Effect of desensitizing agents on dentin permeability and dentin tubule occlusion.

Purpose: The aim of this study was to evaluate: 1) the effect of five dentin desensitizing agents (DDAs) on permeability, using hydraulic conductance, and 2) morphological tubule changes, with scanning electron microscopy (SEM). The agents can be categorized by their proposed mechanism of decreasing fluid flow in the dentinal tubules; i.e., resin occlusion: Seal and Protect, Gluma & HurriSeal, precipitation of proteins: Gluma, or precipitation of crystals: D/Sense 2 & Super Seal. Materials and Methods: Thirty extracted human molars were sectioned into 1mm mid-coronal dentin disks. Dentin permeability was measured at baseline and after treatment using bovine serum and phosphate-buffered saline at 10psi. Treatments were applied to the occlusal surfaces of dentin according to the manufactures’ instructions. Representatives from each group were selected for SEM observation. Kruskal-Wallis ANOVA and Tukey’s were used to evaluate differences between groups. Results: Mean percent reduction in dentin permeability for each group: SuperSeal= 97.5±4.0, HurriSeal= 54.2±35.3, D/Sense 2= 46.6±20.4, Gluma = 39.6±26.7, and Seal & Protect = 33.8±19.4. The data provided strong evidence of differences in permeability reduction among the agents (p<0.01). Pairwise comparisons of means demonstrated the effects of SuperSeal differed significantly from the reductions achieved using Seal & Protect, Gluma, and D/Sense 2. Differences in the degree and content of dentinal tubule occlusion were seen among all DDAs under SEM. Conclusions: Of the materials tested, SuperSeal may be the most beneficial when treating dentin sensitivity. The wide range of results may reflect the various approaches and chemistries used to occlude tubules.