Designing a complete-arch digital trial tooth arrangement for completely edentulous patients by using an open-source CAD software program: A dental technique

In vitro evaluation of the impact of intraoral scanner, scanning aids, and the scanned arch on the scan accuracy of edentulous arches

PURPOSE

To assess the accuracy of complete maxillary and mandibular edentulous arch scans obtained using two different intraoral scanners (IOSs), with and without scanning aids, and to compare these results to those obtained using conventional impression methods.

MATERIALS AND METHODS

Two IOSs were used (TRIOS 4 [TRI] and Emerald S [EMR]) to scan maxillary and mandibular typodonts. The typodonts were scanned without scanning aids [TRI_WSA and EMR_WSA groups] (n = 10). The typodonts were then scanned under four scanning aid conditions (n = 10): composite markers [TRI_MRK and EMR_MRK groups], scanning spray [TRI_SPR and EMR_SPR groups], pressure indicating paste [TRI_PIP and EMR_PIP groups], and liquid-type scanning aid [TRI_LQD and EMR_LQD groups]. Conventional impressions of both arches were also made using irreversible hydrocolloids in stock trays [IHC] and using polyvinyl siloxane (PVS) impression material in custom trays (n = 10) which were digitized using a laboratory scanner. Using a metrology software program, all scans were compared to a reference scan in order to assess trueness and to each other to assess precision. Trueness and precision were expressed as the root mean square (RMS) of the absolute deviation values and the statistical analysis was modeled on a logarithmic scale using fixed-effects models to meet model assumptions (α = 0.05).

RESULTS

The main effect of arch (p = 0.004), scanner (p < 0.001), scanning aid (p = 0.041), and the interaction between scanner and scanning aid (p = 0.027) had a significant effect on mean RMS values of trueness. The arch (p = 0.015) and scanner (p < 0.001) had a significant effect on the mean RMS values of precision. The maxillary arch had better accuracy compared to the mandible. The TRIOS 4 scanner had better accuracy than both the Emerald S scanner and conventional impressions. The Emerald S had better precision than conventional impressions. The scanning spray and liquid-type scanning aids produced the best trueness with the TRIOS 4 scanner, while the liquid-type scanning aid and composite markers produced the best trueness for the Emerald S scanner.

CONCLUSION

The scanned arch and the type of scanner had a significant effect on the accuracy of digital scans of completely edentulous arches. The scanning aid had a significant effect on the trueness of digital scans of completely edentulous arches which varied depending on the scanner used.

Digital articulation of a complete arch fixed implant prosthesis using the implant prosthetic connections: A dental technique

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.

Fabricating a custom monoblock mandibular advancement device by using an open-source nondental CAD software program and additive manufacturing: A dental technique

Custom mandibular advancement devices (MADs) can be fabricated by using either conventional processes or computer-aided design and computer-aided manufacturing (CAD-CAM). The CAD-CAM technique involves digitizing the dental arches of the patients, designing by using a dental CAD software program, and additive manufacturing with a suitable material. This article describes the steps of the design of a custom MAD by using an open-source nondental CAD software program and of the fabrication with additive manufacturing.

Design and fabrication of an interim fixed restoration with an open-source nondental CAD software program and additive manufacturing: A technical report

This technique aimed to identify the potential of an open-source software program and to present the design and fabrication procedures of a single interim crown with a nondental CAD software program. The steps included defining the margins, establishing the cement interval value, completing the virtual modeling of the crown, and checking the proximal and occlusal contacts by using color mapping.

Techniques to improve the accuracy of complete-arch implant intraoral digital scans: A systematic review

STATEMENT OF PROBLEM

The best method of optimizing the accuracy of complete-arch intraoral digital scans is still unclear. For instance, the location of the scan bodies can be significantly distorted with respect to their actual positions, which would lead to a nonpassive fit of the definitive prosthesis.

PURPOSE

The purpose of this systematic review was to analyze available techniques for improving the accuracy of digital scans in implant-supported complete-arch fixed prostheses.

MATERIAL AND METHODS

Three databases (Medline, Embase, and Google Scholar) were searched, and the results obtained were supplemented by a hand search. Specific descriptors identified techniques whose objective were to increase the accuracy of digital scans in implant-supported complete-arch fixed prostheses. Titles and abstracts were screened by 2 independent reviewers, and unclear results were discussed with a third independent reviewer. A qualitative analysis based on procedural parameters was used. The interexaminer agreements of both were assessed by the Cohen kappa statistic, and the Risk of Bias Tool was used to assess the risk of bias across the studies.

RESULTS

A total of 17 techniques matching the inclusion criteria were evaluated. Higher accuracy but also differences regarding the need for supplementary devices, number of intraoral scans, and time consumption of clinical and software program steps were observed compared with the conventional digital scanning protocol. The use of a splinting device was common to most of the studies. The outcome variables for the evaluation of the effectiveness of these protocols were heterogeneous.

CONCLUSIONS

The use of additional techniques during intraoral scanning can improve accuracy in implant-supported complete-arch fixed prostheses. However, higher complexity for those procedures should be expected.

A Combined Digital Technique for Manufacturing Functional Fixed Implant Prosthesis Prototypes Using a CAD/CAM Software

The manufacture of complete-arch fixed implant prostheses requires many technical steps to ensure a successful outcome. With the use of monolithic materials such as zirconia, the design of the prosthesis is crucial for a superior result. The aim of this article is to outline a combined technique using a CAD/CAM software for the manufacture of fixed implant prosthesis prototypes for complete-arch implant rehabilitations, which can be done in-house with minimal equipment. This makes it accessible and feasible for those who wish to be involved in the design phase of such prostheses. The method involves collecting several 3D data files including the patient's current prosthesis, the definitive cast, occlusal records and photographs. The technique is described using a patient case that has been provided with digitally designed and in-house manufactured prototypes.