title: Tomographic, histological, and immunohistochemical evidences on the use of N-butyl-2-cyanoacrilate for onlay graft fixation in rabbits.
abstract: BACKGROUND
  The bone tissue responses to Cyanoacrylate have been described in the literature, but none used N-butyl-2-cyanoacrilate (NB-Cn) for bone graft fixation.
  
  
  OBJECTIVE
  The aims of the study were: (a) to analyze the bone grafts volume maintenance fixed either with NB-Cn or titanium screw; (b) to assess the incorporation of onlay grafts on perforated recipient bed; and (c) the differences of expression level of tartrate-resistant acid phosphatase (TRAP) protein involved in bone resorption.
  
  
  METHODS
  Eighteen New Zealand White rabbits were submitted to calvaria onlay grafting on both sides of the mandible. On one side, the graft was fixed with NB-Cn, while on the other hand the bone graft was secured with an osteosynthesis screw. The computed tomography (CT) was performed just after surgery and at animals sacrifice, after 1 (n = 9) and 6 weeks (n = 9), in order to estimate the bone grafts volume along the experiments. Histological sections of the grafted areas were prepared to evaluate the healing of bone grafts and to assess the expression of TRAP protein.
  
  
  RESULTS
  The CT scan showed better volume maintenance of bone grafts fixed with NB-Cn (p ≤ 0.05) compared with those fixed with screws, in both experimental times (analysis of variance). The immunohistochemical evaluation showed that the TRAP expression in a 6-week period was significantly higher compared with the 1-week period, without showing significant difference between the groups (Wilcoxon and Mann-Whitney). Histological analysis revealed that the NB-Cn caused periosteum damage, but provided bone graft stabilization and incorporation similar to the control group.
  
  
  CONCLUSIONS
  The perforation provided by screw insertion into the graft during fixation may have triggered early revascularization and remodeling to render increased volume loss compared with the experimental group. These results indicate that the NB-Cn possesses equivalent properties to titanium screw to be used as bone fixation material in osteosynthesis.
authors.affiliation: Department of Oral and Maxillofacial Surgery and Periodontics, Faculty of Dentistry of Ribeirao Preto, University of Sao Paulo, Ribeirao Preto, SP, Brazil.
authors.forename: Patricio José
authors.initials: PJ
authors.lastname: de Oliveira Neto
authors.forename: Giovanni
authors.initials: G
authors.lastname: Cricchio
authors.forename: Ana Carolina
authors.initials: AC
authors.lastname: Hawthorne
authors.forename: Roberta
authors.initials: R
authors.lastname: Okamoto
authors.forename: Lars
authors.initials: L
authors.lastname: Sennerby
authors.forename: Stefan
authors.initials: S
authors.lastname: Lungren
authors.forename: Luiz Antonio
authors.initials: LA
authors.lastname: Salata
mesh_terms: D000135:Acid Phosphatase / Q000378:metabolism; D000818:Animals; D016723:Bone Remodeling / Q000502:physiology; D001862:Bone Resorption; D016025:Bone Transplantation / Q000379:methods*; D004659:Enbucrilate / Q000494:pharmacology*; D007124:Immunoenzyme Techniques; D007284:Inlays; D007527:Isoenzymes / Q000378:metabolism; D008334:Mandible / Q000000981:diagnostic imaging / Q000601:surgery*; D011817:Rabbits; D012886:Skull / Q000637:transplantation*; D000071681:Tartrate-Resistant Acid Phosphatase; D014057:Tomography, X-Ray Computed; D014945:Wound Healing / Q000502:physiology
chemical_list: D007527:Isoenzymes; D000135:Acid Phosphatase; D000071681:Tartrate-Resistant Acid Phosphatase; D004659:Enbucrilate