The ability of 1.23% acidulated phosphate fluoride gel to inhibit simulated endogenous erosion in tooth roots

Abstract

Background: Endogenous dental erosion is that produced by contact of gastric acids with tooth structure. It may affect exposed root cementum/ dentine as well as coronal enamel, causing marked loss of mineral. The aim of this study was to determine whether 1.23 per cent acidulated phosphate fluoride gel, if applied to the surface cementum at certain intervals during an erosive acid challenge, could provide any protection against demineralization. Materials and methods: Roots of preserved extracted human teeth were painted with a water and acid resistant varnish, leaving two windows (3x1mm) of exposed dentine. These were placed in a solution containing 0.06MHCl and 2.2mMCaHPO4, which has been shown to simulate gastric acid when it meets the tooth surface. The roots were placed in the erosive solution unprotected (controls), or subject to APF application for four minutes prior to and every 10, 30 or 120 minutes during the erosive challenge. Roots were removed at either 6 or 12 hours, washed thoroughly and cut into 120μm thick sections. Depths of demineralization were measured using an optical graticule under polarized light microscopy. Results: A high level of protection was provided when the roots were coated with APF gel every 10 or 30 minutes. Conclusions: APF gel will partially inhibit endogenous erosion of roots for up to 30 minutes if applied, for example, the night before a morning reflux episode. This should be considered along with other erosion control or reduction procedures for patients suffering from the effects of endogenous erosion.