Reduction in dentin permeability using a slurry containing dicalcium phosphate and calcium hydroxide

Treatments that obdurate dentin tubules have been used for reducing dentin hypersensitivity. The purpose of this study was to determine the effect of a treatment with a slurry of micron sized calcium phosphate on the hydraulic conductance ( L p ) of etched dentin discs in vitro. The treatment slurry was prepared by mixing a powder mixture of dicalcium phosphate anhydrous and calcium hydroxide with a solution that contained sodium fluoride and carboxymethyl cellulose. The mean baseline L p (in mL cm −2 s –1 H 2 O cm –1 ) was 2.07 ± 1.45 (mean ± SD; n = 13)). After one treatment and 2, 4, and 7 days of incubation in a protein‐free saliva‐like solution (SLS), the mean relative L p , presented as % of baseline, were 65 ± 16, 42 ± 27, 36 ± 26, and 33 ± 27 ( n = 13), respectively. The L p values of the baseline and treatment after incubation in the SLS were significantly ( p < 0.05) different. Scanning electron microscopic examination showed partial obturation of dentin tubules in the treated dentin. X‐ray diffraction and chemical analyses indicated the major product formed from the slurry was a fluoride‐containing hydroxyapatite. Treatment appeared effective in further reducing L p of dentin discs after incubation in the SLS. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006