title: Are insertion torque and early osseointegration proportional? A histologic evaluation.
abstract: OBJECTIVE
  The objective of this histologic study was to determine the effect of three drilling protocols (oversized, intermediate, and undersized) on biologic responses to a single implant type at early healing periods (2 weeks in vivo) in a beagle dog model.
  
  
  METHODS
  Ten beagle dogs were acquired and subjected to surgeries in the tibia 2 weeks before euthanasia. During surgery, each dog received three Unitite implants, 4 mm in diameter by 10 mm in length, in bone sites drilled to 3.5, 3.75, and 4.0 mm in final diameter. The insertion torque was recorded during surgery, and bone-to-implant contact (BIC), and bone area fraction occupied (BAFO) measured from the histology. Each outcome measure was compared between treatment conditions with the Wilcoxon signed-rank test. Bonferroni-corrected statistical significance was set to 95%.
  
  
  RESULTS
  Insertion torque increased as an inverse function of drilling diameter, as indicated by significant differences in torque levels between each pair of conditions (P = 0.005). BIC and BAFO levels were highest and statistically similar in the recommended and undersized conditions and significantly reduced in the oversized condition (P < 0.01).
  
  
  CONCLUSIONS
  Reduced drilling dimensions resulted in increased insertion torque (primary stability). While BIC and BAFO were maximized when drilling the recommended diameter hole, only the oversized hole resulted in evidence of statistically reduced integration.
authors.affiliation: Division of Oral and Maxillofacial Surgery, Department of Oral Surgery, School of Dentistry, Federal University of Uberlândia, Uberlândia, MG, Brazil.
authors.forename: Felipe E B
authors.initials: FE
authors.lastname: Campos
authors.affiliation: Department of Prosthodontics, Faculty of Odontology, Malmö University, Malmö, Sweden.
authors.forename: Ryo
authors.initials: R
authors.lastname: Jimbo
authors.affiliation: Department of Prosthodontics, University of São Paulo - Bauru College of Dentistry, Bauru, SP, Brazil.
authors.forename: Estevam A
authors.initials: EA
authors.lastname: Bonfante
authors.affiliation: Division of Oral and Maxillofacial Surgery, Department of Oral Surgery, School of Dentistry, Federal University of Uberlândia, Uberlândia, MG, Brazil.
authors.forename: Darceny Z
authors.initials: DZ
authors.lastname: Barbosa
authors.affiliation: Division of Oral and Maxillofacial Surgery, Department of Oral Surgery, School of Dentistry, Federal University of Uberlândia, Uberlândia, MG, Brazil.
authors.forename: Maiolino T F
authors.initials: MT
authors.lastname: Oliveira
authors.affiliation: Department of Epidemiology and Health Promotion, New York University College of Dentistry, New York, NY, USA.
authors.forename: Malvin N
authors.initials: MN
authors.lastname: Janal
authors.affiliation: Department of Biomaterials and Biomimetics, New York University, New York, NY, USA.|Director for Research, Department of Periodontology and Implant Dentistry, New York University College of Dentistry, New York, NY, USA.|Affiliated Faculty, Division of Engineering, New York University Abu Dhabi, Abu Dhabi, UAE.
authors.forename: Paulo G
authors.initials: PG
authors.lastname: Coelho
mesh_terms: D000818:Animals; D016723:Bone Remodeling; D003758:Dental Implantation, Endosseous / Q000379:methods*; D015921:Dental Implants; D004285:Dogs; D023421:Models, Animal; D019415:Torque; D014945:Wound Healing
chemical_list: D015921:Dental Implants
keywords: histomorphometry; implant; initial stability; insertion torque; osseointegration