CPP-ACP Paste with Fluoride: In Vitro Root Surface Caries Formation

OBJECTIVE: This in vitro study evaluated the effects of a casein phosphopeptide-amorphous calcium phosphate paste (CPP-ACP) that contains fluoride on artificial caries formation in human root surfaces. METHODS: 15 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 with No Fluoride (MI Paste, GC America, n=15); 2) FL-CPP-ACP with Fluoride Added (MI Paste with Fluoride, GC America, n=15); and 3) No Treatment Control (n=15). CPP-ACP and FL-CPP-ACP root segments were treated with the appropriate assigned agent for 120 seconds, followed by air-water rinsing for 60 seconds, and then exposed to synthetic saliva for 24 hours. CPP-ACP and FL-CPP-ACP 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=45 lesions/group, ANOVA, DMR). RESULTS: Mean root surface lesion depths were: 1) No Treatment Control Group: 326±31um; 2) CPP-ACP Group: 268±23um; 3) FL-CPP-ACP Group: 197±26um. Mean lesion depth reductions compared with the No Treatment Control Group were: 18% for CPP-ACP Group (P<.05, ANOVA, DMR) and 39% for FL-CPP-ACP (P<.05, ANOVA, DMR). Mean lesion depth reduction for FL-CPP-ACP was 26% compared with CPP-ACP (P<.05, ANOVA, DMR). CONCLUSIONS: Treatment of root surfaces with CPP-ACP and Fl-CPP-ACP significantly improved caries resistance of root surfaces compared with the no treatment control group (P<.05). Incorporation of fluoride into CPP-ACP paste significantly lessened the effects of an in vitro root surface caries challenge compared with CPP-ACP alone (P<.05). (Funded by GC America, Inc.)