Impact of Periodontitis Grading on Peri-Implant Clinical and Bone Health: A 60-Month Prospective Study

This prospective cohort study evaluated the effect of periodontitis grading on peri-implant clinical and radiographic outcomes over a 60-month follow-up. Fifty-five partially edentulous patients were classified into three groups according to periodontal status: generalized aggressive periodontitis (Grade C), generalized chronic periodontitis (Grade B), and no history of periodontitis. A total of 92 implants (tissue- or bone-level) were placed and restored with single crowns, followed by biannual supportive periodontal therapy. Peri-implant clinical parameters (probing depth, clinical attachment level, plaque index, and bleeding on probing), marginal bone level changes, peri-implantitis incidence, and implant survival were assessed up to 60 months after prosthetic loading. The objective was to determine whether periodontal history and grading influence long-term peri-implant outcomes under maintenance therapy.

Inclusion Criteria: * Age ≥ 18 years. * Previous diagnosis of aggressive periodontitis, chronic periodontitis, or no history of periodontitis. * Completion of periodontal treatment at least 1 year before study enrollment. * Enrollment in supportive periodontal therapy. * Plaque Index \< 20% at study onset. * Bleeding on Probing \< 20% at study onset. * Presence of at least one single edentulous space with adjacent teeth. * Sufficient bone and soft tissue volume for implant placement without the need for reconstructive procedures. Exclusion Criteria: * Systemic conditions that contraindicate implant surgery. * Use of systemic antimicrobial therapy within 6 months before implant placement. * Untreated or uncontrolled aggressive periodontitis. * Untreated or uncontrolled chronic periodontitis. * Pregnancy or breastfeeding. * Need for bone grafting or soft tissue grafting procedures. * Current smokers or former smokers.