Abstract
Fractures of the abutment screw are an extremely dreadful and taxing experience even for experienced clinicians. Retrieval of fractured screw segments due to excessive torque and improperly placed implants pose a great challenge to the clinician. The authors present a case wherein the fractured abutment screw was retrieved successfully with the help of an intraoral plastic mixing tip of light body putty material. The intraoral plastic mixing tips are a more readily available, cost-effective, and feasible alternative to other means of screw retrieval like ultrasonic scalers, endodontic files, and screw retrieval kits.
Keywords: Abutment screw fracture, dental implants, screw loosening
INTRODUCTION
Complications associated with hardware failure are commonly seen in cases of single-tooth implants due to various mechanical or biological factors.[1] Loosening of the screw and excessive torque are the two main causes that can lead to fracture of the abutment screw.[2]
Fractures of the abutment screw are rare; however, the challenging issue encountered is the retrieval of the fractured segment. Retrieval of fractured screw segments due to excessive torque poses a great challenge to the clinician. With advancements in implant dentistry, various techniques for the removal of fractured abutment screws are mentioned in the literature.[3-5]
These include techniques such as:
-
a.
Use of ultrasonic scalers
-
b.
Dental probes
-
c.
Endodontic files.
Retrieval using kits specially made for this purpose is also commonly done by clinicians;[6] however, these kits are expensive and not readily available. Using rotary instruments can permanently damage the internal architecture of the implant. Hence, devising a technique for retrieval, which results in minimal or no impairment to the internal structure of the implant, is very important for the enduring success of the dental implant.
We present a case where the abutment screw had fractured due to loosening after 5 years of loading the implant due to suspected excess torque during placement.
CASE REPORT
A 45-year-old male patient reported to the department of oral and maxillofacial surgery at our institute with the loosening of an implant-supported prosthesis in the mandibular left first premolar region. The implant prosthesis was done 5 years back. After careful clinical examination, it was ascertained that the abutment screw had fractured just below the implant collar which resulted in the loosening of the prosthesis. Various conservative techniques mentioned in the literature, such as ultrasonic scalers, dental probes, and endodontic files, were tried for retrieval of the fractured segment without success. The authors then decided to use the intraoral plastic mixing tips (available with GC Flexceed light body) that had a hollow end to engage the fractured end of the abutment screw [Figure 1]. Modification of the intraoral mixing tip was done by cutting it so that a snug fit was achieved at the visible end of the fractured segment. It was then rotated in an anticlockwise direction to retrieve the fractured portion of the screw taking care that the internal structure of the implant was not damaged [Figure 2].
Figure 1.
Picture showing fractured abutment screw and engaging of the intraoral putty light body plastic mixing tip to the fractured segment
Figure 2.
Retrieval of the fractured segment of the abutment screw
DISCUSSION
The literature mentions various techniques which have been used for the retrieval of fractured abutment screws. Any approach used for the retrieval of the fractured screw should aim at its removal without impairing the internal structure of the implant. This would enable the clinician to reuse the same implant without causing surgical trauma and financial burden to the patient. If the abutment screw fractures above the implant collar, retrieval becomes easier using a hemostat, or a sharp explorer. However, if the fracture occurs within the body of the implant, its removal is a challenging task due to the lack of adequate space for manipulation by any instrument.
Different techniques such as ultrasonic scalers, dental probes, endodontic files, screw retrieval kits, and rotary instruments have been mentioned in the literature for the retrieval of fractured abutment screws.[3-6] Certain authors have made a slot in the remaining fragment of the screw and then used ultrasonic scalers to loosen the screw.[7] Such techniques although effective have a higher risk of damaging the internal implant collar, thus making the implant no longer functional. The authors in this case used a more feasible alternative like the intraoral plastic mixing tips used for light body impression material.
The tip was modified by cutting the end to get a better fit around the fractured screw fragment due to its curved shape and plasticity; it firmly held onto the fractured segment of the screw. This technique can be used only if the screw fractures are at the level of the implant collar or just below it, making it easier to grasp the portion of the fractured screw.
A few advantages of this technique:
Cost-effective
Readily available in every clinic
Plasticity of the tip allows it to be modified to fit the fractured part of the screw.
However, the authors feel that the plastic mixing tip may not be useful for retrieval if the fractured fragment is broken below the implant collar and is completely tightened.
Although every effort must be made to prevent the fracture of the abutment screw, we would advocate the use of intraoral plastic mixing tips for the successful removal of the fractured segment of the abutment screw without impairing the internal structure of the implant [Figure 3].
Figure 3.
Diagrammatic representation showing retrieval of fractured segment of the abutment screw by the intraoral putty light body plastic mixing tip
CONCLUSION
Within the limits of this technique, it was successfully used to retrieve a fractured fragment of the abutment screw. Even after proper care is taken during the implant procedure, if the abutment screw fractures at the level of the implant collar, this technique may be useful for conservative retrieval without impairing the internal structure of the implant.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given his consent for his images and other clinical information to be reported in the journal. The patient understands that his name and initials will not be published and due efforts will be made to conceal identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
REFERENCES
- 1.McGlumphy EA, Mendel DA, Holloway JA. Implant screw mechanics. Dent Clin North Am. 1998;42:71–89. [PubMed] [Google Scholar]
- 2.Bakaeen LG, Winkler S, Neff PA. The effect of implant diameter, restoration design, and occlusal table variations on screw loosening of posterior single-tooth implant restorations. J Oral Implantol. 2001;27:63–72. doi: 10.1563/1548-1336(2001)027<0063:TEOIDR>2.3.CO;2. [DOI] [PubMed] [Google Scholar]
- 3.Satterthwaite J, Rickman L. Retrieval of a fractured abutment screw thread from an implant: A case report. Br Dent J. 2008;204:177–80. doi: 10.1038/bdj.2008.99. [DOI] [PubMed] [Google Scholar]
- 4.Nayana P, Nayak SS, Chatterjee A, Sivaraman K, Srikanth G, Singh C. Retrieval of fractured implant abutment screws: A narrative review. J Int Soc Prev Community Dent. 2022;12:287–94. doi: 10.4103/jispcd.JISPCD_318_21. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5.Satwalekar P, Chander KS, Reddy BA, Sandeep N, Sandeep N, Satwalekar T. A simple and cost effective method used for removal of a fractured implant abutment screw: A case report. J Int Oral Health. 2013;5:120–3. [PMC free article] [PubMed] [Google Scholar]
- 6.Nergiz I, Schmage P, Shahin R. Removal of a fractured implant abutment screw: A clinical report. J Prosthet Dent. 2004;91:513–7. doi: 10.1016/j.prosdent.2004.03.010. [DOI] [PubMed] [Google Scholar]
- 7.Gooty JR, Palakuru SK, Guntakalla VR, Nera M. Noninvasive method for retrieval of broken dental implant abutment screw. Contemp Clin Dent. 2014;5:264–7. doi: 10.4103/0976-237X.132382. [DOI] [PMC free article] [PubMed] [Google Scholar]