Salivary Pellicle Effect on Sports and Energy Drink Mediated Erosion-Attrition

Objectives: To investigate the effect of sports and energy drinks on polished enamel samples after erosion-attrition process and the protective effect of acquired enamel pellicle (AEP).
Methods: Polished human molar enamel samples (n=40) were randomly distributed to four groups (n=10): water (control), citric acid (pH 3.2), Lucozade (pH 3.34) and Red Bull (pH 3.44), five cycles of erosion in 8ml of solution per sample for 10 minutes per cycle. Samples were immersed in stimulated whole mouth saliva 24 h to for AEP prior to exposure to experimental solutions for erosion process; followed by attrition by enamel cusp antagonist (at 300g force, 60 s). Mean (SD) of non-contact surface profilometry (NCSP) and Knoop microhardness change (KHNc) were calculated. Data were tested for normality using Shapiro-Wilk test and were normally distributed, statistical analysis applied using one-way ANOVA and Tukey's post-hoc test.
Results: All groups showed enamel loss when exposed to the experimental solutions. Mean (SD) step height (µm) for immersion in water, citric acid, Lucozade, and Red Bull were 1.31 (0.4), 13.58 (2.2), 12.84 (2.4) and 11.3 (2.3) respectively; all groups were statistically significant compared to the control group (p<0.0001) but there were no significant difference between experimental solutions.
All groups showed a reduction in KHN after the immersion in whole mouth saliva. Mean (SD) KHNc of immersion in water, citric acid, Lucozade, and Red Bull were 22.2 (4.1), 85.3 (10.4), 165.1 (24.4) and 121.5 (10.7) respectively; all groups were statistically significant compared to control (p<0.0001) and comparing all experimental solutions with each other (p<0.0001).
Conclusions: Presence of AEP caused softening of enamel surface and Lucozade produced greater surface softening after erosion-attrition process when compared to other experimental solutions. Whereas immersion in citric acid formed the highest step height which caused a bulk of enamel surface loss.