Efficacy of CPP-ACP fluoride varnish applied with and without acid etching in preventing enamel demineralization compared to light-curable fluoride varnish.

OBJECTIVES: To compare efficacy of casein phosphopeptide (CPP)-amorphous calcium phosphate (ACP) fluoride varnish and light-curable resin modified glass ionomer fluoride varnish (FV) in preventing white spot lesions and evaluating acid etching prior to CPP-ACPFV application on its efficacy. MATERIALS AND METHODS: Molars and premolars were transected and halves divided into four groups (n = 18/group): (1) resin-modified glass ionomer FV: etched and Clinpro-XT varnish (3M ESPE, Pymble, New South Wales, Australia) application; (2) CPP-ACPFV: MI varnish (GC America, Alsip, IL) application; (3) Etch+CPP-ACPFV: etched and MI varnish application; (4) Control: etched and no surface treatment. To simulate 12 weeks in an intraoral environment, samples were subjected to thermocycling, brushing, and pH cycling. Enamel surface microhardness was evaluated at baseline and after the simulated 12 weeks. Representative samples were also assessed using scanning electron microscopy (SEM). RESULTS: At baseline there was no significant difference in microhardness among groups. After the simulated 12 weeks, all groups showed significant within-group differences (P < .001). Control showed the highest percentage loss of surface microhardness (89%), followed by CPP-ACPFV (58%), RMGIFV (51%), and Etch+CPP-ACPFV (24%). The control group had a significant decrease in microhardness compared to all experimental groups (P < .001). No difference was found between the RMGIFV and CPP-ACPFV varnish groups. The Etch+CPP-ACPFV group had significantly less decrease in microhardness compared to the RMGIFV (P < .001) and CPP-ACPFV groups (P < .001). With SEM, control samples showed signs of enamel surface damage, while experimental groups showed spherical particles on a relatively intact surface. CONCLUSIONS: RMGIFV and CPP-ACPFV are effective in reducing enamel demineralization. Acid etching the enamel surface prior to CPP-ACPFV varnish application increased its efficacy.