Loss on drying, calcium concentration and pH of fluoride dentifrices.

Introduction: Fluoride dentifrices containing calcium carbonate have advantages such as control of dental plaque and progression of dental caries, also contributing to oral hygiene, represent most dentifrices marketed in Brazil.

Aim: To evaluate the physicochemical properties of seven fluoride dentifrices containing calcium carbonate in relation to hydrogen potential (pH), loss on drying and calcium concentration.

Materials And Methods: Data collection was performed using the potentiometric method for pH ranges, gravimetric analysis for loss on drying and atomic absorption spectrometry for the concentration of calcium ions. All tests were performed in triplicate and the analysis was performed entirely at random according to one-way analysis of variance at 5% significance level.

Results: The pH values were alkaline and ranged from 8.67 (Oral-B 123(®)) to 10.03 (Colgate Máxima Proteção Anticáries(®)). The results of loss on drying ranged from 33.81% (Oral-B 123(®)) to 61.13% (Close Up(®)), with significant differences between brands tested. In relation to the calcium content, the highest and lowest concentrations were found in dentifrices Even(®) (155.55 g/kg) and Colgate Ultra Branco(®) (129 g/kg), respectively, with significant difference (P < 0.05).

Conclusion: Fluoride dentifrices analyzed showed alkaline pH and high levels of loss on drying and calcium concentration. However, these physicochemical characteristics differed according to the different brands tested.