De/remineralisation from different commercial dentifrices: A pH-cycling study

Abstract

In our previous study, fluoride uptake of dentifrices manufactured locally in some developing countries have been evaluated and compared1. The objective of this study was to test whether the modified pH-cycling model and in vitro single-section technique could be used to evaluate and compare the de/remineralisation effects of those dentifrices such as Maxam Tartar Control, Advanced Formula Crest and Colgate MFP2. One non-fluoride dentifrice was included as a control. A sound molar was painted, leaving a 1mm wide 'window' on the buccal and lingual side, and placed in the demineralisation solution for 96 hours to produce artificial caries, 100-120mm deep. The tooth was then longitudinally sectioned, 100mm thick, and randomly divided into 4 groups (4 sections/group). The pH cycling model was utilised for 10 days, involving 3-hour demineralisation twice daily with 2-hour remineralisation in between, one minute fluoride treatments were given three times a day and the sections were placed in remineralisation solution overnight. Polarized light microscopy and microradiography were used to evaluate the lesion depth, lesion area and mineral content of the lesion before and after treatment. The control group showed an increase in lesion depth of 51 per cent, and was statistically different from all test groups which ranged from -7 per cent to 18 per cent. No statistical difference was observed among the fluoride containing groups. It has been concluded that the in vitro single-section technique used with the pH cycling system in this preliminary study was able to work successfully to show lesion progression and mineral changes in the initial lesions.