Assistant Professor Department of Operative Dentistry, Endodontology and Periodontology, School of Dentistry, Matsumoto Dental University., Nagano, Japan
Background and objective: The pathogenesis and course of peri-implantitis (PI) have not been fully clarified. Furthermore, few reports have described the implant surfaces affected by PI. We herein report our histological observations of the surfaces of implants that were removed after 30 years because of PI. Materials and
Methods: Two implants were cut in the remaining osseointegration area using a carbide bar and extracted. The implant samples were immersed and fixed in a 10% neutral formalin solution. The sample of the first molar area was encapsulated in resin, and a polished specimen was prepared for observation under an optical microscope. The sample of the second bicuspid area was dehydrated and freeze-dried, and specimens for scanning electron microscopy (SEM) were prepared.
Results: The surface of the extracted implant showed black discolored areas with no attachment of tissue other than inflammatory tissue, including a small piece of bone, under SEM examination. In the polished specimen, inflammatory tissue and exfoliated bone tissue were observed on the implant interface. SEM observation also showed numerous foci of bacterial adherence, mainly filamentous bacteria. Sulfide reactions were observed in areas that appeared black microscopically. In addition, the degenerated bone tissue showed many fatty droplets, which are seen in poorly metabolized tissue.
Conclusion: The PI–implant interface was contaminated by sulfide adherence and bacterial infection, and degenerated bone tissue was also observed. These findings, when considered in conjunction with clinical symptoms, may assist in the selection of treatment for PI.
