Removal and Replacement of a Fractured Dental Implant: Case Report

Removal and Replacement of a Fractured Dental Implant: Case Report
September 2003
Muroff, Fredrick I. DDS, MScD*
Implant Dentistry: Volume 12(3) September 2003 pp 206-210
Lippincott Williams & Wilkins
* Associate Professor, McGill University, Faculty of Dentistry, Private practice, Montreal, Quebec
Reprint requests and correspondence to: Fredrick I. Muroff, DDS, MScD, 1414 Drummond Street Suite 1110, Montreal, Quebec, Canada, H3G 1W1 Phone: 514-844-2388 Fax: 514-844-4879 e-mail: fredrick.muroff@mcgill.ca
Abstract TOP
To achieve satisfactory function and esthetics following the fracture of a dental implant, the clinician is often faced with the imposing prospect of fixture removal and the restoration of adequate osseous support for subsequent fixture placement and eventual restoration. This article describes a technique that allowed re- moval of the fractured fixture, conservative elevation of the sinus floor and the immediate insertion of a larger diameter fixture, to permit eventual replacement.
The utilization of dental implants in the treatment of partial and total edentulism has offered patients a predictable treatment modality with success rates of 95% reported. 1-4 A possible cause of failure is the inopportune occurrence of fixture fracture. 4-9 This infrequent complication can create a management crisis for the most experienced clinician.
An exhaustive list of possible causes of fixture fractures has been reviewed by Green and includes: TOP
- design or production flaws 9,11
- non-passive fit of the superstructure 12,13
- occlusal forces (magnitude and direction) 14-16
- parafunctional forces 11-14
- superstructure design(eg cantilever bridges) 4,17
- implant location 18
- implant size 19
- metal fatigue 20,21
- bone resorption around the implant produces greater bending stress on implant 14,20
- galvanic activity of semi-precious metal restorations on titanium fixtures. 10
In a similar review, 9 Balshi concluded that most fractures occur in the posterior areas and are associated with bending overload created by a combination of parafunctional forces, cantilevers and framework discrepancies and stresses. Because Balshi found that fractured fixtures occurred primarily when they were part of a multiple-implant-supported fixed prosthesis in partially edentulous patients, he stressed avoiding straight line implant placement which may contribute to greater bending moments.
Implant fixture fracture presents several clinical challenges. Firstly, the fractured fragment must be removed atraumatically, with a minimal loss of bone. Secondly, adequate length and diameter of the implant site must be re-established. And lastly, osseointegration of a replacement fixture must be achieved before restorative replacement can be initiated.
This article demonstrates an expedient approach to treatment, whereby the fractured fixture is removed using a trephine. This is immediately followed by conservative elevation of the sinus floor and the insertion of a larger diameter fixture that will permit future restoration that is functionally and esthetically acceptable.
Summers in a series of articles 22-25 described the use of osteotomes (Summers Osteotome Kit, Implant Innovations Inc., West Palm Beach, FL), a set of tapered hand- instruments that have concave tips and matched sizing, for ridge expansion and sinus floor elevation.
Successful use of the osteotome technique as a minimally invasive surgical approach to sinus floor elevation has been reported. 24-33 The objective of the technique is to avoid removal of bone with rotary instruments and to conserve and increase bone volume by compacting the patient's bone; often with added grafted bone, laterally and/or apically.
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