Reliability assessment of the 2018 classification case definitions of peri-implant health, peri-implant mucositis, and peri-implantitis.

Background: The purpose of this study was to evaluate the reliability and accuracy in the assignment of the case definitions of peri-implant health and diseases according to the 2018 Classification of Periodontal and Peri-implant Diseases and Conditions.

Methods: Ten undergraduate students, 10 general dentists, and 10 experts in implant dentistry participated in this study. All examiners were provided with clinical and radiographic documentation of 25 dental implants. Eleven out the 25 cases were also accompanied by baseline readings. Examiners were asked to define all cases using the 2018 classification case definitions. Reliability among examiners was evaluated using the Fleiss kappa statistic. Accuracy was estimated using percentage of complete agreement and quadratic weighted kappa for pairwise comparisons between each rater and a gold standard diagnosis.

Results: The Fleiss kappa was 0.50 (95% CI: 0.48 to 0.51) and the mean quadratic weighted kappa value was 0.544. Complete agreement with the gold standard diagnosis was achieved in 59.8% of the cases. Expertise in implantology affected accuracy positively (p < 0.001) while the absence of baseline readings affected it negatively (p < 0.001).

Conclusion: Both reliability and accuracy in assigning case definitions to dental implants according to the 2018 classification were mostly moderate. Some difficulties arose in the presence of specific challenging scenarios.