Removable acrylic resin disk as a sampling system for the study of denture biofilms in vivo

Statement of problem. The adhesion of microorganisms to a denture surface can result in denture stomatitis. Purpose. The purpose of this study was to evaluate denture biofilm in vivo using a new sampling system to gain a better understanding of plaque organization in Candida-induced denture stomatitis. Removable acrylic resin disks were used with self-adhesive paper disks to compare biofilm formation and retention efficacy of both sampling systems. Material and methods. Twenty-one subjects with a complete maxillary denture were recruited, 12 with a clinical diagnosis of chronic denture stomatitis and 9 with a clinically healthy palatal mucosa. A custom-made autopolymerized 3.0-mm-diameter acrylic resin disk inlay was inserted in a cavity prepared within the intaglio surface of the maxillary denture in contact with either normal or inflamed mucosa. Next to the acrylic resin disk, a self-adhesive paper disk was placed for comparison of the 2 sampling techniques. Denture biofilms were collected within variable time periods of I hour to several months, and descriptive data were provided by means of scanning electron microscopy analyses. The method of retention and recovery of specimen disks were evaluated between both sampling techniques using a chi-square test to assess significant differences (alpha = .05). Results. Early event features of denture biofilms showed differences in biofilm organization between the 2 sampling techniques but became subtler with increased time periods. Regardless of the sampling technique, interparticipant variations could be observed as to rate, microorganism density, and architectural pattern. In general, denture biofilm formation was increased when the sampling disks were localized in areas affected by denture stomatitis. Conclusion. The new sampling technique provides reliable information with controlled formation time of denture biofilm in its natural environment.