Background: Relative Dentin Abrasivity (RDA), as set by ISO 11609, is a standardized measurement on the abrasiveness of toothpaste. There are no published RDA values for Philippine-brand toothpastes. This study evaluated the degree of abrasion of five Philippine-brand toothpastes.

Objective: To compare qualitatively and quantitatively the abrasivity of five Philippine-brand toothpastes (Brands X, U, H, HN, G) to two foreign-brand toothpastes Brand C (RDA 68) and Brand P (RDA 150).

Methods: Twenty-four bovine dentin samples were brushed with a slurry of each of the toothpaste using a toothbrushing machine. A profilometer, scanning electron microscope and a visual measuring scope were used to determine abrasivity through the before-and-after-brushing surface roughness.

Results: Ranked based on the difference of the means for surface roughness, before-and-after brushing, in decreasing order of abrasivity are: Brands P, X, U, H, C, HN, and G. Using Dunn's test-post hoc test for Kruskal-Wallis test at p ? 0.05, we showed that the abrasivity of Brands G, H, and HN were not significantly different from Brand C, and Brand X was not significantly different from Brand P. Brand U was significantly less abrasive than Brand P and significantly more abrasive than Brand C.

Conclusion: Brands G, H, and HN can be considered as low-abrasive toothpastes, Brand X a high abrasive toothpaste, and with Brand U was unclear as to category. Findings from qualitative data support the quantitative data.

Dentin ; Toothpastes ; Tooth Abrasion