EFFECT OF TRAUMATIC OCCLUSION ON PERIAPICAL LESIONS IN RATS

The effect of traumatic occlusion on periapical lesions in rats was in vestigated histologically and histometrically. Rats were divided equal ly into groups A to D. Rats in group A received no treatment; in group B, rats received pulpar exposure of the left mandibular first molar; in group C, a resin prate was cemented onto the occlusal surface of th e corresponding maxillary molar; and in group D, the molar pulp was ex posed and the resin plate was installed. At 1 and 2 wk, compression of the periodontal ligament and inflammation were less in group D than i n group B. Lesions in the periapical periodontal ligament at 1, 2, and 4 wk in group D were significantly smaller than those in group B. Thi s study suggests that traumatic occlusion delayed the enlargement of t he periapical lesions in rats.