title: Effects of ionizing radiation on bone neoformation: histometric study in Wistar rats tibiae.
abstract: OBJECTIVE
  Comparing the ionizing radiation effects on bone neoformation of rats tibiae previously submitted to radiotherapy with a single dosage of 30Gy with the contralateral tibiae that have received secondary radiation.
  
  
  METHODS
  In thirty male Wistar rats, 30 days before surgical procedure when round defects would be created on the bone, the right tibia was irradiated with 30Gy and the left tibia received a calculated secondary radiation dose of 7Gy. Sacrifices were performed after 4, 7, 14, 21, 56 and 84 postoperative days and both tibiae were removed for histological processing.
  
  
  RESULTS
  The left tibiae that received the dose of 7Gy has shown more bone neoformation from 14(th) postoperative days, giving evidences of less damage to cellular population responsible by bone neoformation. On the other hand, the dose of 30Gyon right tibiae did not exhibit significant differences among the periods, suggesting damage of long-lasting or even permanent duration.
  
  
  CONCLUSIONS
  Tibiae submitted to radiation dose of 30Gy have shown more damage to bone cells than tibiae that received secondary radiation dose of 7Gy, especially observed on 14(th), 56(th) and 84(th) postoperative days.
authors: Department of Otorhinolaringology and Head and Neck Surgery, UNIFESP, Sao Paulo, Brazil.
authors: Susette Cavicchioli
authors: SC
authors: Lucatto
authors: Arnaldo
authors: A
authors: Guilherme
authors: Luciano Lauria
authors: LL
authors: Dib
authors: Helena Regina Comodo
authors: HR
authors: Segreto
authors: Maria Tereza de Seixas
authors: MT
authors: Alves
authors: Emne Hammoud
authors: EH
authors: Gumieiro
authors: Ricardo Schmitutz
authors: RS
authors: Jahn
authors: Ronaldo Antonio
authors: RA
authors: Leite
mesh_terms: D000818:Animals; D001861:Bone Regeneration / Q000528:radiation effects*; D004195:Disease Models, Animal; D004307:Dose-Response Relationship, Radiation; D008297:Male; D011829:Radiation Dosage; D011833:Radiation Injuries, Experimental / Q000473:pathology* / Q000503:physiopathology; D051381:Rats; D017208:Rats, Wistar; D013977:Tibia / Q000502:physiology / Q000528:radiation effects*; D013978:Tibial Fractures / Q000473:pathology / Q000532:radiotherapy*