title: Bone augmentation ability of autogenous bone graft particles with different sizes: a histological and micro-computed tomography study.
abstract: OBJECTIVE
  The purpose of this study was to investigate the augmentation process and ability of autogenous bone graft particles of two different sizes in a vertical augmentation chamber.
  
  
  METHODS
  The cranial bones of 24 rabbits were used. Two polytetrafluoroethylene chambers were filled with harvested bone from tibia with small bone (SB; 150-400 microm) and large bone (LB; 1.0-2.0 mm) of the same weight. Animals were sacrificed after 1, 2, 4 and 8 weeks. The samples were analyzed by micro-computed tomography (micro-CT) for quantitative analysis, and embedded in polyester resin as non-decalcified specimens for histological analysis. Total bone volume (TBV), bone height (BH) and distribution of bone structure were calculated by micro-CT.
  
  
  RESULTS
  Micro-CT evaluation and histology revealed a significant difference between the investigated specimens. TBV and BH of SB decreased to about 50% of the initial situation, and there was a statistically significant difference between 1 and 8 weeks. In contrast, TBV and BH of LB were almost retained at all experimental time points. Significant differences in TBV and BH were also observed between LB and SB at 8 weeks. Bone volume of SB decreased predominantly in the upper half of the chamber at 4 and 8 weeks. In the histological observations, SB showed favorable new bone formation and rapid bone resorption in a time-dependent manner during the entire experimental period. However, LB exhibited favorable morphological stability and continued new bone formation.
  
  
  CONCLUSIONS
  SB follows a smooth osteogenic process, whereas it is not effective in volume augmentation. LB is superior to SB in augmentation ability.
authors.affiliation: Department of Oral Implantology and Regenerative Dental Medicine, Tokyo Medical and Dental University, Bunkyo-ku, Tokyo, Japan. k-kon.irm@tmd.ac.jp
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Kon
authors.forename: Makoto
authors.initials: M
authors.lastname: Shiota
authors.forename: Maho
authors.initials: M
authors.lastname: Ozeki
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Yamashita
authors.forename: Shohei
authors.initials: S
authors.lastname: Kasugai
mesh_terms: D000540:Alveolar Ridge Augmentation / Q000295:instrumentation / Q000379:methods*; D000818:Animals; D001857:Bone Matrix / Q000033:anatomy & histology / Q000637:transplantation*; D016025:Bone Transplantation / Q000379:methods*; D020007:Implants, Experimental; D008297:Male; D016348:Osseointegration / Q000502:physiology*; D010012:Osteogenesis / Q000502:physiology; D010294:Parietal Bone / Q000033:anatomy & histology / Q000601:surgery*; D010316:Particle Size; D011817:Rabbits; D055114:X-Ray Microtomography