Threshold values affect predictive accuracy of caries risk assessment.

OBJECTIVE: To evaluate effects of thresholds on estimates of predictive accuracy of methods for caries risk assessment. MATERIAL AND METHODS: Adolescents, aged 12 visiting two dental clinics, were examined by visual/tactile examination and bitewing radiography at baseline and after one year. Three methods for caries risk assessment were applied: previous caries experience, dentists' risk assessment according to set criteria (presence or absence of caries lesion) and acid tolerance of dental biofilm. The measure for validity (the reference standard) comprised caries lesion progression at 1 year. Predictive accuracy estimates were calculated for several thresholds. RESULTS: Accuracy estimates changed with threshold values of the methods and the reference standard. Patient spectrum differed between the clinics, which resulted in different accuracy estimates for the two samples. Generally, negative predictive values were high while positive ones were low indicating that these methods were more efficient in finding individuals who are at low risk of developing caries lesions than those with increased risk. CONCLUSIONS: As thresholds and patient spectrum affected predictive accuracy, it may be difficult to design a universal model with set thresholds for caries risk assessment. Foremost, a model should consider the level of aspiration for prediction and clinical decisions that will be made based on the risk assessment in the actual clinical setting.

A novel classification system for assessment of approximal caries lesion progression in bitewing radiographs.

OBJECTIVES: To design and pilot a novel classification system for the assessment of caries lesion progression in bitewing radiography and to report rater agreement of the system. METHODS: A classification system with drawings and text was designed to assess caries lesion progression. Guidelines for Reporting Reliability and Agreement Studies were used to study and report rater agreement. Pairs of posterior bitewing radiographs (baseline and 1-year follow-up) with different status concerning caries lesion progression were selected from files from public dental health clinics. 10 raters, 5 general dental practitioners and 5 specialists in oral and maxillofacial radiology were asked to assess the radiographs with the aid of the classification system. Seven raters repeated their assessments. Rater agreement was expressed as percentage of agreement and kappa. RESULTS: Kappa for the interrater agreement of 10 raters assessing progression was 0.61, indicating substantial agreement. Agreement was moderate for progression in the outer half of the dentine (kappa 0.55) and within enamel (kappa 0.44). Pairwise interrater agreement varied (range 69-92%; kappa 0.42-0.84). For about half of the pairs of raters, kappa was substantial (≥0.61). Intrarater agreement assessing progression was substantial (kappa 0.66-0.82). CONCLUSIONS: We demonstrated the applicability of the proposed classification system on caries lesion progression with respect to rater agreement. This system can provide a common framework for clinical decision-making on caries interventional methods and patient visiting intervals. Scientifically, this system allows for a comparative analysis of different methods of prevention and treatment of caries as well as of different caries risk assessment methods.

Diagnostic accuracy of different caries risk assessment methods. A systematic review.

OBJECTIVES: To evaluate the accuracy of different methods used to identify individuals with increased risk of developing dental coronal caries. DATA: Studies on following methods were included: previous caries experience, tests using microbiota, buffering capacity, salivary flow rate, oral hygiene, dietary habits and sociodemographic variables. QUADAS-2 was used to assess risk of bias. Sensitivity, specificity, predictive values, and likelihood ratios (LR) were calculated. Quality of evidence based on ≥3 studies of a method was rated according to GRADE. SOURCES: PubMed, Cochrane Library, Web of Science and reference lists of included publications were searched up to January 2015. STUDY SELECTION: From 5776 identified articles, 18 were included. Assessment of study quality identified methodological limitations concerning study design, test technology and reporting. No study presented low risk of bias in all domains. Three or more studies were found only for previous caries experience and salivary mutans streptococci and quality of evidence for these methods was low. Evidence regarding other methods was lacking. For previous caries experience, sensitivity ranged between 0.21 and 0.94 and specificity between 0.20 and 1. Tests using salivary mutans streptococci resulted in low sensitivity and high specificity. For children with primary teeth at baseline, pooled LR for a positive test was 3 for previous caries experience and 4 for salivary mutans streptococci, given a threshold ≥10(5) CFU/ml. CONCLUSIONS: Evidence on the validity of analysed methods used for caries risk assessment is limited. As methodological quality was low, there is a need to improve study design. CLINICAL SIGNIFICANCE: Low validity for the analysed methods may lead to patients with increased risk not being identified, whereas some are falsely identified as being at risk. As caries risk assessment guides individualized decisions on interventions and intervals for patient recall, improved performance based on best evidence is greatly needed.