Amino acid composition of acquired enamel pellicle collected in vivo after 2 hours and after 24 hours.

The adsorption of salivary proteins to dental enamel during pellicle formation has been shown to be a specific process and dependent on the chemical composition of the surfaces. Most studies on the amino acid composition of the acquired enamel pellicle have, however, been performed on the "2-h-pellicle" under controlled experimental conditions. This may have eliminated some natural factors involved in pellicle formation. The aim of the present study was to investigate the effect of extended time of formation and diet on the pellicle formation. Pellicle material was collected from the same subject after 2 and after 24 h when food and beverages were avoided, and after 24 h with the intake of a normal diet. The collected pellicle materials were hydrolyzed and amino acid analyzed. The results showed that pellicle material collected after 24 h and fasting had a chemical composition similar to the "2-h-pellicle", whereas pellicle material collected after 24 h and a normal diet was different, indicating a dietary contribution to pellicle formation or a bacterial degradation of the pellicle.