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

This prospective cohort study was conducted to evaluate the long-term influence of a history of periodontitis on peri-implant clinical and radiographic outcomes in partially edentulous patients. Patients were classified according to their periodontal status into three groups: generalized aggressive periodontitis (currently classified as Grade C periodontitis), generalized chronic periodontitis (Grade B periodontitis), and individuals without a history of periodontitis.

A total of 55 patients received 92 dental implants, either tissue-level or bone-level, placed in healed sites and restored with single screw-retained crowns. All patients were enrolled in a structured supportive periodontal therapy program and were followed for 60 months after prosthetic loading.

Peri-implant and periodontal health were assessed longitudinally using clinical parameters (probing depth, clinical attachment levels, plaque accumulation, and bleeding on probing) as well as radiographic evaluation of marginal bone level changes. Assessments were performed at multiple time points throughout follow-up to monitor tissue stability and disease occurrence.

The primary aim of the study was to compare peri-implant outcomes among patients with different periodontal backgrounds and to determine whether a history and severity of periodontitis influence long-term implant success and disease incidence under strict maintenance conditions. Secondary outcomes included evaluation of marginal bone remodeling, incidence of peri-implantitis, and implant survival over time.

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.