Evaluation of surface loss and tubular occlusion of dentin, and cell differentiation with different in-office treatments for dentin hypersensitivity, associated or not with photobiomodulation therapy

Abstract

The aims of this study are: 1. to verify the effects of an experimental bioglass on the tubular occlusion and the loss of dentine structure, against erosive and abrasive challenges, comparing it with other in office desensitizing products; 2. to analyze the effects of the association of bioglass and other treatments with photobiomodulation therapy on the differentiation of pulp stem cells, indicating the potential for tertiary dentin formation and biological occlusion of the dentinal tubules. In the first phase of the study, the following treatments: negative control (distilled water); BV: bioglass; NP: NuPro®; CXT: ClinPro" XT Varnish will be tested for Dentin Permeability (DP) and Surface Loss (SL) using human dentin disks (1 mm). To simulate the hypersensitive dentin, 17% EDTA solution will be applied for 5 minutes. After analyzing the maximum permeability, the fragments will be randomly allocated in the 4 experimental groups (n = 12) and the treatments will be applied. The specimens will then undergo an erosion-abrasion cycling for 5 days. DP will be analyzed after cycling. The percentage of dentin permeability for each experimental time will be calculated in relation to the maximum permeability (%Lp). Three Scanning Electron Microscopy images (SEM-A) will be performed for illustration. The SL will be analyzed with the optical profilometer. In the second phase, the same treatments will be tested, associated or not to the photobiomodulation therapy [PBM - indium-gallium-aluminum phosphide diode laser, InGAlP, (660 nm, 0.028 cm2, 20 mW, 0.71 W/cm2, 5 J/cm2) 7 s, continuous mode, punctual and in contact], regarding the differentiation of human dental pulp stem cells. For this, dentin disks (1.5 mm thick) will be coupled in an artificial pulp chamber, in order to allow the investigation of the indirect effects of the treatments on the pulp cells. The alizarin red test will be performed to quantify the optical density. The data will be submitted to adequate statistical analysis, considering ±=0.05. (AU)