Bacterial Findings in Prosthodontic Patients with and without Dental Implants

Objectives: Prosthodontic therapy with dental implants is one of the solutions for partially and totally edentulous patients. The long-term success directly depends on microbiota around implants. The purpose of this study was to determinate the differences in subgingival anaerobic and facultative anaerobic microflora in patients with and without implants. Methods: Subgingival bacterial samples were collected in 55 patients. 28 of them had implants and metal-ceramics suprastructures (mean value of insertion=2 years). Most of the implants were “ITI” and “IMPLA”. Second group with 27 patients had bridges on natural teeth (mean value of loading period=6years). Bridges were made of Co-Cr alloys (in both groups). Samples were taken with sterile paper points by smear method. Transport medium was VMGA II. Samples were inoculated on selective anaerobic media (Zambon, Hunt, Mandell, Korman and Walker). Final identification of selected bacteria was performed microscopically and with API test. Following periodontal parameters were evaluated: Sulcus bleeding index (Mühlemann), Plaque index (Silnessa), and probing pocket depth. Results: It has been identified 17 anaerobic (facultative anaerobic) genera of microorganisms around implants and 15 around natural teeth. The most frequent microorganisms around implants were Prevotella spp. (79% of patients), Peptostreptococcus spp. (69%), Vellonella Parvula (59%), Fusobacterium spp. (44%), Bacteroides spp. (34%), Porphyromonas spp. (37%) and Actinomyces spp. (28%). Actinobacillus actinomycetemcomitans was found in one case. Prevotella spp., Peptostreptococcus spp., Vellonella Parvula and Porphyromonas spp. showed similar rates in both patient groups, unlike rates of Fusobacterium spp., Bacteroides spp., Actinobacillus actinomycetemcomitans and Actinomyces spp. which were significantly differed (p<0,05). Patients with natural teeth had inferior quality of periodontal parameters and greater portion of Gram-negative rods. Conclusion: The results showed similarity in booth groups of patients. The differences are most probably caused by loading period. Poor periodontal parameters showed correlation with portion of Gram-negative rods.