A comparison of root caries diagnosis based on visual-tactile criteria and DIAGNOdent in vivo

ObjectivesThis clinical study aimed to evaluate the validity of using DIAGNOdent in diagnosing root caries, and to assess the sensitivity and specificity of different cut-off DIAGNOdent values in assessing root caries with reference to visual-tactile criteria.MethodsExposed root surfaces were assessed by one examiner for root caries on 266 subjects using visual-tactile criteria and DIAGNOdent 2095 after dental scaling. Associations between DIAGNOdent values and visual-tactile diagnosis of root caries were determined. The cut-off level for statistical significance was 0.05. The sensitivity and specificity of DIAGNOdent with difference cut-off points were analysed compared to visual-tactile diagnosis of root caries.ResultsThere was significant difference between DIAGNOdent values obtained from sound and carious root surfaces (p < 0.001). On carious surfaces, active root caries obtained significantly higher DIAGNOdent values than inactive root caries (p < 0.001). With increasing cut-off point DIAGNOdent values from 5 to 35, sensitivity decreased from 91.4% to 16.2% and specificity increased from 64.4% to 98.2%. A cut-off point of DIAGNOdent value between 5 and 10 produced the highest combined sensitivity and specificity.ConclusionsThere was a significant difference in DIAGNOdent values between sound and carious root surfaces diagnosed by visual-tactile criteria supporting the validity of DIAGNOdent for assessing root caries. A DIAGNOdent value between 5 and 10 produced the highest combined sensitivity and specificity when visual-tactile assessment of root caries was regarded as the criterion. These findings have implications in using and explaining DIAGNOdent values in assessing root caries.