Evaluation of Bone Loss in Implants Adjacent to a Tooth or Edentulous Area in Peri-Implantitis and Control Murine Models

Peri-implantitis (PI) is an inflammatory disease that affects supportive tissues around dental implants, and its progression eventually leads to bone loss and implant failure. However, PI effects may be different based on the presence or absence of adjacent teeth. The objective was to investigate the differences in bone loss and inflammation between implants placed adjacent to a tooth or edentulous area in a ligature-induced PI model. Materials and methods include the following: Three-week-old C57BL/6J male mice underwent maxillary first (AT; n = 12) or first and second (AE; n = 8) left molar extractions. In both groups, implants were placed in the first molar region 8 weeks after tooth extraction. Each group was further divided into control (C) or ligature (PI) 4 weeks after osseointegration. The mice were euthanized 12–14 days after ligature placement. The samples were analyzed using micro-computed tomography and histology. Statistical analysis was performed using analysis of variance and Tukey multiple comparison test (P < .05). Radiographic linear analysis revealed no statistically significant differences in bone levels between the two C and PI groups. Linear bone loss was significantly greater in the PI group than in the C group. Volumetric analysis yielded similar results. Histologically, hematoxylin and eosin staining revealed no notable differences between the two C and PI groups. The PI groups showed increased levels of inflammatory infiltrates and bone resorption. Qualitative assessment of collagen through picrosirius red staining demonstrated increased collagen disorganization in the PI group compared with that in the C group. No notable differences were observed between the AT and AE groups. The presence or absence of an adjacent tooth does not influence PI-induced soft and hard tissue alterations.