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Objective The aim of this in vitro study was to evaluate the effects of substrate colors, different levels of ceramic thickness and translucency, and cement shades on the color difference from a reference color of lithium‐disilicate crowns. Materials and Methods A premolar tooth preparation was made on a study model for 1.0 and 1.5 mm thick full‐ceramic crowns. Digital impressions were taken (3Shape TRIOS) and crowns designed in a CAD program (DentalDesigner). Shade A1 crowns were milled (Everest, Kavo) from high‐translucency (HT) and low‐translucency IPS e.max (Ivoclar Vivadent) blocks. Twelve substrates were made of different colors and materials (Natural Die Material, Co‐Cr, zirconia, and gold‐colored alloy). Three different shades of try‐in pastes were used to simulate the effect of cements (Variolink Esthetic try‐in paste; Ivoclar). Shade measurement was done three times for each crown by a spectrophotometer (VITA Easyshade Advance); averages were compared to a reference crown (A1, HT, 1.5 mm, ND2 abutment, neutral try‐in paste) with ΔE00 (CIEDE2000, according to the CIE latest standard) calculated. Results All the examined parameters influenced the ΔE00 of the crowns. The weakest effect was exerted by the try‐in paste. Conclusions All examined parameters influenced the final color of e.max CAD lithium‐disilicate ceramic crowns. Clinical Significance Matching the shade of ceramic crowns to the natural tooth color is a great challenge in dentistry. To meet patients' increasing esthetical expectations, CAD/CAM methods are very popular for full‐ceramic crowns. However, several factors such as the shade of the abutment, luting cement color, ceramic thickness, and translucency may influence the final color. Our objective was to measure the optical effect of these factors on the final shade of CAD/CAM lithium‐disilicate ceramic crowns.

Anatomical changes in the structure of the temporomandibular joint caused by complete edentulousness Background: The posterior slope of the articular eminence of completely edentulous patients compared to patients with maintained occlusion shows significant flattening. Objective: The aim of this present study was to reveal a possible correlation between edentulousness and the flattening of the eminence and to find out whether this deformation is connected to age. Material and methods: Thirty patients were examined in three groups, each consisting of 10 persons (group I: 18-to 25-year-old patients with maintained occlusion, group II: patients over 60 with maintained occlusion, group III: edentulous patients over 60). The three groups were compared according to dental status, age, sex and side. Measurements were carried out on orthopantomographic images taken with Kodak 8000 Digital Panoramic System. The angle of the posterior slope of the articular eminence relative to the Frankfort plane was measured on both sides. Data were analysed statistically with the one-way ANOVA test (a = 0.05). Results:The highest values were measured in group I (right side: 39.8 ± 5.4°, left side: 43.0 ± 5.9°), values were somewhat lower in group II (right side: 38.9 ± 4.7°, left side: 39.5 ± 7.4°) and were the lowest in group III, which was significantly lower on both sides than the results of group I and group II (right side: 29.8 ± 6.0°, left side: 31.9 ± 5.2°, p < 0.01). The correlation coefficient between age and the flattening of the eminence in group I, II and III was 0.23, 0.35 and 0.92, respectively. Conclusion: The flattening of the articular eminence could be correlated with age; however, the rate of deformation is significantly higher in completely edentulous patients than in patients with maintained occlusion.

This cross sectional study, representative of the Hungarian population, clearly shows that one-third of the adult population suffers from xerostomia. The clinical severity of the xerostomia demonstrated a strong relationship with the lower levels of UWS flow rate. Reduced levels of UWS flow rate in this study were also shown to be associated with dysphagia, fatigue, and increased DMF-T numbers. The data show that oral dryness, its associated desiccation symptoms and its clinical manifestations are significant health problems in Hungary.

The increasing use of online news, particularly by young Americans, pointsto the importance of understanding what users learn from this form of news and whether features of online news encourage or discourage various types of learning. This experimental study demonstrates that online news that takes advantage of one of the key characteristics of the Web—the use of in-text hyperlinks—may actually discourage learning of the facts that make up many news stories. But this same linking structure apparently encourages those who commonly use the Web to have more densely interconnected knowledge structures for public affairs topics. However, those who rarely use the Webfor news do not gain such advantages and may even suffer disadvantages. These findings point to limitations in most past online news learning research, which has been limited to “just the facts” in its measurement of learning from the news.