Objective: This study aims to evaluate the effect of acidic solutions (AS) on surface roughness (Ra) and microhardness of restorative materials (RM). Materials and Methods: Eight volunteers wore intraoral palatal devices (IPD) containing samples of RM: Ketac Nano (KN); Ketac Nano + Biscover LV (KN-B); Esthet-X (EX); Esthet-X + Biscover LV (EX-B); Supreme XT (SXT); Supreme XT + Biscover LV (SXT-B); and bovine enamel. The samples were submitted to three phases: (1) immersion in 0.01M hydrochloric acid (HCl) – 10 min, three times/day (14 days); (2) immersion in soft drink (Sprite®) – 10 min, three times/day (14 days); and (3) keeping in saliva (14 days). Changes in Ra/microhardness were measured before/after the three phases. Statistical Analysis: ANOVA (α = 0.05) and Fisher's test. Results: Materials sealed with Biscover LV (B) presented lowest values in all periods. KN glass ionomer cement showed highest Ra values after exposure in AS. Application of B did not reduce the Ra for the composites studied, except for EX after immersion in HCl. AS promoted changes in Ra/microhardness of RM, except for sealed materials. Conclusions: The acids used were able to change the Ra and microhardness of RM, except of the sealed materials. The resin-modified GIC showed the most significant changes after immersion in AS; and the composites sealed with B, even after immersion in acidic solutions (AS), showed the lowest Ra values and the least degradation in microhardness, especially when subjected to low pH solutions.
1 December 2019 in Journal of the Mechanical Behavior of Biomedical Materials
This case report presents a minimally invasive diastema treatment using cordless gingival displacement system allowing a very conservative intervention. A 32-year-old female patient who presented with diastema in her upper front teeth opted for a treatment using laminate veneers to ensure achieving adequate tooth proportion and gingival levels. Having a displacement material that exerts excessive pressure during the displacement process can lead to disruption of the junctional epithelium and damage to periodontal tissues. This case report focuses on the effectiveness of the use of a minimally invasive method of gingival management. Two-year follow-up no infiltration, sensitivities, or fractures were detected on teeth, and indirect restorations, the purposed treatment allowed a quick, effective, and durable resolution for diastema.
Objective: the aim of this study to evaluate the microhardness and color change (?E) of composite resins, light cured with different LEDs, submitted to staining drink. Materials and Methods: Two composite resins with lucerin-TPO (Tetric N-Ceram/ Vit-l-escence) and camphorquinone (Filtek Z350) were select. Specimens (n=120) were prepared. Then were photopolymerized with LED of singlewave or polywave. Microhardness and color evaluations were performed before and after chalanges. Data were evaluated by two-way ANOVA, Tukey's test (p?0,05). Results: No statistically significant difference between the two generations of LEDs was found for microhardness data. Regarding the ?E, statistical difference between the two LEDs was observed for Tetric N- Ceram and Filtek Z350. Conclusion: Compostion of composites appears to have more influence on analyses than the type of LEDs.