title: The effect of different surgical drilling procedures on full laser-etched microgrooves surface-treated implants: an experimental study in sheep.
abstract: OBJECTIVE
  To evaluate the influence of instrumentation technique on the early osseointegration histomorphometrics and biomechanical fixation of fully laser-etched microgrooves implant surfaces in a sheep model.
  
  
  METHODS
  Six sheep were subjected to bilateral hip surgeries 3 and 6 weeks before euthanasia. A total of 48 implants (∅4.5 mm, 8 mm in length) were distributed among four sites (8 per animal) and placed in bone sites drilled to 4.6 mm (reamer), 4.1 mm (loose), 3.7 mm (medium) and 3.2 mm (tight) in diameter. After healing, the animals were euthanized and half of the implants were biomechanically tested, while the remainder was subjected to non-decalcified histologic processing. The histomorphometric parameters assessed were bone-to-implant contact (BIC) and bone area fraction occupancy (BAFO). Statistical analysis was performed using a mixed-model analysis of variance with significance level set at P < 0.05.
  
  
  RESULTS
  A general increasing trend is present from 3 to 6 weeks for most of the variables. The groups prepared to be press fit seemed to present higher values, which were maintained throughout the observation period. The reamer group presented the lowest BIC probably due to the drilling technique; however qualitatively, more new bone seemed to be in contact to the implant surface, at 3 weeks, whereas the implants placed in press-fit situations were mainly supported by cortical bone.
  
  
  CONCLUSIONS
  The laser-etched microgrooved implant presented osteoconductive and biocompatible properties for all surgical procedures tested. However, procedures providing increasingly higher press-fit scenarios presented the strongest histomorphometric and biomechanical responses at 3 and 6 weeks.
authors.affiliation: Department of Prosthodontics, Faculty of Odontology, Malmo University, Malmo, Sweden.
authors.forename: Ryo
authors.initials: R
authors.lastname: Jimbo
authors.forename: Nick
authors.initials: N
authors.lastname: Tovar
authors.forename: Daniel Y
authors.initials: DY
authors.lastname: Yoo
authors.forename: Malvin N
authors.initials: MN
authors.lastname: Janal
authors.forename: Rodolfo B
authors.initials: RB
authors.lastname: Anchieta
authors.forename: Paulo G
authors.initials: PG
authors.lastname: Coelho
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D003758:Dental Implantation, Endosseous / Q000379:methods*; D015921:Dental Implants; D020007:Implants, Experimental; D007834:Lasers; D016348:Osseointegration; D010384:Pelvic Bones / Q000601:surgery*; D034561:Sheep, Domestic; D013499:Surface Properties; D019415:Torque
chemical_list: D015921:Dental Implants
keywords: histology; implant surface; laser etching; osseointegration; removal torque