Short-term effects of different toothpaste formulations on total salivary calcium: A randomized crossover study.

Abstract

Dental calculus formation can be inhibited by toothpastes containing pyrophosphate, which chelates calcium ions and prevents hydroxyapatite crystal formation. Although pyrophosphate may also influence salivary calcium availability, the short-term effects of commercially available toothpaste formulations on salivary calcium concentrations remain insufficiently characterized. This study investigated and compared the short-term effects of three fluoride toothpastes on salivary calcium concentration. A randomized, three-treatment, three-period crossover trial was conducted in 48 healthy volunteers. The participants used three commercially available sodium fluoride toothpastes in randomized order: a formulation containing methyl vinyl ether/maleic acid copolymer, PVM/MA copolymer (Sensodyne), a formulation containing pyrophosphate and zinc (Dentalux), and a formulation containing sodium bicarbonate (Parodontax). Treatment periods were separated by a 2-day washout. Unstimulated saliva was collected at baseline (T0), immediately after brushing (T1), 30 min (T2), and 60 min (T3). Salivary calcium concentrations were quantified using a colorimetric assay. Data were analysed using linear mixed-effects models with toothpaste formulation, measurement time, treatment sequence, and the toothpaste-by-time interaction as fixed effects and participant as a random effect. Significant effects were observed for toothpaste formulation (F(2,103.35)=42.31, P < 0.001), measurement time (F(3,141)=39.78, P < 0.001), and the toothpaste-by-time interaction (F(6,141)=23.91, P < 0.001), whereas treatment sequence had no significant effect (P = 0.927). Compared with Dentalux® and Sensodyne®, Parodontax® resulted in significantly lower salivary calcium concentrations (both Bonferroni-adjusted P < 0.001), immediately after brushing (T1). The differences decreased after 30 min and were no longer significant after 60 min. No significant differences were observed between Dentalux® and Sensodyne® at any time point. Commercially available fluoride toothpastes produced different short-term effects on the salivary calcium concentration, with the greatest differences occurring immediately after brushing. Because the products differed in terms of multiple formulation ingredients, the findings reflect product-level effects rather than ingredient-specific effects. Further multicentre studies are warranted to confirm these findings and evaluate their clinical relevance.