Effect of hygiene protocols on color change, roughness, wettability and hardness, and on the biofilm formed on the surface of 3D-printed teeth resin and 3D-printed base resin of complete dentures.

Abstract

This study aims to evaluate the effect of hygiene protocols on physical properties such ascolor change, roughness and wettability and mechanical property such as hardness, and onthe biofilm formed on the surface of acrylic resin for impression of base and teeth ofcomplete dentures (Makertech ) and compare the results with those of conventional resins(Clássico, for base; Vipi, artificial teeth). Circular specimens (20.8 mm Ø x 4 mm) will beobtained for the color change, hardness, roughness, wettability tests (n=10), and circularspecimens (6 mm Ø x 2 mm) will be obtained for microbiological assays. They will berandomly distributed into the following groups: 1. Brushing and immersion in whater; 2.brushing and immersion in 0.25% sodium hypochlorite; 3. brushing and immersion in0.15% Triclosan. Daily 6-minute brushing (brushing machine) (simulating three 2-minutebrushings) with a soft brush and neutral soap and daily 20-minute immersions will be used.The measurements of color change, hardness and surface roughness will be performedimmediately after obtaining the specimens (T0) and after simulating 01 (T1), 03 (T2) and05 (T3) years of exposure to hygiene protocols. Wettability evaluation will be carried outon the surface of the specimens only at T0. The analysis of biofilm formation and the effectof hygiene protocols on mixed biofilm of Candida albicans, Staphylococcus aureus andStreptococcus mutans (n=9/group) will be measured by counting Colony Forming Units(CFU) and by epifluorescence microscopy after 20-seconds brushing and 20-minutesoaking. Data will be evaluated for normal distribution (Shapiro-Wilk Test) andhomoscedasticity (Levene Test) to define the statistical tests to be used, considering a 95%confidence interval (SPSS 21.0 software) and the performance of multifactorial analyzeswith linked factor.