Avaliação das características de superfície e variação de massa de diferentes tipos de resina após escovação dentária simulada

Abstract

Introduction: The increasing of the aesthetic exigency by the patients and the continual development of materials – such as bulk fill and flow composites, demands a crescent need of studies on this area to evaluate the properties of the materials when submitted to the wear occasioned by toothbrushing abrasion over time. Objective: To evaluate the surface characteristics of restorations performed before and after the process of simulated toothbrushing and to compare the results between the composites. Materials and methods: In total, 80 samples were made (7x4mm), being 20 to each type of resin utilized, color A1: Bulk Fill One (3M/ESPE, St. Paul, MN, USA), Bulk Fill Flow (3M/ESPE, St. Paul, MN, USA), Z350XT (3M/ESPE St. Paul, MN, USA) and Z350XT Flow (3M/ESPE, St. Paul, MN, USA). After the confection of the specimens, the samples were immersed in distilled water for 24 hours and stored at 37°C in stove, moment that was performed the finishing and polishing with the sequence of sandpaper discs (TDV, Brasil). Half of the specimens was submitted to 60,000 cycles of simulated toothbrushing, meanwhile the other half was the control group (n=10). The surface of the restorations was evaluated through Scanning Electronic Microscopy (SEM), surface roughness (Ra), and weight loss (through measurements), in two moments: before and after the process of simulated toothbrushing. To the statistical analysis, it was used the variance analysis ANOVA two factors and Tukey’s post test. Results: In the analysis performed by SEM, in amplification of 500x, it was observed the presence of medium and small protruding particles in all resins tested after simulated toothbrushing, with exception of the resin Z350 flow. All materials presented increasing on Ra after simulated toothbrushing. Regarding to mass variation, there was not any significant statistical difference. Conclusion: The abrasive process occasioned by toothbrushing leads to changes on the particles disposition, which causes changes on the surface and increase on the roughness. On the other hand, there was not any difference regarding to mass variation.