title: Osseointegration of titanium alloy and HA-coated implants in healthy and ovariectomized animals: a histomorphometric study.
abstract: OBJECTIVE
  The objective of the present study is to evaluate the response to dental implants in healthy and osteoporotic bone.
  
  
  METHODS
  Ten ovariectomized (OVX) New Zealand rabbits submitted to a hypocalcic diet and 10 sham-aged rabbits were used. All animals were submitted to bone mineral density (BMD) measurements before ovariectomy, and also 4 months afterwards, using dual energy X-ray absorptiometry. The BMD measurements showed a significant loss of bone mass, between the first and second examinations, only in the experimental group (P<0.05). After the bone mass loss induction period, three different implants were installed in the proximal tibia metaphisis of each animal: a titanium alloy implant (Ti), a plasma-spray hydroxyapatite-coated implant (HA-PS), and another implant coated with hydroxyapatite with the biomimetic process (HA-B).
  
  
  RESULTS
  After 3 months, histomorphometry showed a bone-to-implant contact (BIC) for Ti implants of 73.09+/-13.74% in healthy and 66.09+/-30.01% in OVX animals. The BIC for the HA-PS was 64.83+/-15.65% and 90.17+/-8.14% for healthy and OVX animals, respectively, and 88.66+/-5.30% and 87.96+/-10.71% for the HA-B implants placed in the same conditions. The differences between the implants in healthy and OVX conditions were not statistically significant (P>0.05). The only significant difference within groups was observed in the healthy animals between HA-B and Ti implants (P<0.06).
  
  
  CONCLUSIONS
  Within the parameters used in this animal model it was not possible to observe BIC differences between osteoporotic and healthy animals.
authors.affiliation: Department at Grande Rio University, Duque de Caxias, RJ, Brazil. vidigal@globo.com
authors.forename: Guaracilei Maciel
authors.initials: GM
authors.lastname: Vidigal
authors.forename: Mario
authors.initials: M
authors.lastname: Groisman
authors.forename: Luiz Henrique
authors.initials: LH
authors.lastname: Gregório
authors.forename: Gloria de Almeida
authors.initials: Gde A
authors.lastname: Soares
mesh_terms: D000818:Animals; D040761:Biomimetic Materials / Q000008:administration & dosage*; D015519:Bone Density / Q000187:drug effects / Q000502:physiology; D020099:Coated Materials, Biocompatible / Q000008:administration & dosage; D003722:Dental Alloys; D015921:Dental Implants; D004195:Disease Models, Animal; D005260:Female; D006801:Humans; D006882:Hydroxyapatites / Q000008:administration & dosage*; D016348:Osseointegration / Q000187:drug effects* / Q000502:physiology; D015663:Osteoporosis, Postmenopausal / Q000503:physiopathology*; D010052:Ovariectomy; D011817:Rabbits; D018709:Statistics, Nonparametric; D013499:Surface Properties; D013977:Tibia / Q000601:surgery; D014025:Titanium
chemical_list: D020099:Coated Materials, Biocompatible; D003722:Dental Alloys; D015921:Dental Implants; D006882:Hydroxyapatites; D014025:Titanium