Objective: Solutions containing fluoride-calcium-phosphate were reported to occlude open dentin tubules mainly with fluoroapatite precipitates by a rapid ionic reaction and be effective in treating dentin hypersensitivity. Although these solutions are innovative, their ability to reduce dentin permeability (Lp) is unknown. The aim of this study was to evaluate the effects of these solutions on Lp in an in vitro model.
Methods: Seven extracted, non-carious, and defect-free human third molars were sectioned transversely to obtain 0.5mm-thick discs just cervical to the occlusal DEJ. The discs were etched for 3 minutes in 6% citric acid, and rinsed with distilled water. Aqueous solutions of 5% disodium phosphate with 0.3% sodium fluoride (A) and 10% calcium chloride (B) were prepared. Solution A was applied to the discs using a cotton swab for 5 seconds, immediately followed by an application of solution B using another cotton swab for 5 additional seconds. This application was repeated three times on each disc, which was then rinsed with distilled water. The discs' Lp was measured before and after the application using a modified Pashley's quantitative fluid flow measuring system. Differences between the two measurements were compared with a paired t-test.
Results: All seven discs consistently indicated Lp reduction. There was a significant change in mean Lp (µL/(cm2・sec・cmH2O) ) following the AB solution application from baseline. (-0.20±0.19, p=0.035). The corresponding 95% confidence interval for the new change ranged from 0.020 to 0.379. Overall, an average of 26 % Lp decrease was observed after the AB solution application.
Conclusion: The AB solution application was effective in reducing the Lp of dentin discs. Supported by NIH KL2RR024983(TK), UL1RR024982, NIDCR DE11789, ADAHF, and NIST.