PubMed ID (PMID): 17343243Pages 289-298, Language: English, GermanArnetzl, Gerwin V. / Arnetzl, GerwinBecause of the developments in the field of all-ceramic materials, which have quite different material properties compared with traditional materials for prosthetic treatment, it was also important to adapt the preparation to the new circumstances.
Practiced design guidelines for the restorative treatment of teeth for allceramic restoration are illustrated in this article.
Based on traditional retentive preparation shapes, modifications of these geometries "designed for ceramics" were developed and postulated. Despite excellent 15-year long-term results, it is important to draw the appropriate conclusions from failures that have occurred. The geometry of the cavities for all-ceramic inlays must be matched much more to the material-specific properties of hard and brittle restoration materials. Cavities designed for ceramics must therefore have the simplest possible basic geometry. Because of adhesive bonding, a retentive shape of the preparation is not necessary. Previous ceramic inlay designs must be redefined to achieve an increase in the fracture resistance of the ceramic.
Keywords: CAD/CAM technology, strength characteristics, preparation backgrounds, hard core materials, static load test, all-ceramic restoration
PubMed ID (PMID): 17343244Pages 299-306, Language: English, GermanBrüllmann, D. / Briseno, B. / Willershausen, B. / d'Hoedt, B.Real-time image analysis in endodontics opens new options of treatment support in dentistry. Imaging software was developed to detect the root canal orifices in video sequences of trepanated teeth acquired by a digital video microscope, the Motic DM 143. The software developed is capable of communicating with any video camera connected to it and can automatically detect almost all root canal orifices in trepanated teeth. To recognize the root canal orifices we used the socalled Minimum-Distance Classification. The Minimum-Distance Classification provides a color-based pattern recognition algorithm, which is directly implemented in the function accessing the video stream, and is therefore very fast. Processing speed varied between 30 and 64 ms per image with an input image resolution of 352 x 288 pixels on the Pentium 4 computer (2 GHz). The developed software was tested in this study on 78 trepanated teeth. The mean detection sensitivity of the software found for all 78 teeth is 97.01%.
Keywords: Intraoralcamera, computer vision, digital microscope, root canals, endodontics
PubMed ID (PMID): 17343246Pages 321-331, Language: English, ItalianBonaudo, Diego / Raimondo, Carlo / Rubino, GianpaoloPurpose: Definitive restoration of missing tooth 25 in a single visit by positioning a tapered, immediately loaded implant, a titanium/zirconia abutment, and an allceramic crown.
Materials and Methods: Surgery was planned using a software application which processed CT scan images to obtain a 3-D virtual model. With these images, the crest height and axial orientation of the virtual implants can be reproduced from an implant analog on a working cast using the Ray-Set Implant Ready-to-Load transfer procedure developed on the Ray-Set device (Biaggini Medical Devices, La Spezia, Italy). A tapered Exacta CV implant with a diameter of 4.0 mm (Biaggini Medical Devices, La Spezia, Italy) was chosen for its primary stability, an essential prerequisite for immediate loading. The allceramic crown on the Exacta Z CAD abutment was designed and fabricated using a CAD/CAM system.
Conclusions: Using a computerized method, a surgical treatment plan can be defined using a prosthetic approach to implant positioning and pre-construction of a mesostructure and superstructure for chairside insertion and immediate loading, requiring only a single surgical session to obtain an excellent functional and esthetic result with superior accuracy and long-term predictability.
Keywords: CAD/CAM, Ray-Set, flapless procedures, immediate loading, all-ceramic restorations, addons