ABSTRACT
This report describes a clinical and laboratory protocol used in the fabrication of a removable partial dental prosthesis with a digital workflow in a 73-year-old patient. The metal framework was produced with a selective laser melting technique. For quality assurance and discrepancy analysis, the framework was superimposed and compared to the respective digital design file, and the printed model was also compared to the digital impression and rendered as a 3D colour map. Differences were detected in the framework on the clasp of tooth 17 (upper right second molar) and on the printed model on the interproximal surfaces of the abutments, particularly on tooth 17 and palatine area. The use of this digital workflow allowed for the achievement of an removable partial dental prosthesis with a good fit and occlusion with minimal adjustments, with the reduction of both clinical and laboratory time. Further studies are needed to gain a better understanding of these techniques.
ABSTRACT
OBJECTIVE: Titanium is the most commonly used material to manufacture dental implants and abutments. Recently, zirconia abutments have been manufactured with better aesthetic properties. However, zirconia abutments are harder than titanium implants; therefore, they could wear the implant surface. Therefore, this article aims to describe a sphere-plane system that can be used to assess the wear that different abutment materials cause in the titanium of dental implants when submitted to cyclic loading. This method can be used to simulate the oral cavity, where the abutment (sphere) applies loads onto the implant (titanium plane). The spheres were made of different materials (titanium and zirconia), and the specimens were loaded for 4,000,000 cycles. The scar size and area on titanium planes were measured with stereoscopic images and analysed through profilometry. RESULTS: The wear of titanium planes was similar when tested against zirconia or titanium spheres. The sphere-plane system is a method that can be used to evaluate and quantify the wear of the titanium of dental implants, and compared with methods that use real implants, this system is simpler and less expensive. This method could facilitate further research to evaluate the wear of titanium against different materials and under different testing conditions.