Toothpaste factors related to dentine tubule occlusion and dentine protection against erosion and abrasion

Objectives To investigate the effect of toothpastes on dentine surface loss and tubule occlusion, and the association of toothpaste-related factors to each of the outcomes. Materials and methods One hundred and sixty human dentine specimens were randomly distributed into 10 groups, according to different toothpastes. The specimens were submitted to artificial saliva (60 min), citric acid (3 min), and brushing abrasion (25 s; totalizing 2 min in toothpaste slurries). This was repeated five times and two outcome variables were analyzed: dentine surface loss (dSL; μm) and tubule occlusion by measurement of the total area of open tubules (Area-OT; μm 2 ). Data were analyzed with Kruskal-Wallis and Mann-Whitney tests (α = 0.05); bivariate and multivariate regressions were used to model the association of the chemical (pH, concentration of F − , Ca 2+ , and PO 4 3− and presence of Sn 2+ ) and physical (% weight of solid particles, particle size, and wettability) factors of the toothpastes to both outcome variables. Results Toothpastes caused different degrees of dSL and did not differ in Area-OT. All chemical and physical factors, except the presence of Sn 2+ , were associated with dSL ( p