Reduction in dentin permeability using mildly supersaturated calcium phosphate solutions

Abstract 

Treatments that obturate dentin tubules have been used for reducing dentin hypersensitivity. The objective of this study was to determine the effects of multiple treatments with a mildly supersaturated calcium phosphate solution on the hydraulic conductance (Lp) of partially occluded dentin discs in vitro. The treatment solution contained 6.5mmoll⁻¹ each of calcium and phosphate, 0.25mmoll⁻¹ fluoride, 30mmoll⁻¹ KCl, and 50mmoll⁻¹ HEPES buffer (pH adjusted to 7.0). The mean baseline Lp (in μlcm⁻²min⁻¹ H₂O cm⁻¹) was 0.108±0.041 (mean ± S.D.; n=9, μlcm⁻²min⁻¹ H₂O cm⁻¹ = 10.20μlcm⁻²min⁻¹KPa⁻¹) and after five consecutive treatments, the mean relative Lp, presented as percentage of baseline, were 71±11, 58±10, 46±18, 40±14, and 25±10, respectively. The Lp values of the baseline and treatment groups were significantly (P<0.05) different. Consecutive treatments appeared effective in further reducing Lp of dentin discs.

Keywords:  Calcium phosphate, Smear layer, Multiple treatments, Tubule obturation, Dentin permeability