title: Comparison of primary stability of straight-walled and tapered implants using an insertion torque device.
abstract: OBJECTIVE
  Implant geometry has a major impact on insertion torque values and primary stability, and bone engagement during implant insertion differs according to implant morphology. Primary stability of straight-walled and tapered implants was compared using insertion torque monitoring.
  
  
  METHODS
  A total of 57 implants (36 straight-walled OSSEOTITE and 21 tapered OSSEOTITE NT) were inserted in 20 patients. Implant torque values and insertion times were recorded, and the data were processed and interpolated to determine torque as a function of time.
  
  
  RESULTS
  Tapered implants required less insertion time and a higher insertion torque than straight-walled implants; this provided better primary stability, although the success rate was 86% for tapered and 100% for straight-walled implants.
  
  
  CONCLUSIONS
  Tapered implants showed better primary stability than straight-walled implants but had a lower success rate. The authors suggest that in low-density bone, in which only a thin dense cortical layer can contribute to primary stability, a higher insertion torque can lead to the destruction of peri-implant bone, compromising osseointegration.
authors.affiliation: Department of Biomedical Sciences and Human Oncology, Universita di Torino, Torino, Italy. giulio.menicucci@unito.it
authors.forename: Giulio
authors.initials: G
authors.lastname: Menicucci
authors.forename: Emanuela
authors.initials: E
authors.lastname: Pachie
authors.forename: Massimo
authors.initials: M
authors.lastname: Lorenzetti
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Migliaretti
authors.forename: Stefano
authors.initials: S
authors.lastname: Carossa
mesh_terms: D000328:Adult; D015519:Bone Density; D003758:Dental Implantation, Endosseous / Q000295:instrumentation*; D015921:Dental Implants; D017267:Dental Prosthesis Design; D017268:Dental Prosthesis Retention; D019232:Dental Restoration Failure; D003799:Dental Stress Analysis; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016348:Osseointegration; D018709:Statistics, Nonparametric; D013997:Time Factors; D019415:Torque
chemical_list: D015921:Dental Implants