Attitudes of dentists toward maintaining, repairing, or replacing direct composite resin restorations.

This study aimed to report the reasons for replacement of direct composite resin restorations in dental practices in Brazil. The study used a convenience sample of 213 dentists. A questionnaire was developed from previously validated instruments and sent electronically to prospective participants. The questions pertained to professional characteristics; criteria most frequently used in determining whether a direct composite resin restoration warranted replacement; and respondents' choice of treatment options (maintain, repair, or replace the restoration) in various clinical scenarios based on FDI World Dental Federation evaluation criteria, which are categorized into 3 groups: esthetic, functional, and biological properties. The descriptive statistical analysis was conducted using percentage frequencies, and associations between variables were tested using chi-square tests (α = 0.05). According to 47.9% of respondents, staining was the esthetic property that most often warranted replacement. For the functional property, 53.8% of respondents reported that fracture of material and retention was the most important factor indicating the need for replacement. For the clinical scenarios, 41.7% of respondents chose restoration replacement when evaluating esthetic properties, 59.8% when evaluating functional properties, and 64.4% when evaluating biological properties. Replacement, rather than maintenance or repair, was the most frequently reported clinical decision, and the dentists' professional profiles influenced treatment recommendations, with specialists exhibiting a slightly lower frequency of recommendations for replacement of direct composite resin restorations.

Influence of different application protocols of universal adhesive system on the clinical behavior of Class I and II restorations of composite resin - a randomized and double-blind controlled clinical trial.

BACKGROUND: Multimode adhesives incorporate the versatility of adapting to various clinical situations by its capacity to be used in different protocols. This study aimed to evaluate the clinical behavior of composite resin direct restorations (Class I and II) performed with different universal dentin adhesive application protocols comparing adapted FDI and adapted USPHS criteria. METHODS: The current study is a randomized, double-blind, split-mouth, and convenience sample controlled clinical trial. The participants (age ≥ 18 years) had restorative need of Class I and/or II due to the presence of carious lesions and/or unsatisfactory restorations in at least three dental elements. Each participant received three application protocols for Scotchbond Universal adhesive (3M ESPE), one in each tooth to be restored: ER = etch-and-rinse + adhesive (n = 50); SEE = selective enamel etch + adhesive (n = 50) and SE = self-etch adhesive (n = 50). All teeth were restored in a similar way using Filtek™ Supreme composite resin (3M ESPE). Restorations were evaluated using the adapted FDI and adapted USPHS criteria, at baseline after 7 to 21 (12.02 ± 5.68) days (T1; n = 50 per group) and after 12 to 20 (15.8 ± 2.7) months (T2; n = 46 per group) by two previously calibrated evaluators (Kappa > 0.80). The statistical tests were performed between groups (Friedman), intragroup (Wilcoxon), and between the criteria considering acceptable and not acceptable restorations (McNemar), α = 0.05. RESULTS: A statistically significant difference was observed only for the property "superficial staining", between groups at T2 (p = 0.01) for ER (n = 13 with score 2 or more) and SEE (n = 3 with score 2 or more) and intragroup for ER (T1, n = 1 with score 2 or more; T2, n = 13 with score 2 or more, p = 0.001) and SE (T1, n = 0 with score 2 or more; T2, n = 8 with score 2 or more p = 0.007). For the other comparisons between groups, intragroup, and between the adapted FDI and adapted USPHS criteria, there were no statistically significant differences (p ≥ 0.05). CONCLUSIONS: It can be concluded that the different application protocols of the universal adhesive resulted in clinically "acceptable" restorations after 15.8 ± 2.7 months of follow-up. Adapted FDI and adapted USPHS criteria provided similar results to each other. TRIAL REGISTRATION: Number in Brazilian Registry of Clinical Trials (ReBEC): RBR-9p3hdp. Registered 24 May 2015.

Bond Strength of Resin Cements to Zirconia Ceramic Using Adhesive Primers.

PURPOSE: To evaluate the influence of adhesive primers on the microshear bond strength of resin cements to zirconia ceramic. MATERIALS AND METHODS: Fifty zirconia plates (12 mm × 5 mm × 1.5 mm thick) of a commercially available zirconium oxide ceramic (ZirCad) were sintered, sandblasted with aluminum oxide particles, and cleaned ultrasonically before bonding. The plates were randomly divided into five groups of 10. Three resin cements were selected (RelyX ARC, Multilink Automix, Clearfil SA Cement self-adhesive resin cement), along with two primers (Metal-Zirconia Primer, Alloy Primer) and one control group. The primers and resin cements were used according to manufacturers' recommendations. The control group comprised the conventional resin cement (RelyX ARC) without adhesive primer. Test cylinders (0.75 mm diameter × 1 mm high) were formed on zirconia surfaces by filling cylindrical Tygon tube molds with resin cement. The specimens were stored in distilled water for 24 hours at 37°C, then tested for shear strength on a Shimadzu EZ Test testing machine at 0.5 mm/min. Bond strength data were analyzed statistically by two-way ANOVA and Dunnett's test (5%). RESULTS: The bond strength means in MPa (± s.d.) were: RelyX ARC: 28.1 (6.6); Multilink Automix: 37.6 (4.5); Multilink Automix + Metal-Zirconia Primer: 55.7 (4.0); Clearfil SA Cement: 46.2 (3.3); and Clearfil SA Cement + Alloy Primer: 47.0 (4.1). CONCLUSION: Metal-Zirconia Primer increased the bond strength of Multilink Automix resin cement to zirconia, but no effect was observed for Alloy Primer using Clearfil SA Cement. RelyX ARC showed the lowest bond strength to zirconia.

Effect of light source and solvent on the sorption and solubility of two dual-cured cements photocured through ceramic.

The purpose of this study was to verify the polymerization efficiency of two curing units through a ceramic barrier. Forty specimens apiece of two resin luting cements (AllCem and RelyX U100) were made in a stainless steel mold. The experimental group was photocured through a ceramic barrier, while the control group was photocured without a barrier. The specimens were stored in deionized water or 75% ethanol for 28 days and submitted to tests of sorption and solubility (ISO 4049:2000). Values obtained were subjected to ANOVA and Tukey multiple comparison tests (P < 0.05). RelyX U100 suffered more sorption and solubility than AllCem. The light sources did not influence sorption and solubility values, except for the specimens of RelyX U100 that were photocured with an LED unit through ceramic and stored in ethanol; these specimens demonstrated higher values than those photocured using a halogen lamp.

Effect of light sources and curing mode techniques on sorption, solubility and biaxial flexural strength of a composite resin.

UNLABELLED: Adequate polymerization plays an important role on the longevity of the composite resin restorations. OBJECTIVES: The aim of this study was to evaluate the effect of light-curing units, curing mode techniques and storage media on sorption, solubility and biaxial flexural strength (BFS) of a composite resin. MATERIAL AND METHODS: Two hundred and forty specimens were made of one composite resin (Esthet-X) in a stainless steel mold (2 mm x 8 mm Ø), and divided into 24 groups (n=10) established according to the 4 study factors: light-curing units: quartz tungsten halogen (QTH) lamp and light-emitting diodes (LED); energy densities: 16 J/cm² and 20 J/cm²; curing modes: conventional (CM) and pulse-delay (PD); and permeants: deionized water and 75% ethanol for 28 days. Sorption and solubility tests were performed according to ISO 4049:2000 specifications. All specimens were then tested for BFS according to ASTM F394-78 specification. Data were analyzed by three-way ANOVA followed by Tukey, Kruskal-Wallis and Mann-Whitney tests (α=0.05). RESULTS: In general, no significant differences were found regarding sorption, solubility or BFS means for the light-curing units and curing modes (p>0.05). Only LED unit using 16 J/cm² and PD using 10 s produced higher sorption and solubility values than QTH. Otherwise, using CM (16 J/cm²), LED produced lower values of BFS than QTH (p<0.05). 75% ethanol permeant produced higher values of sorption and solubility and lower values of BFS than water (p<0.05). CONCLUSION: Ethanol storage media produced more damage on composite resin than water. In general the LED and QTH curing units using 16 and 20 J/cm² by CM and PD curing modes produced no influence on the sorption, solubility or BFS of the tested resin.

Influence of curing mode of resin luting cements on bond strength to dentin

Self-adhesive, dual-polymerizing resin cements require no treatment to the prepared tooth surfaces before cementation. Aim: The aim of this study was to evaluate the influence of curing mode on bond strength (BS) of three cementing systems to bovine dentin. Methods: The buccal enamel surfaces of 50 bovine incisors were removed to expose dentin and to flat the surface. The teeth were divided into five groups (n=10), which consisted of two resin cements (Multilink and Clearfil SA Cement) that were tested in dual- (halogen light for 40 s) and self-cured modes, and a control (RelyX ARC). Two cylinders of resin cements (1.0 mm X 0.75 mm) were prepared on each bonded dentin surface. After 24h at 37oC, resin cylinders were subjected to micro-shear testing in a universal testing machine (4411/Instron - 0.5 mm/min). Data were statistically analyzed by two-way ANOVA, Tukey and Dunnett`s test (5%). Results: Multilink showed higher BS than those observed on Clearfil SA. Light-curing resulted in higher BS for both Multilink and Clearfil SA. When Multilink was light-cured, no significant difference on BS was demonstrated between it and RelyX ARC. Conclusions: The highest BS values were obtained in control group and light-cured Multilink resin cement (AU)

Effect of light sources and curing mode techniques on sorption, solubility and biaxial flexural strength of a composite resin

Adequate polymerization plays an important role on the longevity of the composite resin restorations. OBJECTIVES: The aim of this study was to evaluate the effect of light-curing units, curing mode techniques and storage media on sorption, solubility and biaxial flexural strength (BFS) of a composite resin. MATERIAL AND METHODS: Two hundred and forty specimens were made of one composite resin (Esthet-X) in a stainless steel mold (2 mm x 8 mm Ø), and divided into 24 groups (n=10) established according to the 4 study factors: light-curing units: quartz tungsten halogen (QTH) lamp and light-emitting diodes (LED); energy densities: 16 J/cm² and 20 J/cm²; curing modes: conventional (CM) and pulse-delay (PD); and permeants: deionized water and 75% ethanol for 28 days. Sorption and solubility tests were performed according to ISO 4049:2000 specifications. All specimens were then tested for BFS according to ASTM F394-78 specification. Data were analyzed by three-way ANOVA followed by Tukey, Kruskal-Wallis and Mann-Whitney tests (α=0.05). RESULTS: In general, no significant differences were found regarding sorption, solubility or BFS means for the light-curing units and curing modes (p>0.05). Only LED unit using 16 J/cm² and PD using 10 s produced higher sorption and solubility values than QTH. Otherwise, using CM (16 J/cm²), LED produced lower values of BFS than QTH (p<0.05). 75% ethanol permeant produced higher values of sorption and solubility and lower values of BFS than water (p<0.05). CONCLUSION: Ethanol storage media produced more damage on composite resin than water. In general the LED and QTH curing units using 16 and 20 J/cm² by CM and PD curing modes produced no influence on the sorption, solubility or BFS of the tested resin.

Abordagens sobre o ozônio no tratamento de lesão cariosa e em procedimento restaurador adesivo / Approaches on ozone in the treatment of carious lesion and adhesive restorative procedure

O ozônio é uma variedade alotrópica do oxigênio constituída por uma molécula triatômica desse elemento. Tem sido considerado um potente oxidante que pode ser usado na Odontologia. O seu uso apresenta-se como nova alternativa no tratamento de lesões de cárie, uma vez que sua eficácia clínica tem sido comprovada por diversos estudos relacionados à inativação de vírus, bactérias e fungos. Em função de apresentar propriedade comprovada na inibição e/ou destruição de muitas bactérias da cavidade bucal - tais como Streptococcus mutans, Streptococcus sanguis e Actinomyces odontolyticus -, o seu uso no tratamento das lesões cariosas é baseado em sua atividade antimicrobiana, com diminuição da acidez do biofilme, possibilitando a difusão de íons cálcio e fosfato nas lesões cariosas e permitindo a remineralização da dentina e esmalte afetados. Atualmente, a ozonioterapia é considerada uma alternativa promissora pelo seu baixo custo de investimento e manutenção, facilidade de aplicação e resultados clínicos satisfatórios. Porém o ozônio decompõe-se rapidamente e a presença de radicais de oxigênio pode interferir na polimerização de materiais adesivos. Dessa forma, o objetivo deste trabalho é apresentar uma revisão de literatura sobre a utilização do ozônio no tratamento de lesões cariosas e seu efeito sobre procedimentos restauradores adesivos.