TY - THES A1 - Simon, Mona T1 - In-vitro Untersuchung der Bruchlast zweier dental keramischer Werkstoffe in Abhängigkeit der darunter verklebten Zahnstruktur und dessen Steifigkeit T1 - In vitro testing of the fracture load of two dental ceramic materials bonded to tooth substructure regarding the stiffness of the substructure N2 - Restaurationen aus Vollkeramik sind im Fokus der modernen Zahnmedizin. Die aktuell gängigen Keramiken sind Lithiumdisilikatkeramik (=LiSi2), eine Glaskeramik mit eingelagerten Silikatkristallen und Zirkoniumdioxidkeramik (=ZrO2), eine Oxidkeramik. Erstere zeichnet sich durch exzellente optische und letztere durch hervorragende mechanische Eigenschaften aus. In der vorliegenden Studie wurde der Einfluss der Schichtdicke der beiden Keramiken, des künstlichen Alterungsprozesses und der Substruktur, auf die die Keramik verklebt wurde, untersucht. Insgesamt wurden 256 Proben nach einem standardisierten Verfahren hergestellt: 64 reine Materialproben und 192 Echtzahnkeramikproben. Von den Zahnproben durchlief die Hälfte einen Alterungsprozess. Sechs der LiSi2 und zwei der ZrO2 Echtzahnkeramikproben brachen bereits beim Alterungsprozess. Die höchsten Bruchlastwerte bei den Keramikechtzahnproben erzielte ZrO2 (2420 N) und LiSi2 (1.783 N) in einer Schichtdicke von 2 mm jeweils ohne Alterung. Die zu Bruch gegangenen außer Acht gelassen, entstanden die niedrigsten Werte bei den dünnen Keramikproben ohne Zahnanteil in 0,5 mm Schichtdicke (140 N ZrO2 Vgl. 99 N LiSi2). Außerdem veranschaulichen die Ergebnisse, dass die Keramikproben mit Schmelzanteil signifikant höhere Bruchlastwerte (p< 0,002) erzielten, als ihre Vergleichspartner mit mehr Dentinanteil. Zudem zeigt sich, dass Zirkoniumdioxidkeramik höhere Bruchlastwerte erreichte als Lithiumdisilikatkeramik, sowohl nach dem Alterungsprozess, als auch bei sehr dünner Schichtstärke. Im Vergleich zur aktuellen Literatur fällt auf, dass es bisher wenige standarisierte Verfahren zur Herstellung von Keramikechtzahnproben gibt. Andere, aber dennoch vergleichbare Studien, kommen zu ähnlichen Ergebnissen: Scheinbar hat der Zahnschmelz einen unterstützenden Effekt auf die Keramikechtzahnprobe. Der Einfluss des Alterungsprozesses bei den Proben darf nicht unterschätzt werden und die Schichtdicke der Keramik wirkt sich auf das Bruchlastverhalten der Probenkörper aus. In der Simulation einer möglichst realitätsnahen Situation der Mundhöhle gilt es viele Variablen wie etwa Lagerung der Proben, Schleifrichtung der Zahnhartsubstanz, Verklebung der Proben und Belastung im Kausimulator zu beachten. N2 - Restorations made of all-ceramics have become an important focus of modern dentistry. The ceramics currently in use are lithium disilicate ceramics (=LiSi2), a glass ceramic with embedded silicate crystals, and zirconium dioxide ceramics (=ZrO2), an oxide ceramic. While the former is characterized by excellent optical properties, the latter possesses superior mechanical properties. The study presented here investigates the effect of the layer thickness of the two ceramics, the artificial ageing process, and the substructure to which the ceramics were bonded to the fracture load. Altogether, 256 samples were prepared according to a standardized procedure: 64 material-only samples and 192 ceramic samples on real teeth. Half of the samples of ceramics on real tooth underwent an artificial ageing process. Six of the LiSi2 and two of the ZrO2 ceramic samples on real teeth fractured during the ageing process. The highest values of breaking load for the samples on real tooth were achieved by ZrO2 (2420 N) and LiSi2 (1,783 N) at a coating thickness of 2 mm, both without ageing. Excluding those that fractured, the lowest breaking values were obtained for the thin material-only samples at a coating thickness of 0.5 mm (140 N ZrO2 vs. 99 N LiSi2). The results illustrate that the ceramic samples with enamel content achieved significantly higher breaking load values (p< 0.002) than their counterparts with more dentin content. Furthermore, the results show that the zirconium dioxide ceramics achieved higher breaking load values than lithium disilicate ceramics, not only after the ageing process, but also at very thin layer thickness. Looking at the current literature, it is striking that there are only few standardized procedures for the fabrication of ceramic samples on teeth to date. Yet, other comparable studies come to similar results: It appears that the enamel has a supportive effect on the ceramic tooth sample. The influence of the ageing process on the samples should not be underestimated and the layer thickness of the ceramic influences the fracture load behavior of the samples. In the simulation of a situation of the oral cavity that is as close to reality as possible, many variables must be considered, such as storage of the samples, grinding direction of the tooth structure, bonding of the samples and the loading in the chewing simulator. KW - Dentalkeramik KW - Zahnmedizin KW - Bruchlast KW - Echtzahnkeramikprobe Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-296652 ER - TY - JOUR A1 - Nemes, Karolina A1 - Johann, Pascal D. A1 - Steinbügl, Mona A1 - Gruhle, Miriam A1 - Bens, Susanne A1 - Kachanov, Denis A1 - Teleshova, Margarita A1 - Hauser, Peter A1 - Simon, Thorsten A1 - Tippelt, Stephan A1 - Eberl, Wolfgang A1 - Chada, Martin A1 - Lopez, Vicente Santa-Maria A1 - Grigull, Lorenz A1 - Hernáiz-Driever, Pablo A1 - Eyrich, Matthias A1 - Pears, Jane A1 - Milde, Till A1 - Reinhard, Harald A1 - Leipold, Alfred A1 - van de Wetering, Marianne A1 - Gil-da-Costa, Maria João A1 - Ebetsberger-Dachs, Georg A1 - Kerl, Kornelius A1 - Lemmer, Andreas A1 - Boztug, Heidrun A1 - Furtwängler, Rhoikos A1 - Kordes, Uwe A1 - Vokuhl, Christian A1 - Hasselblatt, Martin A1 - Bison, Brigitte A1 - Kröncke, Thomas A1 - Melchior, Patrick A1 - Timmermann, Beate A1 - Gerss, Joachim A1 - Siebert, Reiner A1 - Frühwald, Michael C. T1 - Infants and newborns with atypical teratoid rhabdoid tumors (ATRT) and extracranial malignant rhabdoid tumors (eMRT) in the EU-RHAB registry: a unique and challenging population JF - Cancers N2 - Introduction: Malignant rhabdoid tumors (MRT) predominantly affect infants and young children. Patients below six months of age represent a particularly therapeutically challenging group. Toxicity to developing organ sites limits intensity of treatment. Information on prognostic factors, genetics, toxicity of treatment and long-term outcomes is sparse. Methods: Clinical, genetic, and treatment data of 100 patients (aged below 6 months at diagnosis) from 13 European countries were analyzed (2005–2020). Tumors and matching blood samples were examined for SMARCB1 mutations using FISH, MLPA and Sanger sequencing. DNA methylation subgroups (ATRT-TYR, ATRT-SHH, and ATRT-MYC) were determined using 450 k / 850 k-profiling. Results: A total of 45 patients presented with ATRT, 29 with extracranial, extrarenal (eMRT) and 9 with renal rhabdoid tumors (RTK). Seventeen patients demonstrated synchronous tumors (SYN). Metastases (M+) were present in 27% (26/97) at diagnosis. A germline mutation (GLM) was detected in 55% (47/86). DNA methylation subgrouping was available in 50% (31 / 62) with ATRT or SYN; for eMRT, methylation-based subgrouping was not performed. The 5-year overall (OS) and event free survival (EFS) rates were 23.5 ± 4.6% and 19 ± 4.1%, respectively. Male sex (11 ± 5% vs. 35.8 ± 7.4%), M+ stage (6.1 ± 5.4% vs. 36.2 ± 7.4%), presence of SYN (7.1 ± 6.9% vs. 26.6 ± 5.3%) and GLM (7.7 ± 4.2% vs. 45.7 ± 8.6%) were significant prognostic factors for 5-year OS. Molecular subgrouping and survival analyses confirm a previously described survival advantage for ATRT-TYR. In an adjusted multivariate model, clinical factors that favorably influence the prognosis were female sex, localized stage, absence of a GLM and maintenance therapy. Conclusions: In this cohort of homogenously treated infants with MRT, significant predictors of outcome were sex, M-stage, GLM and maintenance therapy. We confirm the need to stratify which patient groups benefit from multimodal treatment, and which need novel therapeutic strategies. Biomarker-driven tailored trials may be a key option. KW - atypical teratoid rhabdoid tumors KW - extracranial malignant rhabdoid tumor KW - RTPS1 KW - RTPS2 KW - germline mutation KW - EU-RHAB registry Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-270730 SN - 2072-6694 VL - 14 IS - 9 ER -