Methods: Twenty patients with moderate-to-severe periodontal disease underwent both FPPR and CBCT examinations. Six general dental practioners (GDP), nine periodontist trainees (PT) and five registered periodontists (P) were conveniently recruited to the study. They performed tooth-by-tooth radiographic periodontal assessments on a structured form of the FPPR and CBCT on two separate occasions. One senior registered periodontist was selected to be the reference assessor and weighted Kappa statistic was calculated for each individual assessor against the reference assessor based on the radiographic assessment scores to measure inter-operator assessment agreement. Time taken for CBCT and FPPR assessments were recorded. Comparisons of the time used and inter-operator agreement among the three groups were performed using one-way ANOVA. While comparisons within the same groups were performed using paired sample t-tests.
Results: Large variations in the time used for assessment of CBCT (Range:57.8-190.8mins) and FPPR (Range:33.5-100.3mins) were observed. No significant differences were observed in the time used for assessing CBCT (GDP:135.1; PT:134.8; P:97.2mins) and FPPR (GDP:62.4; PT:52.2; P:46.0mins) among the groups (p>0.05). Significantly longer time was taken to assess CBCT comparing to FPPR in GDP and PT groups (p<0.05). Compared to the reference assessor, the mean Kappa values on CBCT and FPPR assessments were 0.76/0.79/0.78 and 0.72/0.74/0.72 for GDP, PT and P groups respectively with no significant difference among groups (p>0.05). Significantly higher Kappa values on CBCT compared to FPPR were found in all groups (p<0.05). Conclusions: In general, assessments of CBCT took longer time to perform than assessments of FPPR. CBCT appeared to assist operators to achieve radiographic periodontal assessments comparable to those of an experienced periodontist.