Plenary Lecture
3D Framework Design Optimization of All-Ceramic Crowns
Professor Liliana Porojan
Department of Prostheses Technology, Specialization Dental Technology
University School of Dentistry
"V. Babes" University of Medicine and Pharmacy Timisoara
Romania
E-mail: sliliana@umft.ro
Abstract: Yttria-stabilized zirconia cores veneered with dental ceramics are highly aesthetic alternatives to conventional metal-ceramic crowns. By applying veneering materials aesthetically superior results can be achieved, but these materials have mechanical properties inferior to those of the frameworks. Failure of all-ceramic dental restorations is predominately caused by cohesive fractures of the ceramic veneering material. An important factor influencing the chipping behavior of veneered zirconia restorations is the framework design. Zirconia ceramics can be processed only with CAD/CAM (computer aided design/computer aided manufacturing) technologies and in current practice, the framework is obtained by milling an even thickness copies, rather than using a scientific-based design. The aim of the studies was to suggest the optimal design for the framework of zirconia-ceramic crowns and to evaluate the effect of core design on stress distribution in all ceramic crowns. Finite element analyses were used to provide a biomechanical explanation of the behaviour of different all ceramic bilayer crowns.The recent possibility of the softwares to scan the bite-registration allows achieving a digital improved design of the framework, regarding the control of the veneer thickness in case of the cutback design and also of the occlusal contacts in case of a vestibular veneering. Optimization of the zirconia substructure 3D design has been proven as a considerable factor in reducing chipping failures, and coping modifications are still a topic of current investigations.
Brief Biography of the Speaker: Professor at the "Victor Babes" 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: tridimenional reconstructions of dental structures and prosthetic restorations, 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 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: 13 published books and monographs, 10 published courses and practical work handbooks, 164 scientific papers published in extenso, 160 papers published in summary, 221 papers presented at scientific meetings, 92 participation in conferences and symposia, 33 courses and training programs.