Citotoxicidade e alteração da composição dentinária promovida por diferentes removedores químico-mecânicos de cárie: um estudo preliminar in vitro

Abstract

This study aimed to assess the cytotoxicity of chemomechanical caries removal agents (Brix 3000™ - BX and Papacarie Duo™ - PD) when applied at different dilutions directly to the pulp cells from deciduous teeth, as well as to assess the morphology and chemical compositions of the dentin surface after applying these materials. The cells from dental pulp were seeded (20,000 cells/cm²) using a culture medium (DMEM with 10% bovine fetal serum - BFS). After 24 hours, the BX and PD materials were added to dilutions of 1:20, 1:100, and 1:1000. The cells that only contacted the culture medium without BFS were considered the control group. The viability test (MTT), trypan blue assay (TB), and cell morphology test (Scanning Electron Microscopy - SEM) were performed after 24 hours of contact with the agents. For the morphological (SEM) and chemical (energy-dispersive X-ray spectrometry - EDS) dentin analyses, 0.3-mm-thick dentin discs were obtained and divided into the following groups: control (no treatment) and surface covered with phosphoric acid, BX, or PD. The statistical analysis was performed using one-way ANOVA and Tukey's test (p<0.05). The MTT results indicated a viability decrease of 47.5%, 28.7%, and 18.9% for BX and 80.2%, 55.3%, and 25.3% for PD, at dilutions of 1:20, 1:100, and 1:1000 respectively, compared to the control group (p<0.05). Similarly, the number of viable cells decreased 42.2%, 36.0% and 17.2% for BX and 64.1%, 53.2% and 40.7% for PD, at dilutions of 1:20, 1:100, and 1:1000 respectively, compared to the control group (p<0.05). The SEM images showed a lower number of cells and morphological changes for both agents, especially at dilutions of 1:20 and 1:100. The BX and PD materials did not cause visually perceptible changes by SEM on the surface of dentinal discs. The chemical analysis (EDS) did not indicate a statistical difference in the levels of calcium (Ca) and phosphorus (P) between the materials and the control group (P<0.05). Both materials presented cytotoxicity in direct contact with the pulp cells from deciduous teeth, and the BX material presented lower cytotoxicity than the PD material. Moreover, both materials could not change significantly the dentinal structure.