title: Development of implant/interconnected porous hydroxyapatite complex as new concept graft material.
abstract: BACKGROUND
  Dental implant has been successfully used to replace missing teeth. However, in some clinical situations, implant placement may be difficult because of a large bone defect. We designed novel complex biomaterial to simultaneously restore bone and place implant. This complex was incorporated implant into interconnected porous calcium hydroxyapatite (IP-CHA). We then tested this Implant/IP-CHA complex and evaluated its effect on subsequent bone regeneration and implant stability in vivo.
  
  
  RESULTS
  A cylinder-type IP-CHA was used in this study. After forming inside of the cylinder, an implant was placed inside to fabricate the Implant/IP-CHA complex. This complex was then placed into the prepared bone socket in the femur of four beagle-Labrador hybrid dogs. As a control, implants were placed directly into the femur without any bone substrate. Bone sockets were allowed to heal for 2, 3 and 6 months and implant stability quotients (ISQ) were measured. Finally, tissue blocks containing the Implant/IP-CHA complexes were harvested. Specimens were processed for histology and stained with toluidine blue and bone implant contact (BIC) was measured. The ISQs of complex groups was 77.8±2.9 in the 6-month, 72.0±5.7 in the 3-month and 47.4±11.0 in the 2-month. There was no significant difference between the 3- or 6-month complex groups and implant control groups. In the 2-month group, connective tissue, including capillary angiogenesis, was predominant around the implants, although newly formed bone could also be observed. While, in the 3 and 6-month groups, newly formed bone could be seen in contact to most of the implant surface. The BICs of complex groups was 2.18±3.77 in the 2-month, 44.03±29.58 in the 3-month, and 51.23±8.25 in the 6-month. Significant difference was detected between the 2 and 6-month.
  
  
  CONCLUSIONS
  Within the results of this study, the IP-CHA/implant complex might be able to achieve both bone reconstruction and implant stability.
authors.affiliation: Department of Advanced Prosthodontics, Hiroshima University Graduate School of Biomedical Sciences, Hiroshima, Japan. kazuya17@hiroshima-u.ac.jp
authors.forename: Kazuya
authors.initials: K
authors.lastname: Doi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Oue
authors.forename: Koji
authors.initials: K
authors.lastname: Morita
authors.forename: Shiho
authors.initials: S
authors.lastname: Kajihara
authors.forename: Takayasu
authors.initials: T
authors.lastname: Kubo
authors.forename: Katsunori
authors.initials: K
authors.lastname: Koretake
authors.forename: Vittoria
authors.initials: V
authors.lastname: Perrotti
authors.forename: Giovanna
authors.initials: G
authors.lastname: Iezzi
authors.forename: Adriano
authors.initials: A
authors.lastname: Piattelli
authors.forename: Yasumasa
authors.initials: Y
authors.lastname: Akagawa
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000494:pharmacology*; D004285:Dogs; D017886:Durapatite / Q000494:pharmacology*; D005269:Femur / Q000187:drug effects / Q000473:pathology; D020007:Implants, Experimental; D008297:Male; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D016062:Porosity; D013499:Surface Properties; D014025:Titanium / Q000494:pharmacology*
chemical_list: D001672:Biocompatible Materials; D017886:Durapatite; D014025:Titanium