title: Biologic mechanical advantages of 3 different cranial bone grafting techniques for implant reconstruction of the atrophic maxilla.
abstract: OBJECTIVE
  The purpose of this study was to test the mechanical capacities of 3 different bone grafting techniques in the atrophic maxilla when co-stabilized with dental implants. Reconstruction of the atrophic maxilla is a difficult clinical challenge and implants cannot be placed without adequate bone.
  
  
  METHODS
  The biomechanical performance of 3 different grafting techniques was evaluated in vitro using a maxillary model, cadaveric cranial bone blocks, and dental implants. A maxillary model fabricated from polyurethane (sawbone) was selected as a substrate for this study because of consistency in shape, size, and mechanical properties. This anatomic model was more consistent than different cadaveric maxilla, where significant variation was found to exist among atrophic specimens. Cadaveric cranial bone graft blocks were secured to the model maxilla (sandwich, ridge only, and sinus inlay) with a dental implant. The strength of the implant/bone graft complex was tested to failure in an Instron machine (Instron Inc, Canton, MA).
  
  
  RESULTS
  The 3 bone grafting methods showed significantly different deformation and strength characteristics. The sandwich technique enhanced resistance to deformation under higher imposed loads. The location of the graft influenced the overall mechanical performance (eg, the ridge onlay) and showed a significantly higher resistance to compressive loads applied toward the alveolar ridge (mastication force).
  
  
  CONCLUSIONS
  The ridge onlay grafting procedures created a higher biomechanical tolerance to imposed load than the sinus grafting (sinus inlay). Sinus grafting, although successful, was not the most ideal location for immediate mechanical loading resistance when compared with ridge augmentation in this in vitro model.
authors.affiliation: Department of Oral and Maxillofacial Surgery, University of Alabama at Birmingham, School of Dentistry, Birmingham, AL 35294, USA. pwaite@uab.edu
authors.forename: Peter D
authors.initials: PD
authors.lastname: Waite
authors.forename: Panunn
authors.initials: P
authors.lastname: Sastravaha
authors.forename: Jack E
authors.initials: JE
authors.lastname: Lemons
mesh_terms: D016301:Alveolar Bone Loss / Q000601:surgery*; D000540:Alveolar Ridge Augmentation / Q000379:methods*; D001696:Biomechanical Phenomena; D001732:Bite Force; D016025:Bone Transplantation / Q000379:methods*; D002102:Cadaver; D003758:Dental Implantation, Endosseous; D003799:Dental Stress Analysis; D006801:Humans; D016018:Least-Squares Analysis; D008297:Male; D008437:Maxilla / Q000601:surgery*; D008443:Maxillary Sinus / Q000601:surgery; D008875:Middle Aged; D003765:Models, Dental; D013516:Oral Surgical Procedures, Preprosthetic; D012886:Skull / Q000601:surgery