[Influence of micro-pattern on adherence of graphite powder and three kinds of oral microbes]

Trying to find out the mechanism of microstructure influencing bacterial adhesion, we prepared different microstructures to compare the adsorptive behavior of graphite powder and adhesive behavior of oral microbe.

We used polydimethylsiloxane (PDMS) to copy 23 microstructures of hydroxyapatite (HA) chip, and cultured them with different sizes graphite powder and oral microbes respectively, to observe and compare their behavior on microstructures.

The adsorption of 30-50 microm powder on different microstructures was insignificant, while 10-20 microm powder had maximum adsorption on 10 microm and 20 microm microstructures. Saccharomyces albicans was most likely to adhere to 5 microm microstructures which was equivalent to its own size. However, microstructures had little effect on adhesion of Streptococcus mutans which grew in a chain.

The size of microstructure was the most effective factor that affects the adsorption of non-living powder, and it also had the same effect on the microbial adhesion; but some special bacteria, such as Streptococcus mutans which grew in a chain, was not affected by the sizes or shapes of microstructures.