Preliminary Clinical Application of Removable Partial Denture Frameworks Fabricated Using Computer-Aided Design and Rapid Prototyping Techniques

Abstract

The aim of this study was to explore the application of computer-aided design and rapid prototyping (CAD/RP) for removable partial denture (RPD) frameworks and evaluate the fitness of the technique for clinical application. Materials and Methods: Three-dimensional (3D) images of dentition defects were obtained using a lab scanner. The RPD frameworks were designed using commercial dental software and manufactured using selective laser melting (SLM). A total of 15 cases of RPD prostheses were selected, wherein each patient received two types of RPD frameworks, prepared by CAD/RP and investment casting. Primary evaluation of the CAD/RP framework was performed by visual inspection. The gap between the occlusal rest and the relevant rest seat was then replaced using silicone, and the specimens were observed and measured. Paired t test was used to compare the average thickness and distributed thickness between the CAD/RP and investment casting frameworks. Analysis of variance test was used to compare the difference in thickness among different zones. Results: The RPD framework was designed and directly manufactured using the SLM technique. CAD/ RP frameworks may meet the clinical requirements with satisfactory retention and stability and no undesired rotation. Although the average gap between the occlusal rest and the corresponding rest seat of the CAD/RP frameworks was slightly larger than that of the investment casting frameworks (P < .05), it was acceptable for clinical application. Conclusion: RPD frameworks can be designed and fabricated directly using digital techniques with acceptable results in clinical application.

Influence of novel implant selective laser melting framework design on mechanical durability of acrylic veneer

“…Since no SLM framework had metal failure at the cantilever region, this study may suggest that the additive manufacturing technology is capable of producing durable prosthesis frameworks . This is consistent with the few clinical studies on SLM removable partial dentures and single crowns that indicated SLM is a viable method of producing metal without failure related to the SLM manufacturing . However, the obvious limitation of SLM frameworks that was disclosed in the present study is the metal failure at the screw base that had occurred in six frameworks, where the metal under the screw head was separated from the framework mesial cylinder due to opposing stress to the cantilever forces.…”

“…24,25,30 This is consistent with the few clinical studies on SLM removable partial dentures and single crowns that indicated SLM is a viable method of producing metal without failure related to the SLM manufacturing. [26][27][28][29] However, the obvious limitation of SLM frameworks that was disclosed in the present study is the metal failure at the screw base that had occurred in six frameworks, where the metal under the screw head was separated from the framework mesial cylinder due to opposing stress to the cantilever forces. This problem can be due to the quality of the SLM metal at the thin sections, the minimal thickness of framework metal under the screw head, and the retained stresses induced within the framework after tightening the screws.…”

“…Recent research indicates improvements of metal objects produced by SLM . Currently, SLM is used by several laboratories to produce crown copings, removable partial frameworks, and implants . However, there is very limited literature on the use of this method for implant prosthesis fabrication.…”

“…22,24,25 Currently, SLM is used by several laboratories to produce crown copings, removable partial frameworks, and implants. [26][27][28][29][30] However, there is very limited literature on the use of this method for implant prosthesis fabrication. This research proposes and investigates a novel implant SLM framework design that is distinguished by a complex 3D metal network that enhances resin infiltration.…”

Digital dentistry : studies on the trueness and precision of additive manufacturing and intraoral scanning

“…Additive manufacturing applications in dentistry The limitation of use for dental application is correlated to materials that are biocompatible or bioinert; the continuing material development from additive manufacturers enables more dental applications. For the production of polymers, AM technologies are being used for the fabrication of dental models [66,67], provisional reconstructions [68], surgical guides [69], occlusal devices [70], prosthetic metallic frameworks for both fixed [71] and removable prosthodontics [72]. For metallic applications AM technologies are being used for prosthetic frameworks in Ti-6Al-4V alloys, and Co-Cr.…”