Stabilised Delivery of SnF₂ by Casein Phosphopeptide-Amorphous Calcium Phosphate

Objectives: Modern dentifrices contain SnF₂ for its superior oral health benefits. Recently it has been reported that using CPP-ACP with SnF₂ results in enhanced anticariogenicity. This has led to the development of SnF₂-toothpaste formulations with added CPP-ACP. The aim of this double-blind, randomised crossover in situ clinical trial was to compare enamel and dentine remineralisation by three SnF₂-containing dentifrices with two also containing CPP-ACP.
Methods: Participants wore removable intraoral appliances holding human enamel and dentine half-blocks with subsurface demineralised lesions and rinsed with a 1:4 diluted slurry of one of three dentifrices containing either 5% CPP-ACP+1100 ppm F as SnF₂ (MIP5), 10% CPP-ACP+1100 ppm F as SnF₂ (MIP10) or 1100 ppm F as SnF₂ (CT), for 1 min, four times a day for 14 consecutive days. The participants crossed-over to each treatment after a one-week washout period. Enamel and dentine half-blocks were removed at the completion of each treatment period, paired with their untreated control half-blocks, and analysed for percent remineralisation (%R) using transverse microradiography and percent surface microhardness recovery (%SMHR) and statistically analysed using a repeated measures ANOVA (p<0.05).
Results: MIP10 (36.3±1.8 %) and MIP5 (25.6±1.9%) produced significantly higher %R than CT (15.2±1.0%) for enamel, and significantly higher %R MIP10 (37.9±2.5%) and MIP5 (33.6±2.9%) for dentine compared to 20.6±1.0% with CT. Additionally, MIP10 and MIP5 produced significantly higher %SMHR (38.1±8.8% and 15.5±8.4% respectively) compared with CT (4.1±3.0%). SEM/EDS analysis of the CPP-ACP-stabilised SnF₂ indicated that Sn²⁺ cross linked the CPP-ACFP nanocomplexes into larger complexes facilitating delivery of calcium, phosphate and fluoride ions into the lesions and binding of Sn-CPP to the tooth surface in situ.
Conclusions: Both CPP-ACP-containing SnF₂ dentifrices (MIP5 and MIP10) were superior to the SnF₂ -alone dentifrice (CT), with the CPP-ACP demonstrating a clear dose response enhancement of SnF₂ remineralisation in situ.