This Article Full Text (PDF) References Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Saved Citations Download to citation manager Request Permissions Request Reprints Add to My Marked Citations Citing Articles Citing Articles via Google Scholar Citing Articles via Scopus Google Scholar Articles by Suge, T. Articles by Ebisu, S. Search for Related Content PubMed PubMed Citation Articles by Suge, T. Articles by Ebisu, S. Social Bookmarking                         What's this?

Duration of Dentinal Tubule Occlusion Formed by Calcium Phosphate Precipitation Method: In vitro Evaluation Using Synthetic Saliva

Department of Conservative Dentistry, School of Dentistry, Tokushima University, 3-18-15 Kuramoto, Tokushima, 770 Japan

K. Ishikawa

Department of Dental Engineering, School of Dentistry, Tokushima University, 3-18-15 Kuramoto, Tokushima, 770 Japan

A. Kawasaki

Department of Conservative Dentistry, School of Dentistry, Tokushima University, 3-18-15 Kuramoto, Tokushima, 770 Japan

M. Yoshiyama

Department of Conservative Dentistry, School of Dentistry, Tokushima University, 3-18-15 Kuramoto, Tokushima, 770 Japan

K. Asaoka

Department of Dental Engineering, School of Dentistry, Tokushima University, 3-18-15 Kuramoto, Tokushima, 770 Japan

S. Ebisu

Department of Conservative Dentistry, School of Dentistry, Tokushima University, 3-18-15 Kuramoto, Tokushima, 770 Japan

The use of a calcium phosphate precipitation method occluded dentin tubules with apatitic mineral and, thus, showed good potential for the treatment of dentin hypersensitivity. The aim of this study was to elucidate the occluding behavior of the precipitate in the oral environment. Dentin disks treated by the calcium phosphate precipitation method, and disks treated with potassium oxalate, NaF, and SrCl₂ solutions, were immersed in synthetic saliva, which was regularly replenished so that ionic concentration would be maintained. Treatment of dentin disks by the calcium phosphate precipitation method immediately reduced dentin permeability to 6 ± 8%. When the disk was immersed in synthetic saliva, dentin permeability remained low, even seven days after immersion. Scanning electron microscopic observation showed no distinct boundary line between the precipitate and intertubular dentin; this indicated further mineralization on the precipitate. Potassium oxalate treatment also reduced the dentin permeability to 8 ± 3%. However, the dentin permeability gradually but steadily increased with immersion time, reaching 39 ± 14% at seven days. To elucidate the mechanism underlying dentin permeability changes in synthetic saliva, we immersed the precipitates, i.e., apatitic mineral and calcium oxalate, in a fixed volume of synthetic saliva. When calcium oxalate was immersed in synthetic saliva, there was a large concentration of oxalate ions, indicating dissolution of the calcium oxalate; this phenomenon was ascribed to the increase in dentin permeability. In contrast, calcium and phosphate ions decreased when apatitic powder, the precipitate formed by the calcium phosphate precipitation method, was immersed in synthetic saliva. The decrease in the calcium and phosphate ions in synthetic saliva indicated further precipitation of calcium phosphate on the apatitic precipitate. We concluded, therefore, that the calcium phosphate precipitation method would have a continuous effect in reducing dentin permeability in the oral environment.

Key Words: calcium phosphate precipitation • dentin hypersensitivity • occlusion • dentin tubule • hydroxyapatite

Journal of Dental Research, Vol. 74, No. 10, 1709-1714 (1995)
DOI: 10.1177/00220345950740101301


CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?