ABSTRACT
Ceramic prosthesis fabrication using CAD/CAM has advantages such as high convenience, fast fabrication speed, and high esthetics, resulted in increasing use in clinical practice. Among them, the multi-layered zirconia block for dental CAD/CAM is a product that consists of a single block with layers of different shades, so that natural tooth color can be reproduced.However, research on the material is insufficient, and in particular, the study on the characteristics of low-temperature degradation, which is known to be important for zirconia-based medical devices, is required to evaluate the performance and safety of the material. In this study, in order to evaluate the effect of low-temperature degradation on the properties of multi-layered zirconia blocks, three-point flexural strength, fracture surface and phase changes before and after low-temperature degradation of three companies’ dental CAD/CAM multi-layered zirconia block products were compared. As a result of this experiment, all products of the three manufacturers met International Standards, and there was no change in strength even after low-temperature degradation. However, it was found that there were differences in monoclinic content, three-point flexural strength, and the surface crystal structure for each zirconia block.
ABSTRACT
Biocompatibility testing of bone graft materials are important aspect for development of the device as well as the approval and certification by each individual country’s regulatory authority. Recently, importance in identification and quantification of degradation product as well as application of Good Laboratory Practice (GLP) in the process of biocompatibility testing has been emphasized. Hence, here identification and quantification of degradation products from bone graft materials were carried out in accordance with GLP process. Commercially available bone graft material from the animal source was used in this study.The test was carried out in accordance with International Standard, ISO 10993-14 Biological evaluation of medical devices -Part 14: Identification and quantification of degradation products from ceramics. Also, entire process followed Institute for Management of Good Laboratory Practice, published by Ministry of Food and Drug Safety, Korea. Degradation test of the bone graft materials resulted in degradation of bone graft, ranging between 0.32 g to 0.86 g, while Ca and P were detected. In terms of GLP process, it has been noted that consideration of other International Standard such as ISO 10993-12 is required for planning of the GLP test, especially during the sample preparation.
ABSTRACT
Biocompatibility testing of bone graft materials are important aspect for development of the device as well as the approval and certification by each individual country’s regulatory authority. Recently, importance in identification and quantification of degradation product as well as application of Good Laboratory Practice (GLP) in the process of biocompatibility testing has been emphasized. Hence, here identification and quantification of degradation products from bone graft materials were carried out in accordance with GLP process. Commercially available bone graft material from the animal source was used in this study.The test was carried out in accordance with International Standard, ISO 10993-14 Biological evaluation of medical devices -Part 14: Identification and quantification of degradation products from ceramics. Also, entire process followed Institute for Management of Good Laboratory Practice, published by Ministry of Food and Drug Safety, Korea. Degradation test of the bone graft materials resulted in degradation of bone graft, ranging between 0.32 g to 0.86 g, while Ca and P were detected. In terms of GLP process, it has been noted that consideration of other International Standard such as ISO 10993-12 is required for planning of the GLP test, especially during the sample preparation.