Measuring the Hardness of Three Different Types of Commercially Available Zirconia Blanks Applied to Dentistry

Mohamed M. Aboras; Nidal Wanis Elshereksi; Mustafa H. Esmaio

doi:10.33214/k7ccb935

Authors

Mohamed M. Aboras Department of Dental Technology, College of Medical Technology, Benghazi, Libya Author
Nidal Wanis Elshereksi Department of Dental Technology, Faculty of Medical Technology, Misurata, Libya Author
Mustafa H. Esmaio Department of Dental Technology, Faculty of Medical Technology, Misurata, Libya Author

DOI:

https://doi.org/10.33214/k7ccb935

Keywords:

Dental Zirconia; Sintering; Hardness; Density; Elastic Modulus

Abstract

Problem Statement: The use of polycrystalline yttria-stabilized tetragonal zirconia (3Y-TZP) in dental restorations has increased due to its exceptional properties. Among these characteristics is hardness, which provides durability to zirconia dental restorations under special conditions within the oral cavity. Aim: To investigate the hardness and density of pre-sintered and sintered different types of commercially available zirconia blanks applied to dentistry. Materials and Methods: Three different types of commercial zirconia blanks (HT4, 89HT, and A214) were designed and manufactured, followed by sintering at 1530 °C to achieve the final shape. The apparent density of the samples was determined after collecting pre-sintered and sintered samples. The shore D hardness test was conducted according to ASTM D2240. The mechanical properties are typically measured through indentation. For each group, three specimens were examined. Results: The results indicated that sintering temperature contributed to the densification of zirconia samples, with relative density values reaching up to 97.5%, 94.8%, and 93% of the theoretical density (6.1 g/cm³) for HT4, 89HT, and A214, respectively. An increase in the density of zirconia samples after the sintering process led to a significant rise in elastic modulus and hardness. The hardness values for HT4, 98HT, and A214 were 83 SHN, 83 SHN, and 80,17 SHN, respectively, while the elastic modulus values for the same samples were 12 MPa, 12 MPa, and 11.23 MPa, respectively. Conclusion: The density, elastic modulus, and hardness values of the tested commercial zirconia blanks exhibited no significant differences and successfully fulfilled the required criteria for dental applications.Dental Zirconia; Sintering; Hardness; Density; Elastic Modulus

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