Resposta da polpa dental ao capeamento direto com nanopartículas poliméricas carregadas com própolis vermelha brasileira: ensaio clínico randomizado triplo-cego

Abstract

Mineral trioxide aggregate (MTA) has been suggested as gold standard material for direct pulp capping treatment by trauma or during the removal of carious tissue. However, its low antibacterial activity and high cost have led researchers to discover other alternatives. Brazilian red propolis (PVB) has demonstrated excellent antimicrobial, antioxidant, anti-inflammatory activities and cell migration and proliferation induction. The aim of this clinical study was to evaluate pulp response to direct pulp capping with polymeric nanoparticles loaded with PVP (NPP) at two concentrations, 100μg and 50μg, and to MTA plus NPP, compared to the pulp response to conventional MTA. After preparation, the NPP was analyzed in infrared spectroscopy (FTIR). The in vitro cytotoxicity of the materials used in pulp capping was tested in macrophages J774.A1. For the clinical trial, third sixty molars were divided into fifteen groups (n = 4) according to the treatment and the experimental time (15, 45 and 60 days). After the intervention period, the teeth were extracted and processed for histological analysis. The inflammatory response of the pulp, the formation of a dentin bridge and the presence or absence of bacteria were observed. Statistical significance was assigned a value of p <0.05. There were no changes in the qualitative FTIR spectra of the NPPV exposed to UV radiation and the NPPV and MTA mixture. The direct pulp capping agents used in the study did not present cytotoxicity, which may be indicative of safety for clinical application. There was no significant difference between the experimental groups in relation to inflammatory responses and organization of the pulp tissue, however in the analysis of these variables a larger number of samples with characteristics of normal tissue was observed in the groups containing propolis in fifteen and 45 days. Regarding the formation of mineralized tissue, there was also no significant difference between the tested materials. The direct pulp capping agents used in the study were biocompatible and induced formation of mineralized tissue similar to the control.