Ultrastructural investigation of the effect of toothpastes containing different remineralizing agents on demineralized enamel.
Journal of Esthetic and Restorative Dentistry. 2024;36(4):663-672.
ABSTRACT
Objective: The present study aimed to evaluate the effect of remineralizing agents on demineralized enamel intended for use as fluoride substitutes or supplements for oral hygiene applications.
Methodology: Enamel samples were obtained from 30 bovine teeth. The enamel blocks were stored in 20 mL of demineralization solution for 72 h. They were then brushed with the following toothpaste for the remineralization protocol: NaF, NaF/SnF2 combination, NovaMin, or nano-hydroxyapatite. SEM/EDX examinations and microhardness measurements of the samples were performed to investigate the remineralization efficacy of the studied toothpaste. One-way analysis of variance (ANOVA) with post hoc Tukey's HSD test was used to analyze the change in microhardness values in different remineralization protocols (p < 0.05).
Results: Differences in the mean remineralization (%RP) and hardness recovery (%HR) were determined between the groups (p < 0.05). Groups 1 and 4 showed significant differences in %RP (p < 0.05). In the SEM/EDX examinations, the samples treated with n-HAp showed an accumulation of crystal deposits on the enamel surface, although at a lower density than those treated with NaF and NaF/SnF2 combination.
Conclusion: The remineralization strategy in toothpaste plays an important role in enamel remineralization. NovaMin-containing toothpaste showed positive effects on the enamel surface with better Ca/P ratio. Toothpastes containing n-HAp triggered less change in the increase of microhardness values compared to other toothpastes. The use of SnF2 in toothpaste in combination with NaF significantly increased the binding of fluoride to demineralized enamel compared to toothpaste containing NaF alone.
KEYWORDS
fluoride · hydroxyapatite · NovaMin · remineralization · toothpaste
STUDY SUMMARY
This laboratory study compared four toothpastes containing different remineralizing agents on bovine enamel blocks that had been demineralized for 72 hours, using microhardness measurements and SEM/EDX analysis of the enamel surface. Remineralization percentage and hardness recovery differed significantly between the groups, the NovaMin-containing paste was associated with a more favourable surface Ca/P ratio, and the nano-hydroxyapatite paste produced a smaller increase in microhardness than the fluoride-containing pastes. Combining stannous fluoride with sodium fluoride increased fluoride binding to demineralized enamel compared with sodium fluoride alone under these conditions.