Management of perishing implants with abutment screw fracture – A systematic review

Abstract

Aim: To systematically review the reported techniques, for evaluating the risk and difficulty encountered in the management of fractured abutment screw in accordance with the location of fracture, and to develop a logical sequence in managing an implant abutment screw fracture. Settings and Design: Systematic review following PRISMA guidelines. Materials and Methods: A systematic search of the PubMed/MEDLINE database for articles published between January 2000 and March 2020 was performed by 2 independent reviewers. Case reports and case series that described the management of fractured implant abutment screw were included. Published articles were qualitatively analyzed employing CARE guidelines and were classified according to the location of screw fracture with respect to implant platform, risk of damage to the implant, and intervention for managing the fractured screw. Statistical Analysis Used: Qualitative analyisis. Results: A total of 28 articles were included in the review. Two of them explained the management of screw fracture at or above the implant platform and required only mild approach with low risk while the others explained the management of screw fracture below the level of implant platform. Among them, 6 were considered mild approach with low risk, 13 moderate approach with moderate risk, and 8 of them severe approach with high risk. Conclusion: Irrespective of the technique, any attempt to retrieve abutment screw fragment poses some risk to the implant which is varying from mild to severe. As the location of fracture is more gingival to the implant platform, difficulty of retrieval as well as risk to the implant increases. The proposed decisionmaking tree will be a useful tool in helping clinicians to manage abutment screw fracture.

Removal of broken abutment screws using ultrasonic tip – a heat development in-vitro study

“…By taking these factors into account, clinicians can proactively address the issue of screw loosening in implant-supported restorations, ultimately enhancing the longevity and stability of the treatment [ 35 ]. The etiology of screw fractures is multifactorial and can include factors such as inadequate treatment planning, misfit of components, inadequate screw tightening, excessive loading, and inadequate screw design [ 36 ]. Inadequate treatment design and planning can stem from patient assessment and insufficient number and positioning of implants.…”

Surface demineralized freeze-dried bone allograft followed by reimplantation in a failed mandibular dental implant

“…The initial step in the management of fractured screws is to obtain a detailed history and perform a thorough clinical examination. Raju et al systematically reviewed the management of fractured abutment screws to develop a logical sequence for management [ 18 ]. They reported that the harm to implants resulting from the removal of abutment screw fragments ranges from mild to severe regardless of the technique used.…”

“…A retrieval kit may also be used. A hole can be made in the fractured screw to unwind it by engaging a drill [ 18 ]. Abutment screws modified with a prefabricated access hole are easier to retrieve [ 19 ].…”

“…If the implant’s internal screw threads are significantly damaged, or the fractured screw cannot be retrieved, the implant may need to be removed. The fabrication of a custom cast post and core is the final option in case the patient cannot be persuaded to implant removal [ 18 ]. However, this weakens the implant and produces excessive heat during the cutting of the fractured screw [ 18 ].…”

Evaluation of physical changes due to simulated loading on prosthetic screw supporting 4- and 6-unit implant prosthesis: An in vitro study

“…There are few studies[ 7 8 9 18 24 25 ] to explain the causes of screw loosening, but none of them are conclusive. Almost all agree that loosening will not happen until the friction force between the threads is reduced by some external mechanism.…”