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

OBJECTIVES: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.