Title : The effect of cyclic loading on fracture strength of 3D printed zirconia crowns and cad/Cam zirconia crowns. An in-vitro study
Monolithic zirconia crowns with full anatomic contour without the need for adding a veneer layer have been developed allowing an improvement in color and translucency of zirconia materials, and the development of the final contour of the dental crown using computer-aided design and computer-aided manufacturing (CAD/CAM) principles. The subtractive technology allows the usage of tooth-colored restorations with highly accepted properties but the waste from the manufacturing process increases the need for additive technology. In the past years, the innovation in 3D printing allows the production of 3D-printed zirconia crowns, but the data available for their properties and their long-term functions is limited and needs more investigation. Moreover, it produces geometries whose shapes are almost identical to the final geometries. The fracture resistance of all-ceramic restorations is one of the major concerns in clinical applications of these materials, also dynamic loading reduces the fracture resistance of dental ceramics.
To test the properties of 3D printed crowns and if the technique produces clinically accepted results: 30 zirconia crowns will be divided into 2 groups according to the fabrication technique: Group A: 3D printed zirconia crowns (n=15), Group B: CAD/CAM monolithic zirconia crowns. (n=15)
Each group will be further subdivided into 2 subgroups; one subgroup will be immediately loaded under static load until fracture, and the other will be subjected to 1.2million cycles followed by static loading until fracture:
Subgroup Ai: 3D printed zirconia crowns immediately loaded until fracture. (n=9), Subgroup Af: 3D printed zirconia crowns subjected to 1.2 million cycles and then statically loaded until fracture. (n=6), Subgroup Bi: CAD/CAM monolithic zirconia crowns immediately loaded until fracture. (n=9), Subgroup Bf: CAD/CAM monolithic zirconia crowns subjected to 1.2 million cycles and then statically loaded until fracture. (n=6).
Audience Takes Away Notes:
- Recent advances in 3D printing technology
- The steps of manufacturing of 3D-printed crowns
- Is the 3D-printed zirconia can withstand the forces in the patient's mouth
- Effect of cyclic loading on strength of the 3D Printed crowns
- Our results will help other researchers to investigate more about the other properties of the 3D- printed zirconia crowns and help in modifying their properties.