PERIODONTAL BACTERIA COLONIZING ORAL MUCOUS-MEMBRANES IN EDENTULOUS PATIENTS WEARING DENTAL IMPLANTS

THE PURPOSE OF THIS STUDY was to investigate the prevalence of the mic robiota on the oral mucosal surfaces and in the peri-implant pocket in edentulous subjects with a past history of periodontitis. Twenty eden tulous subjects wearing dental implants for at least one year and with a history of periodontitis participated in this study. Clinical param eters were assessed (plaque, redness, swelling, peri-implant probing d epth [PIPD], and bleeding on probing) and microbiological samples were taken (oral mucosal surfaces, saliva, plaque, and peri-implant pocket ). Based on the clinical results, the group as a whole showed healthy peri-implant tissues. A mean PIPD of 3.6 mm was found. A statistically significant correlation was found between the PIPD and bleeding upon probing, plaque scores, redness, and swelling. Actinobacillus actinomy cetemcomitans and Porphyromonas gingivalis were not detected. The subj ects harboring Prevotella intermedia showed presence of PIPD of greate r than or equal to 5 mm. All subjects harbored Peptostreptococcus spp. , Fusobacterium spp., and other Prevotella species. Actinomyces odonto lyticus, Bacteroides forsythus, Campylobacter rectus, Pseudomonas spp. , and enterobacteria were detected less frequently. Three subjects sho wed signs of overt soft tissue inflammation. They harbored higher prop ortions of Peptostreptococcus spp. than the other subjects. The result s corroborate the suggestion that the primary source of colonization f or dental implants in edentulous patients are the oral mucous membrane s. The results indicate that the microbiota of subjects wearing dental implants with a past history of periodontitis are composed of bacteri a associated with a healthy periodontium or gingivitis. It is suggeste d that elimination of the subgingival environment by extraction of all natural teeth probably initiates the disappearance of the two periodo ntal bacteria A. actinomycetemcomitans and P. gingivalis.