Comparison of observer reliability in assessing alveolar bone height on direct digital and conventional radiographs

Radiographs are an important adjunct in the assessment of periodontal disease in clinical practice and research. The purpose of this study is to compare intraexaminer and interexaminer reproducibility in assessing alveolar bone height on direct digital and conventional radiographs.

Matched sets of conventional radiographs and digital radiographs were taken on 23 subjects. Bone levels were measured on radiographs as the distance from the cementoenamel junction to the alveolar crest in millimetres at the mesial and distal surfaces of all available teeth excluding third molars. Two examiners measured bone levels twice on each type of imaging system independent of one another. Correlations and paired t-test values were computed.

Intraexaminer relative agreement (r-value) on both digital and conventional radiographs ranged from 0.73 to 0.98, P<0.05; however, differences between measurements (absolute agreement) for each examiner were non-significant, P>0.05. Interexaminer relative agreement on both digital and conventional radiographs ranged from 0.70 to 0.95, P<0.05, and measurement differences between the two examiners were also significant, P<0.05. One examiner tended to score higher measurements than the other, P<0.05.

Alveolar bone measurements are reproducible on both digital and conventional radiographs. Intraexaminer reproducibility is superior to interexaminer reproducibility. Direct digital radiographs did not enhance examiner agreement over conventional radiographs.