In situ evaluation of different remineralization periods to decrease brushing abrasion of demineralized enamel

The aim of the present in situ study was to evaluate the effect of differen t periods of intraoral remineralization to decrease the susceptibility of p reviously demineralized enamel against toothbrushing abrasion. Six human en amel specimens (A-F) were recessed in the buccal aspects of each of eight i ntraoral appliances which were worn for 21 days by 8 panelists. Demineraliz ation of the samples was performed twice a day extraorally in the acidic be verage Sprite Light for 90 s. Subsequently, the enamel specimens were brush ed at different times. Specimen A was brushed immediately after the deminer alization. The remaining samples B-E were brushed after the intraoral appli ances had been worn for various periods of remineralization: specimen B, 10 min; C, 20 min; D, 30 min and E, 60 min, respectively. Specimen F was only demineralized and remineralized, but not brushed. After 21 days, enamel we ar was measured with a laser profilometer. The following values (mean F sta ndard deviation) were obtained: specimen A, 6.78 +/- 2.71 mum; B, 5.47 +/- 13.39 mum; C, 6.06 +/- 3.18 mum; D, 5.43 +/- 2.58 mum; E 4.78 +/- 2.57 mum, and F 0.66 +/- 1.11 mum. Analysis of variance revealed a significant influ ence of remineralization period on abrasive wear. However, even after a rem ineralization period of 60 min the wear was significantly increased as comp ared to the demineralized, but not brushed control. It is concluded that(l) abrasion resistance of softened enamel increases with remineralization per iod and (2) at least 60 min should elapse before toothbrushing after an ero sive attack. Copyright (C) 2001 S. Karger AG, Basel.