Effect of three dessentizing agents on dentin permeability

Objectives: Evaluate the effect of three desensitizing agents on reducing permeability immediately and after simulation of oral cavity’s conditions.
Methods: Fifteen (15) extracted non-carious human third molar teeth were sectioned to obtain 0.7mm thick mid-coronal dentin disks. The specimens were assigned to three groups and treated with: 1) fluoride varnish (5% Duraphat ® Colgate Palmolive, New York, United States of America) (DP); 2) toothpaste with 8% arginine in a calcium carbonate and silica-based (CG) (Sensitive Pro-Relief^TM Colgate-Palmolive, NY, USA) and a 3) toothpaste containing Casein Phosphopeptides- Amourphous Calcium Phosphate (CPP-ACP) (Tooth Mousse®, GC Corp, Tokyo, Japan). All specimens were then exposed to conditions similar to the oral cavity (artificial saliva and citric acid). A modified Pashley´s hydraulic pressure system was used to measure dentin permeability at baseline, after product and after artificial saliva and citric acid. ANOVA and Scheffe´s post-hoc comparisons were used to evaluate differences among groups (α=0.05).
Results: The three agents showed a significant reduction on dentin permeability (p<0,02). The percentage of permeability reduction did not differ significantly among the three agents on the immediate, although DP had the higher permeability reduction (88%), follow by CPP-ACP (69,74%), and CG (64,04%). On each group, there is no significant change on permeability reduction comparing the three different moments. Nonetheless, the comparison of the three agents on the three moments, showed a significant difference between DP and CPP-ACP after the exposure to artificial saliva and citric acid (p <0,05), being DP more efficient on these later conditions.
Conclusions: These three agents should be consider to dentin hypersensibility treatment, because of their capacity on reducing dentin permeability. After the simulation of oral cavity conditions their action is reduced but not significantly. CPP-ACP probably needs multiple applications to be efficient.