A Comparative Analysis Of Intraoral 3d Digital Scanners For Restorative Dentistry

摘要

Today, intra-oral mapping technology is one of the most exciting new areas in dentistry since three-dimensional scanning of the mouth is required in a large number of procedures in dentistry such as restorative dentistry and orthodontics. Nowadays, ten intra-oral scanning devices for restorative dentistry have been developed all over the world. Only some of those devices are currently available on the market; the others are still passing the clinical testing stages. All the existing intraoral scanners try to face with problems and disadvantages of traditional impression fabrication process and are driven by several non-contact optical technologies and principles. The aim of the present publication is to provide an extensive review of the existing intraoral scanners for restorative dentistry with particular attention to the evaluation of working principles, features and performances. Introduction The introduction of CAD/CAM concepts into dental applications was the brainchild of Dr. Francois Duret in his thesis presented at the Université Claude Bernard, Faculté d’Odontologie, in Lyon, France in 1973, entitled “Empreinte Optique” (Optical Impression). In detail he developed and patented a CAD/CAM device in 1984. The developed system was presented at the Chicago Midwinter Meeting in 1989 by fabricating a dental crown in 4 hours (1, 2). Digital impressions have been introduced, and successfully used, for a number of years in orthodontics, as well, including Cadent’s IOC/OrthoCad, DENTSPLY/GAC’s OrthoPlex, Stratos/Orametrix’s SureSmile, and EMS’RapidForm but the introduction of the first digital intraoral scanner for restorative dentistry was in the 1980s by a Swiss dentist, Dr. Werner M?rmann, and an Italian electrical engineer, Marco Brandestini, that developed the concept for what was to be introduced in 1987 CEREC? by Sirona Dental Systems LLC (Charlotte, NC) as the first commercially CAD/CAM system for dental restorations (1, 3). Ever since research and development sectors at a lot of companies have improved the technologies and created in-office intraoral scanners that are increasingly user-friendly and produce precisely fitting dental restorations. These systems are capable of capturing three-dimensional virtual images of tooth preparations; from such images restorations may be directly fabricated (using CAD/CAM systems) or can be used to create accurate master models for the restorations in a dental laboratory (1). Nowadays, ten intra-oral scanning devices for restorative dentistry are available all over the world: four of them are made in USA, two in Israel, two in Germany and one in Italy, in Switzerland and in Denmark. Generally speaking such scanners try to face with problems and disadvantages of traditional impression fabrication process such as, in particular, mould instability, plaster pouring, laceration on margins, geometrical and dimensional discrepancy between the die and the mould. The main advantages in the employment of those devices are: high fidelity models, creation of 3D archives and surgery simulation and a process simplification. Existing devices are driven by several non-contact optical technologies such as confocal microscopy, optical coherence tomography, photogrammetry, active and passive stereovision and triangulation, interferometry and phase shift principles. Basically, all these devices combine some of the cited imaging techniques to minimize the noise source related to the scanning inside an oral cavity as, for example: optical features of the target surfaces (translucency and the different reflectivity of the target materials as teeth, gums, preparations, resins, etc.), wetness and random relative motions. Also several typologies of structured light sources and optical components are employed. The ten existing intra-oral scanning devices for restorative dentistry are listed below:CEREC? – by Sirona Dental System GMBH (DE)iTero – by CADENT LTD (IL)E4D – by D4D TECHNOLOGIES, LLC (US)Lava?C.O.S.