Correlation between periodontal parameters at teeth and implants: An up to 20-year long-term observational cohort study in periodontitis patients.

OBJECTIVES

The study aimed to evaluate the long-term correlation between periodontal parameters at implants and contra-lateral natural teeth over a follow-up period of up to 20 years in periodontitis patients undergoing supportive periodontal care (SPC).

MATERIALS AND

METHODS

This observational cohort study involved systemically healthy, non-smoking patients who received periodontal and implant therapy, followed by regular SPC. The following parameters were assessed at baseline (i.e. implant loading) and at 5, 10, 15 and 20 years: clinical attachment level (CAL), pocket probing depth (PPD), gingival margin (GM) and bleeding on probing (BOP). Intra- and inter-group differences over time between implants and teeth were analysed. Survival rates were calculated.

RESULTS

167 patients with 419 implants were included. Mean CAL increased significantly over time at implants and teeth (p ≤ 0.015), approximately doubling every five years. After 20 years, CAL loss amounted to 4.47±2.45 mm at implants and 4.38±2.64 mm at teeth. Implants demonstrated significantly greater PPD increases after 10 and 15 years compared with teeth (p ≤ 0.027), whereas differences in CAL between implants and teeth were largely non-significant beyond 5 years. Differences in GM and BOP were small and inconsistent. No association was observed between SPC frequency and changes in CAL or PPD. Implant survival was 100% and three contra-lateral teeth were lost over 20 years.

CONCLUSIONS

In patients with treated periodontitis under regular SPC, implants and natural teeth exhibited comparable long-term clinical stability and survival. However, a non-linear progression of CAL loss occurs at teeth and implants, which SPC effectively limits but does not completely prevent.

CLINICAL SIGNIFICANCE: For systemically healthy, non-smoking patients with treated periodontitis who attend SPC programme twice per year, implants can provide durable tooth replacement. Survival is comparable to that of contra-lateral teeth over 20 years. Clinicians should prioritise maintenance and monitoring, as CAL and PPD may progress despite overall excellent long-term survival.