SUMMARY Objectives: This study aimed to evaluate the hydrolytic degradation ( in vitro ) and biodegradation ( in situ ) of different resin composites: bulk-fill (XTra Fill, XTF/VOCO; Tetric EvoCeram Bulk Fil, TBF/ Ivoclar Vivadent), self-adhering (Vertise Flow, VTF/ Kerr; Fusio Liquid Dentin, FUS/ Pentron Clinical), and a conventional resin composite (Filtek Z250, Z250/ 3M ESPE), which was used as a control. Methods and Materials: Seventy-five cylindrical specimens (7 × 1 mm) were desiccated and immersed into distilled water (DW), artificial saliva (AS), and 0.1 M lactic acid (LA) (n=5) for 180 days. Specimens were weighed after 180 days, after which they were desiccated again. The sorption (μg/mm 3 ) and solubility (μg/mm 3 ) were calculated based on ISO 4049. For the in situ phase, an intraoral palatal device containing five cylindrical specimens (5 × 1.5 mm) was used by 20 volunteers for seven days. Surface roughness was evaluated before and after this period to analyze the superficial biodegradation. Sorption and solubility data were submitted to Kruskal-Wallis and Mann-Whitney tests. The Wilcoxon signed-rank test was used to compare roughness at different observation times. The statistical significance for all tests was considered α =0.05. Results: For in vitro , self-adhering resin composites (VTF and FUS) showed, respectively, higher sorption values independent of the solution (62.55 and 50.81 μg/mm 3 in DW, 67.26 and 50.46 μg/mm 3 in AS, and 64.98 and 59.86 μg/mm 3 in LA). Self-adhering VTF also had a greater solubility value in DW (22.18 μg/mm 3 ) and FUS in LA (65.87 μg/mm 3 ). In AS, the bulk-fill resin composite XTF showed higher solubility (22.13 μg/mm 3 ). All resins were biodegraded, but the XTF specimens were more resistant ( p =0.278) to chemical attack. Conclusions: The self-adhering resin composites showed the highest hydrolytic degradation, and the bulk-fill resin composites exhibited comparable or superior results to the conventional resin composites. Not all resin composites underwent biodegradation in the in situ environment. The storage environment influenced the final characteristics of each material tested.
Clinical Relevance The new formulations of nano-silver fluoride caused less dentin staining than the already available commercial agents 35% silver fluoride and silver diamine fluoride at 30% and 38%. SUMMARY The objective of this study was to evaluate the dentin staining potential of nano-silver fluoride (NSF 600 and 1500 ppm) compared with the following commercially available cariostatic agents: Advantage Arrest (Elevate Oral Care, West Palm Beach, FL, USA), Riva Star (SDI, Victoria, Australia), and Cariestop (Biodinâmica, Paraná, Brazil). Seventy-five extracted human molars were sectioned at the cementoenamel junction, and the occlusal enamel was removed for exposure of coronary dentin. The samples were divided among the five agents tested (n=15). The dentin staining (ΔE/ΔL) was analyzed with a digital spectrophotometer (VITA Easyshade, VITA Zahnfabrik, Bad Säckingen, Germany) at three different time points (before application, after two weeks, and after four weeks). Photographic images were also performed. The Kruskal-Wallis and Mann-Whitney tests compared the mean ΔE and ΔL values between groups. The NSF 600 and 1500 ppm resulted in the smallest color change (ΔE=1.02 and 1.53) and dentin staining after four weeks (ΔL=−0.76 and −1.2). The new formulations differed significantly from the commercial cariostatic agents ( p <0.001). NSF might be an alternative to silver diamine fluoride since it does not compromise esthetics.
SUMMARY The objective of this longitudinal clinical randomized trial was to evaluate the clinical performance of a nanofilled and a nanohybrid resin composite in Class I occlusal restorations of posterior teeth over the course of 54 months. Forty-one adolescents participated in the study. The teeth were restored with Adper Single Bond 2 (3M ESPE) and nanofilled (Filtek Z350, 3M ESPE), nanohybrid (Esthet-X, Dentsply) and microhybrid Filtek Z250 (3M ESPE) used as a control. After 54 months, the restorations were evaluated in accordance with the modified United States Public Health Service criteria. The McNemar and Friedman tests were used for statistical analysis, at a level of significance of 5%. Five failed restorations were observed during the follow-up. A change to unacceptable restoration occurred for one Esthet-X, two Filtek Z350, and two Filtek Z250 restorations, which received the clinically unacceptable score, Charlie, for both anatomic form and marginal adaptation. Secondary caries and postoperative sensitivity occurred in one Filtek Z250 and one Filtek Z350 restoration. When the five evaluation periods (baseline and six, 12, 30, and 54 months) were compared, significant differences were found in the marginal adaptation of Filtek Z250 and Filtek Z350. Significant differences in the roughness criteria ( p =0.005) were also observed when the three composites were compared after 54 months (Filtek Z350 > Filtek Z250 > Esthet-X), always within clinically acceptable limits. The materials investigated showed acceptable clinical performance for Class I restoration after 54 months. Long-term reevaluations are necessary for a more detailed analysis of these composites.