Comparative Effects of Experimental Bioactive Glasses on Dentin Permeability and Tubule Occlusion In Vitro

This study aimed to evaluate the effects of experimental bioactive glass solutions on dentinal fluid flow and hydraulic conductance in vitro. Dentin blocks of 50 bovine incisors were divided into 5 groups according to the desensitizing agent used (n = 10): Group 1-control (no treatment); Group 2-Bioglass^® 45S5; Group 3-Bioglass^® F18; Group 4-Biosilicate gel; Group 5-Desensibilize Nano P (FGM). Treatments were applied for 20 min daily over 15 days. The specimens were subjected to a citric acid challenge to simulate oral demineralizing conditions. Dentinal fluid flow and hydraulic conductance were evaluated before and after the desensitizing procedures and the acidic challenge. Scanning electron microscopy (SEM) provided qualitative dentin surface analysis. Dentinal fluid flow and hydraulic conductance data were analyzed by two-way repeated measures ANOVA and Tukey's test (α = 0.05). The control group showed the highest dentinal fluid flow and hydraulic conductance values after the acid challenge (p < 0.05). After product application, Bioglass^® 45S5 and Bioglass^® F18 showed the lowest dentinal fluid flow (0.463 ± 0.124 Lp and 0.549 ± 0.239 Lp, respectively) and hydraulic conductance values (0.025 ± 0.007 Lp and 0.026 ± 0.007 Lp, respectively), differing significantly from Biosilicate Gel and Desensibilize Nano P (p < 0.0001). Biosilicate Gel and Desensibilize Nano P showed higher dentinal fluid flow (0.864 ± 0.180 Lp and 0.840 ± 0.173 Lp, respectively) and hydraulic conductance values (0.047 ± 0.010 Lp and 0.046 ± 0.009 Lp, respectively) after application (p < 0.0001). After the acid challenge, no significant differences were observed among the groups (p > 0.05), although all experimental groups showed numerically lower values than the control group. Bioactive glass-based desensitizing agents reduced dentinal fluid flow and hydraulic conductance, suggesting dentinal tubule occlusion. Bioglass^® 45S5 and Bioglass^® F18 showed the most stable performance, maintaining lower values even after the acid challenge, suggesting potential for the management of dentin hypersensitivity.