The effect of surface roughness on the adhesion ofCandida albicansto acrylic

Abstract

The upper fitting surface of the maxillary denture is frequently a reservoir of infection for Candida albicans. The surface is not smooth, yet the majority of studies on Candida adhesion to denture materials have used smooth, often polished surfaces. In the present work, the effect of surface roughness on adhesion of C. albicans was studied. Sheets of polished, clear acrylic were abraded using emery paper of increasing grit size. Measurements describing roughness were calculated from a magnified trace of the surface. Standardised cell suspensions were incubated with the acrylic at 37°C for 1 h. Attachment was measured in terms of the percentage area of a microscopic field covered by cells, using an automated image analysis system, or by counting the number of adherent cells per field. Cells adhered in significantly (P <0.001) higher numbers to roughened acrylic than to smooth acrylic, but maximal adhesion was achieved on acrylic surfaces roughened with medium grit size emery paper. Scanning electron microscopy revealed cells adhering between surface ridges, often in clumps, and often to any debris present. Cells did not adhere in the large lesions produced by roughening with coarsest emery paper.