1983 Volume 25 Issue 2 Pages 393-398
The purpose of this investigation was to study the relation between the area of root surfaces and the level of existing periodontal supporting tissues when affected with periodontal disease, especially with furcation involvement. 83 teeth (the upper first and second molar, the lower first and second molar) were used for this study. The root of each tooth was separated into three parts which consist of the root trunk except the furcation area, the furcation area and the divisional roots. On the upper molar the divisional roots were the palatal root, the bucco-mesial root and the bucco-distal root and on the lower molar they were the mesial root and distal root. The surface area of each separated part was measured by the modified membrane technique (vinyl-acetate coating method).
The results were as follows.
1) The surface area of the divisional root
The range of the means of the surface area in the divisional roots was 79.5mm2 to 159.4mm2. The surface area of the lower first molar mesial root was the largest, the upper second molar bucco-distal root, the smallest. On the upper first molar, the palatal root was significantly larger than the other roots.
2) The surface area of the furcation
The range of the means of the surface area was 11.4mm2 to 15.1mm2. No significant difference was found among all the surface areas of the furcations.
3) The proportion of the surface area of the divisional roots to the total root surface (root trunk+divisional roots)
The proportion was the largest in the lower first molar of all the molars.
It may be necessary to base on the results of this study in periodontal examination, diagnosis and treatment.
