PubMed ID (PMID): 22891414Pages 93-107, Language: English, GermanKordaß, Bernd / Hugger, Alfons / Bernhardt, Olaf
197 subjects (74 male, 123 female) were evaluated in this Study of Health in Pomerania associated project (SHIP 0). Both a clinical functional status and an instrumental analysis of functional movement patterns of the mandible were performed in each subject, in the latter case using an ultrasonic jaw motion analysis system. Correlations between instrumental movement pattern features and clinical signs and symptoms of temporomandibular joint dysfunction (TMD), such as joint sounds, palpable impairment of jaw movement, and the termination of opening movement at the incisal point, were particularly significant (p < 0.005). Correlations for TMJ crepitation sounds and joint pain on palpitation from the lateral or posterior aspect tended to be less significant (p < 0.1). No association was found for pain on jaw movement or muscle tenderness in response to pressure. A multivariate logistic regression model showed a significant correlation between Helkimo Clinical Dysfunction grades 2 and 3 and the following independent variables: frequent headaches (odds ratio [OR] 4.12; p = 0.032), frequent popping sounds in the jaw joints (OR 5.79; p = 0.012), incisal paths showing conspicuous signs of dysfunction such as deviation or deflection (OR 4.35; p = 0.05), and condylar path anomalies such as jumpy, straight/inverse or irregular tracings (OR 28.59; p = 0.006). Instrumental functional analysis of condylar path tracings allows one to draw statistically valid conclusions about the occurrence of TMD symptoms. It can be helpful to perform condylar path analysis when performing risk assessments for temporomandibular dysfunction in certain situations, particularly before prosthetic rehabilitation.
Keywords: temporomandibular joint dysfunction, TMD, craniomandibular dysfunction, CMD, instrumental functional analysis, temporomandibular disorders, jaw motion analysis, three-dimensional jaw tracking
PubMed ID (PMID): 22891415Pages 109-123, Language: English, GermanMehl, Albert
In den letzten Jahren sind entscheidende Fortschritte in der dentalen CAD/CAM-Technik erzielt worden. Durch Verbesserungen in der intraoralen optischen Scantechnik lassen sich ganze Quadranten und Kiefer einschließlich der Gegenbezahnung direkt am Patienten in kurzer Zeit dreidimensional vermessen. Zusätzlich kann die statische Relation von Oberkiefer und Unterkiefer über Bissregistrate oder Bukkalaufnahmen in einfacher Art und Weise intraoral erfasst werden. Diese Informationen stellen dann die Ausgangsbasis dar, um die digitale Kauflächengestaltung und die Oberflächenrekonstruktion durchzuführen. Auch hier hat sich mit dem wissensbasierten Ansatz der Biogenerik ein Verfahren herauskristallisiert, bei dem automatisch für die jeweilige individuelle Situation ein gut passender Restaurationsvorschlag berechnet wird. Damit wird die Nachbearbeitungszeit für die digitale Modellation deutlich reduziert oder ist zum Teil gar nicht mehr notwendig. Dem digitalen Arbeitsprozess fehlt jedoch bisher eine Strategie, mit geringem Aufwand und hoher Zuverlässigkeit die dynamische Okklusion zu integrieren. Digitale Konzepte bieten inzwischen Lösungsansätze, zu denen hier erste Ergebnisse vorgestellt werden sollen.
Keywords: CAD/CAM, virtuelle Artikulation, funktionelles Bissregistrat, virtuelles FGP, Mittelwertartikulation, CAD/ CAM
PubMed ID (PMID): 22891416Pages 125-136, Language: English, GermanTsitrou, Efrosyni / Tsangaria, Kyriaki N.
Purpose: To examine the performance of CAD/CAM allceramic resin-bonded bridges (RBBs) fabricated from a glass ceramic material, and determine the influence of two different preparation designs on the fracture strength of these prostheses.
Materials and Methods: Twenty human central incisors were used, placed into two groups. A clinical situation where a lateral incisor was missing was simulated. A minimal preparation design (palatal veneer preparation) and one that extended into the proximal area were applied in each group. The Cerec InEos and the Cerec 3D software were used to scan, design, and mill the restorations. A lithium disilicate glass ceramic material was used for the fabrication of the bridges (IPS e.max CAD). Twenty bridges were milled which were adhesively bonded on their abutments (Variolink II). A universal testing machine was used to evaluate the fracture strength and the mode of failure of the bridges.
Results: The mean fracture strength for the minimal design group was 774 N (± 341) and for the extended preparation group 814 N (± 474). No statistically significant difference was found between the two designs (p > 0.05). The mode of failure was fracture at the connector area between the pontic and the retainer wing.
Conclusion: The fracture strength of the RBBs fabricated with IPS e.max CAD was in a clinically acceptable range. The two preparation designs did not have a significant influence on the fracture strength of the RBBs.
Keywords: resin bonded bridge, Cerec, lithium disilicate, fracture strength, kompositverklebte Brücke, Cerec, Lithiumdisilikat, Bruchfestigkeit
PubMed ID (PMID): 22891419Pages 159-164, Language: English, GermanKoller, Martin / Arnetzl, Gerwin V. / Holly, L. / Arnetzl, Gerwin
Lava Ultimate Resin Nano Ceramic (RNC) blocks are innovative new CAD/CAM materials that make it possible to achieve superior esthetic results in easy steps. The blocks are made of nano ceramic particles embedded in a highly cured resin matrix. Therefore, composite materials can be used to characterize and adjust resin nano ceramic restorations after milling. The milled RNC restorations can be individualized intra-orally or extra-orally, either before or after insertion. Unlike conventional ceramic restorations, customization and glaze firing is neither necessary nor possible with RNC restorations. This opens up the opportunity for intraoral individualization and adaptation of the restorations.