Influence of soft drinks on the thickness and morphology of in situ acquired pellicle layer on enamel.

Diet-induced demineralization is a key factor in tooth enamel loss, with soft drinks being a significant aetiological agent. In the oral environment, the acquired pellicle layer might modify the demineralization potential of drinks. The objectives of this exploratory in situ study were to determine the influence of soft drinks, volunteers, and exposure times on the thickness and morphology of pellicle layers using an atomic force microscope (AFM). Polished uninterrupted third molars were partly taped and exposed to the oral environment for periods of 2 and 5 days, respectively. Each day 1L of either mineral water, a "toothkind" blackcurrant drink, a "prototype" blackcurrant drink, or orange juice was consumed in this four-way crossover, single-center study. Subsequently the tape was removed and the surfaces imaged with an AFM before and after chemical cleaning. The pellicle layer morphology and thickness were investigated. The maximum pellicle layer thickness was observed after the consumption of the prototype blackcurrant drink, followed by the toothkind blackcurrant drink, orange juice, and water on days 2 and 5, respectively. A three-way ANOVA at the 95% confidence level showed statistically significant differences between the pellicle layer thicknesses, factors being drinks (p=0.0046), exposure time (p=0.0009), and volunteers (p=0.0244). Depending on the volunteer either a uniform or a patchy pellicle layer was observed. This demonstrates that AFM is a useful tool in obtaining simultaneously qualitative and quantitative data of in situ acquired pellicle layers.