TI : An experimental study of the effect of Co-60 irradiation on the healing process of extraction wounds in white rats
AU : You YJ; Ahn HK
AD : Dept. of Dental Radiology, Graduate School, Seoul National University
SO : JKAMFR. 1982;12(1):105-113
ISSN : 1225-049X
LA : KOREAN
CP : KOREA
AB : Because of the development of rampant caries, osteomyelitis and osteoradionecrosis that occur after radiation therapy of oral cancers, extraction of teeth at or near the malignant lesion has been done in the past. Few, however, have studied the radiation effect on the healing of extraction wounds. The study is concerned with the effect of Co-60 irradiation on the healing process of extraction wounds in rats.
Fifty six, male, Sprague-Dawley rats are used. The right first molar of the mandible is extracted from all animals. They are divided into three experimental groups of 14 each and a control group of 14. There experimental groups are irradiated respectively with 200 rad, 400 rad and 600 rad and a pair of rats in each group are killed on days 1, 3, 5, 7, 14, 21 and 28 after irradiation. Two animals from the control group are killed on the day when the experimental rats are killed. The irradiated hemimandibles are fixed in 10% neutral formalin, decalcified in 5% trichloroacetic acid, embedded in paraffin and sectioned. The sections are stained in hematoxylin and eosin, van Gison, Masson's trichrome or silver nitrate.
Results show that in general radiation effects on healing extraction wounds are dose dependent; i.e., the higher is the dose, the greater is the histologic changes observed:
1. Irradiation tends to retard blood clot organization and epithelial regeneration.
2. An increase in th number of giant cells and osteoclasts is noted after irradiation.
3. Formation of regenerating connective tissues around and within the extraction site is compromised, and a clear reduction of primitive mesenchymal type connective cells is noted.
4. The healing process begins along the lateral aspect of the extraction socket in the control, while irregular histologic appearances of the trabecular pattern is present in the experimental rats.