# Identifying Key Factors for Implant Failure in a Periodontally Treated Population: A Retrospective Analysis

## TL;DR

This study finds that the severity of periodontal disease before surgery is the strongest predictor of dental implant failure in patients with a history of periodontitis.

## Contribution

The study identifies pre-implant probing depth as a critical risk factor for implant failure in periodontally treated patients.

## Key findings

- Higher pre-implant mean probing depth significantly increases the odds of implant failure.
- Patients with more sites having probing depths ≥4mm are at greater risk of implant failure.
- Other demographic and systemic factors were not significantly associated with implant failure.

## Abstract

The long-term success of dental implants is often compromised in patients with a history of periodontitis. This study aimed to identify the specific pre-implant clinical, demographic, and systemic risk factors associated with implant failure in a large cohort of periodontally susceptible patients who had received prior non-surgical therapy.

This retrospective cohort study utilized electronic health records from the multi-center BigMouth network (2011-2022). A final cohort of 434 patients with a history of periodontitis was analyzed at the patient level. Patients were stratified into an implant failure group (n=32) and a survival group (n=402). A comprehensive range of pre-implant variables, including detailed periodontal measurements from the most recent exam before surgery, demographics, and systemic conditions, was compared using t-tests and Chi-squared tests. Binary logistic regression was used to calculate odds ratios (OR) for significant predictors.

The analysis revealed that the severity of pre-existing periodontal disease was the primary predictor of failure. The failure group had a significantly higher pre-implant Mean Probing Depth (3.34 mm vs. 3.07 mm, p=0.0311) and more sites with PPD ≥ 4mm (p=0.0488). Logistic regression showed that for every 1 mm increase in Mean PPD, the odds of implant failure increased by a factor of 2.45 (OR=2.45, 95% CI: 1.08-5.56). Other patient-level factors, including demographics, systemic conditions, and medication use, as well as implant-level characteristics, were not significantly associated with implant failure.

The severity of residual periodontal disease, specifically elevated pre-implant probing depths, is the most significant and powerful predictor of dental implant failure in patients with a history of non-surgically managed periodontitis. Achieving periodontal stability before surgery is paramount for long-term implant success in this high-risk population.

Key words:Dental Implants, Implant Failure, Periodontitis, Risk Factors, Probing Depth.