Initial bioadhesion on surfaces in the oral cavity investigated by scanning force microscopy

Scanning force microscopy (SFM) was used to measure the adhesion forces between BSA, a saliva protein, and two dental surfaces, natural enamel and a filling material (Dyract APTM). Measurements were taken in phosphate buffered aqueous solutions (PBS). Forces were resolved down to the piconewton regime. The dependency of the adhesion force on the interaction time, pH-value and substrate surface was monitored. In a further step, surface samples were fixed on an enamel brace and carried for a defined time in the oral cavity. The formed biofilm, called pellicle, shows a different morphology on the different substrates. This can be explained by the above-mentioned substrate dependence of the adhesion force.