title: Two different implant designs and impact of related drilling protocols on primary stability in different bone densities: an in vitro comparison study.
abstract: OBJECTIVE
  To conduct an in vitro comparison study on the primary stability of two different clinically used dental implant designs.
  
  
  METHODS
  Eighteen pairs of osteotomies were prepared in fresh bovine bone specimens. The control implant had a subtle tapering and was placed using straight drills. The test implant had a marked tapering and was placed using tapered drills. The bone density at the experimental sites was determined in Hounsfield units (HUs) by using cone beam computed tomography and imaging software. The implants were inserted during continuous registration of insertion torque. The bone blocks were embedded in plaster for firm fixation in a rig for displacement measurements. Resonance frequency analysis (RFA) measurements were taken. A lateral force of 15 N was applied to the RFA transducer and the displacement measured in micrometers. A flex constant (μm/N) was calculated for each measurement.
  
  
  RESULTS
  The test implants displayed statistically significantly higher primary stability than the control implants for all parameters. There was a marked difference in displacement and flex constant in low-density bone in favor of the test implant, but there was no obvious difference in higher-density bone.
  
  
  CONCLUSIONS
  In this study, placement of a tapered implant design using tapered drills resulted in higher primary stability than a control implant with subtle tapering using straight drills. The results indicate that the novel implant may work particularly well in soft bone densities such as the posterior maxilla. However, clinical studies are needed to confirm this.
authors.forename: Lars
authors.initials: L
authors.lastname: Sennerby
authors.forename: Luca
authors.initials: L
authors.lastname: Pagliani
authors.forename: Anders
authors.initials: A
authors.lastname: Petersson
authors.forename: Damiano
authors.initials: D
authors.lastname: Verrocchi
authors.forename: Stefano
authors.initials: S
authors.lastname: Volpe
authors.forename: Peter
authors.initials: P
authors.lastname: Andersson
mesh_terms: D000818:Animals; D015519:Bone Density; D002417:Cattle; D054893:Cone-Beam Computed Tomography / Q000379:methods; D003758:Dental Implantation, Endosseous / Q000379:methods; D015921:Dental Implants; D003762:Dental Instruments; D017267:Dental Prosthesis Design; D017268:Dental Prosthesis Retention; D008437:Maxilla / Q000601:surgery; D010027:Osteotomy / Q000379:methods; D019415:Torque; D014732:Vibration
chemical_list: D015921:Dental Implants