The effect of different commercial dentifrices on enamel lesion progression: an in vitro pH-cycling study

Aims/objectives: To evaluate and compare the de/remineralisation effects of dentifrices manufactured locally in some developing countries. Design: Uti lisation of the in vitro single-section and the pH-cycling model. Setting: Laboratory. Test materials: Dentifrices: Maxam DFP(R), Maxam Tartar Control (R), First(R), Tianqi Medicated(R) from China; Vicco Vajradenti(R) from Ind ia; Colgate MFP2(R), Crest Tartar Control from USA; and one non-fluoride de ntifrice as control. Methods: Sound molars were painted, leaving a 1 mm wid e 'window' on the buccal and/or lingual surface and placed in a demineralis ation solution for 96h to produce artificial caries lesion approximate to 8 0-100mm deep. The teeth were then longitudinally sectioned (approximate to 100mm thick), and randomly divided into 8 groups (22 sections/group). The p H cycling model was utilised for 16 days. Outcome measures: Polarised light microscopy and microradiography were used to evaluate the lesion progressi on before and after treatment. Results: The control group showed an increas e in lesion depth of 70 per cent and was statistically different from some test groups which ranged from -2 per cent to 68 per cent (P<0.01, t-test). Statistically significant differences were also observed among some of the fluoride containing groups. Conclusions: This study suggests that, when com pared to 'multinational dentifrices', Chinese and Indian dentifrices manufa ctured locally failed to show 'healing' efficacy even though they claimed t o contain varying levels of fluoride.