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Pérez MM, Pecho OE, Ghinea R, Pulgar R, Bona AD. Recent Advances in Color and Whiteness Evaluations in Dentistry. ACTA ACUST UNITED AC 2019. [DOI: 10.2174/2542579x01666180719125137] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Background:
The final goal of color measurement or shade specification in dentistry is
the reproduction by prosthetic materials of all important appearance characteristics of natural oral
structures. The application of color science in dentistry is an objective way to measure and evaluate
such structures and dental materials in clinical practice and dental research.
Methods:
Literature on color science was reviewed to present new metrics to evaluate color differences
of dental materials and dental structures. Visual acceptability and perceptibility values of color
differences are reviewed and new whiteness indexes to describe whiteness in dentistry are presented.
Results:
In the last decade, the CIELAB 50:50% perceptibility and acceptability thresholds were set
to 1.2 and 2.7, respectively, and the CIEDE2000 50:50% perceptibility and acceptability thresholds
were set to 0.8 and 1.8. The CIEDE2000 color-difference formula became increasingly popular in
dentistry. Developments in color science have led to the description of tooth whiteness and changes
in tooth whiteness based on whiteness indexes, with the most relevant being the WID whiteness index,
which is a customized index based in CIELAB color space.
Conclusion:
The application of color science in dentistry has allowed the precise description of
tooth color and whiteness. The revised and new CIEDE2000 color-difference formula is expected to
fully replace the outdated CIELAB formula in almost all dental applications. Recent psychophysical
studies have reported values of visual thresholds and new whiteness indexes, which can serve as
quality control tools to guide the selection of esthetic dental materials, evaluate clinical performance,
and interpret visual and instrumental findings in clinical dentistry, dental research, and subsequent
standardization.
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Affiliation(s)
- María M. Pérez
- Department of Optics, Faculty of Science, Campus Fuente Nueva, Edificio Mecenas, s/n E-18071, University of Granada, Spain
| | - Oscar E. Pecho
- Department of Optics, Faculty of Science, Campus Fuente Nueva, Edificio Mecenas, s/n E-18071, University of Granada, Spain
| | - Razvan Ghinea
- Department of Optics, Faculty of Science, Campus Fuente Nueva, Edificio Mecenas, s/n E-18071, University of Granada, Spain
| | - Rosa Pulgar
- Department of Stomatology, Faculty of Dentistry, Campus de Cartuja s/n E-18071, University of Granada, Spain
| | - Alvaro Della Bona
- Post-Graduate Program in Dentistry, Dental School, University of Passo Fundo, Campus I, Passo Fundo, RS, Brazil
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Heintze SD, Rousson V, Hickel R. Clinical effectiveness of direct anterior restorations—A meta-analysis. Dent Mater 2015; 31:481-95. [DOI: 10.1016/j.dental.2015.01.015] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Revised: 04/08/2014] [Accepted: 01/28/2015] [Indexed: 10/23/2022]
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Paravina RD, Ghinea R, Herrera LJ, Bona AD, Igiel C, Linninger M, Sakai M, Takahashi H, Tashkandi E, Mar Perez MD. Color Difference Thresholds in Dentistry. J ESTHET RESTOR DENT 2015; 27 Suppl 1:S1-9. [DOI: 10.1111/jerd.12149] [Citation(s) in RCA: 453] [Impact Index Per Article: 50.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Rade D. Paravina
- Department of Restorative Dentistry and Prosthodontics; School of Dentistry; University of Texas; Houston TX USA
- Houston Center for Biomaterials and Biomimetics (HCBB); Houston TX USA
| | - Razvan Ghinea
- Department of Optics; University of Granada Faculty of Sciences; Granada Spain
| | - Luis J. Herrera
- Department of Computer Architecture and Computer Technology; School of Information Technology and Telecommunications Engineering; University of Granada Higher Technical; Granada Spain
| | - Alvaro D. Bona
- School of Dentistry; University of Passo Fundo; Passo Fundo Brazil
| | - Christopher Igiel
- University Medical Center; Johannes Gutenberg University; Mainz Germany
| | - Mercedes Linninger
- Department of Prosthodontics; Semmelweis University Faculty of Dentistry; Budapest Hungary
| | - Maiko Sakai
- Department of Restorative Dentistry and Biomaterials Sciences; Harvard University School of Dental Medicine; Boston MA USA
| | - Hidekazu Takahashi
- Oral Biomaterials Engineering; Faculty of Dentistry; Tokyo Medical and Dental University; Tokyo Japan
| | - Esam Tashkandi
- Department of Prosthodontics; College of Dentistry; King Saud University; Riyadh Saudi Arabia
| | - Maria del Mar Perez
- Department of Optics; University of Granada Faculty of Sciences; Granada Spain
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Kaizer MDR, Diesel PG, Mallmann A, Jacques LB. Ageing of silorane-based and methacrylate-based composite resins: Effects on translucency. J Dent 2012; 40 Suppl 1:e64-71. [DOI: 10.1016/j.jdent.2012.04.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2012] [Revised: 04/02/2012] [Accepted: 04/19/2012] [Indexed: 10/28/2022] Open
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Hadis MA, Shortall AC, Palin WM. Competitive light absorbers in photoactive dental resin-based materials. Dent Mater 2012; 28:831-41. [PMID: 22578661 DOI: 10.1016/j.dental.2012.04.029] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Revised: 03/16/2012] [Accepted: 04/16/2012] [Indexed: 10/28/2022]
Abstract
OBJECTIVES The absorbance profile of photoinitiators prior to, during and following polymerization of light curable resin-based materials will have a significant effect on the cure and color properties of the final material. So-called "colorless" photoinitiators are used in some light-activated resin-based composite restorative materials to lessen the yellowing effect of camphoroquinone (CQ) in order to improve the esthetic quality of dental restorations. This work characterizes absorption properties of commonly used photoinitiators, an acylphosphine oxide (TPO) and CQ, and assesses their influence on material discoloration. METHODS Dimethacrylate resin formulations contained low (0.0134 mol/dm(3)), intermediate (0.0405 mol/dm(3)) or high (0.0678 mol/dm(3)) concentrations of the photoinitiators and the inhibitor, butylated hydroxytoluene (BHT) at 0, 0.1 or 0.2% by mass. Disc shaped specimens (n = 3) of each resin were polymerized for 60s using a halogen light curing unit. Dynamic measurements of photoinitiator absorption, polymer conversion and reaction temperature were performed. A spectrophotometer was used to measure the color change before and after cure. RESULTS GLM three-way analysis of variance revealed significant differences (p<0.001), where photoinitiator concentration (df = 2; F = 618.83)>photoinitiator type (df = 1; F = 176.12)>% BHT (df = 2, F = 13.17). BHT concentration affected the rate of polymerization and produced lower conversion in some of the CQ-based resins. Significant differences between photoinitiator type and concentrations were seen in color (where TPO resins became yellower and camphoroquinone resins became less yellow upon irradiation). Reaction temperature, kinetics and conversion also differed significantly for both initiators (p<0.001). Despite TPO-based resins producing a visually perceptible color change upon polymerization, the color change was significantly less than that produced with CQ-based resins. SIGNIFICANCE Although some photoinitiators such as TPO may be a more esthetic alternative to CQ, they may actually cause significant color contamination when used in high concentrations and therefore manufacturers should limit its concentration in order to improve its esthetic quality.
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Affiliation(s)
- Mohammed A Hadis
- Biomaterials Unit, University of Birmingham, School of Dentistry, College of Medical and Dental Sciences, St Chads Queensway, Birmingham B4 6NN, United Kingdom.
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Color stability of silorane-based composites submitted to accelerated artificial ageing—An in situ study. J Dent 2011; 39 Suppl 1:e18-24. [DOI: 10.1016/j.jdent.2011.03.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2011] [Revised: 02/28/2011] [Accepted: 03/09/2011] [Indexed: 11/21/2022] Open
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Lee YK, Yu B, Lim HN, Lim JI. Difference in the color stability of direct and indirect resin composites. J Appl Oral Sci 2011; 19:154-60. [PMID: 21552717 PMCID: PMC4243754 DOI: 10.1590/s1678-77572011000200012] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2009] [Accepted: 02/16/2010] [Indexed: 11/29/2022] Open
Abstract
Indirect resin composites are generally regarded to have better color stability than
direct resin composites since they possess higher conversion degree
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Affiliation(s)
- Yong-Keun Lee
- Institute for Clinical Performance of Biomaterials, Seoul, Korea.
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Brandt WC, Schneider LFJ, Frollini E, Correr-Sobrinho L, Sinhoreti MAC. Effect of different photo-initiators and light curing units on degree of conversion of composites. Braz Oral Res 2010; 24:263-70. [DOI: 10.1590/s1806-83242010000300002] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2010] [Accepted: 05/17/2010] [Indexed: 11/22/2022] Open
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Brandão RB, Martin CCS, Catirse ABCEB, de Castro E Silva M, Evison MP, Guimarães MA. Heat induced changes to dental resin composites: a reference in forensic investigations? J Forensic Sci 2007; 52:913-9. [PMID: 17553091 DOI: 10.1111/j.1556-4029.2007.00474.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The objective was to investigate color change and surface damage in dental resin composites exposed to high temperatures over different time intervals for comparative purposes. Samples were prepared using two resins - Z100(R) (R1) and Charisma (R2), heated at the following temperatures: 200 degrees C, 400 degrees C, 600 degrees C, 1000 degrees C, for 15, 30 and 45 min (n = 104 for each resin sample). Color (DeltaE) and brightness (DeltaL) changes were analyzed by spectrophotometry using the CIE Lab system and surface changes by Scanning Electron Microscopy (SEM). R1 showed more intense color changes after heat exposure than R2. DeltaL values were found to be the best parameter for evaluation of light and color change. A biphasic pattern after thermal exposure was detected, from dark brown to light white. SEM showed more intense alterations in R2 than in R1. These results indicate that the parameters observed in both resins are useful as a guide in forensic analyses.
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Affiliation(s)
- Renata B Brandão
- Department of Pathology, Medico Legal Centre (CEMEL), Faculty of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
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Sato S, Cavalcante MRS, Orsi IA, Paranhos HDFO, Zaniquelli O. Assessment of flexural strength and color alteration of heat-polymerized acrylic resins after simulated use of denture cleansers. Braz Dent J 2005; 16:124-8. [PMID: 16475606 DOI: 10.1590/s0103-64402005000200007] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The purpose of this study was to assess flexural strength and color alteration of acrylic resins immersed in denture cleansers for different periods of time. Rectangular specimens (65x10x3mm) made from three heat-polymerized acrylic resins (Lucitone 550, QC-20 and Triplex) were assigned to three denture cleansers groups (Bony Plus, Corega Tabs and Efferdent Plus) and a control group (immersion in water). Soaking trials of 15 min and 8 h simulated 30 days of use. Flexural strength testing was carried out with 105 specimens on a universal testing machine. Color alterations were visually assessed by examination of photographs taken from 21 specimens. Flexural strength means (in MPa) were analyzed statistically by analysis of variance and Tukey's test at 5% significance level. There were significant differences (p<0.01) among the resins Lucitone (89.439 ± 7.962), Triplex (88.024 ± 5.167) and QC-20 (83.379 ± 7.153). No significant differences (p>0.05) were found either among the denture cleansers (Bony Plus = 87.693 ± 6.943; Corega Tabs = 86.955 ± 7.114; Efferdent Plus = 86.195 ± 7.865 and control = 86.536 ± 7.012) or between the soaking periods (15 min = 86.875 ± 7.625 and 8 h = 87.432 ± 7.355) throughout the soaking cycles simulating 30 days of use. No color alterations were identified by visual examination. The findings of this study showed that chemical denture cleansers used according to the manufacturers' specifications did not cause flexural strength alterations or color changes in heat-polymerized acrylic resins submitted to soaking cycles that simulated 30 days of use.
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Affiliation(s)
- Sandra Sato
- Department of Dental Materials and Prosthodontics, Faculty of Dentistry of Ribeirão Preto, University of São Paulo, Brazil
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Tanoue N, Soeno K, Kawasaki K, Atsuta M. Influence of acidulated phosphate fluoride solution on the color stability of indirect composites. J Prosthet Dent 2004; 92:343-7. [PMID: 15507906 DOI: 10.1016/j.prosdent.2004.07.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
STATEMENT OF PROBLEM Although acidulated phosphate fluoride (APF) agents are known to be useful for caries-preventive interventions, few studies have examined the influence of APF agents on indirect composite materials. PURPOSE This study examined whether exposure to APF agents affects color stability when a composite is exposed to a common staining agent. MATERIALS AND METHODS Forty light-polymerized composite disks (8 x 2.0 mm) were fabricated with midifilled (Cesead II; n = 20) and microfilled (Newmetacolor Infis; n = 20) composites. The specimens were polymerized with a light for 90 seconds on each side, ground with silicon carbide paper, finished using a polishing kit, and colorimetrically evaluated to determine baseline L*a *b* values. After storage in distilled water at 37 degrees C for 24 hours, half of the disks for each composite (n = 10) was treated with an APF solution (Fluodent A) for 32 minutes, while the remaining half of the specimens were untreated (controls). Half the treated and untreated specimens were immersed in tea or distilled water (n = 5, respectively), and after 4 weeks color changes were measured. To determine the influence of APF on each composite, the CIE L*a*b* color difference baseline values after 4 weeks were compared using 2- and 1-way analyses of variance and post-hoc Sheffe's S intervals (alpha=.05). RESULTS The color differences of both materials when immersed in tea were significantly influenced by APF (P < .05). The mean DeltaE values of APF-treated Cesead II and Newmetacolor Infis immersed in tea were 5.4 +/- 1.2 and 4.5 +/- 1.3, respectively, while the untreated values were 3.8 +/- 0.6 and 3.0 +/- 0.1, respectively. When immersed in water, neither material was affected by APF in respect to change in color. CONCLUSION The color of both composites tested were significantly influenced by APF treatment when immersed in tea, indicating that the in vitro color stability of the indirect composites was negatively affected by applications of APF.
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Affiliation(s)
- Naomi Tanoue
- Nagasaki University Hospital of Dentistry, Nagasaki, Japan.
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Janda R, Roulet JF, Kaminsky M, Steffin G, Latta M. Color stability of resin matrix restorative materials as a function of the method of light activation. Eur J Oral Sci 2004; 112:280-5. [PMID: 15154928 DOI: 10.1111/j.1600-0722.2004.00125.x] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The purpose was to investigate the influence of curing devices and curing times on the yellow value (b-value) of composites, ormocers and compomers after performing a suntest (EN ISO 7491). Eight samples of Charisma (CH), Durafill (DU), Definite (DE), and Dyract AP (DY) each were light cured with Translux Energy (tungsten halogen light) for 20, 40 or 60 s and with Apollo 95-E (plasma light) for 3, 10 or 20 s. All samples were subjected to a suntest. Before and after the suntest the yellow values (b-values) were determined and the change (Delta b) was calculated. When cured with Translux Energy for 20 and 40 s DU, CH, and DY revealed significantly negative Delta b-values. The b-value of DE remained nearly constant. When cured for 60 s, DU and DE shifted to more yellow while CH and DY still bleached a little. When cured with Apollo 95-E, a dramatic bleaching process of all materials investigated occurred after the suntest (significant negative Delta b). It may be concluded that the bleaching of composites, ormocers and compomers depends on (i) the used light curing device and (ii) the chosen curing times. The tungsten halogen light provided highly significantly superior results.
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Affiliation(s)
- Ralf Janda
- Humboldt-University, Medical Faculty-Charité, Center of Dentistry, Augustenburger Platz, Berlin, Germany.
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Hersek N, Canay S, Uzun G, Yildiz F. Color stability of denture base acrylic resins in three food colorants. J Prosthet Dent 1999; 81:375-9. [PMID: 10095204 DOI: 10.1016/s0022-3913(99)80001-8] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
STATEMENT OF PROBLEM Three commonly used artificial dyes in food technology are erythrosine, tartrazine, and sunset yellow. PURPOSE The color stability of 5 commercially available denture base acrylic resins (QC-20, Meliodent, Trevalon, Trevalon High, and Lucitone) was studied in vitro. METHODS The specimens were exposed to 3% erythrosine, tartrazine, and sunset yellow solutions at 23 degrees C +/- 1 degrees C. Color changes were determined with a computer-controlled spectrophotometer. Five specimens from each material were processed, and initial color measurements were made after 1, 3, and 6 months of exposure to the staining solutions. Finally, the color stability was quantitatively measured again, and color differences (DeltaE) were calculated. RESULTS For the observations made in 1, 3, and 6 months intervals, the specimens that exhibited the least color change were in the sunset yellow solution. The greatest color changes observed according to the National Bureau of Standards unit system were Lucitone (2.71) in erythrosine solution, Lucitone (2.54), QC-20 (1.71) in tartrazine solution, and QC-20 (1.66) in sunset yellow solution. The changes in the other acrylic resins in the 3 solutions were slight and at trace level. CONCLUSIONS All materials tested were acceptable from the standpoint of color stability for long-term exposure to these food colorants.
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Affiliation(s)
- N Hersek
- Faculty of Dentistry, University of Hacettepe, Ankara, Turkey
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Indrani DJ, Cook WD, Televantos F, Tyas MJ, Harcourt JK. Fracture toughness of water-aged resin composite restorative materials. Dent Mater 1995; 11:201-7. [PMID: 8600014 DOI: 10.1016/0109-5641(95)80019-0] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
OBJECTIVES The purpose of this study was to assess the effects of aging experimental dimethacrylate resin composites in water at 37 degrees C for periods up to 6 wk by measuring the variations in fracture toughness (K(c)), elastic modulus (E), fracture energy (G(c)), and water sorption. METHODS Six experimental resins were formulated from dimethacrylate resins, and were filled to 86 wt% (ca. 70 vol%) with treated inorganic filler to form six experimental composites. The fracture toughness was determined using a double torsion technique, the elastic modulus was measured in flexure, and the fracture energy was calculated from the fracture toughness and elastic modulus. RESULTS As a result of aging in water, K(c) and the G(c) increased, and the elastic modulus decreased, but all values approached a plateau near 6 wk. Water sorption also occurred during this period, mainly during the first 2 wk. SIGNIFICANCE Variations in the mechanical properties are interpreted as being due to plasticization of the resin matrix by water, which appears to lower the yield stress and increase in the size of the plastic zone ahead of the crack, thereby causing the observed increase in G(c) and K(c). After approximately 6 wk, no further changes in properties occurred.
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Affiliation(s)
- D J Indrani
- University of Melbourne, School of Dental Science, Melbourne, Australia
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Dietschi D, Campanile G, Holz J, Meyer JM. Comparison of the color stability of ten new-generation composites: an in vitro study. Dent Mater 1994; 10:353-62. [PMID: 7498599 DOI: 10.1016/0109-5641(94)90059-0] [Citation(s) in RCA: 177] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
OBJECTIVES The aim of this in vitro study was to evaluate the color stability of modern light-cured composites when subjected to various physico-chemical and staining conditions. METHODS Ten brands were evaluated including hybrids, microfine hybrids and microfilled composites. Some universal shade samples underwent only staining tests, while others were subjected to one of the following experimental conditions: thermocycling, postcuring, polishing or a 1 wk immersion in saline, prior to staining. The coloring solutions used for the staining tests were: coffee, E 110 food dye, vinegar and erythrosin. A colorimetric evaluation according to the CIE L*a*b* system was performed after experimental periods of 1 and 3 wk. RESULTS Erythrosin caused the greatest color change for the composites tested. A reduced susceptibility to staining was observed where surfaces had been polished. Low water sorption, a high filler-resin ratio, reduced particle size and hardness, and an optimal filler-matrix coupling system were related to improved composite resistance to discoloration. SIGNIFICANCE Resistance of modern composites to discolorations still depends on their structure and manipulation.
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Affiliation(s)
- D Dietschi
- Department of Restorative Dentistry and Endodontics, University of Geneva, Switzerland
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Abstract
Ninety three Class III cavities were prepared in 66 patients, and restored with one of three resin-based restorative materials; a hybrid self-cure material, a microfine self-cure material, or a microfine light-cure material. Standard sets of clinical colour transparencies were used to evaluate colour match with the surrounding tooth and marginal discoloration over five years. After five years, all materials had become slightly darker, the microfine self-cure material significantly more so than the light-cure material. There was no significant development of marginal discoloration.
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Affiliation(s)
- M J Tyas
- School of Dental Science, University of Melbourne
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17
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Cook WD, Moopnar M. Influence of chemical structure on the fracture behaviour of dimethacrylate composite resins. Biomaterials 1990; 11:272-6. [PMID: 2383623 DOI: 10.1016/0142-9612(90)90009-f] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Previous studies have shown that the fracture resistance of dimethacrylate-based dental composite resins is enhanced by post-curing the matrix. Here, the influence of the chemical nature of the resin matrix is examined by a study of the fracture properties of composite resins formulated from 15 homologous dimethacrylate monomers and filled to 75 wt% with treated silica. The fracture toughness was determined via the double torsion technique and the elastic modulus and flexural strength were measured in flexure. The fracture energy calculated from the fracture toughness and elastic modulus, varied between 60 and 300 J/m2 while the fracture toughness ranged from 0.2 to 2.0 MN/m3/2 and the flexural strength varied from 17 to 111 MPa. The use of a blend of monomers was found to have a synergistic effect on the fracture resistance. Increasing the length of flexible spacer units (methylene or oxyethylene) between the methacrylate groups initially improved the fracture properties; however, beyond a certain length, these properties were impaired.
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Affiliation(s)
- W D Cook
- Australian Dental Standards Laboratory, Abbotsford, Victoria
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Tyas MJ. Correlation between fracture properties and clinical performance of composite resins in Class IV cavities. Aust Dent J 1990; 35:46-9. [PMID: 2322172 DOI: 10.1111/j.1834-7819.1990.tb03027.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
One hundred and two Class IV cavities were restored randomly with four composite resins. The restorations were assessed at six months, one year, two years and three years for surface chipping, bulk fracture and incisal wear. The data were correlated with various mechanical properties of the materials. A significant correlation was found between surface chipping/bulk fracture and fracture toughness (P = 0.002), elastic modulus (P = 0.006) and tensile strength (P = 0.045). There was a trend towards an association between incisal wear and both elastic modulus and inherent flaw size. Fracture toughness may be a useful indicator of the clinical performance of composites in Class IV cavities.
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Affiliation(s)
- M J Tyas
- Australian Dental Standards Laboratory, School of Dental Science, University of Melbourne
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Tyas MJ, Burns GA, Byrne PF, Cunningham PJ, Dobson BC, Widdop FT. Clinical evaluation of Scotchbond: three-year results. Aust Dent J 1989; 34:277-9. [PMID: 2527492 DOI: 10.1111/j.1834-7819.1989.tb00683.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
In a previous paper, the one-year retention of composite resin in non-undercut Class V abrasion lesions mediated by self-cure Scotchbond dentine bonding agent without enamel etching was reported. The present paper reports the three-year results. Initially, a total of 310 restorations was placed using Silux, Silar, Ketac-Fil and Fuji II. The percentage cumulative loss of the restorations at two and three years, respectively, was: Silux 27, 30; Silar 58, 58; Ketac-Fil 0, 0; Fuji II 4, 14. Over the total study period, there was a high loss rate of composite restorations in the first six months, and a tendency to increased loss over one to three years. There was a significant increase in marginal discoloration, assessed photographically, over the three-year period, and caries was present around some restorations.
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Ruyter IE, Nilner K, Moller B. Color stability of dental composite resin materials for crown and bridge veneers. Dent Mater 1987; 3:246-51. [PMID: 3479360 DOI: 10.1016/s0109-5641(87)80081-7] [Citation(s) in RCA: 440] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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van Noort R, Brown D, Causton BE, Combe EC, Fletcher AM, Lloyd CH, McCabe JF, Sherriff M, Strang R, Waters NE. Dental materials: 1984-85 literature review. Part 2. J Dent 1987; 15:93-115. [PMID: 3301932 DOI: 10.1016/0300-5712(87)90065-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
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Gatti AM. UV-radiation aging test on composite materials for dental restorations. JOURNAL OF BIOMEDICAL MATERIALS RESEARCH 1987; 21:603-12. [PMID: 3584165 DOI: 10.1002/jbm.820210506] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Seven composite materials for dental restorations were examined in order to investigate their color stability. Five of these materials are available for anterior and two for posterior teeth. The change in color was achieved by an accelerated aging test with ultraviolet rays and evaluated, for each material, with the measurement of reflectance. Such measurement was obtained by means of a video display computer working as a computerized photometer. The results show two different types of behavior: some materials turn slightly to yellow, while others bleach. The test was completed with a scanning electron microscope morphologic examination of the surfaces.
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Cook WD, Beech DR, Tyas MJ. Structure and properties of methacrylate based dental restorative materials. Biomaterials 1985; 6:362-8. [PMID: 3910123 DOI: 10.1016/0142-9612(85)90094-8] [Citation(s) in RCA: 36] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The chemistry and structure of the dimethacrylate resins and the nature of the filler systems in dental composite resins are reviewed in relation to their influence on the setting behaviour, dimensional stability, aesthetics, fracture behaviour and adhesive potential. It is clear that a deeper understanding of the structure of the polymeric matrix and the mechanism of clinical wear is required. As a result of ongoing research in this area and with the development of dentine adhesives, the future prospects of composite resins are encouraging.
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