Lesion Formation Inhibition with NaF Pastes Containing TCP or CPP-ACP

Objective: This study evaluated the potential of Clinpro Tooth Crème (950ppm F plus TCP) and MI Paste Plus (900ppm F plus CPP-ACP) to inhibit white-spot lesion formation relative to a fluoride-free dentifrice. 

Method: Ground and polished bovine specimens were mounted in acrylic rods, analyzed for baseline microhardness and divided into three groups (N=8): 1: fluoride-free Silly Strawberry (Tom’s of Maine); 2: MI Paste Plus (GC America); 3: Clinpro Tooth Crème (3M ESPE). The groups were immersed upside-down in a daily cycling regimen consisting of two one-minute treatments (four-fold dilution with distilled water) separated by one seven-hour acid challenge (Carbopol-lactic acid saturated with 50% hydroxyapatite, pH=4.9). After the second treatment, specimens were immersed in artificial saliva (pH=7.0). The treatment slurries and artificial saliva were continuously agitated at 300rpm while the acid challenge was static. The artificial saliva and acid solution were refreshed daily. After 14 days, surface microhardness measurements were made (percent surface microhardness loss, %SMHL), followed by fluoride uptake measurements (EFU, µg F/cm², N=4), and cross-sectional microhardness (relative lesion size, ΔZ, √KHN•µm, N=4). 

Result: Statistical comparisons were made using ANOVA, Tukey, p<0.05. Mean (SEM) %SMHL were as follows: A: 78.7(1.0); B: 70.8(2.5); C: 60.0(2.5), with C<B<A. Mean (SEM) EFU were as follows: A: 1.4(0.2); B: 2.1(0.3); C: 2.4(0.8), with A=B=C. Mean (SEM) ΔZ calculations were as follows: A: 736.3(57.5); B: 504.9(32.7); C: 301.7(36.8), with A>B>C.

Conclusion: Statistical splitting between the two fluoride groups and the placebo demonstrates model sensitivity to standard fluoride levels of topical pastes. Although no significant differences were observed in fluoride uptake, both fluoride groups exhibited protection against white-spot lesion formation relative to placebo. Paste C improved lesion inhibition at both the enamel surface and subsurface relative to paste B. These results suggest Clinpro Tooth Crème may provide additional lesion formation protection relative to MI Paste Plus.