Periodontal Probing Versus Radiographs for the Diagnosis of Furcation Involvement

Background : Decisions in periodontal therapy for multirooted teeth are essentially based on accurate diagnosis of the furcation involvement (FI). Furcation probing (FP) is still the basic diagnostic measure, although the assessment may be difficult. The aim of this study is to evaluate the validity of FP and radiographic assessment of FI compared with visual assessment during open flap surgery (OFS). Methods: In this retrospective clinical cohort study, 215 participants with periodontal disease and at least one molar treated with OFS were enrolled, and a total of 834 molars were assigned for FI by FP and in radiographs analyzed by an experienced (EE) and less experienced examiner (LE). For the investigation, 143 panoramic radiographs (OPGs) and 77 intra‐oral radiographs (I‐Os) were evaluated. Results: The Class of FI by FP was confirmed in 56%, whereas 15% were overestimated and 29% underestimated. FI Class 0 and I had been detected with high probability (74% and 54%, respectively). Of all FI Class III, 57% were detected correctly by radiographs and 32% by FP. FP and OFS revealed a weighted κ‐coefficient (κ_w) = 0.588; radiographs and OFS had κ_w = 0.542 (OPG κ_w = 0.555 and I‐O κ_w = 0.521). The interrater reliability for radiographs was dependent on the experience of the examiner (EE κ_w = 0.618; LE κ_w = 0.426). Conclusions: Experience in analyzing conventional radiographs increases the potential of correct diagnosis of advanced FI. The reliability of FP compared with radiographic assessment depends on the anatomy and location of the tooth. Both diagnostic tools should be used in cases of suspected FI.