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

Abstract

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 avoid
unnecessary treatments.
Materials and Methods: In this cross‑sectional study, 109 maxillary second primary molars
were evaluated in cooperative children aged 4–9 years, who had distal caries in their maxillary
first primary molars. First, TSRs were recorded on periapical radiographs of each maxillary second
primary molar’s proximal surface. Then, after excavating distal caries in the adjacent teeth “D,” a
pedodontist examined the mesial surfaces of teeth “E.” Chi‑square test was used to compare the
distribution of caries in different variables, and the kappa coefficient was applied to evaluate clinical
and radiographic agreements. A P < 0.05 was considered statistically significant.
Results: Forty‑four cases were found to be carious both clinically and radiographically, and
54 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 detection
methods in children whose periapical radiographs contained TSRs, and most of the subjects had
similar diagnoses. Value of caries detection sensitivity, specificity, positive predictive value, and
negative predictive value in TSRs was 88%, 92%, 90%, and 90%, respectively.
Conclusion: Considering high radiographic sensitivity for caries detection in TSRs, clinicians should
be more cautious about them being carious or not, and both radiographic and clinical examinations
are necessary. Further, to avoid misinterpretation in radiographs, additional education is necessary
for young dentists.
Key Words: Artifact, deciduous tooth, dental decay, dental radiography