Intra- and Inter-Examiner Repeatability of Diagnostic Peri-implant Clinical Measurement: A Pilot Study

Abstract

Despite the crucial role of examiner reliability on quality research and practice, there is still limited literature analyzing factors affecting examiner variability of peri-implant clinical measurements. The present study investigated clinical peri-implant parameters to quantify their repeatability and investigate factors that may affect their accuracy. Thirty-three implants were examined by four operators. Peri-implant probing depth (PD), recession (REC) and gingival index (GI) were measured for agreement and included for analysis. Agreement was quantified using intraclass correlation coefficients (ICC; 95% CI); mixed linear and logistic regressions were used to assess additional variables. The overall inter-examiner agreement was comparable between PD (0.80) and REC (0.78), but significantly worse for GI (0.45) (p<0.001). Similarly, the intra-examiner agreement was similar for PD (0.81) and REC (0.80), but significantly worse for GI (0.57) (p<0.05). The magnitude of PD did not influence agreement. In contrast, increasing disagreement was noted for positive REC (OR: 3.0), negative REC (OR: 4.8) and lower GI (OR: 4.4). The incidence of bleeding on probing and severity of GI increased for deeper PD (0.113 unit increase per mm). Negative and positive values of recession and lower GI were associated with increasing disagreement. Radiographic bone loss, restoration contour and implant diameter did not impact PD accuracy within this study. In conclusion, within the limitations of the study, GI measurements presented higher variability than PD and REC. PD and GI were associated with one another and increased after multiple measurements.