The longevity of casein phosphopeptide–amorphous calcium phosphate fluoride varnish's preventative effects: Assessment of white spot lesion formation

ABSTRACT Objectives: To test how long casein phosphopeptide–amorphous calcium phosphate (CPP-ACP) fluoride varnish prevents enamel demineralization in vitro. Materials and Methods: Human molars and premolars were sectioned buccolingually and randomly assigned to two groups. Standardized pretreatment images of enamel surfaces were obtained using FluoreCam. The control group received no treatment, and the experimental group received an application of CPP-ACP fluoride varnish. Over simulated periods of 2, 4, 8, and 12 weeks, specimens were placed in a toothbrushing simulator, thermocycled, subjected to 9 days of pH cycling, and imaged with FluoreCam. Samples were sectioned and polished for polarized light microscope (PLM) evaluation. Results: There were statistically significant time (P < .001) and varnish (P < .001) effects on area, intensity, and impact of enamel demineralization. The control group showed significant and progressive demineralization over the 12 weeks (P < .001). The experimental group revealed no significant demineralization during the first 4 weeks (P > .05) and significant (P < .001) increases thereafter. Experimental demineralization after 12 weeks was comparable to 2-week demineralization in the controls, with significant between-group differences (P < .001) in enamel demineralization at all time points. PLM of the control and experimental groups revealed lesion depths of 90 ± 34 μm and 37 ± 9 μm, respectively. Conclusions: Within the limitations of this in vitro study, CPP-ACP fluoride varnish prevents enamel demineralization for at least 4 weeks and limits demineralization up to 12 weeks.