Atividade antibiofilme de nanopartículas poliméricas carregadas com ácido anacárdio e seu efeito desmineralizante em esmalte bovino

Abstract

Introduction: Caries represents a public health problem, which despite the prophylactic methods, is still very prevalent. It can be triggered by several factors, but its formation is dependente on the bacterial biofilm. Objective: To evaluate the anticaries prophilatic activity and the demineralization associated with anacardic acid loaded zein nanoparticles in bovine enamel slabs. Methodology: Standard cavities were made in 36 slabs, restored with conventional glass ionomer cement subjected to different treatments, while 12 sound slabs, without cavities were used as controls, 6 cleansed with the test nanoparticles and 6 with sterile saline solution. The slabs were submitted to Streptococcus mutans biofilm formation assay in BHI sterile broth supplemented with 10% glucose, cultured in microanaerobiosis. The antimicrobial effect was assessed by counting the CFU per mg of biofilm dried weight. The microhardness loss (ΔS) was measured at distances of 50 μm and 150 μm at different depths. The results were submitted to analysis of variance (ANOVA) with Tukey post-test, assuming a confidence level of 5%.Results and discussion: Although the CHX and AaNp-L-GIC groups were prominently superior to their pairs, no significant difference was found in the biofilm inhibition within the groups. However, the groups treated with anacardic acid nanoparticles presented a notorious reduction in the mean growth in comparasion to the other groups, demonstrating its antimicrobial effect. Regarding the loss of hardness, BNp-C-GIC group differed statistically from some groups, presenting the highest demineralization, what could be related to the nutrients removal from the biofilm. Conclusions: Our findings indicate that the use of polymeric anacardic acid nanoparticles, incorporated into the GIC or as cleanser, could be a prophylactic option against the S. mutans biofilm in both restored and unrestored enamel and as such could be tested as a potential anticaries agent