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

Abstract

AIMS/OBJECTIVES: To evaluate and compare the de/remineralization effects of dentifrices manufactured locally in some developing countries. DESIGN: Utilisation of the in vitro single-section and the pH-cycling model. SETTING: Laboratory. TEST MATERIALS: Dentifrices: Maxam DFP, Maxam Tartar Control, First, Tianqi Medicated from China; Vicco Vajradenti from India; Colgate MFP2, Crest Tartar Control from USA; and one non-fluoride dentifrice as control. METHODS: Sound molars were painted, leaving a 1 mm wide 'window' on the buccal and/or lingual surface and placed in a demineralisation solution for 96 h to produce artificial caries lesion approximately 80-100 mm deep. The teeth were then longitudinally sectioned (approximately 100 mm thick), and randomly divided into 8 groups (22 sections/group). The pH cycling model was utilised for 10 days. OUTCOME MEASURES: Polarised light microscopy and microradiography were used to evaluate the lesion progression before and after treatment. RESULTS: The control group showed an increase 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 compared to 'multinational dentifrices', Chinese and Indian dentifrices manufactured locally failed to show 'healing' efficacy even though they claimed to contain varying levels of fluoride.