Frequency of caries in triangular‑shaped radiolucencies on periapical radiographs of maxillary deciduous second molars

Background: Dentists might face various artifacts (such as triangular‑shaped radiolucencies [TSRs])during the assessment of radiographs and should be able to differentiate them from caries to avoidunnecessary treatments.Materials and Methods: In this cross‑sectional study, 109 maxillary second primary molarswere evaluated in cooperative children aged 4–9 years, who had distal caries in their maxillaryfirst primary molars. First, TSRs were recorded on periapical radiographs of each maxillary secondprimary molar’s proximal surface. Then, after excavating distal caries in the adjacent teeth “D,” apedodontist examined the mesial surfaces of teeth “E.” Chi‑square test was used to compare thedistribution of caries in different variables, and the kappa coefficient was applied to evaluate clinicaland radiographic agreements. A P 0.05 was considered statistically significant.Results: Forty‑four cases were found to be carious both clinically and radiographically, and54 cases were noncarious by both methods, while for 11 cases, the diagnosis was controversial.No statistically significant difference was found between radiographic and clinical caries detectionmethods in children whose periapical radiographs contained TSRs, and most of the subjects hadsimilar diagnoses. Value of caries detection sensitivity, specificity, positive predictive value, andnegative predictive value in TSRs was 88%, 92%, 90%, and 90%, respectively.Conclusion: Considering high radiographic sensitivity for caries detection in TSRs, clinicians shouldbe more cautious about them being carious or not, and both radiographic and clinical examinationsare necessary. Further, to avoid misinterpretation in radiographs, additional education is necessaryfor young dentists.