Method: Human enamel specimens were polished flat and divided into five treatment groups: i) deionised water, ii) Sensodyne Pronamel mouthrinse (NaF, 0.0225% w/v F ion) iii) Act Total Care mouthrinse (NaF, 0.01% w/v F ion), iv) Listerine Whitening Restoring mouthrinse (NaF, 0.01% w/v F ion) or v) Crest Pro-Health Complete mouthrinse (NaF, 0.01% w/v F ion). The specimen surfaces were partially masked by taping, before incubation for 1 minute in the treatment solutions. After subsequent washing with deionised water, the enamel was exposed to an artificial erosive challenge consisting of immersion in 1.0% citric acid, pH 3.8, for 5 mins. Surface topography was investigated using an ADE PhaseShift MicroXAM White Light Interferometer.
Result: Surface roughness values (Sa) from enamel treated with deionised water were the highest after the acidic challenge. Enamel treated with the mouthrinse containing the polymer system and sodium fluoride showed the lowest increase in surface roughness. After removal of the tape mask from the specimens and subsequent measurement of step heights, trends in enamel tissue loss data were found to mirror the surface roughness findings. All trends were statistically significant apart from those comparing Crest Pro-Health mouthrinse with deionised water.
Conclusion: This study has shown that pre-treatment of human enamel with a novel mouthrinse formulation containing three specific polymers and sodium fluoride, protects the enamel from the damaging effects of a dietary acid mimic to a greater extent than treatment using a number of currently marketed US mouthrinse formulations.