title: Evaluation of extrashort 4-mm implants in mandibular edentulous patients with reduced bone height in comparison with standard implants: a 12-month results.
abstract: OBJECTIVE
  The aim of this research was to evaluate the primary stability, the marginal bone loss, the survival, and the success criteria, of 4-mm-length implants compared with implants of conventional length supporting fixed prostheses.
  
  
  METHODS
  Ten patients were selected for treatment of their atrophic edentulous jaws. Each patient received the following treatment: six dental implants were inserted, two anterior implants of conventional length (10-mm) in the interforaminal area and four posterior short implants of 4-mm length (Standard Plus, Roxolid, SLActive, Institut Straumann AG). The implants supported screw-retained fixed complete dentures. Examinations were conducted at day 0, three, six, and twelve months after surgery for the evaluation of the implant primary stability, secondary stability, crestal bone loss and survival by clinical evaluations, insertion torque values, resonance frequency analysis (RFA), and periapical radiography, respectively.
  
  
  RESULTS
  Sixty implants were inserted in ten patients. Mean insertion torque was slightly lower for 4-mm implants than 10-mm implants (38.1 Ncm vs. 42.2 Ncm) but without statistically significant difference. Implant stability was similar for extrashort and conventional implants. Marginal bone loss was similar for both groups for all the time periods. One short implant was lost before loading. The survival rates twelve months after implant placement were of 97.5% and 100% for short and conventional implants, respectively. Similarly, implant stability as measured by RFA was nonsignificantly lower for the 4-mm implants compared to the 10-mm implants. The marginal bone loss was lower for short implants three, six, and twelve months after the surgery without statistical significant difference.
  
  
  CONCLUSIONS
  Within the limitations of this study, we conclude that short dental implants (8 mm or less in length) supporting single crowns or fixed bridges are a feasible treatment option with radiographic and clinical success rates similar to longer implants for patients with compromised ridges. Long-term data with larger number of implants and subjects are needed to confirm these preliminary results.
authors.affiliation: International Dentistry Research Cathedra, Universidad Católica San Antonio de Murcia (UCAM), Murcia, Spain.
authors.forename: José Luis
authors.initials: JL
authors.lastname: Calvo-Guirado
authors.affiliation: International Dentistry Research Cathedra, Universidad Católica San Antonio de Murcia (UCAM), Murcia, Spain.
authors.forename: José Alberto
authors.initials: JA
authors.lastname: López Torres
authors.affiliation: New York University, New York City, NY, USA.
authors.forename: Michel
authors.initials: M
authors.lastname: Dard
authors.affiliation: Eastman Institute for Oral Health, University of Rochester, Rochester, NY, USA.
authors.forename: Fawad
authors.initials: F
authors.lastname: Javed
authors.affiliation: International Dentistry Research Cathedra, Universidad Católica San Antonio de Murcia (UCAM), Murcia, Spain.
authors.forename: Carlos
authors.initials: C
authors.lastname: Pérez-Albacete Martínez
authors.affiliation: International Dentistry Research Cathedra, Universidad Católica San Antonio de Murcia (UCAM), Murcia, Spain.
authors.forename: José Eduardo
authors.initials: JE
authors.lastname: Maté Sánchez de Val
keywords: edentulous patients; extrashort implants; short dental implants; short implants