Does Cone-Beam Computed Tomography Provide Additional Benefit to Periodontal Infrabony Defect Topography Assessment? A Multi-Centre Case-Based Questionnaire

Objectives: The objectives of this study were to investigate whether cone-beam computed tomography (CBCT) provides additional benefit in assessing periodontal infrabony defect topography, and whether assessment accuracy differed between clinicians in periodontology with different levels of experience. Background: A comprehensive assessment of the periodontal condition usually comprises clinical periodontal examination and two-dimensional radiographic evaluation. Whilst periapical radiographs are the most frequently employed for radiographic assessment of periodontal bone loss, they have some limitations in assessing infrabony defects. As a result, CBCT has been gaining attention recently as an adjunctive periodontal diagnostic modality that can overcome these limitations. It is well established that the use of CBCT for periodontal diagnosis is not routine and should only be reserved for judicious case selection in accordance with the as low as reasonably achievable (ALARA) principle. Given these considerations, studies evaluating whether CBCT provides any additional benefit in the assessment of periodontal infrabony defects remain limited, and no formal guidelines currently exist regarding its role or implementation in postgraduate periodontal education. Methods: Forty-six participants (26 residents and 20 specialists in periodontology) from three European Federation of Periodontology (EFP)-accredited centres were invited: King’s College London (KCL), United Kingdom; KU Leuven, Belgium; and The University of Hong Kong (HKU), Hong Kong SAR, China. The participants were required to complete two case-based questionnaires on infrabony defect assessment, with a two-week washout period in between. Eight complex cases were presented, once with periodontal charting and periapical radiography (Questionnaire S1), and once with CBCT images in addition to the conventional data (Questionnaire S2). For all eight cases, an HKU panel performed reference-standard intra-surgical or CBCT measurements against which the participants’ answers were scored. Results: Forty participants returned the questionnaires (25 residents and 15 specialists). The response rate was, therefore, 87.0%. Participants assessed the infrabony defects more accurately in Questionnaire S2 compared with Questionnaire S1 (the mean scores [%] were 69.8 ± 11.9 and 63.5 ± 11.8 respectively); the mean difference was statistically significant (p < 0.001). When comparing residents and specialists, the mean difference in scores (%) was 0.5 (95% CI: −7.4–8.5) for Questionnaire S1 and −2.5 (95% CI: −10.4–5.5) for Questionnaire S2, with neither difference reaching statistical significance (p > 0.05). However, a larger study is required to draw more definitive conclusions about differences between clinician groups. Conclusions: CBCT, adjunctive to conventional periodontal diagnostics, provided statistically significant additional benefit in assessing infrabony defect topography by increasing assessment accuracy. However, whether the magnitude of this improvement is clinically meaningful requires further research. This study shows that between residents and specialists in periodontology, there was no statistically significant difference in the accuracy of infrabony defect topography assessment; nonetheless, given the limited sample size, further work is needed to clarify potential between-group differences. Whilst keeping the ALARA principle in mind, this study highlights the need for further investigation into the value of CBCT in complex periodontal cases, emphasises the importance of defining its role in postgraduate periodontal education, and underscores the need for a larger-scale study involving additional EFP-accredited centres to enable more robust conclusions.