title: Reduction in dentin permeability using a slurry containing dicalcium phosphate and calcium hydroxide.
abstract: 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.
authors.affiliation: American Dental Association Foundation, Paffenbarger Research Center, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA. maria.cherng@nist.gov
authors.forename: Aishuan Maria
authors.initials: AM
authors.lastname: Cherng
authors.forename: Shozo
authors.initials: S
authors.lastname: Takagi
authors.forename: Laurence
authors.initials: L
authors.lastname: Chow
mesh_terms: D002126:Calcium Hydroxide / Q000737:chemistry*; D002130:Calcium Phosphates / Q000737:chemistry*; D002266:Carboxymethylcellulose Sodium; D003804:Dentin / Q000648:ultrastructure; D003806:Dentin Permeability; D006801:Humans; D012969:Sodium Fluoride; D013997:Time Factors
chemical_list: D002130:Calcium Phosphates; D012969:Sodium Fluoride; D002266:Carboxymethylcellulose Sodium; C485829:calcium phosphate, dibasic, anhydrous; D002126:Calcium Hydroxide