Effect of hydrogen peroxide application on color and surface roughness of two restorative materials

Aim: This study investigated the effect of an in-office bleaching technique on lightness, color and surface roughness of two commercially available materials: a resin-modified glass-ionomer cement and a nanohybrid resin composite. Methods: Twelve disk-shaped specimens were prepared with both materials. The samples were bleached with 35% hydrogen peroxide. Bleaching was tested initially onto a smooth surface and later onto a polished one of the same specimens. The effect of the treatments on lightness and color was verified with a spectrophotometer. Surface roughness was measured with a digital surface roughness tester. The data were statistically analyzed by repeated measures ANOVA and post hoc Tukey's test (alpha = 0.05). Results: Significant variation in lightness and color was observed on the resin-modified glass-ionomer cement after the first bleaching procedure. Roughness increased significantly only after polishing the resin-modified glass-ionomer cement surface. Composite color variation was evident in the last observation period, but roughness and lightness variation due to bleaching and polishing was not significant. Conclusion: The bleaching treatment caused significant color alterations on the materials tested. This study observed that the application of in-office bleaching onto the glass-ionomer cement promoted clinically observable color alteration, and polishing after bleaching is contraindicated for this material. (AU)

Knowledge of triathlon athletes about the relationship between oral health and performance

Introduction: The triathlon athletes have great energy loss due to physical activity of high intensity and resets are based on a highcarbohydrate diet and acid elements (acids replacers), both substrates to decay and periodontal disease. Objective: This study aimed to evaluate, through a questionnaire whether triathlon athletes relate oral health to their physical performance. Material and methods: We developed a questionnaire with 20 objective questions and applied during marathons and at fitness centers, in the city of Curitiba, in 2015. Results: The majority of athletes use supplements with high levels of carbohydrates and acids for energy replacement daily and do not brush their teeth after workouts / nutrition. Of the 254 respondents, only 96 relate oral health to their performance in sports. Conclusion: The athletes do not relate the importance of oral health care to performance and largely do not brush the teeth after the activities, leaving the oral environment more susceptible to the onset of periodontal disease and caries, which can decrease their performance. It is necessary to inform triathlon athletes about the relationship oral health x systemic health x performance, as well as the dentists about the need of oral health care for these athletes.