International Journal of Computerized Dentistry, 02/2003

With digital transversal slice imaging (TSI) as a supplementary program to pantomographic devices and digital volume tomography (DVT), images of the viscerocranium are now possible in several planes. The two procedures, TSI and DVT, are complementary. They should be applied where the indication justifies it in dentistry and maxillofacial surgery for diagnostic and forensic purposes. To minimize patient exposure to radiation, computer tomography (CT) should only be used in complex situations of the viscerocranium where soft tissues are involved or in tumor diagnosis. Keywords: pantomographic slice technique, digital transversal slice imaging (TSI), digital volume tomography (DVT), radiology of the facial skeleton

Purpose: Two intraoral CCD sensor systems were compared with respect to image quality and interobserver agreement. Materials and Methods: Forty intraoral images from each of the sensors (Trophy RVG5, Sirona Sidexis) were examined by 4 observers in terms of anatomical landmarks and general image quality. The images were divided into 2 groups - filtered and unfiltered. Kappa values for interobserver agreement were calculated for all assessed points. Results: The Trophy sensor showed better image quality in the filtered group, and the Sirona sensor demonstrated good image quality in the unfiltered group. Moderate to substantial interobserver agreement was achieved. The use of filters increased edge artefacts. Sensor specific artefacts in the Trophy system were observed. Keywords: intraoral digital imaging, CCD sensors, RVG5 filter, edge artefacts, blooming, interobserver agreement, Kappa value

The goal of the present study was to objectify whether the design modes of "Correlation", "Function", and "Extrapolation" of the Cerec 2 system are suitable for generating a functionally perfect occlusal surface of a first mandibular molar crown. For this purpose, an occlusal surface was waxed up according to the biomechanical concept of MH Polz, and this served as the reference occlusal surface. Four different Cerec 2 comparison crowns (produced in the laboratory, Extrapolation mode, Correlation mode, Function mode) were produced and the positions of the cusps were measured. It was shown that the Correlation mode delivers the most accurate results, and the manually produced occlusal surface also showed good results. The occlusal surfaces of the crowns produced according to the Extrapolation and Function mode were clearly inferior. Keywords: all-ceramic crown, Cerec, occlusal surface

The development of adhesive systems is briefly presented. The advantages of adhesively bonded ceramic restorations are discussed, as are the steps involved in creating an adhesive bond to ceramic. Keywords: adhesive technique, silicate ceramic restorations

The DCS Precident system is suitable for the dental practice and enables the processing of different materials and dental structures. The surface is acquired precisely and without contact by means of a semiconductor laser. Easy-to-use software is employed for the three-dimensional design of the restorations. An almost fully automatic milling machine efficiently mills the framework. A clinical case is documented. Keywords: DCS Precident system, zirconium oxide restorations, CAD/ CAM technology