March 2012

Objective: To evaluate the reproducibility of caries detection and treatment planning among public health dentists and estimate the possible impact of their decisions on financial costs. Research design and settings: Thirty nine dentists working in the public health service of Piracicaba, São Paulo, Brazil made a combined visual–radiographic caries examination of 40 occlusal surfaces of extracted permanent teeth mounted on two dental mannequins and proposed treatment plans for each tooth. Histological validation then evaluated the diagnoses validity and the suitability of the treatment plans. Outcome measures: Inter-examiner agreement was calculated by Cohen’s Kappa statistics. The sensitivity and specificity of caries detection and treatment decision were calculated. The costs of dental treatment plans for public health system were calculated from a Brazilian public health service fee scale. Results: Inter-examiner agreement for caries detection was moderate (к=0.42) while for treatment decisions it was fair (к=0.29). The sensitivity and specificity were 0.69 and 0.65 for caries detection and 0.56 and 0.65 for treatment decision respectively. Dentists overestimated the presence and depth of carious lesions and there was a tendency to treat enamel lesions using invasive therapeutic procedures. Mean treatment cost across the two cases was 32US$ (range 9-65) while the histologically validated cost was 23US$. Conclusion: The variability in caries detection and treatment decision negatively affected the cost of the dental treatment. Key words: oral diagnosis, inter-examiner variability, health care costs, economics, public health system