Structural Reliability of Lithium Disilicate-based Glass-ceramics
Objectives: The aim of this study is to evaluate the structural reliability of the restorations made of industrially machinable and laboratory-processed lithium disilicate-based glass-ceramic blocks. Methods: Two commercial machinable glass-ceramic discs and two pressable glass-ceramic discs were prepared with diameter of 13mm and thickness of 1mm. All specimens were polished sequentially using abrasive SiC papers from #320 to #1200 and finished with a 1μm diamond paste. Specimen was etched with 4% HF and 30% H2SO4 solution for 30 seconds and then observed by FE-SEM to examine the microstructure. Biaxial flexural test was conducted using a piston-on-three-ball method at the crosshead speed of 0.5mm/min. Weibull statistics were used for the analysis of the biaxial flexural strength. Fracture toughness was obtained by an indentation fracture method. Vickers indentation was obtained using a micro-hardness tester at a load of 19.6N and loading time of 15 seconds. The indentation crack patterns were examined by an optical microscopy. Results: The mean strength and standard deviation values for pressable glass-ceramic disks were as follows: IPS e.max Press 343.7±19.3MPa, Rosetta SP 360.7±20.2MPa. The mean strength and standard deviation values for machinable glass-ceramic disks were as follows: IPS e.max CAD 417.7±58.2MPa, Rosetta SM 430.35±55.2MPa. Biaxial flexural strength data of all samples showed good fit to single mode Weibull distribution. The Rosetta SM sample exhibited a highest Weibull modulus value and fracture toughness (19.5 and 1.908, respectively). Also, the smallest size of needle-like lithium disilicate crystals was observed in the Rosetta SM. Conclusions: The restorations made of the industrially machinable glass-ceramic block are structurally reliable than those made of pressable ingots for dental applications.
Division: IADR/APR General Session
Meeting:2016 IADR/APR General Session (Seoul, Korea) Location: Seoul, Korea
Year: 2016 Final Presentation ID:0409 Abstract Category|Abstract Category(s):Dental Materials 1: Ceramic-based Materials
Authors
Bae, Tae Sung
( Institute of Biodegradable material and Oral Bioscience and BK21 plus project, School of Dentistry, Chonbuk National University
, Jeonju
, Korea (the Republic of)
)
Byeon, Seon Mi
( Institute of Biodegradable material and Oral Bioscience and BK21 plus project, School of Dentistry, Chonbuk National University
, Jeonju
, Korea (the Republic of)
)
Lee, Yu Ri
( Institute of Biodegradable material and Oral Bioscience and BK21 plus project, School of Dentistry, Chonbuk National University
, Jeonju
, Korea (the Republic of)
)
Nguyen, Thi Thuy Duong
( Institute of Biodegradable material and Oral Bioscience and BK21 plus project, School of Dentistry, Chonbuk National University
, Jeonju
, Korea (the Republic of)
)
Song, Hye Jin
( Institute of Biodegradable material and Oral Bioscience and BK21 plus project, School of Dentistry, Chonbuk National University
, Jeonju
, Korea (the Republic of)
)
Lee, Min-ho
( Institute of Biodegradable material and Oral Bioscience and BK21 plus project, School of Dentistry, Chonbuk National University
, Jeonju
, Korea (the Republic of)
)
Support Funding Agency/Grant Number: This work (Grants No. C0275257) was supported by Business for Cooperative R&D between Industry, Academy, and Research Institute funded Korea Small and Medium Business Administration in 2015. This work was supported by the National Research Foundation of K
Financial Interest Disclosure: None