Abstract
The incidence of serious dental caries has recently been on the decline. In step with this tendency, it has become a common practice for dentists to promote recalcification or arrest the development of the decay process in incipient cases, and place their patients under doctor-monitored observation instead of choosing restrative treatment right away. The situation is such that conventional mass screenings for dental caries alone are inadequate. It is now imperative to work on such dental examination programs that lay more emphasis on the importance of personal oral health maintenance and provide the public with up-to-date information on tooth decay preventing methods. Our department has conducted studies in order to formulate a new dental caries index based on which we could offer instruction in oral hygiene measures as well as information on caries prevention measures. In this paper, we will report the results of an 8-year follow-up study of caries incidence in primary and junior high school students in a rural community, Niigata Prefecture, by using a criteria we proposed earlier. The criteria is based on the ratio of the number of untreated teeth in the year X plus 1 to the total number of healthy and treated teeth in the year X after eruption. The following is a brief summary of our findings.
1. The untreated tooth ratio came to less than 1% in the incisor-premolar tooth group.
2. The untreated tooth ratio in the molar group at the maximum worked out at 8.1% for the maxillary first molars,4.2% for the maxillary second molars,12.4% for the mandibular first molars and 5.2%for the mandibular second molars.
3. The untreated tooth ratio in the molar group as a whole peaked one year after eruption of the teeth, kept declining until three years after eruption and remained unchanged thereafter.
4. The ratio of the number of untreated teeth compared to the number of healthy teeth was higher than the ratio from the number of treated tooth ratio-by around 10% after eruption. The untreated tooth ratio compared to the treated tooth reached a maximum of 6.3%. A significant difference was observed in some of the samples.
These findings suggested that the untreated tooth ratio can be useful as a new index for assessing the caries incidence.
