Validation of pH cycling model to induce artificial carious lesions in bovine dentin

ABSTRACT

Introduction and objective:The purpose of the study was to evaluate different pH cycling protocols on the induction of artificial carious lesions in bovine dentin, since the most appropriate protocol to be applied is still not fully established. Material and methods: Fragments of bovine dentin (4 x 4 x 2 mm) were embedded in resin, polished and 7 mm² of each fragment was isolated with wax. The specimens were divided into three groups (A, B, C) according to the time of immersion in the demineralizing solution (1.5 ml). Group A - 15 minutes; Group B - 30 minutes; Group C - 60 minutes and subsequently immersed for 22 hours in a remineralizing solution (1.5 ml). Microhardness measurements were conducted initially, daily and after each pH cycling for 4 days. The Split-plot design (ANOVA) was applied. Results: There was a significant interaction between time and cariogenic challenge (p<0.0001). Bonferroni comparisons were executed to identify the differences over the cariogenic challenge, showing that increasing the immersion time in demineralizing solution for each pH cycling assessed, the cariogenic challenge aggressiveness increased (A hardness in the cariogenic challenge over the time.

Conclusion:

The three models tested proved to be viable, regardless of the time of cariogenic challenge that was applied.