Effects on accuracy of rubber impression materials and trays. The change in volume ΔV is very nearly ΔV = 3αVΔT. The elastic modulus of porcelain-to-Ti6Al4V samples showed to be less sensitive to porcelain thickness variations. In these cases the materials are considered to be thermally incompatible. The Young's modulus of both ceramics was most accurately measured at lower indentation loads of about 0.5 kgf, while more accurate hardness and fracture toughness values were obtained at intermediate and at higher indentation loads beyond 5 kgf, respectively. CONCLUSION The linear thermal expansion coefficients of the dental composites ranged from 28 to 33.7 10-6/, i.e. Guiraldo RD, Berger SB, Punhagui MF, Moretto TS, Lopes MB, Gonini-Júnior A, Sinhoreti MAC. The change in length was digitally registered by two strain sensors (type 1318, Mahr, GmbH, Göttingen, Germany), while the temperature was measured by using a standard thermocouple (K-type) together with a calibrated TC-08 datalogger (Pico Technology Limited, St. Neots, UK). Weibull analysis revealed a substantially higher Weibull modulus and slightly higher characteristic strength for ZirTough (Kuraray Noritake) than for LAVA Plus (3M ESPE). Fully-sintered zirconia specimens (4.0 × 3.0 × 45.0 mm3) of Y-TZP zirconia (LAVA Plus, 3M ESPE) and Y-TZP/Al2O3 zirconia (ZirTough, Kuraray Noritake) were subjected to four surface treatments: (1) ‘GROUND’: all surfaces were ground with a diamond-coated grinding wheel on a grinding machine; (2) ‘GROUND + HEAT’: (1) followed by annealing at 1100 °C for 30 min; (3) ‘GROUND + Al2O3 SANDBLASTED’: (1) followed by sandblasting using Al2O3; (4) ‘GROUND + CoJet SANDBLASTED’: (1) followed by tribochemical silica (CoJet) sandblasting. The human tooth structure in the oral environment is affected by considerable thermal fluctuations while consuming hot and cold aliments. Residual compressive surface stress increased the bending strength of dental zirconia. The calculated reliabilities of crowns under different loading conditions showed that too small occlusal contact areas or too great a difference of the thermal coefficient between veneer and core layer led to high failure possibilities. Dental impression materials for prosthodontic treatment must be easy to use, precisely replicate of oral tissue, be dimensionally stable, and be compatible with gypsum materials. Since the 1960s, the main components of RBCs have been modified to achieve improved mechanical, biological, and esthetic properties. The average total transmittance was 46.3% for leucite–diopside ceramic and 39.8% for VITA VM9 (P = 0.01). defective castings --Dental cements. | The hypothesis is that the thermal dimensional behavior of dental ceramic materials cannot always be properly described as linear relation for the different types of ceramic materials. • Brittle/ductile transition temperature. Afterwards, nanoindentation tests and Scanning Electron Microscopy (SEM) imaging coupled to an Energy Dispersive Spectroscopy (EDS) system were carried out across interfaces extending from the metal towards the porcelain area. However for all-ceramic systems where the ductile metal reinforcing structure is replaced by a strong but brittle and therefore less forgiving ceramic, the influence of the second term of the formula on the thermal compatibility of the ceramic materials involved might be of importance. In the ISO-standard 9693 it was assumed that the thermal compatibility of metal–ceramic systems can be properly predicted by their respective linear thermal expansion coefficients. In the metal–ceramic systems it is claimed that a small positive mismatch in thermal expansion coefficient values, less than 0.5 ppm/°C , results in a beneficial compression stress on the veneering porcelain layer. The excess of liquid was blotted off from the slurry with absorbent paper. In addition, the Empress veneer and an additional three veneering porcelain materials, including Eris (Ivoclar-Vivadent, Schaan, Liechtenstein), Vitadur-Alpha (Vita Zahnfabrik, Bad Säckingen, Germany), and Carrara Vincent Porcelain (Elephant, Dental BV, Hoorn, NL), were used with the Empress II core to analyze the effect of residual thermal stress on the reliability of the crowns.The variables and the associated mechanical properties used in the model are provided in Table 1 [10–12].This study applied the stress–strength interference theory to analyze the reliability of all-ceramic crowns. The data are shown in Table 1. A higher percentage of osteoblast cell proliferation and mineralization was detected on LZS surfaces when compared to LZSA surfaces. The mean BFS was 109 ± 8 MPa for leucite–diopside ceramic and 79 ± 11 MPa for VITA VM9 ceramic (P = 0.01). Epub 2020 Sep 15. USA: Wiley; 1976. p.... International Standard Organization (ISO) 9693 Geneve. The dimensional stability of a metal refers to any observed change in size or composition when it is used or reprocessed. The thermal expansion of the impression materials was measured with a thermomechanical analyzer (TMA 2940, TA Instruments, USA) between 23-37 degrees C. Data were analyzed via the Mann-Whitney Usage Test.