ABSTRACT
Prosthodontics is an important undergraduate course in stomatology. It's an unprecedented challenge for teachers to give theoretical lectures completely by online teaching methods. After several months of online teaching practice, a complete closed-loop online teaching mode of "pre-class, in-class and after-class" has been formed by using online teaching tools such as Tencent meeting, Superstar learning platform and WeChat. A comprehensive feedback and assessment mechanism has also been established. On the premise of the teaching quality, online teaching has also promoted the exploration and reform of the information-based teaching of prosthodontics course.
ABSTRACT
Objective:To study the residual stress distribution through the thickness of bilayered dental ceramic subjected to thermal stress, in order to improve the restoration. Methods: The finite element model of bilayered dental ceramic was set up based on International Organization for Standardization(ISO) 96936:1999. The residual stresses were calculated in viscoelastic and elastic phases during cooling of dental ceramic to analyze the residual stress distribution. Results: The deformation of core was greater than the veneer ceramics during the cooling period of dental ceramic. The residual stress increased with the decreasing of the temperature approaching the interface of core and veneer ceramics. But it decreased with the increasing of the thickness of veneer ceramics.Conclusion: Thermal compatibility of core and veneer ceramics is very important to the residual stress distribution in the bilayered dental ceramic, which may benefit to All-ceramic restorations. The viscoelastic behavior of ceramic should be taken into account in the thermal compatibility.