry, Seoul National University, Seoul, Korea
| | - Sun-Hong Min
- Department of Conservative Dentistry, School of Dentistry, Seoul National University, Seoul, Korea
| | - Deog-Gyu Seo
- Department of Conservative Dentistry, School of Dentistry, Seoul National University, Seoul, Korea
| | - Sun-Young Kim
- Department of Conservative Dentistry, School of Dentistry, Seoul National University, Seoul, Korea
| | - Youngchul Kwon
- Department of Conservative Dentistry, School of Dentistry, Seoul National University, Seoul, Korea
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Aggarwal V, Logani A, Jain V, Shah N. Effect of cyclic loading on marginal adaptation and bond strength in direct vs. indirect class II MO composite restorations. Oper Dent 2008; 33:587-92. [PMID: 18833866 DOI: 10.2341/07-152] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
This study evaluated the effect of cyclic loading on the marginal adaptation and microtensile bond strength of direct vs indirect Class II composite restorations in an in-vitro model. Forty Class II cavities were prepared on the mesial surface of extracted human maxillary first premolars and divided into two groups: Group I--direct composite restorations and Group II--indirect composite restorations. Groups I and II were further divided into subgroups: A (without cyclic loading) and B (with cyclic loading of 150,000 cycles at 60N). The gingival margin of the proximal box was evaluated at 200x magnification for marginal adaptation in a low vacuum scanning electron microscope. The restorations were sectioned perpendicular to the bonded surface into 1 mm thickslabs. The slabswere further trimmed at the interface to produce a cross-sectional surface area of approximately 1 mm2. All specimens were subjected to microtensile bond strength testing. The marginal adaptation was analyzed using descriptive studies and bond strength data were analyzed by one-way ANOVA test. The indirect composite restorations performed better under cyclic loading.
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Affiliation(s)
- Vivek Aggarwal
- Department of Conservative Dentistry and Endodontics, Centre for Dental Education and Research, All India Institute of Medical Sciences, New Delhi, India
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Yamamoto A, Miyazaki M, Rikuta A, Kurokawa H, Takamizawa T. Comparison of two methods for measuring the polymerization characteristics of flowable resin composites. Dent Mater 2007; 23:792-8. [PMID: 16890986 DOI: 10.1016/j.dental.2006.06.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2005] [Revised: 06/20/2006] [Accepted: 06/22/2006] [Indexed: 10/24/2022]
Abstract
OBJECTIVES The purpose of this study was to compare two methods for assessing the polymerization characteristics of flowable resin composites. METHODS Two different flowable resin composites and a hybrid resin composite control were investigated. In order to measure the volumetric shrinkage (DeltaV), each material was placed into a mould and extruded into a water-filled dilatometer. The specimens were then light irradiated for 30s using a curing unit with the power density adjusted to either 100 or 600mW/cm(2). For the speckle contrast measurement, each resin composite was condensed into a glass tube and irradiated. The laser-speckle field was recorded in a digital frame. The calculated values were obtained for each pair of adjacent patterns and the changes in speckle contrast as a function of time were obtained. RESULTS The average DeltaV values of the resins after 180s ranged from approximately 3.3 to 4.4% for the flowable composites and from approximately 1.8 to 2.3% for the hybrid composite control. The overall magnitude of the speckle contrasts decreased soon after the initial light exposure commenced and gradually increased thereafter. The speckle contrast measurements revealed changes in the pastes due to the polymerization of the flowable resins that were greater than those obtained with the water-filled dilatometer. SIGNIFICANCE These data suggest that the polymerization characteristics of flowable resins can be measured successfully using two different methods. Moreover, our findings are of clinical relevance, as the data obtained under laboratory conditions might give an indication of the suitability of flowable resin composites for specific clinical applications.
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Affiliation(s)
- Akira Yamamoto
- Department of Operative Dentistry, Nihon University School of Dentistry, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan
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Idriss S, Abduljabbar T, Habib C, Omar R. Factors Associated with Microleakage in Class II Resin Composite Restorations. Oper Dent 2007; 32:60-6. [PMID: 17288330 DOI: 10.2341/06-16] [Citation(s) in RCA: 18] [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
Even though marginal gap size was not shown to be a direct predictor for the extent of microleakage in resin composite restorations, both material and placement technique appear to be important determinants in microleakage and, thus, probably in clinical outcomes.
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UYAMA S, IROKAWA A, IWASA M, TONEGAWA M, SHIBUYA Y, TSUBOTA K, TAKAMIZAWA T, MIYAZAKI M. Influence of Irradiation Time on Volumetric Shrinkage and Flexural Properties of Flowable Resins. Dent Mater J 2007; 26:892-7. [DOI: 10.4012/dmj.26.892] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Lee IB, Cho BH, Son HH, Um CM, Lim BS. The effect of consistency, specimen geometry and adhesion on the axial polymerization shrinkage measurement of light cured composites. Dent Mater 2006; 22:1071-9. [PMID: 16368132 DOI: 10.1016/j.dental.2005.08.012] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2004] [Revised: 06/23/2005] [Accepted: 08/10/2005] [Indexed: 11/22/2022]
Abstract
OBJECTIVES This study investigated the effect of the consistency, specimen geometry and adhesion on the measurements of axial polymerization shrinkage of light cured composite resins using an axial shrinkage-measuring device. METHODS Four commercially available composites were examined: an anterior posterior hybrid composite Z100, a posterior packable composite P60 and two flowable composites, Filtek flow and Tetric flow. The axial polymerization shrinkage of the composites was determined using a 'bonded disc method' and 'non-bonded' free shrinkage method at varying C-factors by altering the specimen geometry. These measured axial shrinkages were compared with the free volumetric shrinkages. The consistency of the composites was also compared using a squeeze test. RESULTS Using the non-bonded method, the axial shrinkage was approximately one third of the true volumetric shrinkage as a result of isotropic contraction. However, in the bonded disc method, the axial shrinkage increased up to the volumetric shrinkage by anisotropic contraction as the bonded surface increased. The axial shrinkage increased with the increasing C-factor. It approached the true volumetric shrinkage and reached a plateau at near a C-factor of 5-6. However, in flowable composites, a lower level of axial shrinkage was measured by the compensational radial flow. SIGNIFICANCE When estimating the volumetric shrinkage from the axial shrinkage measured using the bonded disc method, the C-factor of the specimen should be higher than 5 and the consistency of the composite is also an important factor that needs to be considered.
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Affiliation(s)
- In-Bog Lee
- Department of Conservative Dentistry and Dental Research Institute, College of Dentistry, Seoul National University, 28-2 Yeongeon-Dong, Jongro-Ku, Seoul 110-749, South Korea.
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Lee MR, Cho BH, Son HH, Um CM, Lee IB. Influence of cavity dimension and restoration methods on the cusp deflection of premolars in composite restoration. Dent Mater 2006; 23:288-95. [PMID: 16530819 DOI: 10.1016/j.dental.2006.01.025] [Citation(s) in RCA: 106] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2005] [Revised: 12/12/2005] [Accepted: 01/10/2006] [Indexed: 11/15/2022]
Abstract
OBJECTIVES The aim of this study was to measure the cusp deflection by polymerization shrinkage during composite restoration for mesio-occluso-distal (MOD) cavities in premolars, and to examine the influence of cavity dimension, C-factor and restoration method on the cusp deflection. METHODS Thirty extracted maxillary premolars of similar size were prepared with four different sizes of MOD cavity, and divided into six groups. The width and depth of the pulpal wall of the cavity were as follows: group 1: 1.5x1 mm, group 2: 1.5x2 mm, group 3: 3x1 mm, and groups 4-6: 3x2 mm. Groups 1-4 were restored using a bulk filling with a composite. Group 5 was restored incrementally, and group 6 was restored with an indirect composite inlay. Cusp deflections were measured using LVDT transducers. The cusp deflections were compared between groups using ANOVA and Scheffe tests, and a correlation analysis was done. RESULTS The cusp deflections of groups 1-4 were 12.1 (2.2), 17.2 (1.9), 16.2 (0.8) and 26.4 (4.2) microm, respectively. There was a strong positive correlation between the length cubed divided by the thickness cubed of the remaining cusp (L3/T3) and cusp deflection. The C-factor was related to the % flexure (100xcusp deflection/cavity width). The cusp deflections of groups 5 and 6 were 17.4 (2.0) and 17.9 (1.4) microm, respectively, which were much lower values than those of group 4. SIGNIFICANCE The cusp deflection increased with increasing cavity dimension and C-factor. Use of an incremental filling technique or an indirect composite inlay restoration could reduce the cuspal strain.
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Affiliation(s)
- Mi-Ra Lee
- Department of Conservative Dentistry and Dental Research Institute, College of Dentistry, Seoul National University, 28-2 Yeongeon-Dong, Jongro-Gu, Seoul 110-749, South Korea
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Tiba A, Charlton DG, Vandewalle KS, Ragain JC. Comparison of two video-imaging instruments for measuring volumetric shrinkage of dental resin composites. J Dent 2005; 33:757-63. [PMID: 16199284 DOI: 10.1016/j.jdent.2005.02.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2004] [Revised: 02/03/2005] [Accepted: 02/09/2005] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVES The purpose of this study was to measure the polymerization shrinkage of three dental resin composites using two commercially available video-imaging devices to determine if the devices produced equivalent results. METHODS Small, semi-spherical specimens of a microhybrid (Venus), microfill (Filtek A110), and flowable (Esthet*X Flow) resin composite were manually formed and light activated for 40s using a light-curing unit. The volumetric polymerization shrinkage of fifteen specimens of each brand of resin composite was measured using the AcuVol and the Drop Shape Analysis System model DSA10 Mk2 (DSAS) video-imaging devices. Mean volumetric shrinkage values were calculated for each resin composite and equivalence was evaluated using the two one-sided tests approach. Differences between the means that were less than approximately 5% of the observed shrinkage were considered indicative of clinical equivalence. RESULTS Mean volumetric shrinkage values measured for the resin composites were: Venus (AcuVol, 3.07+/-0.07%; DSAS, 2.90+/-0.07%); Filtek A110 (AcuVol, 2.26+/-0.10%; DSAS, 2.25+/-0.09%); and Esthet*X Flow (AcuVol, 5.01+/-0.17%; DSAS, 5.14+/-0.11%). Statistical analysis revealed that the two imaging devices produced equivalent results for Filtek A110 and Esthet*X Flow but not for Venus. CONCLUSIONS Video-imaging systems provide an easy method for measuring volumetric shrinkage of resin composites. As with other methods for measuring volumetric shrinkage, however, they are best used to comparatively measure different materials within the same laboratory.
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Affiliation(s)
- Amer Tiba
- Applied Clinical Sciences Department, Naval Institute for Dental and Biomedical Research, 310A B Street, Bldg 1H, Great Lakes, IL, USA
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Lee IB, Cho BH, Son HH, Um CM. A new method to measure the polymerization shrinkage kinetics of light cured composites. J Oral Rehabil 2005; 32:304-14. [PMID: 15790386 DOI: 10.1111/j.1365-2842.2004.01414.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
This study was undertaken to develop a new measurement method to determine the initial dynamic volumetric shrinkage of composite resins during polymerization, and to investigate the effect of curing light intensity on the polymerization shrinkage kinetics. The instrument was basically an electromagnetic balance that was constructed with a force transducer using a position sensitive photo detector (PSPD) and a negative feedback servo amplifier. The volumetric change of composites during polymerization was detected continuously as a buoyancy change in distilled water by means of the Archimedes' principle. Using this new instrument, the dynamic patterns of the polymerization shrinkage of seven commercial composite resins were measured. The polymerization shrinkage of the composites was 1.92 approximately 4.05 volume %. The shrinkage of a packable composite was the lowest, and that of a flowable composite was the highest. The maximum rate of polymerization shrinkage increased with increasing light intensity but the peak shrinkage rate time decreased with increasing light intensity. A strong positive relationship was observed between the square root of the light intensity and the maximum shrinkage rate. The shrinkage rate per unit time, dVol%/dt, showed that the instrument can be a valuable research method for investigating the polymerization reaction kinetics. This new shrinkage-measuring instrument has some advantages that it was insensitive to temperature changes and could measure the dynamic volumetric shrinkage in real time without complicated processes. Therefore, it can be used to characterize the shrinkage kinetics in a wide range of commercial and experimental visible-light-cure materials in relation to their composition and chemistry.
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Affiliation(s)
- I B Lee
- Department of Conservative Dentistry, College of Dentistry, Seoul National University, Seoul 110-749, Korea.
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Sato T, Miyazaki M, Rikuta A. Real-time dimensional change in light-cured composites at various depths using laser speckle contrast analysis. Eur J Oral Sci 2005; 112:538-44. [PMID: 15560838 DOI: 10.1111/j.1600-0722.2004.00179.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Laser speckle contrast analysis is an interferometric technique that is used to measure the displacement of the rough surface of a specimen. The purpose of this study was to present a laser speckle correlation method for monitoring real-time dimensional changes of light-cured composites. Uncured composite was condensed into a glass tube and irradiated for 30 s with 600 or 200 mW cm(-2). The speckle patterns obtained from lateral and bottom composite surfaces were monitored using a speckle analyser. The speckle field is recorded in a digital frame and stored by image processing system as the carrier of information on the displacement of the tested surface. The calculated values were obtained for each pair of adjacent patterns and the changes in speckle contrast as a function time were obtained from five repeated measurements. The overall magnitude of the speckle contrasts decreased soon after the initial light exposure and gradually increased thereafter. The speckle contrasts obtained from the bottom surface were smaller than those obtained from the lateral surface. This tendency was more pronounced when the specimen was irradiated with lower power density. It can be concluded that monitoring differential shrinkage at various levels of depth can be achieved with this new technique.
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Affiliation(s)
- Tomomi Sato
- Department of Operative Dentistry, Nihon University Graduate School of Dentistry, 1-8-13, Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan
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Fano L, Fano V, Ma W, Wang X, Zhu F. Hydrolytic degradation and cracks in resin-modified glass-ionomer cements. J Biomed Mater Res B Appl Biomater 2004; 69:87-93. [PMID: 15015215 DOI: 10.1002/jbm.b.20037] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Water-absorption affects the basic properties of resin-modified glass-ionomer cements (RMGICs). Fick's law is usually invoked to explain the absorption process. The purpose of this study is to show that the absorption in accordance with the Fickian model cannot be extended to the whole of the specimen, and that microcrack formation is the main degradation mechanism for specimens cured in a closed environment. For this purpose, flat disk-shaped paste specimens 1.5 mm thick (aspect ratio 4), irradiated in closed conditions between two glass slides and stored in water for approximately 20 months, were analyzed periodically gravimetrically and under confocal fluorescence microscopy, with absorbed eosin used as the fluorescent probe. At pH 7.0, the specimen surface (10-20 micrometers in depth) absorbed water rapidly, swelled, and disintegrated in 20-40 days. Long-term storage produced isolated cracks and grains, no progress in the swelling, and a slow weight decrease. A lower pH (pH 3.5) produced a significant increase of the number of microcracks. The decrease in the irradiation time (30 s or less) enhanced the erosion process, producing very broad cracks. It was concluded that the prevalent mechanism of long-term hydrolytic degradation was based on the slow formation of cracks, whereas only in the early stage of storage did absorption occur quickly in accordance with the Fickian diffusion.
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Affiliation(s)
- Luca Fano
- Department of Public Health, Section of Physics, Istituto Nazionale Fisica della Materia, University of Parma, via Volturno 39, Parma, Italy.
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Lai JH, Johnson AE, Douglas RB. Organosilicon dental composite restoratives based on 1,3-bis[(p-acryloxymethyl) phenethyl] tetramethyldisiloxane. Dent Mater 2004; 20:570-8. [PMID: 15134945 DOI: 10.1016/j.dental.2003.10.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2003] [Revised: 08/04/2003] [Accepted: 10/09/2003] [Indexed: 10/26/2022]
Abstract
OBJECTIVES The major concern associated with the use of polysiloxanes as polymer matrices in dental restorative materials, is the generally modest mechanical properties of the polymers. However, it has long been demonstrated that thermal stability, and mechanical properties of polysiloxanes can be substantially modified by incorporation of bulkier substituents such as phenyl groups or more polar groups in the chains. The purpose of this research was to evaluate visible light activated dental composites based on the high molecular weight siloxane monomer 1,3-bis[(p-acryloxymethyl) phenethyl] tetramethyldisiloxane (BAPD). METHODS Hardness, diametral tensile strength (DTS), degree of conversion (DC), water sorption (WS) and polymerization shrinkage of BAPD-based composites and bis-GMA-based composites were determined and compared. RESULTS Composites based on BAPD exhibited low WS, high DC, low polymerization shrinkage, and had hardness and DTS values that were not significantly lower than those of dental composites based on bis-GMA. SIGNIFICANCE BAPD is a high molecular weight monomer (MW = 511) with a low viscosity. It did not require the use of low molecular weight diluent monomers in formulating composite resins. The DC of BAPD was high, ranging from 86 to 94%. Although the DC of BAPD was significantly higher than the conventional difunctional dental monomers, the polymerization shrinkage of the siloxane composites (1.70 - 1.81 vol%) was comparable to several composites based on bis-GMA.
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Affiliation(s)
- J H Lai
- LAI Laboratories Inc., 14617 White Oak Drive, Burnsville, MN 55337, USA.
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Versluis A, Tantbirojn D, Pintado MR, DeLong R, Douglas WH. Residual shrinkage stress distributions in molars after composite restoration. Dent Mater 2004; 20:554-64. [PMID: 15134943 DOI: 10.1016/j.dental.2003.05.007] [Citation(s) in RCA: 121] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2002] [Revised: 05/16/2003] [Accepted: 05/29/2003] [Indexed: 10/26/2022]
Abstract
OBJECTIVE Experimental measurements on various restoration configurations have shown that restored teeth deform under the influence of polymerization shrinkage, but actual residual stresses could not be determined. The purpose of this study was to calculate and validate shrinkage stresses associated with the reported tooth deformations. METHODS Three different restoration configurations were applied in a finite element model of a molar. The composite properties were based on experimentally determined composite behavior during polymerization. The occlusal deformation pattern and the residual stress states of the tooth, restoration, and tooth-restoration interface were calculated using a polymerization model based on the post-gel shrinkage concept. Reported strain gauge measurements and occlusal deformation patterns were used for validation. RESULTS The shrinkage stresses depended on the configuration and size of the restorations. The tooth's resistance against polymerization shrinkage diminished with loss of dental hard tissue. Larger restorations resulted in lower stress levels in the restoration and tooth-restoration interface, but increased stresses in the tooth. The maximum stress values found for different configurations were not decisively different. SIGNIFICANCE The validated model indicated that shrinkage stress cannot be based on composite properties or restoration configuration alone, but has to be approached as a distributed pattern that depends on the location and on the properties of tooth and restoration, geometry, constraints, and restoration procedures. Tooth deformation was indicative of stresses in the tooth rather than in the restoration or across the tooth-restoration interface.
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Affiliation(s)
- Antheunis Versluis
- Department of Oral Science, Minnesota Dental Research Center for Biomaterials and Biomechanics, University of Minnesota, 16-212 Moos Tower, 515 Delaware Street SE, Minneapolis 55455, USA.
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Idriss S, Habib C, Abduljabbar T, Omar R. Marginal adaptation of class II resin composite restorations using incremental and bulk placement techniques: an ESEM study. J Oral Rehabil 2003; 30:1000-7. [PMID: 12974860 DOI: 10.1046/j.1365-2842.2003.01082.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
This in vitro study compared marginal gap formation in class II resin composite restorations. Forty caries-free extracted molars were prepared in a standardized manner for class II restoration by one of four methods: bulk- or incrementally-placed light-activated resin composite (Amelogen), and bulk- or incrementally-placed chemically activated composite (Rapidfill). The restored teeth, after finishing and polishing, and thermocycling, were examined using environmental scanning electron microscopy. Marginal gap measurements at predetermined facial and lingual margin sites showed no significant differences between the two sites within any of the groups. Both the light- and the chemically-activated restorations showed no significant differences in mean marginal gap sizes whether they were placed by incremental or bulk techniques. Amelogen restorations placed by both methods had significantly larger margin gaps than those of each of the Rapidfill groups (P<0.05). Thus, although method of placement of a given material had no significant effect on the quality of marginal adaptation, both of the chemically activated resin composite restorations produced significantly smaller marginal gaps than both the bulk- and incrementally-placed light-activated composites.
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Affiliation(s)
- S Idriss
- School of Dental Medicine, Tufts University, Boston, MA, USA
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Kim JG, Chung CM. Trifunctional methacrylate monomers and their photocured composites with reduced curing shrinkage, water sorption, and water solubility. Biomaterials 2003; 24:3845-51. [PMID: 12818557 DOI: 10.1016/s0142-9612(03)00242-4] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Novel trifunctional methacrylates, 1,1,1-tris[4-(2'-acetoxy-3'-methacryloyloxypropoxy)phenyl]ethane (Ac-THMPE) and 1,1,1-tris[4-(2'-acetoxy-3'-methacryloyloxypropoxy)phenyl]methane (Ac-THMPM), have been prepared by acetylation of the hydrophilic hydroxyl groups of 1,1,1-tris[4-(2'-hydroxy-3'-methacryloyloxypropoxy)phenyl]ethane (THMPE) and 1,1,1-tris[4-(2'-hydroxy-3'-methacryloyloxypropoxy)phenyl]methane (THMPM), respectively, for use as dental monomers. Decrease in monomer viscosity resulted from the acetylation. Unfilled resins and composites based on the four trimethacrylates were evaluated for photopolymerization conversion, water contact angle, and curing shrinkage. Water sorption, water solubility, and flexural strength of the composites prepared from the trimethacrylate were measured. Those data obtained for the trimethacrylate-containing materials were compared with control 2,2-bis[4-(2'-hydroxy-3'-methacryloyloxypropoxy)phenyl]propane (bis-GMA)-based materials in order to evaluate the applicability of the trimethacrylates as dental monomers. The acetylation of hydroxyl groups appeared to be an effective method to decrease curing shrinkage, water sorption, and water solubility of the dental composites. When compared with the bis-GMA composite, the composites based on Ac-THMPM and Ac-THMPM showed much lower curing shrinkage, water sorption, and water solubility, along with approximately equal conversion and flexural strength.
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Affiliation(s)
- Joong Gon Kim
- Biotechnology Division, Hanwha Chemical R&D Center, 305-345, Taejon, South Korea
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Palin WM, Fleming GJP, Burke FJT, Marquis PM, Randall RC. Monomer conversion versus flexure strength of a novel dental composite. J Dent 2003; 31:341-51. [PMID: 12799119 DOI: 10.1016/s0300-5712(03)00050-2] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
OBJECTIVES To quantify the monomer conversion and flexural strength of an experimental oxirane-based composite material (EXL596) compared with two, commercially available, dimethacrylate based restoratives (Z250 and Z100). METHODS Fourier-transform infra-red spectroscopy (FTIR) was utilised to evaluate the degree of conversion (DC) (n=5) and biaxial flexure strength (BFS) testing (n=20) was used to analyse flexural strength and associated Weibull moduli (m) of each material following 0.1, 0.5, 1, 4, 24 and 48 h immersion in a lightproof waterbath maintained at 37+/-1 degrees C. RESULTS The DC of Z250 and Z100 following 0.1, 0.5 and 1 h post-irradiation was significantly greater than the DC of EXL596 for the same immersion periods. This was manifested as a significant decrease in BFS and associated m of EXL596 compared with Z250 and Z100 for the 0.1, 0.5 and 1 h post-irradiation periods. The DC and BFS of EXL596 were significantly greater than Z250 and Z100 following 24 h immersion. CONCLUSIONS Assessment of FTIR spectra, BFS and associated m has provided a useful method in the quantitative analysis of resin-based composite conversion. Identification of the decreased DC of EXL596 compared with Z250 and Z100 was achieved using FTIR. However, decreased conversion rates within the first hour following irradiation of EXL596 may compromise flexural strength properties (associated with a decrease in BFS and m) which may be inadequate under masticatory loading.
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Affiliation(s)
- William M Palin
- Biomaterials Unit, School of Dentistry, University of Birmingham, St Chad's Queensway, B4 6NN, Birmingham, UK
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Abstract
OBJECTIVE This study involves investigation of the use of video-imaging for measurement of volumetric shrinkage of composites. METHODS Six composites were tested for volumetric shrinkage using video-imaging. The volumetric shrinkage was measured using the single- and multi-view volumetric reconstruction modes. All composites were cured using a VIP(TM) curing light for 40s at 500 mW/cm(2). Dynamic shrinkage was measured using the single-view mode with a red filter placed over the detector opening. RESULTS Analysis of the volumetric shrinkage values by a one way ANOVA for each composite showed no difference for the single- and multi-view measurement mode. The shrinkage values determined by video-imaging were compared to those measured for the same composites by mercury dilatometry by one way ANOVA followed by a paired comparison using the Bonferroni method. CONCLUSION The video-imaging technique gives reproducible results for volumetric shrinkage of composites comparable to those measured by dilatometry.
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Affiliation(s)
- Louis J Sharp
- Research and Development, Bisco Inc., Schaumburg, IL 60193, USA.
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48
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Vaessen DM, Ngantung FA, Palacio MLB, Francis LF, McCormick AV. Effect of lamp cycling on conversion and stress development in ultraviolet-cured acrylate coatings. J Appl Polym Sci 2002. [DOI: 10.1002/app.10652] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Miguel A, de la Macorra JC. A predictive formula of the contraction stress in restorative and luting materials attending to free and adhered surfaces, volume and deformation. Dent Mater 2001; 17:241-6. [PMID: 11257297 DOI: 10.1016/s0109-5641(00)00077-4] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
OBJECTIVES To find a predictive formula of stress, considering the surfaces (free, adhered) involved, the volume and characteristics of material and the deformation of the measuring system. MATERIALS AND METHODS 231 samples of five chemically cured restoratives (Silar (SIL, 23), Clearfil F2 (CLE, 39), P10 (P10, 33), Concise (CON, 30), Isopast (ISO, 28)) and four luting (3M Experimental 241 (EXM, 20), Variolink II (VAR, 13), Vitremer LC (VTM, 20) and Dyract Cem (DYR, 25)) materials were allowed to polymerize until they reached a maximum tension (T(max), 25 min) between six pairs (null 5.81, 8.5, 11.26, 12.42, 17.02, 23.14 mm) of polished metallic discs (range of distances: 0.02-5.9 mm) mounted in a tension machine. The deformation of the measuring system was measured for the recorded forces. RESULTS A descriptive non-linear formula T(max)=KVol(-3.267)FS(3.283)AS(0.642)Def(0.561) was found that individualizes the material's characteristics (K) that considers volume (Vol), free (FS) and adhered (AS) surfaces and deformation (Def) of the system for each force. This formula renders good correlation (material K (r(2) coefficient)): SIL 0.9998 (0.995), CLE 1.0062 (0.989), P10 1.0224 (0.990), CON 0.9908 (0.992), ISO 0.9648 (0.974), EXM 1.0083 (0.991), VAR 0.9777 (0.996), VTM 0.9925 (0.993), DYR 0.9971 (0.997) between actual T(max) and calculated Tension. There are statistically significant differences (p=0.002) between K values of both (restorative and luting) groups. SIGNIFICANCE Predictive parameters have influence in a different way to what is actually considered, if the system is allowed to have deformation, as occurs naturally and volume and material's characteristics are considered.
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Affiliation(s)
- A Miguel
- Conservative Dentistry Department, Faculty of Odontology, Complutense University, Madrid, Spain
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50
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Winkler MM, Chen J, Qian H, Hamula DW, Carlson TJ, Katona TR. Experimental validation of a finite element model of light-activated polymerization shrinkage. JOURNAL OF BIOMEDICAL MATERIALS RESEARCH 2000; 53:554-9. [PMID: 10984704 DOI: 10.1002/1097-4636(200009)53:5<554::aid-jbm15>3.0.co;2-l] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
An important consideration in improving the longevity of dental resin composite restorations is how to minimize the stresses that develop between resin composites and the wall of the preparation as the resin shrinks during polymerization. If the stress is too great, failure of the bonded interface occurs and microleakage results, with possible margin failure, staining, and secondary caries. This present project was performed to validate a previously developed FEM approach for investigating polymerization shrinkage. Light-cured resin composite was condensed into a cylindrical cavity preparation, which contained a centrally located wire. A profilometer stylus was positioned on the end of the wire to detect the initial surface displacement as the wire moved with the superficial layer of composite resin. The plots of the experimentally derived data were compared to the data plot from the FEM. The initial segments of the experimental plots matched the calculated plot very closely in shape, thus validating the FEM approach.
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Affiliation(s)
- M M Winkler
- Department of Operative Dentistry and Biomaterials, LSU School of Dentistry, 1100 Florida Ave., New Orleans, Louisiana 70119, USA.
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