A technique for retrieving cement-retained implant prostheses

doi:10.1016/j.prosdent.2016.04.019

The Journal of Prosthetic Dentistry

Volume 116, Issue 6, December 2016, Pages 848-850

https://doi.org/10.1016/j.prosdent.2016.04.019 Get rights and content

Abstract

Lack of retrievability is one of the most important disadvantages of cement-retained implant restorations. A straightforward and cost-effective technique for accessing the abutment screw channel and unscrewing the abutment and cement-retained prosthesis as 1 unit is described. The technique does not jeopardize the integrity of the restoration, screw, abutment, or implant. A guiding acrylic resin index is fabricated for locating and guiding the access to the screw channel of the abutment, provided that the patient's cast with the implant analog is available. The procedure could be extrapolated to computer-aided designed and computer-aided manufactured (CAD-CAM) implant prostheses, whereby a CAD-CAM index could be fabricated on the digital model.

Section snippets

Technique

For patients who complain of the loosening of an implant-fixed prosthesis, the following procedures are advised:

1.
Make a thorough clinical and radiographic examination to reveal the cause of the mobility of the fixed dental prosthesis and verify abutment screw loosening (Fig. 1).
2.
On the patient’s cast containing the implant analogs with the pick-up impression copings screwed to them, fill the space of the prosthesis with baseplate wax (Set Up Wax; Cavex) and paint the cast with a layer of

Discussion

One of the main advantages of screw-retained prostheses compared with cement-retained ones is their retrievability, which makes it easy to remove them without jeopardizing the integrity of the screw, abutment, and/or implant. In this technique, the patient's cast was used with the implant analogs and the inserted impression copings to facilitate the positioning of the access hole and an acrylic resin template extended to cover the teeth anterior and posterior to the prosthetic area.

In contrast

Summary

A predictable technique for retrieving cement-retained implant restoration that uses an acrylic resin template with plastic guiding tubes and impression copings placed on a patient's cast is described. This approach is straightforward, cost effective, and needs less equipment; however, it requires the patient's cast with implant analogs. The procedure could be extrapolated for CAD-CAM implant restoration, whereby a CAD-CAM index could be fabricated on the digital model.

References (15)

E. Torrado et al.
A comparison of the porcelain fracture resistance of screw-retained and cement-retained implant-supported metal-ceramic crowns
J Prosthet Dent
(2004)
J.R. Agar et al.
Cement removal from restorations luted to titanium abutments with simulated subgingival margins
J Prosthet Dent
(1997)
K.S. Hebel et al.
Cement-retained versus screw-retained implant restorations: achieving optimal occlusion and esthetics in implant dentistry
J Prosthet Dent
(1997)
P. Pesce et al.
Systematic review of some prosthetic risk factors for periimplantitis
J Prosthet Dent
(2015)
J. Nissan et al.
Reliability of retrievable cemented implant-supported prostheses
J Prosthet Dent
(2016)
J. Doerr
Simplified technique for retrieving cemented implant restorations
J Prosthet Dent
(2002)
E.R. Schwedhelm et al.
A technique for locating implant abutment screws of posterior cement-retained metal-ceramic restorations with ceramic occlusal surfaces
J Prosthet Dent
(2006)

There are more references available in the full text version of this article.

Cited by (5)

Techniques for locating the screw access hole in cement-retained implant-supported prostheses: A systematic review
2023, Journal of Prosthetic Dentistry
Citation Excerpt :
The postcementation techniques were divided into 2 subgroups: radiographic records39-41 and postcementation SAH location guides38,42-45 (Table 4). A total of 18 reviewed studies described precementation techniques to record the SAH,19-37 and 8 articles reported postcementation methods to locate the SAH.38-45 Furthermore, 4 studies aimed to assess the efficacy of previously described retrieval techniques, including 1 in vitro study that evaluated the accuracy of a precementation guide technique,46 1 clinical study that evaluated the efficacy of a technique of an identification mark technique to locate SAH after cementation,33 and 2 articles that evaluated the accuracy of a technique using cone beam computer tomography (CBCT).47,48
Different techniques for retrieving cement-retained implant-supported prostheses have been described to minimize damage to the prostheses. Nevertheless, a classification of the described techniques remains ambiguous.
The purpose of this systematic review was to review and classify the described techniques for recording and locating the screw access hole in cement-retained implant-supported prostheses.
A bibliographic search was completed on MEDLINE/PubMed, Web of Science, Scopus, and Cochrane databases. A manual search was also conducted. The articles that described or evaluated techniques for recording and locating the screw access hole of cement-retained implant-supported prostheses were included. Two investigators independently assessed the quality assessment of the studies using the Revised Cochrane risk of bias tool for randomized trials. A third examiner was consulted to resolve the lack of consensus.
A total of 30 articles were included. The different methods were classified according to whether the screw access hole location was registered before or after cementation. The precementation techniques were classified into 4 subgroups: identification marks, photographic records, digital files, and precementation screw access hole location guides. The postcementation techniques were subdivided into 2 subgroups: radiographic records and postcementation screw access hole location guides.
Different techniques have been proposed to facilitate the location of the screw access hole in cement-retained implant-supported restorations. Although the evidence is scarce, studies seem to ascertain that some techniques, such as the use of drilling guides, orientation with cone beam computed tomography images, or holes made in the metal framework, can increase the retrievability of cement-retained implant-supported prostheses and decrease complications in the location of the screw access hole. The proposed classification summarizes precementation and postcementation techniques and provides a tool to decide the most suitable for each specific clinical situation.
Application of 3D-printed guide for locating screw access channels in cement-retained complete arch implant-supported zirconia restorations
2023, Journal of Prosthetic Dentistry
Removal of cement-retained complete arch implant-supported zirconia restorations can be challenging. A predictable and minimally invasive technique combining cone beam computed tomography (CBCT) and intraoral scans with a virtual implant planning software program is described to identify the location of the screw access channels during the retrieval, thus minimizing damage to the existing restoration and allowing reuse.
A three-dimensionally printed template for locating the screw channel in a cement-retained implant-supported crown: A digital workflow
2022, Journal of Prosthetic Dentistry
Locating the screw channel in a cement-retained implant-supported crown is challenging. This article describes a fully digital workflow for fabricating a 3D-printed template which can accurately guide the dentist to find the screw channel. A definitive implant cast from the patient and an implant planning software program are used in the workflow. This technique provides precise guidance for finding the location and angulation of the abutment screw access hole.
Techniques for retrievability and for registering screw access holes in cement-retained implant-supported prostheses: A scoping review of the literature
2020, Journal of Prosthetic Dentistry
Citation Excerpt :
Plastic tubes of a contrasting color can be used to help distinguish and accurately judge the position of the SAH.21 Radi and Alfahd53 modified the technique by using a piece of plastic suction tip to create the guiding sleeves. Techniques using guiding sleeves create 3D guides for precise SAC location and angulation but do require storage space.
After implant rehabilitation, clinicians may need to remove a restoration because of technical and biological complications. For cement-retained implant-supported prostheses (ISPs), the retrievability process may damage the components of the prosthesis, the intaglio surface of the implant, or the abutment screw. To avoid that, the screw access hole (SAH) of the dental implant abutment (DIA) should be registered. Although several clinical reports and dental techniques have been proposed, a review of existing techniques is lacking.
The purpose of this scoping review was to evaluate the different techniques described for retrievability and for registering the SAH of cement-retained ISPs.
An electronic search of English language dental literature in the PubMed, Scopus, Google Scholar, and SciELO databases was conducted from 1980 to December 2017 with appropriate keywords and phrases. A hand search of relevant dental journals was also completed, and exclusion criteria were applied after full-text evaluation.
The electronic and hand search revealed 325 articles. However, 252 publications were discarded after duplicates were removed. After reading the title and abstracts, 15 studies were excluded, and the full text of 64 publications was screened for inclusion and exclusion criteria. Forty studies were selected and included for final evaluation. The evaluation revealed 6 techniques for retrievability and 9 techniques for registering the position of the SAH, divided into 2-dimensional (2D) and 3-dimensional (3D) techniques.
Cement-retained ISPs can be effectively retrieved by using interim cements and possibly by using a combined cement- and screw-retained design. Vacuum guides with guiding sleeves and computer-aided design and computer-aided manufacturing (CAD-CAM) guide templates are possible effective 3D techniques for registering the screw access channel (SAC) location and angulation.
Influence of Cyclic Loading on Load to Failure of Different Ceramic CAD/CAM Implant-Supported Single Crowns
2023, International Journal of Prosthodontics

View full text

Dental TechniqueA technique for retrieving cement-retained implant prostheses

Abstract

Section snippets

Technique

Discussion

Summary

J Prosthet Dent

J Prosthet Dent

J Prosthet Dent

J Prosthet Dent

J Prosthet Dent

J Prosthet Dent

J Prosthet Dent

Dental Technique
A technique for retrieving cement-retained implant prostheses