ROLE OF T-CELLS IN THE PATHOGENESIS OF PERIAPICAL LESIONS - A PRELIMINARY-REPORT

The pulps of mandibular molars of 15 athymic and 15 conventional rats were surgically exposed and left open to their oral flora. Each group was divided into three subgroups of five animals each. The rats were k illed after their pulps were exposed for 2, 4, or 8 weeks. After fixin g, decalcifying, and embedding, the specimens were sectioned and stain ed with hemotoxylin and eosin. They were then examined under a microsc opic grid and quantified by percentages of surface areas of bone, conn ective tissue, bone marrow, intrabony spaces, periapical lesions, and numbers of osteoclasts, with the use of a DataVoice computerized data collection and analysis system. Statistical analysis showed no signifi cant difference between periapical tissue responses of the conventiona l and athymic groups. The results indicate that the pathogenesis of pe riapical lesions is a multifactorial phenomenon and is not totally dep endent on the presence of T-cell lymphocytes.