2810 An in vitro investigation of the effects of casein phosphopeptide-stabilized amorphous calcium phosphate (CPP-ACP) on erosion of human dental enamel by a sports drink

L. RAMALINGAM, L. B MESSER, and E.C. REYNOLDS, The University of Melbourne, Victoria, Australia

Objectives: There have been numerous studies that have attempted to reduce the erosive potential of acidic beverages. Previous studies have demonstrated the erosivity of Powerade™ and the purpose of this study was to determine the lowest concentration of casein phosphopeptide - stabilised amorphous calcium phosphate (CPP-ACP) required to be added to Powerade™ to eliminate erosion of human enamel in vitro.

Methods:Surface changes of 30 human enamel specimens were examined following immersion in Powerade™ (P) containing 0.063%, 0.09%, 0.125%, 0.25% CPP-ACP for 30 minutes at 37°; under constant agitation in a water bath; P and double deionized water (DDW) were positive and negative controls respectively. Enamel surface characteristics were examined qualitatively (stereomicroscopy, scanning electron microscopy) and quantitatively (surface profilometry).

Results:The pH values of test solutions were higher than that of P (2.70), and the pH of each solution increased slightly with increasing concentrations of CPP-ACP (pH 3.07, 3.27, 3.40, 3.90). The titratable acidity decreased on addition of CPP-ACP (P=1.83, 1.61, 1.63, 1.47, 1.36). All enamel specimens immersed in P with or without CPP-ACP exhibited red superficial staining. The mean profile depths were: P: 3.87µm (SD 0.56), P+0.063% CPP-ACP:1.80µm (SD 0.31), P+0.09% CPP-ACP: 0.43µm (SD 0.06), P+0.125% CPP-ACP: 0.34µm (SD 0.17), P+0.25% CPP-ACP: 0.19µm (SD 0.06), DDW: 0.25µm (SD 0.07). P alone and P+0.063% CPP-ACP displayed an erosive step between test and control areas of enamel. The mean erosive depths of DDW, P with 0.09%, 0.125% and 0.25% CPP-ACP did not differ significantly (p>0.05). Type 1 etch patterns predominated with scattered areas of Type 3 in P alone and P+0.063% CPP-ACP. Superficial surface irregularities were displayed for P+0.09% and 0.125% CPP-ACP.

Conclusion:The erosive potential of Powerade™ was eliminated or reduced on addition of low concentrations of CPP-ACP (0.09%, 0.125% and 0.25%) in vitro.