title: Osteoporosis-like bone conditions affect osseointegration of implants.
abstract: OBJECTIVE
  Usage of dental implants has become common for the treatment of edentulous patients, but concerns exist over the use of implants in patients where orofacial bone loss occurs. In the present study, the osseointegration of implants in rabbits under osteoporosis-like (OP-like) conditions simulating several clinically relevant conditions is reported.
  
  
  METHODS
  Forty rabbits were divided into 4 groups of 10. Three groups of animals received daily intramuscular injections of glucocorticoids (7.5 mg/kg) for 8 weeks to induce OP-like conditions either before, simultaneous to, or after implant placement.
  
  
  RESULTS
  The injections of glucocorticoids resulted in cortical thinning, irregular trabecular patterns, and impaired extracellular (ECM) matrix formation and mineralization. Although interfacial strength (8.5 +/- 1.3 MPa for the control group; 9.3 +/- 4.0 to 10.1 +/- 4.0 MPa for the experimental groups) was apparently not affected in this limited sample cohort (n = 3 per group), statistically significant decreases (P < .05) in implant-bone contact were observed in animals with OP-like conditions (49% +/- 10% for the control group; 24% +/- 16% to 42% +/- 16% for the experimental groups).
  
  
  CONCLUSIONS
  Histologic features characteristic of OP-like conditions were observed in each experimental group. ECM expression also appeared to be altered and compromised in all animals with OP-like conditions, which may affect long-term biomechanical stability of the implants.
  
  
  CONCLUSIONS
  OP-like conditions affect the osseointegration characteristics of implants, but long-term biomechanical stability under forces of mastication is unknown as yet.
authors.affiliation: Dows Institute for Dental Research, College of Dentistry, University of Iowa, Iowa City, Iowa 52242-1010, USA. john-keller@uiowa.edu
authors.forename: John C
authors.initials: JC
authors.lastname: Keller
authors.forename: Michelle
authors.initials: M
authors.lastname: Stewart
authors.forename: Melissa
authors.initials: M
authors.lastname: Roehm
authors.forename: Galen B
authors.initials: GB
authors.lastname: Schneider
mesh_terms: D000818:Animals; D015519:Bone Density / Q000187:drug effects; D002113:Calcification, Physiologic / Q000187:drug effects; D003348:Cortisone / Q000008:administration & dosage / Q000009:adverse effects; D015921:Dental Implants; D004195:Disease Models, Animal; D005109:Extracellular Matrix / Q000187:drug effects; D005938:Glucocorticoids / Q000008:administration & dosage / Q000009:adverse effects; D007273:Injections, Intramuscular; D058574:Integrin-Binding Sialoprotein; D008297:Male; D016348:Osseointegration / Q000502:physiology*; D010024:Osteoporosis / Q000139:chemically induced / Q000473:pathology / Q000503:physiopathology*; D011817:Rabbits; D012795:Sialoglycoproteins / Q000187:drug effects; D013314:Stress, Mechanical; D013499:Surface Properties; D013977:Tibia / Q000187:drug effects / Q000473:pathology / Q000601:surgery
chemical_list: D015921:Dental Implants; D005938:Glucocorticoids; D058574:Integrin-Binding Sialoprotein; D012795:Sialoglycoproteins; D003348:Cortisone