A study on homeostatic factors in periodontal ligament of the beagle dog

Immunohistochemical study of cell and vascular distribution and density

Abstract

Cell distribution and density of periodontal ligament in three different areas of the normal molar teeth of the beagle dog were examined using the immunohistochemical technique with antibodies of PKK-1 and PCNA.
Significantly higher numbers of cells were observed in the cementum area than in the alveolar area (p<0.01) and in the middle area (p<0.001). The blood vessels occupied 23.39% in the alveolar area and 17.02% in the middle area but only 2.52% in the cementum area. The number of positive cells for PCNA were significantly higher in the middle area than in the alveolar area (p<0.001) and in the cementum area (p<0.05). These PCNA positive cells related with blood vessels were 69.56% in the middle area. 48.55% in the alveolar area but only 27.81% in the cementum area. Malassez's rests were observed only in the cementum area (2.32%).
These results suggest that the turn-over of the cells located near the cementum were more active than that of the cells located near the alveolar bone. The blastic-cells in the periodontal ligament may be supplied from the cells related to the blood vessels. It is also suggested that homeostasis of periodontal ligament space was regulated by Malassez's rests.