Shrinkage prediction using finite element analysis and experimental validation using three-dimension slurry printing system

Abstract

In dentistry, all ceramic restorations were widely used because of perfect esthetic, especially the zirconia ceramic. Now in digital dentistry, zirconia dental restorations are mostly made from digital manufacturing system such as the computer-aided design and computer-aided manufacturing (CAD/CAM) or three-dimension printing (3DP). After producing, the sintering process is indispensable due to the increase in the mechanical properties. Notably, the side effect of shrinkage of the sintering process is difficult to predict or control and cannot be studied deeply. Reflecting the accurate of zirconia restoration is lower, especially the most important factor of restoration fitness. So the poor fitness of restoration easily leads to secondary caries or micro leakage that the tooth will decay again and the remaining teeth will need to be removed completely. In this paper, the 3DP is the target manufacturing process to avoid the high cost of CAD/CAM processing; the 3DP product needs to be of high precision after the sintering process. However, the shrinkage of the 3DP product is difficult to predict and cannot be studied deeply. Therefore, different shrinkage rates of experimental pieces following the manufacturer’s instructions of the sintering process are first predicted in CAE analysis, experimental design, and regression analysis. The results are then applied in the manufacture of incisor restoration to verify the shrinkage. This can make the restoration fit in the patient’s mouth properly and reduce the medical operation time. It helps the 3DP to successfully apply the dentures.