In situ effect of CPP-ACP chewing gum upon erosive enamel loss

Casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) is able to increase salivary calcium and phosphate levels at an acidic pH. Previous studies demonstrated that a CPP-ACP chewing gum was able to enhance the re-hardening of erosion lesions, but could not diminish enamel hardness loss. Therefore, there is no consensus regarding the effectiveness of CPPACP on dental erosion. Objective: This in situ study investigated the ability of a CPP-ACP chewing gum in preventing erosive enamel loss. Material and Methods: During three experimental crossover phases (one phase pergroup) of seven days each, eight volunteers wore palatal devices with human enamel blocks. The groups were: GI - Sugar free chewing gum with CPP-ACP; GII - Conventional sugar free chewing gum; and GIII - No chewing gum (control). Erosive challenge was extraorally performed by immersion of the enamel blocks in cola drink (5 min, 4x/day). After each challenge, in groups CPP and No CPP, volunteers chewed one unit of the corresponding chewing gum for 30 minutes. Quantitative analysis of enamel loss was performed by profilometry (mu m). Data were analyzed by Repeated-Measures ANOVA and Tukey's test (p<0.05). Results: The use of chewing gum (CPP and No CPP) resulted in lower erosive enamel loss compared with the control group (p<0.05). CPP-ACP chewing gum (CPP) did not improve the protection against erosive enamel loss compared with conventional chewing gum (No CPP) (p>0.05). Conclusion: The CPP-ACP chewing gum was not able to enhance the anti-erosive effect of conventional chewing gum against enamel loss.