PubMed ID (PMID): 19413268Pages 119-130, Language: English, GermanArnetzl, Gerwin V. / Arnetzl, Gerwin
Ziel: In dieser In-vitro-Untersuchung wurden vollkeramische Inlays einem statischen Festigkeitstest unterzogen. Das dabei verwendete Material war Vita Mark II® Keramik (Vita-Zahnfabrik, Bad Säckingen). Ziel der Untersuchung war es, eine Inlaypräparation mit daraus resultierenden unterschiedlich gestalteten Inlays aus Keramik zu evaluieren, die einen größtmöglichen Widerstand gegenüber statischen Bruchbelastungstests bieten. Material und Methode: Auf einem Modell diente der mit einer Standardpräparation mit einem ebenen Boden versehene Zahn 36 als Testobjekt. Es wurden zwei Inserts hergestellt: eines mit klassischem Präparationsmuster, das andere mit modifizierter Kavitätenbodenform. Bei dem einen Inlaydesign wurde der Kavitätenboden nach den für eine vollkeramische Inlayversorgung gültigen zahnmedizinischen Regeln gestaltet, bei dem zweiten Inlaydesign wurde eine differente Gestaltung des Kavitätenbodens gewählt, welche ausschließlich den Vorgaben des Materials Keramik folgte und deren Ziel es war, diese Regeln bestmöglich umzusetzen. Danach erfolgte die Abformung, Konstruktion und Herstellung mittels CAD/CAM-Technologie. Resultate: Die geringere Bruchfestigkeit mit mittleren Bruchlastwerten um 66,6 Newton (N) zeigte sich bei der traditionellen Inlaypräparation mit einem als Kasten ausgeführten Kavitätenbodensegment. Das aus demselben Material bestehende Inlaydesign, mit einem halbkugelförmigen Kavitätenbodensegment wies eine knapp 27,5 Prozent höhere Festigkeit aus, und lag im Mittel bei 84,9 Newton (N). Konklusion: Es stellte sich die Frage, ob es unabhängig von der verwendeten Keramik, möglich ist, eine Festigkeitssteigerung zu erreichen, in dem man die Gestaltung des Inlays modifiziert.
Keywords: Präparationsdesign, FE-Untersuchung, Inlaydesign
PubMed ID (PMID): 19413269Pages 131-145, Language: English, GermanRugani, Petra / Kirnbauer, Barbara / Arnetzl, Gerwin V. / Jakse, Norbert
For the diagnosis of bone pathology, planning of complex implant-supported prosthetic restorations, and guaranteeing oral surgery that is as safe and free of complications as possible, a three-dimensional radiological display is frequently indicated. Cone beam computed tomography (CBCT), which can cover a large part of the indications of the dental and oral surgical spectrum, represents an alternative to computed tomography. Moreover, the method offers the advantage that it can also be used in the dental practice, taking the existing radiation protection regulations into account. This guarantees optimum patient and user friendliness, because referral to a specialized CT facility is thus no longer necessary in most cases. In the first 12 months of the trials of the Planmeca Promax 3D® at the Department of Dental Surgery and Radiology of the University Clinic for Oral and Maxillofacial Medicine in Graz, the overwhelming majority of referrals for CBCT (almost 90%) was concerned with the field of oral surgery and implantology. Oral surgical questions mainly covered aspects of wisdom tooth anatomy, position of impacted canines, premolars, and mesiodents, as well as cystic lesions. Diagnoses of the maxillary sinuses and the area of tooth preservation represented further indications. Apart from diagnostic purposes, the objective of the referrals was facilitating optimum preparation for the pending operation. In the area of implantology, this was combined frequently with pre- or post-augmentative three-dimensional digital therapy planning. CBCT showed good results in the display of hard tissue structures and can be integrated without difficulty in the daily clinical routine.
Keywords: CBCT, CT, oral surgery, oral radiology, computerized implant planning, 3-dimensional diagnostics.
PubMed ID (PMID): 19413270Pages 147-156, Language: English, ItalianBonaudo, Diego / Boschis, D. / Gianpaolo, R.
The continuing development of innovative surgical and prosthodontic techniques has led to a greatly increased interest in and demand for restorations on immediately loadable implants, due to the numerous clinical advantages offered by this treatment mode. By now, numerous clinical observations supported by histological studies have shown that dental implants placed in fresh extraction sockets with subsequent immediate loading result in clinical success.1 Software-assisted approaches to prosthetically driven surgery combined with CAD/CAM methods can result in highly esthetic and functional all-ceramic restorations for single missing teeth or more extensive edentulous areas using an immediate-loading protocol. The most important objectives in this respect are to reduce treatment times, prevent postextraction bone resorption, and preserve the residual periodontal tissues. Implant-supported restorations have become a frequently employed treatment method for the partially or completely edentulous jaw, well documented in long-term observations and histological studies of the osseointegration process.1-4 Numerous treatment protocols have been proposed and employed, depending on the number and distribution of implants used, to obtain a functional rehabilitation, using diagnostic templates during the restorative process to ensure a better axial alignment of the transmucosal units relative to the occlusal load.12 The choice of implant in terms of shape and diameter must be consistent with immediate functional loading with a provisional or definitive restoration, taking into account the effects and specifics of the occlusal loading situation as well as the need for conditioning the soft tissues. Primary stability, biological stability and the BIC (bone-implant contact) index all define the basic parameters of osseointegration, just as with the treatment modalities and osseointegration processes associated with conventional loading protocols.6-11 In this case report, the surgical procedure was driven by the subsequent restoration. We describe the chairside definitive restoration of a single missing tooth 3513 in a single visit by placement of a tapered, immediately loaded implant, a titanium/zirconia abutment, and an all-ceramic crown, including tollow-up and evaluation of the clinical result.
Keywords: prosthetically guided surgery, immediate loading, CAD/CAM technology, all-ceramic restorations
PubMed ID (PMID): 19413271Pages 159-163, Language: English, GermanZiegler, Markus
Im Februar 2008 wurde in den USA erfolgreich der Lava™ Chairside Oral Scanner C.O.S. (Abb. 2) von 3M ESPE (D-Seefeld) eingeführt. Die Erprobungsphase in deutschen Zahnarztpraxen startete im Oktober 2008. Ab April 2009 soll der neue Intraoralscanner für die direkte Digitalisierung von Zahnpräparationen in Deutschland erhältlich sein. Das Aufnahmeverfahren des Lava™ C.O.S. basiert auf der neuartigen 3D-in-motion-Technologie. Diese wurde von dem im Oktober 2006 von 3M akquirierten Unternehmen Brontes Technologies Inc. (US-Lexington), einem Spin-out von Mitarbeitern des Massachusetts Institute of Technology (MIT) entwickelt. Erste Studienergebnisse belegen die reproduzierbar hohe Präzision des Lava C.O.S.
PubMed ID (PMID): 19413273Pages 171-185, Language: English, GermanKurbad, Andreas / Schnock, Heinz A.
Both pressing technology and CAD/CAM methods have proven themselves clinically for the fabrication of allceramic restorations. The advantages of the Cerec technology for the economic fabrication of all-ceramic bridges can be exploited by the use of burn-out blanks of polymer material. The milling process of very hard ceramics in the milling unit, which has some disadvantages, is replaced by the pressing process and makes the IPS e.max press material accessible to CAD/CAM users, primarily for extending the range of indications to splinted crowns and small all-ceramic bridges.
Keywords: all-ceramic, CAD/CAM technology, pressing technique, lithium disilicate.