Caries assessment by clinical examination with or without radiographs of young Chinese adults

Objective: To compare caries status assessment of posterior teeth of young Chinese adults by using clinical examination alone and with the supplemental use of bitewing radiographs. Methods: Two calibrated dentists examined the posterior teeth of 200 Chinese university students (aged 18-24 years) using dental mirrors and probes under optimal lighting. Caries was diagnosed by visual detection of carious cavities. Duplicate examinations were performed to monitor intra- and inter-examiner variations. Bitewing radiographs were taken and examined by an independent dentist. Caries was recorded when a lesion extended into dentine. Results: Among the 3,162 posterior teeth examined, 113 were detected with caries. More than one third (35.4%) of the caries found in the posterior teeth was not detected from reading the radiographs but was detected by clinical examination. About half (51.4%) of the caries was found on the bitewing radiographs only, leaving 13.2% being detected by using either method. With the supplement of bitewing radiographs, there was a 105% increase in the number of carious lesions detected. This leads to a correction factor of 1.13 for adjustment of the mean DMFT score obtained from conducting clinical examinations alone. Conclusion: Due to the significant number of clinically undetected carious cavities in these young Chinese adults who live in a community with water fluoridation, it may be advisable to use a correction factor to adjust the caries experience obtained from epidemiological surveys when bitewing radiographs are not available.