PubMed ID (PMID): 21323011Pages 303-316, Language: English, GermanFasbinder, Dennis J. / Poticny, Daniel J.
Information from the opposing dentition is used to design and fabricate occlusal contacts with a reasonable level of accuracy for a given restoration. The Dental Database with the Antagonist design process utilizes a bite registration to propose the construction of a virtual opposing model. The Articulation design technique utilizes a functionally generated bite registration to control both the maximum intercuspation and excursive contacts on the restoration. Correlation design technique offers the opportunity to copy the established occlusal anatomy to the preparation. Although these techniques offer a workflow to establish occlusal contacts with the Cerec system, there is a lack of quantitative data as to the accuracy achieved. Alternative techniques to control the occlusal contacts have been suggested which rely on "user customized design techniques" that recommend altered program settings, manual override of automated features in the software, or modification of the established software design programs. The purpose of this study was to measure the occlusal vertical discrepancy for various design techniques. Full crowns made using Dental Database with the Antagonist design technique had a significantly smaller occlusal vertical discrepancy than those made with Correlation. Dental Database with the Antagonist had a significantly smaller occlusal vertical discrepancy than all suggested alternative design techniques. Use of the Dental Database with Antagonist design technique provides the most accurate technique for establishing occlusal contacts with the Cerec 3D system.
Keywords: CAD/CAM, occlusion, Cerec, software design
PubMed ID (PMID): 21323012Pages 317-330, Language: English, GermanWakabayashi, Noriyuki / Kondo, Takayuki / Yahagi, Rika / Suzuki, Tetsuya
In dieser Studie sollte untersucht werden, wie sich die Verblockung von unteren Prämolaren mit reduzierter alveolärer Abstützung auf die Kraftverteilung im Parodont auswirkt. Der untere zweite Prämolar einer Patientin mit verringerter alveolärer Knochenhöhe wurde mit einer Metallkeramikkrone versorgt, die mit dem benachbarten ersten Prämolar verblockt wurde. Es wurde eine Erhaltungsphase von drei Jahren eingehalten. Auf der Grundlage der morphologischen Vermessung des Situationsmodells und der Röntgenbilder erfolgte die Erstellung eines patientenbasierten dreidimensionalen Finite- Element-Modells, in das auch In-vivo-Bissregistrate integriert wurden. Anhand dieses Modells wurden Zugund Druckspannungen im Parodont für verblockte und nicht verblockte simulierte Situationen analysiert. Außerdem wurden modifizierte Modelle erstellt, um die Auswirkungen der relativen Knochenhöhe auf die Verteilung von Zug- und Druckspannungen zu untersuchen. Die maximalen Zug- und Druckspannungen im Parodont des zweiten Prämolar waren nach dem Verblocken erheblich reduziert. Ursprünglich waren diese Spannungen fast so stark, dass Mikroschäden am Knochen angenommen wurden. Im Gegensatz dazu stiegen die Zug- und Druckspannungen am ersten Prämolar nach dem Verblocken. Die modifizierten Modelle zeigten, dass eine unterschiedliche Alveolarkammhöhe an den verblockten Zähnen zu einer erhöhten Druckspannung am ersten Prämolar beitrug. Da das beschriebene prothetische Vorgehen nicht dem Standard entspricht, lassen sich die Ergebnisse nicht verallgemeinern. Immerhin kann der Schluss gezogen werden, dass ein Verblocken die Belastung des Parodonts eines Prämolaren mit geringer parodontaler Abstützung verringern kann, jedoch auf Kosten einer höheren Belastung am verblockten Zahn.
Keywords: Prothetik, Kaukräfte, Schienen, Verblockung, Finite-Element-Analyse
PubMed ID (PMID): 21323013Pages 331-340, Language: English, GermanVichi, Alessandro / Carrabba, Michele / Louca, Chris / Corciolani, Gabriele / Ferrari, Marco
TriLuxe ceramic blocks for chairside CAD/CAM procedures are color layered to allow natural esthetics, and only require subsequent glazing. The purpose of this study was to compare color repeatability of different batches of TriLuxe blocks. The three commercially available shades (1M2C, 2M2C, 3M2C) of TriLuxe blocks for the Cerec CAD/CAM system were examined. For each of the three colors, three different batches were tested, 5 blocks each. The measurements were made using a spectrophotometer equipped with an integrating sphere using the CIELab colorimetric system. One-way ANOVA showed that the factor "Production Batch" was not statistically significant. Regarding ΔE, none of the 315 color comparisons (neither within the same shade, nor between specimens of the same batch, nor between specimens from different batches) exceeded the proposed ΔE=3.3 threshold for clinical acceptability. All the different batches of the different shades of VITA TriLuxe blocks for the Cerec system showed the high degree of color correspondence necessary in industrially prefabricated CAD/CAM blocks.
Keywords: ceramic, color, CAD/CAM, chairside, Cerec, spectrophotometer
PubMed ID (PMID): 21323014Pages 341-349, Language: English, GermanFrank, Elmar
Since May 2010, the representative of a "completely new class of devices" (statement of the manufacturer) from the Apple company has been on the market. This article describes possibilities for its use in the dental environment.
PubMed ID (PMID): 21323015Pages 351-365, Language: English, GermanKurbad, Andreas
With the aid of an innovatively structured ceramic block, it is possible to achieve results at a high esthetic level with relatively simple means. In the three-dimensionally structured Vitablocs RealLife, translucent enamel ceramic is arranged around a conically structured, opaque dentin core. The virtual restoration can be positioned freely in all three dimensions with the aid of the Cerec / inLab software. The restorations are milled fully anatomically and only minimally glazed or characterized with stains. Results that otherwise can be achieved only with much more complex layering processes are possible.
Keywords: CAD/CAM process, Cerec, inLab, ceramic blocks, polychromatic, esthetics, anterior tooth, crown, veneer