Volume 39 -
J Dent Med-tums 2026, 39 - : 1-13 |
Back to browse issues page
Download citation:
BibTeX | RIS | EndNote | Medlars | ProCite | Reference Manager | RefWorks
Send citation to:
BibTeX | RIS | EndNote | Medlars | ProCite | Reference Manager | RefWorks
Send citation to:
Naghdi Varnosfaderani H, Amini K, Khodaei M. Investigation of the effect of temperature and time of hot-pressing operation on the structural and mechanical properties of lithium silicate blocks for dental applications. J Dent Med-tums 2026; 39 : 28
URL: http://jdm.tums.ac.ir/article-1-6422-en.html
URL: http://jdm.tums.ac.ir/article-1-6422-en.html
1- Department of Mechanical Engineering, Kho.C., Islamic Azad University, Khomeinishahr, Iran
2- Associate Professor, Department of Mechanical Engineering, Kho.C., Islamic Azad University, Khomeinishahr, Iran
3- Associate Professor, Materials Engineering Group, Golpayegan College of Engineering, Isfahan University of Technology, Golpayegan, Iran
2- Associate Professor, Department of Mechanical Engineering, Kho.C., Islamic Azad University, Khomeinishahr, Iran
3- Associate Professor, Materials Engineering Group, Golpayegan College of Engineering, Isfahan University of Technology, Golpayegan, Iran
Abstract: (37 Views)
Background and Aims: It is very important and practical to make machinable blocks with the ability to maintain the edge and at the same time have sufficient hardness for chewing. One of the most important groups of materials for making dental crowns and veneers for dentistry by CAD-CAM is lithium disilicate ceramics such that extensive research is being conducted in the field of modifying their structure and properties. All-ceramic restorations enhance the beauty of teeth due to their closeness to the tooth color and transparency. At the same time, these materials also have high biocompatibility. The main goal of this study was to evaluate the effect of hot-pressing temperature on the microstructure and mechanical properties of the lithium disilicate block fabrication.
Materials and Methods: The present laboratory study was conducted on the lithium disilicate blocks produced by powder metallurgy at Islamic Azad University, Khomeini Shahr Branch. In this regard, initially, the raw materials (including: Tetraethyl orthosilicate, Lithium nitrate, Triethyl phosphate, potassium nitrate) were processed by sol-gel method and the resulting frit (the glassy state of a ceramic) was crushed by a ceramic mortar. Then, the 3 groups of samples (n=3) were subjected to the hot-pressing at different temperatures of 750 and 900 °C for 60 minutes at a constant pressure of 200 kPa. Subsequently, the microstructure and elemental phases of lithium silicate samples were examined using scanning electron microscopy (SEM) and X-ray diffraction (XRD). Statistical analysis of the results was performed using one-way analysis of variance (ANOVA). A p-value of less than 0.05 was considered significant.
Results: X-ray diffraction results on the resulting powder before hot pressing showed the formation of a glass phase with lithium metasilicate and after hot pressing, the formation of a lithium disilicate phase. The results also showed that in all samples, the lithium disilicate phase was formed and had some porosity. In addition, with increasing the pressing temperature, the size of lithium disilicate particles increased. However, with increasing the hot-pressing temperature from 750 to 900°C, the amount of porosity decreased from about 23% to 20%.
Conclusion: The hot-pressing temperature had a significant effect on the microstructure and phases present in the produced ferrite sample. It was concluded that by changing the hot-pressing temperature, the microstructure and consequently the properties of the lithium disilicate blocks can be modified to achieve improved properties for dentistry applications.
Materials and Methods: The present laboratory study was conducted on the lithium disilicate blocks produced by powder metallurgy at Islamic Azad University, Khomeini Shahr Branch. In this regard, initially, the raw materials (including: Tetraethyl orthosilicate, Lithium nitrate, Triethyl phosphate, potassium nitrate) were processed by sol-gel method and the resulting frit (the glassy state of a ceramic) was crushed by a ceramic mortar. Then, the 3 groups of samples (n=3) were subjected to the hot-pressing at different temperatures of 750 and 900 °C for 60 minutes at a constant pressure of 200 kPa. Subsequently, the microstructure and elemental phases of lithium silicate samples were examined using scanning electron microscopy (SEM) and X-ray diffraction (XRD). Statistical analysis of the results was performed using one-way analysis of variance (ANOVA). A p-value of less than 0.05 was considered significant.
Results: X-ray diffraction results on the resulting powder before hot pressing showed the formation of a glass phase with lithium metasilicate and after hot pressing, the formation of a lithium disilicate phase. The results also showed that in all samples, the lithium disilicate phase was formed and had some porosity. In addition, with increasing the pressing temperature, the size of lithium disilicate particles increased. However, with increasing the hot-pressing temperature from 750 to 900°C, the amount of porosity decreased from about 23% to 20%.
Conclusion: The hot-pressing temperature had a significant effect on the microstructure and phases present in the produced ferrite sample. It was concluded that by changing the hot-pressing temperature, the microstructure and consequently the properties of the lithium disilicate blocks can be modified to achieve improved properties for dentistry applications.
Article number: 28
Type of Study: Research |
Subject:
dental biomaterial
Send email to the article author
| Rights and Permissions | |
 |
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License. |
