No abstract

No abstract

A reabilitação oral com prótese total removível (PTR) visa à devolução de estética e função aos pacientes desdentados, apesar de ser considerada facilitadora de várias patologias bucais. Assim, o objetivo deste estudo foi conhecer os hábitos de higiene bucal dos usuários de PTR, o estado de conservação associado à presença de lesões bucais e o recebimento de orientação profissional. Sessenta usuários de PTR foram entrevistados e suas próteses avaliadas quanto à higiene, conservação e saúde bucal. Observou-se que 96,7% dos pesquisados não receberam orientação profissional, o método mecânico foi o mais utilizado para higienização e realizado três vezes ao dia (36,7%). A higiene das PTR apresentou-se moderada e as características funcionais estavam insatisfatórias. A queilite angular não teve significância estatística, quando associada ao nível de higiene. A ausência de retenção e estabilidade estática associou com as lesões no maxilar inferior (p=0,02). As características deficientes das PTR representam uma tendência para a ocorrência de lesões bucais e os participantes, apesar da higiene frequente, não conheciam a forma correta de higienização e não receberam orientação que a PTR poderia causar lesões bucais.

This study aimed to compare the effect of four irrigation solutions for post space cleaning on the bond strength between glass fiber post and root dentine. Forty bovine roots were root-filled and randomly divided into four groups (n=10), according to the irrigation solution: CG (Control Group): saline solution; SH (Sodium Hypochlorite Group); CLX (Chlorhexidine group) and EDTA (ethylenediaminetetraacetic acid group). Specimens were submitted to mechanical aging and push-out test. Statistical analysis (ANOVA two-way and Tukey test; p<0.05) was performed. A stereomicroscope was used for failure mode classification. EDTA showed higher bond strength values, differing statistically from SH and CG (p<0.05). Adhesive failure between dentin and resinous cement was predominant, followed by mixed failures. SEM images showed pronounced smear layer removal in the EDTA group. 17 % EDTA was better than other solutions for cleaning of post space when using glass fiber posts.

The aim of this study was to determine if multiple processing (heat-pressing) of a dental ceramic influences flexural strength, hardness, and microstructure. Ninety bar-shaped specimens (15 mm × 4 mm × 2 mm) of a pressed ceramic (Vita PM9) were fabricated and randomly divided into 6 groups (n = 15) according to the factors "number of pressings" (C1, C2, and C3, fired 1, 2, and 3 times, respectively) and "mechanical cycling" (M). Half of the specimens were mechanically cycled (10 6 cycles, 45 N, 3.4 Hz, in water) and all specimens were tested for 3-point bending (0.5 mm/min, load 1000 kgf) and Vickers hardness (19.6 N for 20 s). X-ray diffraction was used to characterize the phases and scanning electron microscopy to characterize the microstructure. The flexural strength data was statistically analyzed with Weibull analysis, ANOVA, and Tukey test. Hardness data was evaluated by 2-way ANOVA and Fisher test. All tests were performed with a significance level of 0.05. Two-way ANOVA revealed that neither "number of pressings" (p=0.085) or "mechanical cycling" (0.055) significantly affected flexural strength. But Weibull analysis showed significant difference for Weibull moduli and characteristic strength between groups. For hardness, a statistical difference was seen for the interaction "Number of pressings * Mechanical cycling", (p = 0.016). Hardness decreased in the following order: C1 (775±17.2), CM3 (751±101), CM2 (735±45), C3 (701±82), CM1 (671±82), and C2 (663±92). Fewer defects were observed with an increased number of firings. Therefore, the possibility of recycling PM9 ceramic does not interfere in the evaluated mechanical properties and improves microstructure.