The subgingival microbial flora associated with human dental implants

Abstract

I n recent years the microbial colonization on different surfaces in the oral cavity has been studied by oral microbiologists. Resident bacterial populations have been examined from the buccal mucosa,’ the tongue,2 enamel,3 cemental root surfaces,4 epoxy resin crowns,s overhanging amalgam restorations,6 and surfaces of dentures? However, none of the studies has involved surfaces of dental implants, despite their wide use over the past 15 years for the replacement of teethin edentulous spores. Even with clear anatomic and morphologic differences, clinical and histopathologic descriptions of gingival inflammation, pocket formation, and alveolar bone loss around protruding dental implants that are remarkably similar to periodontal lesions associated with natural teeth have been reported.8s’2 With natural teeth the relationship between periodontal disease and the presence of periodontopathic microorganisms in subgingival plaque has become widely accepted. 13,14 In contrast little is known about the nature of the subgingival bacterial populations that colonize around dental implants and their relationship to peri-implant tissue conditions. Direct microscopic examinations of dental plaque enables a rapid and inexpensive study of subgingival bacterial types without encountering the many difficulties inherent in carrying out conventional bacteriologic culturing, and they have been used previously to characterize the microorganisms around natural teeth.‘5,‘6 In this investigation the subgingival microbiologic flora associated with 17 gingival tissue-protruding dental implants was studied with direct phasecontrast microscopy.