Remineralization of Erosive Lesions in a Saliva-Based In Vitro Model

Objectives: The aim of this study was to evaluate the utility of anti-sensitivity dentifrices containing either NaF or NaMFP to promote remineralization of erosive lesions using a saliva-based enamel rehardening model.

Methods: Artificial erosive lesions were prepared in acrylic-mounted human enamel specimens by exposure to 1.0% citric acid pH 3.75 for 30min. Thereafter, baseline microhardness (SMH) was determined and specimens randomised into five treatment groups (n=6). After 2min treatment with a 1:3 toothpaste slurry prepared in fresh pooled stimulated human saliva, specimens were rinsed with deionised water then incubated in pooled human saliva modified by addition of an aliquot of the toothpaste slurry to give a nominal fluoride level of 0.02ppm to mimic in vivo carryover. Lesion repair was monitored by SMH after 24 and 48h.

Results: Lesion rehardening was observed in all treatment groups including the fluoride-free placebo. The Sensodyne Pronamel (1450ppm F as NaF) treatment group, however, exhibited statistically superior rehardening (p<0.001) versus all other treatment groups at both 24 and 48h. A comparison of lesion rehardening associated with the Zendium Sensitive (1500ppm F as NaF), Colgate Sensitive (1500ppm F as NaMPF) and Colgate Sensitive Multi Protection (1500ppm F as NaMPF) treatment groups showed statistical equivalence (p>0.05) at 24 and 48h.

Conclusion: Sensodyne Pronamel containing 1450ppm fluoride (as NaF) conferred statistically superior repair benefits in this in vitro model, based upon rehardening of artificially created enamel erosive lesions, versus its formulation-matched placebo control and the comparator commercial formulations.