Optimization of the Manufacturing Process by Molding Cobalt-Chrome Alloys in Assembled Dental Frameworks

Willi Andrei Uriciuc,Adina Bianca Boșca,Cătălin Ovidiu Popa,Aranka Ilea,Claudia Nicoleta Feurden,Anca Ionel,Anida Maria Babtan,Horațiu Vermeșan

doi:10.3390/prosthesis3030024

Abstract

In oral rehabilitation, the treatment of partial edentulism (PEd) is performed by removable partial dentures (RPD) or assembled prosthetic works (APW) composed of several components, fixed to the prosthetic field (Pa) and a removable one (Pb), in order to facilitate the daily hygiene but also the damping of the occlusal forces applied in mastication. Cobalt-Chromium alloys are materials used to manufacture modern prosthetic assembles. In order for this study to be relevant, it was necessary to standardize the design of the framework (Pa) in terms of shape and volume so that the experiment could be reproducible for the five Co-Cr alloys: 0-A (Co-Cr-Mo), 5-A and 10-A (Co-Cr-Mo-W), 15-A and 16.4-A (Co-Cr-W-Fe) and for the three fabrication methods of dental assembled prosthetic frameworks: refractory duplicate method (RD) resulting removable framework (Pb), direct construction method (DC) resulting removable framework (Pb-) and casting over metal method (CoM) resulting removable framework (Pb+). The time allocated to the adaptation process (AP), mechanical processing and sandblasting, in order to assemble the two components was between 43–70 min, even though the assembly between the Pa-framework and the complementary framework (Pb+) was not necessary, CoM-method hs been provide the elimination of AP step. By applying the arithmetic simple rule of three, the percentages for each of the three methods used were calculated, the values of the difference were obtained. The CoM method improves the joining precision between the components of the removable assembly of prosthetic frameworks by 91.7% compared to the RD method and by 80.62% compared to the DC method. According to the efficiency of the methods used in the precision of joining between frameworks components, their order is: casting over metal, direct construction and refractory duplicate method.

Highlights

In oral rehabilitation, the treatment of partial edentulism (PEd) is performed by removable partial dentures (RPD) or assembled prosthetic works (APW) [1]
Most APWs are composed of a partially removable prosthesis that rests on dental crowns (DCs) [2] that are assembled in the oral cavity to compensate for the lost functions of patients with PEd [3]
Following the direct construction method (DC) as well as the refractory duplicate method (RD), results a structural component that requires mechanical adaptation to merge into a prosthetic assembly of structures. [5]

Summary

Introduction

The treatment of partial edentulism (PEd) is performed by removable partial dentures (RPD) or assembled prosthetic works (APW) [1]. The processing of dental alloys for manufacturing prosthetic metal structures is defined by their technological properties [10]. The casting method or the lost wax method is still popular in dental technique [5,20] This method is time consuming and involves considerable variables related to the technological process [21]. Following the direct construction method (DC) as well as the refractory duplicate method (RD), results a structural component that requires mechanical adaptation to merge into a prosthetic assembly of structures. The method of casting over metal (CoM) is a method that wants to undermine the refractory duplicate and the mechanical adaptation in order to assemble the prosthetic frameworks components, increasing the joining precision between the assembled prosthetic works (APW) and reducing the working time that is usually llocated to obtain the joining precision between the prosthetics frameworks

Materials and Methods

Method

DiscCuosMsion