title: COMPARATIVE STUDY OF BONE NEOFORMATION USING AUTOLOGOUS GRAFTING AND THREE REPLACEMENTS: BONE DEFECTS IN RATS.
abstract: OBJECTIVE
  Compare the percentage of bone neoformation promoted by autologous bone grafting and three kinds of replacement materials with different characteristics in rats' femoral holes.
  
  
  METHODS
  Two holes measuring 5.4×2.7mm, were produced on each femur (right and left) of 14 isogenic Wistar rats. Each of the four defects produced was filled by autologous bone or by one of three tested materials-hydroxyapatite (HA), Genphos(®) (HA+ β-TCP) and GenMix(®) (a combined bovine bone graft). In the end of the 6-week (n = 6) and 12-week (n = 8) periods, the animals were sacrificed. The sections (stained with Picro-Sirius) were assessed by optical microscopy and specific software.
  
  
  RESULTS
  The groups with autologous bone were shown to be significantly superior to the others at both assessed times, showing a mean bone formation rate ± SD of 90.6 ± 10.8% in six weeks, and 98 ± 9.2% in 12 weeks (p > 0.0001 for both assessed times). In six weeks, the results for the other groups were the following: Genphos(®), 46 ± 7.1%; HA, 43.1 ± 8.4%; and GenMix(®), 57.3 ± 4.5%. In 12 weeks: Genphos(®), 47.8 ± 11.1%; HA, 39.9 ± 5.4%; GenMix(®), 59.7 ± 4.8%, significant (p = 0.007).
  
  
  CONCLUSIONS
  In both assessed times, the three bone replacement materials tested in the study showed to be inferior to autologous bone graft for bone neoformation percentage.
authors.affiliation: Master of Health Sciences (Surgical Clinic), PUC/RS; Implantology Specialist, ABO/RS.
authors.forename: Rodrigo Steffen
authors.initials: RS
authors.lastname: Stein
authors.affiliation: PhD in Surgery; Professor at the PUCRS School of Medicine; Lecturer at UNIFESP.
authors.forename: Jefferson Braga
authors.initials: JB
authors.lastname: Silva
authors.affiliation: PhD in Medicine, UFRGS; Professor at the PUCRS School of Medicine.
authors.forename: Vinicius Duval da
authors.initials: VD
authors.lastname: Silva
keywords: Biocompatible materials; Bone regeneration; Bone transplantation; Calcium phosphates; Durapatite; Rats, Wistar; Transplantation, autologous; Transplantation, heterotopic