Effect of CPP-ACP Chewing Gum Previously to Erosive Demineralization

Objectives: The erosive protective effect of CPP-ACP is controversial. On previous studies, our research group found that the use of CPP-ACP chewing gum resulted in higher hardness recovery of eroded enamel compared to traditional chewing gum. However, on an erosive challenge protocol, the CPP-ACP chewing gum was not able to enhance the protective effect of salivary stimulation. It was hypothesized that the inhibition of erosive demineralization might have a higher impact on erosive lesion than the remineralization increase. Thus, this in situ study aimed to investigate the ability of CPP-ACP chewing gum to prevent a single event of erosive demineralization.
Methods: Bovine enamel blocks (114), after selection (initial surface hardness) were randomly assigned to groups: GI-chewing gum with CPP-ACP, GII-chewing gum without CPP-ACP and Control group-salivary effect without stimulation (no gum). Nineteen volunteers participated on this study during 3 crossover phases of 2 h. On GI and GII, the volunteers wore intraoral palatal devices for 90 min and chewed a unit of the corresponding chewing gum for 30 min. On Control group the volunteer wore the appliance for 2 h. On each phase immediately after the intraoral use, devices were extra orally immersed in 150 mL of cola drink for 5 minutes to promote erosive demineralization. The percentage of surface hardness loss was calculated. The data were analyzed by Repeated Measures ANOVA and Tukey's test.
Results: The enamel hardness loss after the use of chewing gum with (GI-32.7 %) and without (GII-33.5%) CPP-ACP was smaller than the salivary effect without stimulation (control- 39.8%)(p<0.05). There was no difference between GI and GII (p>0.05).
Conclusions: The results suggest that the use of chewing gum immediately before an erosive demineralization is able to diminish the enamel hardness loss. However, the presence of CPP-ACP in the chewing gum can not enhance this protective effect.