ABSTRACT
Traditionally, metal-ceramics, metal-reinforced acrylics, and more recently full-contour or layered zirconia have been the materials of choice for definitive fixed implant-supported rehabilitations. Polymethyl Methacrylate (PMMA) is commonly used in implant dentistry for the fabrication of implant-supported interim prostheses and as milled or 3D printed prototypes. This article describes a novel protocol to prosthetically restore a completely edentulous patient following a digital workflow, with fixed, screw-retained, implant-supported prostheses fabricated from CAD/CAM milled polymethyl methacrylate (PMMA), with no metal substructure. After two years follow up in terms of esthetics, phonetics, function and biological tissue response, the outcome remains functional and free of mechanical, biomechanical or biological complications. The aim of this article is to illustrate the feasibility of using milled PMMA as viable definitive prosthetic material for the fixed implant rehabilitation of edentulous patients.
ABSTRACT
OBJECTIVES: Registration of intra-oral surface scans to cone beam computer tomography (CBCT) is critical in the digital workflow for static computer-aided implant surgery (sCAIS). This study aimed to assess the impact of CBCT field of view (FoV) on the precision of digital intra-oral scan registration. MATERIALS AND METHODS: Cone beam computer tomography data and intra-oral scans from 20 patients were included. Small FoV CBCT's were created by digitally segmenting a large FoV into three sextants. Virtual implant planning was performed. Digital intra-oral scans were repeatedly registered onto their corresponding large and small FoV CBCT datasets. The distances and angulations between the matching implant positions of each repeated registration were used to determine the precision of the registration process. Wilcoxon Signed Rank Paired Tests were used to compare the differences between large FoV and small FoV. The threshold for statistical significance was set at p = .05. RESULTS: Differences in 3D implant position based on the registration precision between small FoV and large FoV present at both the implant entry point (0.37 ± 0.25 mm vs 0.35 ± 0.23 mm, p = .482) and implant tip (0.49 ± 0.34 mm vs 0.37 ± 0.24 mm, p < .001). Differences in overall angular precision were observed between small FOV and large FoV (1.43 ± 1.36° vs 0.51 ± 0.38°, p < .001). CONCLUSION: CBCT with a small FoV is accompanied by greater precision errors in intra-oral scan registration. However, when sufficient well-distributed teeth are visible in small FoV CBCT, the precision of digital intra-oral scan registration appears to be within clinically acceptable limits for sCAIS.
Subject(s)
Cone-Beam Computed Tomography , Dental Implantation , Mouth , Surgery, Computer-Assisted , Humans , Dental Implantation/methods , Mouth/diagnostic imagingABSTRACT
A method for the digital articulation of complete arch digital implant scans using the implant abutment prosthetic interfaces is described. This technique provides an effective and efficient method for articulating digital scans without the need for matching soft tissue references or fiduciary markers. This allows for a streamlined workflow with fewer intraoral scans and can provide a precise replication of the intaglio surface and emergence profile of an existing restoration.
ABSTRACT
Static computer assisted implant surgery (s-CAIS) is an integral part of the digital workflow in implant dentistry and provides the link between the virtual planning environment and surgical field. The accuracy of s-CAIS is influenced by many cumulative factors including the fit of the template which is related to the manufacturing process. This critical review provides an overview of the current research on additively manufactured surgical implant guides.
Subject(s)
Dental Implants , Surgery, Computer-Assisted , Computer-Aided Design , Dental Implantation, EndosseousABSTRACT
Recording the maxillomandibular relationship in a patient with an edentulous arch can be challenging in a completely digital workflow. A technique is presented that uses a scan of an existing removable prosthesis to align intraoral scans of the arches.
