Histometric study of the effect of occlusal alteration on periodontal tissue healing after surgical injury.

The effect of occlusal alteration upon healing of the periodontium after surgical injury was studied in 62 male Wistar rats, nine weeks of age. An osteotomy was made with a bur through the vestibular bone plate, the periodontal ligaments and into the superficial part of the root surface of the first mandibular molar. In the same session, the occlusion of the antagonistic tooth was altered in the experimental groups by either placing a high amalgam restoration, grinding, or extraction. The occlusion in the control group was unaltered. The rats were killed 70 days after surgery, and examined histologically. A histometric registration of the periodontal repair revealed a significant narrowing of the periodontal ligament width in the non-occluding teeth, as well as signifiant thickening of cementum at and above the surgical cavity site. The hypo- and hyper-occluding teeth did not show significant changes as compared to the controls.