Computer Engineering Complete Dentures Workflow: Systematic Techniques Review

Background: The progress in the use of computer-aided design/computer aided manufacturing (CAD/CAM) to fabricat removable prosthodontic prostheses in dental clinics has been exponential. Commercially existing CAD/CAM denture techniques grow every year with increasing benefits to dentists and patients. Study Design: Systematic review. Aims: This review assessed and evaluated the different clinical production protocols of presently accessible CAD/CAM denture systems that offer decision support for dental practitioners. Methodology: Data for the current object were collected by surveys from different companies manufacturing the Computer Engineering Complete Denture (CECDs). All related subjects published at the last 10 years were collected and included in this review. Techniques were arranged in alphabetical order, as follows. AvaDent Digital Dentures (Global Dental Science), Baltic Denture Creator System (Merz Dental GmbH), and Ceramill Full Denture System (Amann Girrbach AG) can manufacture denture fabrication in three visits, including a try-in step. DENTCA Digital Dentures (Whole You Nexteeth, Inc) can also perform this in three visits. The Wieland Digital Denture (Ivoclar Vivadent, Inc) can manufacture in four dental appointments. Recently developed VITA VIONIC Digital System (VITA Zahnfabrik, Bad Säckingen, Germany) can perform two-step CECD manufacturing. Results: Most of the systems involved subtractive manufacturing for the fabrication of their dentures and only closed systems. However, Baltic Denture System and VITA VIONIC material types are an open structure that allow users to choose among different handling protocols. It can be shared with several unclosed digital scanner, CAD software options, and milling machines. Conclusions: The six existing CECD fabrication systems offer many advantages. The decision on which technique to use may be contingent on the dentist’s prosthodontic expertise, patient output amount, and requirements concerning denture individualization.

Tension testing of additively manufactured specimens of 17-4 PH processed by Bound Metal Deposition

In contrast to the traditional ways of subtractive manufacturing, additive manufacturing (AM), also known as 3D printing, adapts computer-aided design to iteratively build the component or part layer by layer. The technology has recently gained a high momentum, both within academia, but also within the industrial sector. However, it is common that parts produced by AM will have more defects than parts produced by traditional methods. The objective of this paper is to investigate a new method of additive manufacturing, namely the bound metal deposition method (BMD). This method seemed promising from the perspective that the metal is not iteratively being melted, similar to such as welding. In fact, the part is first printed, then washed, for then to be sintered. Consequently, avoiding the complex thermal histories/cycles. It was found that the material will exhibit anisotropic behaviour, and have a mesh of crack like defects, related to the printing orientation.

Surface roughness variance on different levels of surface inclination of powder bed fused tool steel 1.2709

Evolution of additive manufacturing has allowed increased flexibility and complexity of designs over conventional manufacturing e.g. formative and subtractive manufacturing. Restricting factor of laser powder bed fusion of metals (PBF-LB/M) additive manufacturing is the as-built surface quality. To promote an understanding of the surface roughness and suitable surface measuring technologies octagon shaped tool steel 1.2709 samples was developed and manufactured. Different surface measuring technologies was also literary reviewed. Studied samples were manufactured with commercially available laser-based powder bed fusion system using standard parameter set provided by the system manufacturer. Surface roughness was measured from top and down skins from multiple different building angles in a way that process specific effects, such as direction of movement of the powder re-coater, was considered. Based on these measuring results of the samples the effect surface inclination are discussed. The results show that building angle strongly affects to surface roughness of laser-based powder bed fused parts. Surface roughness was measured to be more than five times worse in unsupported angle manufactured down facing surfaces when compared with vertical walls.

Three-Dimensional Modeling and 3D Printing of Biocompatible Orthodontic Power-Arm Design with Clinical Application

Three-dimensional (3D) printing with biocompatible resins offers new competition to its opposition—subtractive manufacturing, which currently dominates in dentistry. Removing dental material layer-by-layer with lathes, mills or grinders faces its limits when it comes to the fabrication of detailed complex structures. The aim of this original research was to design, materialize and clinically evaluate a functional and resilient shape of the orthodontic power-arm by means of biocompatible 3D printing. To improve power-arm resiliency, we have employed finite element modelling and analyzed stress distribution to improve the original design of the power-arm. After 3D printing, we have also evaluated both designs clinically. This multidisciplinary approach is described in this paper as a feasible workflow that might inspire application other individualized biomechanical appliances in orthodontics. The design is a biocompatible power-arm, a miniature device bonded to a tooth surface, translating significant bio-mechanical force vectors to move a tooth in the bone. Its design must be also resilient and fully individualized to patient oral anatomy. Clinical evaluation of the debonding rate in 50 randomized clinical applications for each power-arm-variant showed significantly less debonding incidents in the improved power-arm design (two failures = 4%) than in the original variant (nine failures = 18%).

Wire Arc Additive and High-Temperature Subtractive Manufacturing of Ti-6Al-4V

We investigated the fabrication and finishing of wall-profile machining by wire and arc additive manufacturing (WAAM) employing plasma welding with Ti-6Al-4V wire. We fabricated and integrated a local shield and a cover for the area below the local shield to achieve higher shielding ability. The tensile strength of the fabricated object met the forging standard for Ti-6Al-4V, but elongation was about 7%. We also focused on the possibility of reducing the cutting force and increasing the efficiency of the finishing process by cutting workpieces softened by high temperature immediately after the deposition process. We investigated the cutting force and tool wear of the fabricated objects heated to 300 °C using ceramics tools. Results showed that although the cutting force was reduced at high temperature, the wear rate of the tools was high, and the increase in cutting force due to wear was significant.

Evaluation of Maraging Steel Produced Using Hybrid Additive/Subtractive Manufacturing

Hybrid manufacturing is often used to describe a combination of additive and subtractive processes in the same build envelope. In this research study, hybrid manufacturing of 18Ni-300 maraging steel was investigated using a Matsuura LUMEX Avance-25 system that integrates metal additive manufacturing using laser powder bed fusion (LPBF) processing with high-speed machining. A series of benchmarking coupons were additively printed at four different power levels (160 W, 240 W, 320 W, 380 W) and with the integration of sequential machining passes after every 10 deposited layers, as well as final finishing of selected surfaces. Using non-contact three-dimensional laser scanning, inspection of the final geometry of the 18Ni-300 maraging steel coupons against the computer-aided design (CAD) model indicated the good capability of the Matsuura LUMEX Avance-25 system for net-shape manufacturing. Linear and areal roughness measurements of the surfaces showed average Ra/Sa values of 8.02–14.64 µm for the as-printed walls versus 0.32–0.80 µm for the machined walls/faces. Using Archimedes and helium (He) gas pycnometry methods, the part density was measured to be lowest for coupons produced at 160 W (relative density of 93.3–98.5%) relative to those at high power levels of 240 W to 380 W (relative density of 99.0–99.8%). This finding agreed well with the results of the porosity size distribution determined through X-ray micro-computed tomography (µCT). Evaluation of the static tensile properties indicated that the coupons manufactured at the lowest power of 160 W were ~30% lower in strength, 24% lower in stiffness, and more than 80% lower in ductility relative to higher power conditions (240 W to 380 W) due to the lower density at 160 W.

Amalgamation of 3D Printing with Fabrication Robotics

3D printing has always been a matter of curiosity to layman. But for engineers and innovators, 3D printer is viewed as a machine of additive manufacturing domain. It is definitely revolutionary in that area but if we remove such a myopic vision, we can say that a 3D printer is devise giving relative motions in 3 directions. Taking the advantage of this, we can assign multiple roles to 3D printer. In normal product building process, raw materials are converted and processed with subtractive manufacturing processes. Than they are treated with number of fabrication processes for final end product. On this journey, they pass through different layouts and machines. But if we develop a single unit machine where raw product is processed and also fabricated on single bed resulting in end product, than we can bring a paradigm shift in manufacturing technology in prevailing world. Keyword: 1. Additive manufacturing, 2. 3D printing, 3. Digital manufacturing, 4. Rapid prototyping, 5. Industrial engineering.