A method for determining the position of the abutment screw of any cement-retained implant-supported prosthesis

doi:10.1016/j.prosdent.2020.03.035

The Journal of Prosthetic Dentistry

Volume 125, Issue 6, June 2021, Pages 846-848

https://doi.org/10.1016/j.prosdent.2020.03.035 Get rights and content

Abstract

Removing cement-retained implant-supported prostheses may be challenging for clinicians. A method combining a cone beam computed tomography (CBCT) and a digital scan with a virtual surgical planning software program is described to identify the perforation site of a cement-retained implant-supported prosthesis to locate the abutment screw.

Section snippets

Technique

1.
Upload the digital imaging and communications in medicine (DICOM) file obtained from the CBCT to the virtual surgical planning software program (Blue Sky Plan 3; Blue Sky Bio LLC). Removing all areas of the CBCT that are not directly related to the cement-retained prosthesis is recommended.
2.
Upload the standard tessellation language (STL) file obtained from the intraoral or extraoral digital scan to the virtual surgical planning software program.
3.
Superimpose the 2 files manually by selecting some

Discussion

The present technique allows the clinician to determine the perforation site on any cemented implant-supported prosthesis to locate the abutment screw by integrating data from a CBCT and an intraoral or extraoral digital scan by using a virtual surgical planning software program.

Unless the clinician is using dynamic screws or implants with integrated subcrestal angle correction (Co-Axis Dental Implants; Southern Implants Inc), the implant axis coincides with one of the abutment screws. However,

Summary

A technique that enables the clinician to determine the perforation site on cement-retained implant-supported prostheses to locate the abutment screw is described. It consists of the planning of a narrower implant in precisely the same site as where the implant is already seated. The location of the perforation site coincides with the emergence of the planned implant on the cemented-retained prosthesis.

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

Cited by (4)

A cast-free approach to fabricating an implant-supported interim restoration: A dental technique
2023, Journal of Prosthetic Dentistry
A cast-free approach is described to fabricate an implant-supported interim restoration by using the postoperative cone beam computed tomography (CBCT) scan to locate the placed implant. A postoperative intraoral scan was aligned to the postoperative CBCT scan through a dental implant planning software program. An attached interim abutment and implant analog complex was then scanned and superimposed on the placed implant in the postoperative CBCT scan. Once the best alignment was achieved, a virtual cast was generated, and an interim restoration with bilateral positioning wings was fabricated on the interim abutment and inserted during the second-stage surgery. This technique offers a cast-free approach to inserting an implant-supported interim restoration immediately after the second-stage surgery to guide the healing of the soft tissue that can minimize chairside time and optimize the clinical workflow.
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.
Accuracy of digitally fabricated drilling guide to form screw-access channels in cement-retained implant prostheses: A randomized clinical trial
2022, Journal of Prosthetic Dentistry
Accurate intraoral preparation of screw channels in cement-retained implant prostheses could be a treatment challenge for tilted or badly positioned implants.
The purpose of this randomized clinical trial was to evaluate screw channel accuracy for retrieving cement-retained implant prostheses by using a digitally fabricated drilling guide.
Twenty-four participants requiring removal of cement-retained implant prostheses were recruited and consecutively assigned to 1 of 2 groups. In the first group, drilling guides were fabricated by using an intraoral scan, computer-aided design (CAD), and 3D printing to facilitate screw channel preparation (guide group). In the second group, screw channel preparation was based on panoramic radiographs without a drilling guide (freehand group). Screw channel accuracy was evaluated with a 3D analysis and subsequently compared with the ideal shape of the screw channel for linear deviation at coronal and apical levels, angular deviation, surface loss deviation, and volume loss deviation. The ideal shape of the screw-access channel was based on the Ø2.2-mm cylinder image marked along the long axis of the implant. The Mann-Whitney U and Kruskal-Wallis tests were used for statistical analyses (α=.05).
The drilling guide group showed higher dimensional accuracy than the freehand group for angular deviation (9.45 degrees versus 15.69 degrees; P=.014) and surface loss deviation (7.40 mm versus 9.53 mm; P=.001), especially when the implant was tilted more than 30 degrees. The deviation values of the screw channels were not significantly different according to implant tilt in either group (P>.05).
Digitally fabricated drilling guides for intraoral preparation of screw channels in cement-retained implant prostheses can improve accuracy and provide a less-destructive screw channel.
Annual review of selected scientific literature: A report of the Committee on Scientific Investigation of the American Academy of Restorative Dentistry
2022, Journal of Prosthetic Dentistry
Citation Excerpt :
In addition to articles selected for detailed review, a sizable number of excellent general reviews, systematic reviews, meta-analyses, and helpful clinical descriptive articles were also published addressing issues important to prosthodontics. Although it is impractical to provide detailed analysis on all these publications, they are listed here, by the topic area, for the reader’s convenience and include the following: general prosthodontic considerations,5-7 conventional fixed prosthodontics,8-14 conventional removable prosthodontics,15-30 general implant considerations,31-59 implant-fixed prosthodontics,60-76 implant removable prosthodontics,77-79 implant complications,80-84 implant integration,85-93 preprosthetic and implant surgery,94-115 peri-implant tissues and disease,116-131 dental occlusion,132-146 dental impressions,147 digital dentistry,148-150 materials science,151-166 endodontic-prosthodontic topics,167-171 periodontal-prosthodontic topics,172-178 operative dentistry,179 geriatric dentistry,180-193 pathology and oral medicine (OM),194-214 dental radiology and imaging,215-231 adolescent and growing patients,232-243 bruxism,244 mastication,245 dental caries,246-250 therapeutic outcomes,251-261 patient management,262-267 research methods,268-270 COVID-19–related topics,271-276 dental education,277 sleep and sleep disordered breathing,278-280 and the temporomandibular joint (TMJ), temporomandibular disorder (TMD), and orofacial pain (OFP).281-299 Peri-implant bone loss coincident with occlusal loading is thought to be related to poorly controlled stress concentration.
The Scientific Investigation Committee of the American Academy of Restorative Dentistry offers this review of the 2021 dental literature in restorative dentistry to inform busy dentists regarding noteworthy scientific and clinical progress over the past year. Each member of the committee brings discipline-specific expertise to coverage of this broad topical area. Specific subject areas addressed, in order of the appearance in this report, include COVID-19 and the dental profession (new); prosthodontics; periodontics, alveolar bone, and peri-implant tissues; implant dentistry; dental materials and therapeutics; occlusion and temporomandibular disorders; sleep-related breathing disorders; oral medicine and oral and maxillofacial surgery; and dental caries and cariology. The authors focused their efforts on reporting information likely to influence daily dental treatment decisions with an emphasis on future trends in dentistry. With the tremendous volume of dentistry and related literature being published daily, this review cannot possibly be comprehensive. Rather, its purpose is to update interested readers and provide important resource material for those interested in pursuing greater details on their own. It remains our intent to assist colleagues in negotiating the extensive volume of important information being published annually. It is our hope that readers find this work useful in successfully managing the patients and dental problems they encounter.

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Dental TechniqueA method for determining the position of the abutment screw of any cement-retained implant-supported prosthesis

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

J Prosthet Dent

J Prosthet Dent

J Prosthet Dent

Dental Technique
A method for determining the position of the abutment screw of any cement-retained implant-supported prosthesis