Yukari Oda*1; Taichi Ito1; Haruka Yasuoka1; Sota Miyazaki1; Hideshi Sekine2

1Department of Oral and Maxillofacial Implantology; 2Department of Fixed Prosthodontics, Tokyo Dental College, Tokyo, Japan

Background: The salivary periodontal pathogen levels in edentulous patients who worn complete-arch implant-supported prostheses is under debate. To our knowledge, the detection of periodontal pathogens particularly after long time follow-up has not been clarified.

Aim/Hypothesis: In this retrospective study, the purpose was to clarify whether periodontal pathogens were detected in saliva in edentulous patients 9–15 years after wearing complete-arch implant-supported prostheses, and whether there were changes in periodontal pathogen levels before and after implant treatment.

Material and Methods: 18 completely edentulous patients who worn complete-arch implant-supported prostheses with 241 implants in Tokyo Dental College Suidobashi Hospital and Chiba Dental Center between April 2006 and March 2012 (9–15 years follow-up) were evaluated. Before and after implant treatment, a total of 3–5 ml stimulated whole saliva was collected from patients. The levels of the following five periodontal pathogens in saliva were evaluated using real-time polymerase chain reaction: Aggregatibacter Actinomycetemcomitans (A.a.), Porphyromonas gingivalis (P.g.), Tannerella forsythia (T.f.), Treponema denticola (T.d.), Prevotella Intermedia (P.i.). This protocol was approved by the ethics committee of Tokyo Dental College (Approval number 838).

Results: Of 18 patients, 8 patients could not be assessed because of lack of visit. A total 10 patients were therefore analyzed: 10 patients with 20 prostheses (10 upper, 10 lower), 132 implants (72 upper, 60 lower), 73.5 years old (min 56, max 79), and 11.7 years of function (min 9, max 15). Before implant treatment, all the 10 patients were classified as Stage Ⅳ Grade C on the classification of periodontal diseases. After implant treatment, peri-implantitis was not observed in all the 10 patients. Patients visited the hospital every 4–6 months for maintenance. The total copy counts number (copy/ml) of bacteria decreased significantly after implant treatment compared to before implant treatment (P < 0.05). Copy counts number (copy/ml) of A.a., P.g., T.f., T.d., and P.i were significantly reduced after treatment compared to before treatment (P < 0.05). Also, ratio (%) of P.g., T.f., T.d., and P.i. to total bacteria were significantly reduced after treatment (P < 0.05).

Conclusion and Clinical implications: In completely edentulous patients with complete-arch implant-supported prostheses, the salivary periodontal pathogen levels were low after 9–15 years follow-up. Even if the salivary periodontal pathogens were detected due to severe periodontitis before implant treatment, the detection levels of bacteria were kept low after implant treatment by maintenance.

Disclosure of Interest: None Declared.

Keywords: dental implants, peri-implantitis, retrospective study