Abstract
Since 1995, the Dental Health Examination at Japanese institutions of instruction (from Kindergartens to universities) has come to include one new category, "CO", meaning that there are apprehensions that caries will evolve on specific teeth of students. However, ever since the new "CO" category was established, there has been insecurity in diagnoses by dentists about what teeth should be judged to have "CO" characteristics, i. e., how to distinguish "CO" from both states of "no defects" and of "caries positive." The purpose of this investigation is to understand the standards of judgement applied by dentists performing "C0"-examinations. We collected 16 molar teeth samples extracted from patients under dental treatment, plugged them into a plastermodel and asked 95 different dentists to pass, within 2 minutes, judgement concerning the states of pit and fissure caries with verdicts of "CO" or "no defects." Inspection of the 16 molar teeth samples showed that the 95 dentists found an average of 3.37 teeth that they considered as "CO." One dentist diagnosed 12 of the tooth samples as being within the "CO" category. Twelve of the dentists did not classify any of the 16 teeth as showing "CO"-features, because they concluded that all teeth were either without problems or had heavier defects. After having obtained these diagnoses from the dentists, the 16 tooth samples were sliced and subjected to examination by means of microscopy. The official definition of "CO" implies an "absence of dental cavities accompanied by changes of tooth surface and color." Microscopy and the application of this official measure revealed that 3 out of the 16 teeth should have been diagnosed as exhibiting "C0"-characteristics. Five of the teeth should have been evaluated as being inflicted by caries. These observations show that in the Dental Health Examination at Japanese institutions of instruction, personal judgement of examining dentists can exhibit considerable variations. Such variations of instant judgement of dentists in diagnosing "C0"-characteristics of teeth of pupils or students, of course, will be reflected in inaccuracies in the official statistics.
