Overdiagnosis of dental caries in South Korea: a pseudo-patient study

To evaluates the tendency of South Korean dentists to over-diagnose clinically healthy teeth in pseudo-patients.

We conducted a pseudo-patient, cross-sectional study in 196 private dental clinics with 58 pseudo-patients in South Korea between August and December 2018. Trained pseudo-patients with no previous oral diseases, including dental caries, diagnosed by two experienced dentists, were sent to each dental clinic. Before visiting each private dental clinic, participants were instructed to state, "I have no symptoms, but I would like to have a dental caries examination". The oral examination was performed using visual and tactile inspection methods only. The interactions between the dental clinic staff and the pseudo-patient were documented on a data collection form shortly after each visit.

In 33.2% (65/196) of these interactions, the pseudo-patients were diagnosed as having no dental caries. 11.7% (23/196), 12.8% (25/196), 10.7% (21/196), and 10.7% (21/196) of the sample were diagnosed with dental caries in one, two, three, and four teeth, respectively. Dentists diagnosed five or more dental caries in 20.9% (41/196) of the sample. 196 dental clinics diagnosed a total of 503 dental caries. Of these, 392 were in molars. Small solo practice dentists diagnosed 3.54 dental caries and large group practice dentists 1.57, but the difference was not significant (p = 0.07). The recommendation rate for dental caries treatment was highest among 43 (55.1%) large solo practices, and lowest in 7 (33.3%) large group practices. However, small solo practices had the lowest rate of preventive care recommendations at 12 (30.8%) and 10 (47.6%) in large group practices. The data shows that preventive care recommendations increased as the practice size increased.

The study findings indicate that Korean dentists tend to over-diagnose dental caries, which could pose a threat to public health both in Korea and worldwide. Therefore, it is important to carefully consider strategies to improve the correct diagnosis and standard of care for dental caries by private dentists.