title: Micro-morphologic changes around biophysically-stimulated titanium implants in ovariectomized rats.
abstract: BACKGROUND
  Osteoporosis may present a risk factor in achievement of osseointegration because of its impact on bone remodeling properties of skeletal phsiology. The purpose of this study was to evaluate micro-morphological changes in bone around titanium implants exposed to mechanical and electrical-energy in osteoporotic rats.
  
  
  METHODS
  Fifteen 12-week old sprague-dowley rats were ovariectomized to develop osteoporosis. After 8 weeks of healing period, two titanium implants were bilaterally placed in the proximal metaphyses of tibia. The animals were randomly divided into a control group and biophysically-stimulated two test groups with five animals in each group. In the first test group, a pulsed electromagnetic field (PEMF) stimulation was administrated at a 0.2 mT 4 h/day, whereas the second group received low-magnitude high-frequency mechanical vibration (MECHVIB) at 50 Hz 14 min/day. Following completion of two week treatment period, all animals were sacrificed. Bone sites including implants were sectioned, removed en bloc and analyzed using a microCT unit. Relative bone volume and bone micro-structural parameters were evaluated for 144 mum wide peri-implant volume of interest (VOI).
  
  
  RESULTS
  Mean relative bone volume in the peri-implant VOI around implants PEMF and MECHVIB was significantly higher than of those in control (P < .05). Differences in trabecular-thickness and -separation around implants in all groups were similar (P > .05) while the difference in trabecular-number among test and control groups was significant in all VOIs (P < .05).
  
  
  CONCLUSIONS
  Biophysical stimulation remarkably enhances bone volume around titanium implants placed in osteoporotic rats. Low-magnitude high-frequency MECHVIB is more effective than PEMF on bone healing in terms of relative bone volume.
authors.affiliation: Division of Restorative Dentistry, The Jane and Jerry Weintraub Center for Reconstructive Biotechnology, UCLAc School of Dentistry, USA. akcak@hacettepe.edu.tr
authors.forename: Kivanc
authors.initials: K
authors.lastname: Akca
authors.forename: Ebru
authors.initials: E
authors.lastname: Sarac
authors.forename: Ugur
authors.initials: U
authors.lastname: Baysal
authors.forename: Mete
authors.initials: M
authors.lastname: Fanuscu
authors.forename: Ting-Ling
authors.initials: TL
authors.lastname: Chang
authors.forename: Murat
authors.initials: M
authors.lastname: Cehreli
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D015519:Bone Density / Q000502:physiology; D004558:Electric Stimulation; D005260:Female; D020007:Implants, Experimental; D016348:Osseointegration / Q000502:physiology*; D010024:Osteoporosis / Q000209:etiology / Q000601:surgery*; D010052:Ovariectomy; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D013977:Tibia / Q000000981:diagnostic imaging / Q000601:surgery*; D014025:Titanium; D014057:Tomography, X-Ray Computed; D014732:Vibration
chemical_list: D014025:Titanium