Comparative study on the microbial adhesion to acetal resin and metallic removable partial denture

Since the fitting surface of the denture base promotes colonization of micro-organisms, it is important to know how the different types of denture base prevent or promote the colonization of micro-organisms. This study aimed to compare the adhesion of micro-organisms to the fitting surface of acetal resin, metallic removable partial denture (RPD) bases, and mucosa beneath them using the same environmental condition in patient class III mod 1 Kennedy classification. Seven partially edentulous patients, having lower bilateral posterior bounded saddles and a RPD constructed from two bounded base saddles, one from acetal resin and the other from cobalt-chromium (Co-Cr) metal were selected. The fitting surfaces of the denture bases and mucosa beneath them were swabbed before and after insertion at 1 week, 2 weeks, and 4 weeks follow-up periods. Microbial adhesion was determined by counting the colony forming units (CFU) of the micro-organisms in the collected specimens. The mucosa under the acetal denture base retained more micro-organisms than the mucosa under the metallic denture base, and the colonization of micro-organisms increased by time on mucosa and on a denture base made either by metal or acetal resin. The study recommended the use of Co-Cr as denture base in short span bounded saddle in patients highly susceptible to infection.