Predicting peri-implantitis incidence and implant failure via risk-assessment and prognostication tools: A validation study

Background: Identifying individuals at high risk for developing peri-implantitis (PI) and then determining the prognosis for implants with PI is crucial for treatment planning. Methods: This study longitudinally followed implants from implant placement retrospectively. The peri-implant disease risk assessment (IDRA) tool was applied, and the performance of the Kwok and Caton (KC) implant prognostication tool was compared with that of a new tool based on the frequency of progressive bone loss (PBL). The predictive accuracy of IDRA, PBL, and KC was evaluated at the corresponding time points (T1-T5). Fisher's exact test was used to evaluate categorical variables, and the Mann-Whitney test was used to evaluate continuous variables. Multiple regression models were built to correlate the occurrence of peri-implantitis and implant survival. The study followed the OHstat and TRIPOD guidelines for reporting. Results: 146 dental implants in 87 patients were included (age = 63.19 ± 11.38 years). IDRA classified the implants as 85.62% high-, 14.38% moderate-, and 0% low-risk. The KC scores showed 7.53% of implants with a favorable-, 65.07% with a questionable-, and 27.4% with an unfavorable prognosis. IDRA showed limited predictive power with an AUC of 0.533 (95% CI: 0.477-0.590). The KC tool performed much better, where a score of 2 had an AUC of 0.8321 (95% CI: 0.7257-0.9386). PBL yielded a moderate but consistent effectiveness with an AUC of 0.7697 (95% CI: 0.593-0.9463). Conclusion: The KC and PBL prognostication tools exhibited good predictive capability for implant survival, while the IDRA tool demonstrated marginal efficacy in predicting the incidence of peri-implantitis. Plain language summary: In this study, we followed 87 patients with 146 implants over time to test how well different tools can predict implant health and survival. We tested three tools, IDRA for predicting peri-implantitis, the KC system, and a new tool based on progressive bone loss for predicting implant survival. After 2 years with the implant crowns in place, we checked for cases of peri-implantitis. At the final follow-up (up to 8 years), the implant survival was assessed. We found that IDRA was not effective in predicting which implants developed peri-implantitis, even in high- and moderate-risk implants. In contrast, the KC tool was much more accurate, predicting implant survival in about 80% of cases. The PBL tool was also good in predicting implant survival, but slightly less accurate than the KC tool.