Effect of Different Cement Thicknesses on Fracture Resistance of Monolithic Full Anatomic Zirconia Crowns: An In Vitro Study
DOI:
https://doi.org/10.15218/edj.2026.16Keywords:
zirconia, monolithic crowns, cement thickness, fracture resistance, CAD/CAM materialsAbstract
Background: Zirconia has become widely used in all-ceramic restorations because of its mechanical properties and improved esthetics compared with metal-based restorations. Concerns about Zirconia-based prostheses have historically been focused on the risk of chipping and veneering porcelain. Monolithic zirconia restorations eliminate the risk of veneering porcelain chipping commonly associated with layered restorations. In addition, the use of Computer-Aided Design (CAD)/ Computer-Aided Manufacturing (CAM) in the production of these crowns has improved restoration quality by providing a higher degree of material homogeneity.
Objective: To evaluate the effect of different digitally set cement thicknesses (30 µm, 60 µm, and 90 µm) on the fracture resistance of CAD/CAM monolithic zirconia crowns.
Methods: Thirty-six monolithic zirconia crowns were milled via CAD/CAM and divided into three groups based on cement thickness: 30 µm (Group A), 60 µm (Group B), and 90 µm (Group C). Specimens were loaded vertically in a universal testing machine at 1 mm/min with a 10 N preload until fracture, and forces were recorded in Newton.
Results: The mean fracture resistance values were 4305.3 N for Group A, 3696.5 N for Group B, and 4233.4 N for Group C. No statistically significant difference was found among the groups (p = 0.144).
Conclusion: Within the limitations of this in vitro study, cement thicknesses ranging from 30 µm to 90 µm did not significantly affect the fracture resistance of monolithic zirconia crowns.
References
Svanborg P. A systematic review on the accuracy of zirconia crowns and fixed dental prostheses. Biomater Investing Dent. 2020;7(1):9–15. Doi 10.1080/26415275.2019.1708202.
Aswal GS, Rawat R, Dwivedi D, et al. Clinical Outcomes of CAD/CAM (Lithium disilicate and Zirconia) Based and Conventional Full Crowns and Fixed Partial Dentures: A Systematic Review and Meta-Analysis. Cureus. 2023;15(4): e37888. doi:10.7759/cureus.37888.
Ali Z, Al-Dhamin MM, Jassim F. Fracture strength of monolithic zirconia crowns with modified vertical preparation: a comparative in vitro study. BMC Oral Health. 2022;22(1):529. Doi:10.1186/s12903-022-02529-9.
Rizkalla AS, Aziz T. The effect of restoration thickness on the fracture resistance of 5 mol% yttria-containing zirconia crowns. Materials (Basel). 2024;17(2):365. Doi:10.3390/ma17020365.
Baixauli-López M, Roig-Vanaclocha A, Amengual-Lorenzo J, Agustín-Panadero R. Prospective study of monolithic zirconia crowns: Clinical behavior and survival rate at a 5-year follow-up. J Prosthodont Res. 2021; 65:284- 290. doi:10.2186/jpr.JPR_D_20_00034
Mohamed AM, El-Sayed AB, El-Kholany AM. The effect of different cement spaces on the fracture strength of two different types of zirconium CAD/CAM crowns. Indian J Forensic Med Toxicol.2020;14(2):1027-1031. doi:10.37506/ijfmt.v14i2.3042.
Alrabiah M, Jaber N, Abo-Alfaraj S, et al. In-vitro comparison of marginal gap and fracture resistance of prefabricated zirconia crowns and three-dimensional-printed endocrowns for restoration of pulpotomized primary molars. Int J Childb Dent. 2024;1(1):63-71. doi:10.5946/ijcbs.2024.12.
Rahimi H, Salmani M, Hosseini Z, et al. Fracture resistance of monolithic gradient zirconia crowns with different finish line designs and cement spaces. J Tums Med Sci. 2024;82(1):47-56. doi:10.1016/j.jtumed.2024.11.008.
Kim SH, Yeo MY, Choi SY, Park EJ. Fracture resistance of monolithic zirconia crowns depending on different marginal thicknesses. Materials (Basel). 2022;15(14):4861. doi:10.3390/ma15144861.
Denry I, Kelly JR. State of the art of Zirconia for dental applications. Dent Mater. 2008; 24:299-307. doi:10.1016/j.dental.2007.05.007.
Al-Dwairi ZN, Alkhatatbeh RM, Baba NZ, Goodacre CJ. A comparison of the marginal and internal fit of porcelain laminate veneers fabricated by pressing and CAD-CAM milling and cemented with two different resin cements. J Prosthet Dent. 2019;121(3):470–476. (Kept due to its relevance to fit/cementation, being just pre-2020). doi:10.1016/j.prosdent.2018.06.001
Vijan A, Goyal S. Emerging trends and clinical recommendations for zirconia ceramic crowns: a concise review. Key Topics Restor Dent. 2024;1(1):1–10. doi:10.1038/s41415-024-7616-0.
Farag SM, Ghoneim MM, Afifi RR. Effect of die spacer thickness on the fracture resistance of CAD/CAM lithium disilicate veneers on maxillary first premolars. Clin Cosmet Investig Dent. 2021; 13:223-230. doi:10.2147/CCIDE.S313131
Ahn JS, Park CW, Lee SJ, Lee DH, Park YB. Influence of cement film thickness on the fracture resistance of CAD/CAM monolithic lithium disilicate crowns. J Prosthet Dent. 2020;124(1):64-69. doi:10.1016/j.prosdent.2019.02.018
Al-Moussawi H, Hassan R, Al-Rubea N, et al. The Effect of Cement Gap on the Marginal and Internal Fit of 3D-Printed Zirconia Crowns. J Oral Sci. 2022;64(2):167-171. doi:10.2334/josnusd.21-0204
Abad Coronel C, Rosales LS, Morales MER, Cueva NOJ. Comparative fracture resistance analysis of translucent monolithic zirconia dioxide milled in a CAD/CAM system. Prosthesis. 2023;6(2):71. doi:10.3390/ceramics6020071
Zandinejad A, Revilla-León M, Methani MM, Nasiry Khanlar L, Morton D. The fracture resistance of additively manufactured monolithic Zirconia vs. bi-layered alumina toughened zirconia crowns when cemented to zirconia abutments: evaluating the potential of 3D printing of ceramic crowns: an in vitro study. Dent J (Basel). 2021;9(10):115. doi:10.3390/dj9100115
Rezende CE, Borges AF, Gonzaga CC, Duan Y, Rubo JH, Griggs JA. Effect of Cement Space on Stress Distribution in Y-TZP-Based Crowns. Dent Mater. 2017; 33:144-51. doi:10.1016/j.dental.2016.12.003.
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