3275 Casein Phosphopeptide-Amorphous Calcium Phosphate Paste: Root Surface Caries Formation

J. HICKS, Baylor College of Medicine, Houston, TX, USA, and C. FLAITZ, University of Texas - Houston / Health Science Ctr, USA

OBJECTIVE: This in vitro study evaluated the effect of a casein phosphopeptide-amorphous calcium phosphate paste (CPP-ACP) on artificial caries formation in human root surfaces using polarized light microscopy.

METHODS: 12 human teeth with sound root surfaces were sectioned into 3 portions. Each portion from a single tooth was assigned to one of the three treatment groups: 1) CPP-ACP (MI Paste, GC America, n=12); 2) 0.05% sodium fluoride rinse (NaF, ACT McNeil-PPC, n=12); and 3) No Treatment Control (n=12). CPP-ACP and NaF root segments were treated with the appropriate assigned agent for 60 seconds, followed by air-water rinsing for 60 seconds, and then exposed to synthetic saliva for 24 hours. CPP-ACP and NaF treatment, rinsing and synthetic saliva exposure were repeated on a daily basis over a 14-day period. No treatment control root segments were exposed to synthetic saliva only for a 14-day period. Artificial root surface caries were created over a 10-day period (alternating 16 hours demineralization followed by 8 hours remineralization). Longitudinal sections (3 sections/root segment) were obtained and lesion depths were determined using polarized light microscopy (n=36 lesions/group, ANOVA, DMR).

RESULTS: Mean root surface lesion depths were: 1) No Treatment Control Group: 310+/-27um; 2) NaF Rinse Group: 216+/-21um; 3) CPP-ACP Group: 144+/-19um. Mean lesion depth reductions compared with the No Treatment Control Group were: 30% for NaF Rinse (P<.05, ANOVA, DMR) and 54% for CPP-ACP (P<.05, ANOVA, DMR). Mean lesion depth reduction for CPP-ACP was 33% compared with NaF Rinse (P<.05, ANOVA, DMR).

CONCLUSIONS: Casein phosphopeptide-amorphous calcium phosphate paste markedly enhanced the resistance of root surfaces to artificial caries formation, when compared with fluoride rinsing (0.05% NaF). Bioavailable calcium and phosphate in CPP-ACP has been demonstrated to bind to hydroxyapatite, and this may be an important factor in reducing susceptibility of root surfaces to a cariogenic challenge.