Abstract
The purpose of this study was to investigate the epidemiological research of periodontal disease in 357 junior high school students, living in Hiroshima, Japan.
The gingival index(GI: Löe and Silness), plaque index(PlI: Silness and Löe), probing depth (PD) and bleeding index(BI) were recorded on the maxillary right first molar, right second incisor, left first premolar, mandibular left first molar, second incisor and right first premolar. The PD was measured every 0.5 mm for the six teeth. The BI on probing was also recorded.
The results were summarized as follows.
1.89.9% of the students exhibited gingival inflammation as indicated by more than 0.1 of the average GI.82.1% of the students exhibited mild inflammation, and 7.8% of the students exhibited moderate inflammation. Normal gingiva was indicated by less than 0.1 of the GI accounted for 10.1% of the students. There were no significant differences in the distribution of the GI between boys and girls. Gingivitis at the anterior teeth statistically higher than that of other teeth.
2. The PlI score in boys was higher than that of girls, whose PlI score tended to decrease in proportion to their grades. The PlI score in second grade boys was higher than that of first grade and third grade boys. The PlI score in the anterior teeth was statistically higher than that of the premolar and molar teeth.
3. The PD score indicated a peak of 1.0 and 3.0 mm in the anterior teeth and a peak of 1.5 and 3.0mm in molar. There were no differences statistically between boys and girls and among the grades.
4. The BI score in girls was statistically higher than that of boys and the gingiva in girls tended to bleed easily on probing.
5. The GI score in boys increased according to the PlI score, but the GI score in girls rather increased although the PlI score decreased in proportion to their grades.
