Implantologia

Eli E. Machtei Dan Mahler Orit Oettinger-Barak Otman Zuabi Jacob Horwitz

Dental implants placed in previously failed sites: survival rate and factors affecting the outcome

Authors’ affiliations: Eli E. Machtei, Dan Mahler, Orit Oettinger-Barak, Otman Zuabi, Jacob Horwitz, Unit of Periodontology, Department of Oral and Dental Medicine, Rambam Health Care Campus, Haifa, Israel Eli E. Machtei,Orit Oettinger-Barak, Jacob Horwitz, Faculty of Medicine – Technion (Israeli Institute of Technology), Haifa, Israel Correspondence to: Prof. Eli E. Machtei Department of Oral and Dental Medicine Rambam Health Care Campus PO Box 9602, Haifa 31096 Israel Tel.: þ 972 4 8542983 Fax: þ 972 4 8543057 e-mail: machtei@rambam.health.gov.il

Key words: dental implants, failures, modifying factors, redo,replacement, success rate Abstract Objectives: The purpose of the present study was to evaluate the survival rate of dental implants in previously failed implant sites. In addition, factors that might affect the outcome of these redo procedures were also explored. Material and methods: Patients that had failed dental implants, which were replaced with the same implant type at the same site, wereincluded. Data on the failed implants were collected. The same parameters, along with the interval between retrieval and reimplantation, were collected for the second set of implants. Descriptive statistics were used to describe the patients and implants. Life table analysis of these implants was tabulated for both implant sets. The effect of systemic, environmental and local factors on thesurvival of the redo dental implants was evaluated. Results: Fifty-six patients with a total of 79 redo implants were included in this study. Implants were followed for 7–78 months (mean 29.9 Æ 2). Thirteen implants failed that resulted in an overall survival rate of 83.5%. Successful implants had greater diameter (4.05 Æ 0.52 mm) than failed implants (3.72 Æ 0.56 mm); however, these differences wereonly marginal (P ¼ 0.06). Conversely, smoking habits, implants length and location, mode of placement and spontaneous exposure did not have a significant effect on the outcome of this procedure. Conclusion: Redo of dental implants has a lesser survival rate compared with previous reports for implants in pristine sites. These results were not associated with most implantand/or patient-related factors.Thus, a possible negative effect that is associated with the specific implant’s site might account for this phenomenon.

Date: Accepted 13 February 2007
To cite this article: Machtei EE, Mahler D, Oettinger-Barak O, Zuabi O, Horwitz J. Dental implants placed in previously failed sites: survival rate and factors affecting the outcome. Clin. Oral Impl. Res. 19, 2008; 259–264 doi:10.1111/j.1600-0501.2007.01466.x

Dental implants have become an integral part of dental practice. In addition to its traditional role to help replace missing teeth (Stanford 2005), it is currently being used as an anchorage for orthodontic tooth movement (Heymann & Tulloch 2006) and in maxillofacial reconstruction (Landes 2005). The overall first-year survival rate for dental implants has been reported to bebetween 92% and 97% (Rosenberg et al. 2004). An additional 1% of all implants

that were initially successful and rehabilitated are lost every year due to various complications (Perry & Lenchewski 2004). With an estimated 2,000,000 new implants that are performed worldwide every year, and tens of millions of implants currently in service, the estimated number of implants that are failing annuallyis likely in the range of 200,000–250,000. Failed implant sites present a challenging therapeutic dilemma to the clinician: on the one hand the alveolar bone in these

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Machtei et al . The survival of redo dental implants

sites is usually further reduced, thus making it less than ideal for further implant...