Plenary Lecture
Assessment of the Weldability and Electrochemical Behavior of Stainless Steel Orthodontic Archwires, Related to the Ni Content
Professor Liliana Porojan
Department of Dental Prostheses Technology
University School of Dentistry
Specialization Dental Technology
"V. Babeș" University of Medicine and Pharmacy Timișoara
Romania
E-mail: sliliana@umft.ro
Abstract: Joining of metal components is frequently necessary to create individual orthodontic appliances and to achieve efficient treatments. During years there were parallel developments in both materials and joining technologies. Modern welding procedures of orthodontic wires, namely with laser and microplasma, in an inert gas environment, have led to substantial improvements to the traditional joining procedures used in the technology of orthodontic appliances. The advantages of laser and microplasma welding systems are related to the absence of a solder and therefore is no galvanic corrosion in the joint, and to the control of the temperature, allowing a small amounts of metal to be applied to workpiece surfaces without causing significant thermal changes to the base material. Development of orthodontic wires involves critical analysis of a number of characteristics, including their weldability. The ideal wire would have the capacity to be welded under the fabrication conditions imposed into a specific, suitably designed structure and to perform satisfactorily in the intended service. Stainless steel (SS) wires are commonly used for orthodontic appliances. With the release of nickel from these wires, some manufacturers have turned to nickel-free stainless steel alternatives with regard to nickel allergies and sensitivities. The goal of this topic is to compare nickel-free SS wires with traditional SS wires with regard to their weldability and electrochemical behavior. Laser welding of SS orthodontic wires should be acceptable for clinical use, successful joining result due to their good weldability. Ni-free SS wires proved to have a better corrosion resistance, improved by laser welding. Ni-containing SS wires are positive influenced by laser welding, relative to the corrosion behavior. In order to obtain maximum precision and high quality weldings, which would fulfill current requirements, it is necessary to use modern analysis concepts for each particular case, based on an interdisciplinary collaboration.
Brief Biography of the Speaker: Liliana Porojan - Professor at the "Victor Babeș" University of Medicine and Pharmacy Timisoara, Faculty of Dentistry, Specialization Dental Technology, Department of Dental Prostheses Technology, PhD in dentistry, Primary dentist in General Dentistry specialty, Specialist in the specialty of Orthodontics and Dental-Facial Orthopedics , Specialist in specialty Dental Prosthodontics. The areas of research are focused on: threedimensional modeling, computer aided design in the field of dental prosthodontics, numerical simulations (finite element analysis) in fixed prosthetics, removable and combined restaurations, design optimization, modern welding procedures of dental alloys in shielding gas, structural aspects and electrochemical behavior of base metal alloys, design concepts of removable partial dentures, attachments used in combined prosthetic restorations, ceramic systems used in dental technology, CAD / CAM systems used in dental technology. They were evidenced by coordination of 6 research projects in this areas of interest. The dissemination of research results was done by: 18 published books and monographs, 178 scientific papers published in extenso, 241 papers presented at scientific meetings, 114 participation in conferences and symposia, 35 courses and training programs.