Comparative Evaluation of Diagnodent and Digital Radiography in Dental Caries Diagnosis at the National Hospital Abuja: a Diagnostic Accuracy Study

Abstract

Objective

Early caries detection is crucial for preventing and controlling the spread of dental caries. Conventional detection techniques (visual and radiographic) rely on subjective judgment and are prone to misinterpretation, which may lead to mismanagement. This highlights the need for objective and quantitative methods to detect and monitor the progression of carious lesions. Among several e m e r g i n g d i a g n o s t i c d e v i c e s , l a s e r fluorescence—particularly Diagnodent—has generated considerable interest. This study aimed to compare the performance of Diagnodent and digital bitewing radiography in detecting early dental caries, using Ekstrand's criteria and manufacturer-recommended Diagnodent thresholds.

Study Design

This diagnostic accuracy study was conducted at the Restorative Dentistry Unit of the National Hospital, Abuja, from 8 August to 9 November 2022. Ethical approval was obtained from the Health Research Ethics Committee (HREC) of the National Hospital, Abuja (Approval No. NHA/EC/078/2019).

Participants

Thirty-one participants with 130 premolar and molar teeth that met the inclusion criteria were randomly selected.

Test Methods

 Teeth with incipient, non-cavitated enamel caries were examined using Diagnodent, digital bitewing radiographs, and visual examination (considered the gold standard). Visual and radiographic assessments followed Ekstrand's criteria, while Diagnodent results were interpreted using the manufacturer's cut-off values. Sensitivity, specificity, predictive values, overall accuracy, and Kappa scores (intra- and inter-examiner agreement) were calculated. Data were analyzed using IBM SPSS Version 26.0. The significance level was set at P< 0.05.

Outcomes

For occlusal surfaces, the sensitivity of early caries detection was 95.6%, 80.0%, and 100% for visual examination, Diagnodent, and bitewing radiography, respectively. The corresponding specificity values were 90.2%, 95.4%, and 27.3%. On interproximal surfaces, all methods recorded 100% sensitivity, but bitewing radiography had the lowest specificity (70.9%). Differences in specificity among diagnostic methods were statistically significant (P < 0.05) for both occlusal and interproximal surfaces, while sensitivity differences were not. Overall diagnostic accuracy was statistically significant for all three methods on both surfaces. Kappa scores for intra- and inter-examiner agreement were 0.9 for each diagnostic method. Diagnodent was more accurate than bitewing radiography for detecting early carious lesions on both occlusal and interproximal surfaces. Although Diagnodent demonstrated high accuracy, it is recommended as an adjunct to visual and radiographic methods rather than a standalone tool.