title: Immunohistochemical, tomographic, and histological study on onlay bone graft remodeling. Part III: allografts.
abstract: OBJECTIVE
  In the last decades aroused the interest for bone tissue bank as an alternative to autogenous grafting, avoiding donor sites morbidity, surgical time, and costs reduction. The purpose of the study was to compare allografts (ALg) with autografts (AUg) using histology, immunochemistry, and tomographic analysis.
  
  
  METHODS
  Fifty-six New Zealand White rabbits were submitted to surgical procedures. Twenty animals were donors and 36 were actually submitted to onlay grafting with ALg (experimental group) and AUg (control group) randomly placed bilaterally in the mandible. Six animals of each group were sacrificed at 3, 5, 7, 10, 20, and 60 postoperative days. Immunolabeling was accomplished with osteoprotegerin (OPG); receptor activator of nuclear factor-k ligand (RANKL); alkaline phosphatase (ALP); osteopontin (OPN); vascular endothelial growth factor (VEGF); tartrate-resistant acid phosphatase (TRAP); collagen type I (COL I); and osteocalcin (OC). Density and volume of the grafts was evaluated on tomography obtained at the surgery and sacrifice.
  
  
  RESULTS
  The ALg and AUg exhibited similar patterns of density and volume throughout the experiments. The intra-group data showed statistical differences at days 7 and 60 in comparison with other time points (P = 0.001), in both groups. A slight graft expansion from fixation until day 20 (P = 0.532) was observed in the AUg group and then resorbed significantly at the day 60 (P = 0.015). ALg volume remained stable until day 7 and decreased at day 10 (P = 0.045). The light microscopy analysis showed more efficient incorporation of AUg onto the recipient bed if compared with the ALg group. The immunohistochemical labeling picked: at days 10 and 20 with OPG in the AUg group and at day 7 with TRAP in the ALg group (P = 0.001 and P = 0.002, respectively).
  
  
  CONCLUSIONS
  ALg and AUg were not differing in patterns of volume and density during entire experiment. Histological data exhibit more efficient AUg incorporation into recipient bed compared with the ALg group. Immunohistochemistry outcomes demonstrated similar pattern for both ALg and AUg groups, except for an increasing resorption activity in the ALg group mediated by TRAP and in the AUg group by higher OPG labeling. However, this latter observation does not seem to influence clinical outcomes.
authors: Department of Oral and Maxillofacial Surgery, University of Sao Paulo, Ribeirao Preto, Brazil.
authors: Ana Carolina
authors: AC
authors: Hawthorne
authors: Samuel Porfírio
authors: SP
authors: Xavier
authors: Roberta
authors: R
authors: Okamoto
authors: Sérgio Luiz
authors: SL
authors: Salvador
authors: Antonio Azoubel
authors: AA
authors: Antunes
authors: Luiz Antonio
authors: LA
authors: Salata
mesh_terms: D000135:Acid Phosphatase / Q000378:metabolism; D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D016723:Bone Remodeling; D001862:Bone Resorption / Q000378:metabolism; D016025:Bone Transplantation / Q000379:methods*; D024042:Collagen Type I / Q000378:metabolism; D006085:Graft Survival / Q000502:physiology; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000378:metabolism; D008297:Male; D008334:Mandible / Q000000981:diagnostic imaging / Q000601:surgery*; D016348:Osseointegration / Q000502:physiology; D015675:Osteocalcin / Q000378:metabolism; D053495:Osteopontin / Q000378:metabolism; D053245:RANK Ligand / Q000378:metabolism; D011817:Rabbits; D011897:Random Allocation; D012886:Skull / Q000601:surgery*; D000071681:Tartrate-Resistant Acid Phosphatase; D014057:Tomography, X-Ray Computed; D014182:Transplantation, Autologous; D014184:Transplantation, Homologous; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
chemical_list: D024042:Collagen Type I; D007527:Isoenzymes; D053245:RANK Ligand; D042461:Vascular Endothelial Growth Factor A; D015675:Osteocalcin; D053495:Osteopontin; D000469:Alkaline Phosphatase; D000135:Acid Phosphatase; D000071681:Tartrate-Resistant Acid Phosphatase