Abstract Objectives This is a double-blind, split-mouth, randomized clinical study that aims to evaluate the influence of bulk-fill composite packaging presented in syringes (BSy) and capsules (BCa), and the effect of selective enamel etching (SEE) on the clinical performance of class I and II bulk-fill resin composite restorations after 24 months. Methodology A total of 295 class I or class II restorations were performed on 70 patients. One universal adhesive was applied in all restorations. SEE was used in 148 restorations and self-etching mode (SET) in 147 restorations. After the adhesive application, cavities were restored with Filtek Bulk-fill Posterior Restorative in syringes (BSy), Filtek One Bulk-fill in capsules (BCa), or Filtek Supreme Ultra in syringes with the incremental technique (In). All restorations were evaluated using the FDI criteria after one week and after six, 12, and 24 months. Kaplan-Meier survival analysis and Pearson’s Chi-square test were used (α=0.05) for statistical analysis. Results After 24 months, 62 patients were evaluated and four restorations were lost due to fracture (one for SEEBSy, two for SEEIn, and one for SETIn). No significant differences in the fracture and retention rate were found between groups (p>0.05). SEE showed significantly fewer marginal adaptation defects than SET (p<0.05). BCa and BSy groups showed fewer marginal discrepancies compared to In (p<0.05). Restorations performed with BCa showed less color mismatch than BSy or In (p<0.05). Conclusion Although all restorations exhibited satisfactory clinical performance after 24 months of clinical service, the clinical behavior of class I and II restorations’ improved when performed with a bulk-fill composite in capsules, mainly when associated with a universal adhesive applied with SEE.

Abstract The objectives of this double-blind randomized clinical trial were to compare (a) the clinical times and (b) the occurrence and severity of postoperative sensitivity, of posterior restoration that used a universal adhesive, in a self-etch or selective enamel-etching technique, along with incremental or bulk-fill composites (presented in syringes or capsules). A total of 295 posterior restorations were placed according to the following groups: SETB – self-etch/bulk-fill in syringe; SETC – self-etch/bulk-fill in capsules; SETI – self-etch/incremental; SEEB – selective enamel-etching/bulk-fill in syringe; SEEC – selective enamel-etching/bulk-fill in capsules; and SEEI – selective enamel-etching/incremental. Clinical time was assessed by a reason (s/mm3) between the total volume of resin inserted and the total time required to perform the restorations. Postoperative sensitivity was evaluated using two scales (Numeric Rating Scale and Visual Analogue Scale). Mean clinical time results, analyzed by Wald’s Chi-square, showed significant statistical differences among all groups (p<0.001), indicating that the restorative strategy affected the time required for the restoration. A generalized estimating equation model statistical analysis, performed to compare postoperative sensitivity, showed that neither the restorative technique, the adhesive strategy nor the presentation mode of the bulk-fill composite affected the overall risk of postoperative sensitivity (4.06 [2.22–6.81]). The use of bulk-fill composite, presented in capsules or syringes, is less time consuming and does not increase the risk or intensity of postoperative sensitivity relative to the traditional incremental technique.

O objetivo deste estudo foi avaliar o efeito de dois agentes clareadores (peróxido de hidrogênio a 10% e 35%) sobre a estabilidade de cor e rugosidade superficial de dois compósitos, um nanohíbrido e um nanoparticulado. Os espécimes foram polidos, envelhecidos, manchados, clareados e polidos novamente. A ação dos agentes clareadores sobre os compósitos foi analisada em perfilômetro (rugosidade) e um espectrofotômetro (estabilidade de cor). A ação de polimento dos compósitos sobre a rugosidade superficial e a retomada da cor dos compósitos também foi avaliada. Os resultados foram analisados estatisticamente por ANOVA e teste de Tukey (5% de significância). A análise indicou que o compósito nanohíbrido foi mais afetado pelo manchamento. Os agentes clareadores não foram capazes de promover o clareamento dos compósitos ao longo do período de avaliação. O polimento da superfície retornou o compósito nanohíbrido à sua condição de cor original, o que não foi observado para o nanoparticulado. Além disso, o polimento não retornou a rugosidade de superfície dos compósitos para os valores originais. Os autores concluíram que o polimento da superfície após o clareamento não deve ser a opção de tratamento, uma vez que não foi possível inverter a rugosidade dos compósitos à sua rugosidade original, sugerindo que uma degradação mais extensa e irreversível pode ter ocorrido

The objective of this study was to evaluate the effect of two bleaching agents (10% and 35% hydrogen peroxide) on the color stability and surface roughness of two composites, one nanohybrid and one nanoparticle. Specimens were polished, aged, stained, bleached and polished again. The action of the bleaching agents on the composites was analyzed using a profilometer (surface roughness) and a spectrophotometer (color stability). The effect of polishing the composites on the surface roughness and the resumption of the composite color was also evaluated. The results were analyzed statistically by ANOVA and Tukey's test at 5% significance level. The analysis indicated that the nanohybrid composite was more affected by staining. The bleaching agents were not able to promote bleaching of either composite over the evaluation period. Surface polishing returned nanohybrid composite to its original color condition, which did not occur for the nanoparticle composite. Additionally, polishing did not return the surface roughness of either composite to its original value. It may be concluded that polishing surface after bleaching should not be the treatment of choice, as it was not possible to reverse the roughness of the composites to their original values, suggesting that a more extensive and irreversible degradation might have occurred.