Effects of sodium selenite and amiloride on calvarial calcification in closing small cranial defects.

ABSTRACT

OBJECT Fresh autogenous bone graft is the most preferred osteoplastic material, whether the purpose is cosmetic, psychological, or for the protection of the brain. These grafts are not rejected and do not react immunologically. The aim of this study was to evaluate the efficacy of autogenous fat rolled with bone dust derived from the bur hole in closing small cranial defects. Additionally, the authors examined the morphological and biochemical effects of Na selenite and amiloride on calvarial calcification. METHODS: The study group consisted of 20 domestic pigs. These animals were randomly divided into 4 groups. A bur hole with a diameter of 10 mm was made at the right parietal region in all animals, and then the periosteum around the bur hole was cauterized following exposure of the dura mater. The dura was coagulated with bipolar cautery. Group 1 (controls) only a bur hole was opened, and it was then closed with a mixture of the bone dust that had been created during the opening of the bur hole and fat tissue that was taken from the animal's neck. Group 2 (amiloride) 1 nmol/g body weight of amiloride was applied subcutaneously within 15 minutes after closure of the bur hole with bone dust and fat, and then amiloride was applied once a day for 4 weeks. Group 3 (Na selenite) 30 nmol/g body weight of Na selenite was applied subcutaneously within 30 minutes after closure of the bur hole with bone dust and fat, and then Na selenite was applied once a day for 4 weeks. Group 4 (amiloride and Na selenite) 1 nmol/g body weight of amiloride was applied subcutaneously at 15 minutes, and 30 nmol/g body weight of Na selenite was applied subcutaneously at 30 minutes after closure of the bur hole with bone dust and fat, and these 2 injections were repeated once a day for 4 weeks. At the end of 4 weeks, the animals were anesthetized to evaluate the closure of the bur hole. Tissue samples were obtained for ultrastructural and biochemical examination. RESULTS: The defect was covered with diffuse connective tissue in the control group. Although multiple capillary vessels were present, the authors did not observe osteogenic differentiation. Histological examination of the second group revealed osteogenic changes. Although new matrix was formed, calcification was not detected. The authors observed fibroblast, collagen fibers, and dense connective tissue filled with capillary in the third group of pigs, which had undergone Na selenite application. Calcification was not detected in this group. Both connective and osteogenic tissue were observed in specimens obtained in the fourth group, which had undergone amiloride and Na selenite application. CONCLUSIONS: The authors experimentally evaluated the supplementary osteogenic effects of Na selenite and amiloride by using them separately and together. The findings seem promising as a lead-in to new studies in restoring cranial defects.