Remineralization effect of CPP-ACP and fluoride for white spot lesions in vitro

Abstract

Objectives: This in vitro study compared the remineralization effect on white spot lesions of casein phosphopeptide-amorphous calcium phosphate crème, or CPP-ACP (MI Paste™), 1.1% NaF dentifrice containing 5000ppm of fluoride (ControlRX™), or CPP-ACP crème with 900ppm of fluoride (MI Paste Plus™) with that of a control.

Methods: Artificial white spot lesions were created on smooth enamel surfaces of sound molars using a previously reported demineralization model. Specimens were randomly assigned to four treatments (n=35) with a pH-cycling model over 30 days: Control (no treatment); MI Paste (10% CPP-ACP crème); F5000 (1.1% NaF dentifrice); or MI Paste Plus (10% CPP-ACP plus 900ppm fluoride crème). Products were applied following manufacturers' directions. Changes in mean lesion depth expressed by percent fluorescence loss (ΔF%), and lesion area (mm(2)) from baseline to after treatment were measured with light-induced fluorescence (QLF). Mean values of each parameter were compared between groups (p<0.05).

Results: The remineralization pattern for the F5000 group was unique with marked initial remineralization during the first 10 days and little subsequent change. Based on mean lesion area, the F5000 demonstrated greater remineralization than Control, MI Paste and MI Paste Plus groups. Based on mean fluorescence loss, the F5000 group showed improved remineralization relative to MI Paste Plus, but did not differ statistically from the Control at the end of 30 days.

Conclusions: The 1.1% NaF dentifrice demonstrated overall greater remineralization ability than 10% CPP-ACP crème. However, the 1.1% NaF dentifrice was only as effective as the Control to reduce fluorescence loss.

Clinical significance: This study showed that a 1.1% NaF dentifrice (5000ppm) demonstrated greater remineralization ability than the CPP-ACP topical tooth crème and that the addition of fluoride to its formulation seems to enhance remineralization. Saliva also has the ability to exert an important remineralization effect over time.

Keywords: CPP-ACP; Fluoride; QLF; Remineralization; White spot lesions.

Figure 1

QLF screen image representing the analysis process of the circumscripted white spot lesion at baseline and after treatment was applied overtime* * Note the yellow color on the body of the lesion denoting area of higher scattering of light and, consequently, more demineralized tissue. On the second image, note the purple tone in the body of the lesion indicating less scattering of light and, consequently, a more remineralized tissue. In addition, the lesion area is slightly reduced, especially on the borders of the lesion.

Figure 2

Mean fluorescence loss by treatment group and time. Vertical bars indicate +/− two standard errors $(\text{SE}=\sigma /\sqrt{n})$ and give a rough approximation of a 95% confidence interval for the mean. Points are slightly staggered at each time point for better visualization of the vertical bars.

Figure 3

Mean lesion area by treatment group and time. Vertical bars indicate +/− two standard errors $(\text{SE}=\sigma /\sqrt{n})$ and give a rough approximation of a 95% confidence interval for the mean. Points are slightly staggered at each time point for better visualization of the vertical bars.

Figure 4

Model predicted estimates of the mean difference in fluorescence loss from baseline, for each treatment group at each follow-up time point. Estimates were based on the hierarchical random effects model with random effects for tooth and specimen nested within tooth and fixed effects for treatment, time, and treatment*time interaction. Vertical bars indicate model based estimates of 95% confidence intervals for the mean difference from baseline. Points are slightly staggered at each time point for better visualization of the vertical bars.

Figure 5

Model predicted estimates of the mean difference in lesion area from baseline, for each treatment group at each follow-up time point. Estimates were based on the hierarchical random effects model with random effects for tooth and specimen nested within tooth and fixed effects for treatment, time, and treatment*time interaction. Vertical bars indicate model based estimates of 95% confidence intervals for the mean difference from baseline. Points are slightly staggered at each time point for better visualization of the vertical bars.