Dental calculus formation is promoted by precipitation of calcium and phosphate into hydroxyapatite crystals. Certain toothpaste ingredients, notably pyrophosphate, can chelate calcium ions and thereby inhibit calculus formation. However, the short-term effects of commercially available toothpaste formulations on the availability of salivary calcium have not been fully characterized. This randomized crossover trial aimed to compare short-term changes in salivary calcium concentration after brushing with three different sodium fluoride toothpastes.
The investigation was a randomized, three-treatment, three-period crossover trial enrolling 48 healthy volunteers. Each participant received all three toothpaste treatments in randomized order, with a 2-day washout interval separating treatment periods. Treatment sequence was included as a variable in analysis and was found not to have a significant effect on outcomes.
Three commercially available sodium fluoride toothpastes were compared:
Because the products differ in multiple formulation ingredients, the authors emphasize that observed differences reflect product-level effects rather than definitive effects of individual ingredients.
Unstimulated whole saliva samples were collected at four predefined time points for each treatment period:
Salivary calcium concentrations were quantified using a colorimetric assay, as reported in the source study.
Data were analyzed using linear mixed-effects models. Fixed effects in the model included toothpaste formulation, measurement time, treatment sequence, and the toothpaste-by-time interaction. Participant identity was modelled as a random effect to account for within-subject correlations inherent to the crossover design.
Significant model effects reported were:
Treatment sequence did not show a significant effect (P = 0.927).
The primary comparative findings were:
Immediately after brushing (T1), Parodontax produced significantly lower salivary calcium concentrations than both Dentalux and Sensodyne (both Bonferroni-adjusted P < 0.001).
The magnitude of the differences between products decreased by 30 minutes (T2) and were no longer statistically significant at 60 minutes (T3).
No statistically significant differences in salivary calcium were observed between Dentalux (pyrophosphate + zinc) and Sensodyne (PVM/MA copolymer) at any measured time point.
These results indicate that the largest product-related changes in salivary calcium occur immediately following brushing and tend to dissipate within an hour.
The study demonstrates that commercially available fluoride toothpastes can produce different short-term effects on salivary calcium concentration, with the most pronounced differences seen immediately after brushing. Because each tested product contains multiple differing ingredients, the authors caution against attributing the observed effects to a single ingredient; the findings should be interpreted as product-level differences.
The absence of persistent differences at 60 minutes suggests transient modulation of salivary calcium by some formulations rather than sustained alteration of salivary calcium homeostasis.
Ingredient-level effects cannot be determined from this study because the tested products differ in multiple formulation components; the results reflect product-level phenomena.
The trial was performed in a single-centre setting and in healthy adult volunteers; the clinical relevance of short-term changes in salivary calcium for calculus formation or other dental outcomes was not established.
The authors recommend further multicentre studies to confirm these findings and to evaluate their clinical significance.
The study was reported as a randomized controlled trial in PLoS One, with DOI 10.1371/journal.pone.0358715 and PubMed PMID 42752694. The authors declared no competing interests. All numerical results and statistical values reported above are taken directly from the source abstract.