Analysis of transmittance and degree of conversion of composite resins.

The objective of this study was to evaluate and correlate light transmittance (T), initial degree of conversion (IDC), and degree of conversion after 24 hr (DC24) for 22 composite resins (CR) for enamel and dentin use. The transmittance (n = 10) was measured with a spectrometer at a wavelength of 468.14 nm. The degree of conversion (DC; n = 5) was measured with Fourier Transform Near-Infrared Spectroscopy before polymerization, immediately after photoactivation, and 24 hr after photoactivation. Both sets of values are provided as percentages. ANOVA and Games-Howell (α = 5%) tests showed that Filtek Supreme Ultra gave the highest T values of all enamel CRs, while Esthet-X HD presented the lowest. Meanwhile, Venus diamond gave the highest values of all dentin CRs, while Esthet-X HD gave the lowest. For IDC and DC24, ANOVA showed differences between individual CRs and the two CR types (p < .0001). Despite the limitations of this study, it can be concluded that there was no correlation between T and either IDC or DC24 (p > .05); however, IDC and DC24 were strongly correlated (p < .05) by Pearson's correlation. That being said, as a higher DC reflects better mechanical properties, certain conclusions can be drawn about overall performance. The best IDC values were observed for the Opallis enamel resin and the Opallis and Premise dentin resins. Meanwhile, the best DC24 values were observed for the Opallis, Charisma, and Premise enamel resins and the Opallis and Premise dentin resins. Degree of conversion and light transmittance showed differences between composite resin types (enamel and dentin) and brands. It is important to know at the moment of composite choice taking into account mechanical and optical properties.

Impact of excessive gingival display on oral health-related quality of life in a Southern Brazilian young population.

AIM: To compare oral health-related quality of life (OHRQoL) between individuals with and without excessive gingival display (EGD). MATERIALS AND METHODS: A cross-sectional study was conducted in 53 individuals with EGD and 53 controls matched for sex and age. The outcome was OHRQoL, determined using the Oral Health Impact Profile (OHIP-14) and self-perceptions of satisfaction with smile aesthetics. A clinical examination was conducted to evaluate the smile line, colour of the teeth, tooth wear and malocclusion. Poisson regression was used to model the association between excessive gingival display and OHRQoL. RESULTS: Participants with EGD had higher total OHIP-14 score (4.81 ± 4.76) in comparison with the controls (1.85 ± 3.77; p < .001). The percentage of satisfied with smile individuals without and with EGD was 78.9% and 21.1%, respectively (p = .005). In the multivariate analysis, total OHIP-14 scores were 2.10-fold higher individuals with EGD, independently of the other variables analysed. Impacts were evident on the functional limitation, psychological discomfort, psychological disability and social handicap. CONCLUSIONS: The occurrence of EGD exerted a negative impact on OHRQoL independently of confounding variables in this specific population. The present findings justify the planning of treatment for individuals with EGD that impacts quality of life.

Randomized clinical trial of adhesive restorations in primary molars. 18-month results.

PURPOSE: To evaluate the clinical performance of adhesive restorations of resin composite and resin-modified glass-ionomer cements in primary molars. METHODS: This randomized clinical trial included subjects (5-9 year-old children) selected at two university centers (UFRGS and UNIFRA). The sample consisted of 132 primary molars presenting active cavitated carious lesions (with radiographic involvement of the inner half of the dentin), located on the occlusal and occlusal-proximal surface. The sample was randomly divided into three groups, according to the restorative material: (G1) universal restorative system (Adper Single Bond 2 system and Filtek Z350); (G2): Resin-modified glass-ionomer cement (Vitremer); and (G3): Low shrink restorative system (Filtek P90). The restorations were clinically and radiographically followed every 6 months for up to 18 months using the USPHS modified criteria for clinical evaluation. Survival estimates for restoration longevity were evaluated using the Kaplan-Meier method. Log-rank test (P< 0.05) was used to compare the differences in the success rate according to the type of the restorative material. RESULTS: The type of restorative material used did not influence the longevity of the restorations. After clinical follow-up, there was no statistical difference in the rates of success for the three materials used to restore active cavitated carious lesions in primary molars. The survival rates for the follow-up were similar regarding the number of restored surfaces and the caries removal technique (partial or complete). Mean estimated time of survival was 17.2 months (95% CI: 16.7-17.7). Estimated survival rates of the restorations were 100%, 98%, 88% and 65% at 1, 6, 12 and 18 months of clinical evaluations, respectively.

Evaluation of mechanical properties on three nanofilled composites.

The purpose of this study was to evaluate the mechanical behavior of three composites with nanoparticles Filtek Z350 XT (3M ESPE), Esthet X (Dentsply), Grandio (Voco) in enamel and body shades (A2) trough nanohardness, elastic modulus, compressive strength test, flexural strength test, diametral tensile strength, flexural modulus, weight filler content and Knoop microhardness. One sample of each material was submitted to nanohardness and elastic modulus. Five values of ten indentations were considered valids inside confidence intereval. Ten samples of each material were submitted to compressive strength, flexural strength and diametral tensile strength test at universal testing machine. The flexural modulus test was calculated based on flexural strength results. Ten samples of each group were submitted to knoop microhardness test. The results were submitted to ANOVA and Tukey statistical tests. The highest inorganic weight filler content for Grandio was registered after the organic mould decomposition. After statistical analysis Grandio showed the highest averages for nanohardness, elastic modulus, flexural modulus and knoop microhardness. For diametral tensile strength Grandio and Filtek Z350 XT obtained the highest averages. The tested composite resins ranged similar medias statistically for compressive strength. For flexural strength Filtek Z350 XT and Esthet X showed the highest averages. The results suggest that the weight filler content, the filler size and shape and the contact surface between nanofillers and organic phase has direct relation with composite resins with nanoparticles mechanical properties. Further studies should be carried out to improve the knowledge of composites with nanoparticles mechanical behavior.

Avaliação clínica de restaurações de resina composta em dentes posteriores / Clinical evaluation of composite restorations in posterior teeth

Este estudo avalia o comportamento clínico de restaurações diretas de resina composta em dentes posteriores. Para tanto, toma uma série de casos de acompanhamento longitudinal, com a realização de 55 restaurações de classe I e II. Os operadores são alunos de Odontologia do Centro Universitário Franciscano (Unifra, RS). A avaliação foi feita seis meses após a confecção das restaurações, e foi utilizado o critério United States Public Health Service (USPHS) modificado: forma anatômica, estabilidade da cor, descoloração marginal, integridade marginal e lesão de cárie secundária. Foram avaliadas 54 (98,2%) restaurações, delas, duas falharam, e o índice de sobrevivência foi de 91,78%. Conclui que o desempenho clínico das restaurações é aceitável.

This article aims to evaluate the clinical performance of direct composite resin restorations in posterior teeth. Methods: Case series of longitudinal, with the completion of 55 restorations, class I and II. The operators were dental students from Franciscan University Center (Unifra) RS, Brazil. The evaluation was conducted six months after making these, and criterion was utilized United States Public Health Service (USPHS) modified: anatomical form, color stability, marginal discoloration, marginal integrity and caries secondary. A total of 54 (98.2%) restorations, of whom two failed, and the survival rate was 91.78%. In conclusion, it finds that the clinical performance of the restorations was acceptable.

Influência do método de polimerização na microdureza de compósitos microhíbridos armazenados em água destilada / Influence of curing method on the micro hardness of microhybrid composites immersed in distilled water

O objetivo do presente estudo é comparar e avaliar a microdureza Vickers de um compósito restaurador microhíbrido ativado por dois tipos de unidades polimerizadoras e armazenados em água destilada. Trinta espécimes foram feitos com resina Charisma B1, para cada um dos regimes de polimerização: fotopolimerização por luz halógena, fotopolimerização por LED e fotopolimerização mais ciclo adicional em autoclave. Foram feitas duas leituras de microdureza Vickers por corpo de prova em 1 dia, 7 dias e 14 dias de imersões. O ciclo adicional de polimerização mostrou uma tendência de aumentar os valores de microdureza dos compósitos restauradores, não mostrando diferenças estatisticamente significantes entre LED e Luz Halógena (p > 0,05).

The purpose of this study is to evaluate and compare the Vickers microhardness of one microhybrid composite polymerized with different sources and stored in distilled water for up to 14 days. Thirty samples have been prepared with Charisma composite, shade B1, for each polymerization method: halogen light photopolymerization, LED photopolymerization, photopolymerization plus post-cured cycles in autoclave. Two readings of Vichers micro hardness have been done in each sample on 24h, 7days and 14 days of storage. The post curing method tended to improve the microhardness, but it was not statistically different from halogen or LED curing methods (p > 0.05). After 7 days, the hardness values were higher than the first day, but statistically not different to 14 days (p < 0.05). Post-cured samples in autoclave had an improved mean value, however, without differing from those of the LED and halogen.