title: Influence of the implant diameter and bone quality on the primary stability of porous tantalum trabecular metal dental implants: an in vitro biomechanical study.
abstract: OBJECTIVE
  The aim of this study was to evaluate the primary, initial stability of Porous Tantalum Trabecular Metal™implants (TM) compared with Tapered Screw Vent®implants (TSV) with different diameters, inserted in two bone densities.
  
  
  METHODS
  A total of 160 implants (80 TM and 80 TSV) with narrow (3.7 mm) and conventional (4.1 mm) diameters and the same length (10 mm) were placed in artificial bone blocks representing bone qualities II and IV. The implant stability was evaluated by insertion torque (IT) and Resonance Frequency Analysis. Statistical analysis was performed with non-parametric Kruskal-Wallis test with Dunn post-test for the differences between groups.
  
  
  RESULTS
  The results showed higher ISQ values in dense bone compared with soft bone for all the groups (P < 0.05). Conventional-diameter implants (TSV and TM) showed higher ISQ and IT values compared with narrow implants (TSV and TM) in dense and soft bone (P < 0.05). Tapered TSV implants showed higher stability in soft bone compared with TM implants (P < 0.05). In dense bone, differences were not observed between narrow TSV 3.7 mm and TM 3.7 mm implants (P > 0.05).
  
  
  CONCLUSIONS
  Within the limitations of this study, it can be concluded: In dense bone blocks, the wider diameter implants are more stable than narrow implants. In soft bone blocks, the tapered TSV implants are more stable than TM implants.
authors.affiliation: Department of Periodontology, School of Dental Medicine, Stony Brook University, Stony Brook, NY, USA.
authors.forename: Georgios E
authors.initials: GE
authors.lastname: Romanos
authors.affiliation: Department of Prosthodontics and Digital Technology, School of Dental Medicine, Stony Brook University, Stony Brook, NY, USA.
authors.forename: Rafael Arcesio
authors.identifier: http://orcid.org/0000-0003-1721-0509
authors.initials: RA
authors.lastname: Delgado-Ruiz
authors.affiliation: School of Dental Medicine, Stony Brook University, Stony Brook, NY, USA.
authors.forename: Danielle
authors.initials: D
authors.lastname: Sacks
authors.affiliation: Department of International Dentistry Research, Faculty of Medicine and Dentistry, San Antonio Catholic University of Murcia (UCAM), Murcia, Spain.
authors.forename: Josè Luis
authors.initials: JL
authors.lastname: Calvo-Guirado
mesh_terms: D015519:Bone Density; D003758:Dental Implantation, Endosseous; D015921:Dental Implants; D019232:Dental Restoration Failure; D003799:Dental Stress Analysis; D066298:In Vitro Techniques; D000074269:Resonance Frequency Analysis; D019415:Torque
chemical_list: D015921:Dental Implants
keywords: porous tantalum; primary stability; trabecular metal implants