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

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.