Effects of Vegan Toothpastes on Enamel Surface Properties

Objectives: Minimal information is available concerning the effectiveness of natural toothpastes recommended for vegan individuals and its effects on enamel, especially considering the distinct composition of these toothpastes. Therefore, this study evaluated the color change, surface roughness (Ra) and microhardness (SH) of dental enamel brushing with vegan toothpastes.
Methods: Selected bovine enamel specimens (5x5x2mm) were randomly assigned to treatments with (n = 10/group): AS (Artificial Saliva); (CT) Colgate Total 12 Clean Mint; (CC) Natural Extracts of Turmeric, Clove and Maleleuca; (CU) Natural Extracts of Chamomile, Melissa and Grape; (HC) Boni Natural Peppermint and Turmeric; (ZM) Colgate Zero Mint; (ZH) Colgate Zero Peppermint; (ME) Ultra Action Mint Everest; (CM) Boni Natural Coal and Mint; (HA) Smile Herbal Anis Mint and Melaleuca. The specimens were submitted to 15,000 and 30,000 brushing cycles. Color parameters (L*, a*, b*), color change (ΔE₀₀), SH Knoop and Ra were evaluated at baseline (T0), after 15,000 (T1) and after 30,000 (T2) brushing cycles. The pH and concentrations of fluoride (total fluoride, ionic fluoride and total soluble fluoride) were analyzed in toothpastes. Data were evaluated by one-way ANOVA (ΔL, Δa, Δb, ΔE₀₀), two-way repeated measures ANOVA (SH), and Tukey post-hoc tests. Ra was evaluated by Kruskal-Wallis (α=5%). pH and fluoride were analyzed descriptively.
Results: At T0, no differences in color, SH and Ra (p>0.05) were observed among groups. At T1, ZH exhibited the highest ΔE₀₀, and CM maintained the Ra values, while an increase in Ra was observed for the other groups (p<0.05). At T2, ZM and CM showed ΔE₀₀ higher than CC, while ZH and HA displayed Ra higher than ZM, CM, CC, CT and AS (p<0.05). L* and b* values did not change significantly, but a* values increased and SH was maintained at T1 and T2. All toothpastes presented a pH above 7.0 and the total fluoride obtained was similar to that indicated by the manufacturers.
Conclusions: The vegan toothpastes promoted color changes compatible to clinically unacceptable parameters, increased the surface roughness, but did not promote deleterious effects on enamel microhardness.