Efeito das nanopartículas de quitosana nas propriedades físicas de superfície da resina acrílica após desinfecção química

Abstract

Introduction: Chitosan nanoparticles have antifungal properties that allow their application as an inhibitor of biofilm formation on dental prostheses. Some disinfectant agents commercially used can cause changes in the physical properties of the acrylic resin. Objective: To evaluate the effect of chitosan nanoparticles (ChNPs) suspension on the surface roughness and color stability of thermopolymerizable acrylic resin, when used as a dental denture disinfectant. Methodology: Twenty samples of acrylic resin were made (4 x 2mm). Four groups were formed (n=5), according to the disinfectant agent: 1- 0.5% sodium hypochlorite (positive control); 2- Suspension of ChNPs; 3- Chitosan Solution; 4- Distilled water (negative control). Disinfectant agents were applied to the surface of the samples, according to each group, for 20 minutes, once a day, for 30 days; remaining in distilled water for the remainder of the period. Surface roughness (Ra) and color stability measurements (ΔE - CIE L*a*b* method) were performed in the initial period (before the first application) and after 30 days. Data were analyzed using the Student t test and one-way Anova (= 0,05). Results: The acrylic resin samples showed no change in roughness in 30 days, comparing the initial and final period, after application of the solutions of the groups ChNPs (0.08 ± 0.03) and distilled water (0.09 ± 0, 03). The chitosan (0.08 ± 0.02) and hypochlorite (0.17 ± 0.10) groups showed a significant increase in roughness when compared to the initial and finalperiod, and the hypochlorite group had the highest Ra value. All groups showed color change after application of the solutions (Hypochlorite=5.3; ChNPs=6.3; Chitosan=5.9; Water=4.9), with no statistical difference between them. It can be concluded that the use of ChNPs suspension as a disinfectant agent for acrylic resin did not change the roughness and caused color change, which did not differ from other investigated agents.