Comparison of proximal caries detection in primary teeth between laser fluorescence and bitewing radiography

The purposes of this in vitro study were to: (1) compare the accuracy of a laser fluorescence system (DIAGNOdent) in proximal caries diagnosis in primary teeth with that of bitewing radiography, using the histological examination as a gold standard; and (2) evaluate the reliability of the DIAGNOdent examination.

Included were 107 extracted primary molars without obvious cavities on proximal surfaces. The teeth were examined by 2 examiners using DIAGNOdent directly on the lesions (without contact; ie, proximal surfaces were not in contact with other teeth) and indirectly (with contact; ie, proximal surfaces were in contact with adjacent teeth). To simulate contacting teeth, the studied surface was set adjacent to a sound surface in a wax base. The contacting teeth were also diagnosed using bitewing radiography. Results of the diagnoses were compared with a histological gold standard. Sensitivity and specificity were calculated for each diagnostic system. Inter- and intraexaminer reliabilities of DIAGNOdent were calculated using intraclass correlation (ICC).

At the dentine caries (D3) level, the sensitivities of bitewing radiography (with contacting teeth) and DIAGNOdent with and without contacting teeth (direct application) were 0.41, 0.85 and 0.93, respectively, and the specificities were 1, 0.89, and 0.87, respectively. Both inter- and intraexaminer reliabilities using DIAGNOdent with and without contacting teeth (direct application) were very high (ICC=0.97 to 0.99).

The reliability of DIAGNOdent is very high and its diagnostic validity (sum of sensitivity and specificity) is higher than that of bitewing radiography for proximal caries detection in primary teeth.