Abstract
An investigation into the actual condition of the first permanent molars had been carried out on the patients who came to the Tokyo Dental Clinic of Lion Foundation for Dental Health from April,1992to March,1993. Those investigated consist of 711 patients who underwent periodical recall examination at our dental clinic, and 276 new patients, both with ages ranging from 8 to 29.
The items to be investigated were distinction of vital teeth and non-vital teeth, occurrence of missing teeth, condition of dental caries, number of surfaces with caries, condition of caries on proximal surface, and rates of caries experience according to tooth surface.
The results obtained from this study were as follows:
1. In the group who underwent periodical examination, almost all of the subjects had vital teeth. On the other hand, the group consisting of new patients showed a tendency toward having non-vital teeth or missing teeth, especially in the higher age group.
2. In the periodical examination group, there was a high rate of intact teeth and most of them had been treated with pit and fissure sealant. The ratio of teeth with dental caries was 2 to 6 percent in the periodical examination group. This rate exceeds the 20 percent among new patients, and the rate reached nearly 40 percent on the mandible in the group aged 15 to 19.
3. Concerning the number of surfaces having had caries among new patients, there was a tendency for the rate of one surface to decrease and that of three, four, or five surfaces to increase with age.
4. Caries on the medial proximal surface were observed very frequently among new patients, often detected through visual and palpable inspection. In the group undergoing periodical examination, the condition of such caries was slight and generally detected through X-ray examination. As to the distal proximal surface, the rate of caries was low in the periodical examination group compared with new patient group, and not detected at all through visual and palpable inspection.
5. For each dental surface, the rate of caries experience was higher for new patients compared with those of the periodical examination group. As to the rate of caries on the maxillary buccal surface and mandibular lingual surface, the difference between the two groups became larger with increasing age.
Considering above mentioned results, it could be reasoned that periodical dental examination for the first permanent molars before their eruption, including oral examination, X-ray examination, tooth brushing and flossing instruction, prophylaxis, pit and fissure sealant, and fluoride application, was effective for the prevention of caries on the first permanent molar.
