Experimental study on wound healing of alveolar bone sockets in the rat maxilla after X-ray irradiation.

The purpose of this study was to examine the effects of radiation on the healing process of tooth extraction wounds. X-ray doses of 10 Gy were delivered once to the maxillofacial area of Wistar strain rats, and the maxillary first molar was extracted 7 days later. Animals were killed 3, 7, and 14 days after odontectomy, and thin sections of the maxilla were prepared. The specimens were stained with hematoxylin and eosin, azan, alkaline phosphatase and tartrate-resistant acid phosphatase (TRAP) stains for microscopic observation. The ratio of the area of the bone tissue to the area of the alveolar socket (BS/TS) and the numbers of TRAP-positive cells were evaluated. Seven days after odontectomy, BS/TS was significantly lower in the irradiated group than in the nonirradiated group. Alkaline phosphatase staining was observed along the rim of the bone 7 and 14 days after odontectomy in both groups, but it was milder in the irradiated group than in the nonirradiated group. TRAP-positive cells were present on the floor of the postextraction socket and the margins of the septal alveolar bone, and, 3 days after odontectomy, the number of TRAP-positive cells was significantly greater in the irradiation group than in the nonirradiation group.