Sains Malaysiana 53(1)(2024): 217-229

http://doi.org/10.17576/jsm-2024-5301-17

Evaluation and Comparison of Mechanical Properties of Lithium Disilicate-Based CAD/CAM Blocks

(Penilaian dan Perbandingan Sifat Mekanikal Blok CAD/CAM Berasaskan Litium Disilikat)

SOFYA ZULKIFFLI, YEOH OON TAKE*, NOOR AZLIN YAHYA & MURALITHRAN GOVINDAN KUTTY

Department of Restorative Dentistry, Faculty of Dentistry, Universiti Malaya, 50603

Kuala Lumpur, Malaysia

Diserahkan: 23 September 2023/Diterima: 26 Disember 2023

Abstract

Lithium disilicate are commonly used in dental restoration due to its aesthetic and mechanical performance. However, the patent expiration of the IPS emax system has led to the emergence of other variations of the system. Data and studies concerning mechanical properties of these recent lithium disilicate-based CAD/CAM are scarce and it warrants for an investigation to provide scientific evidence to support its routine use. The aim of this study was to investigate and compare the mechanical properties of lithium disilicate-based CAD/CAM blocks from four different brands. Four CAD/CAM lithium disilicate brands were investigated; IPS emax, Mazic Claro, Cameo, and Tessera. Specimens (n=10) were prepared accordingly; for flexural strength (16 × 4 × 1.2 mm) and microhardness test (15 × 13 × 2 mm). One specimen from each brand was analysed for the microstructure, elemental composition and distribution before and after heat treatment using scanning electron microscope and energy dispersive x-ray spectroscopy. The three-point flexural strength test (n=10) and microhardness test (n=10) was performed. Data were analysed using one-way ANOVA and Dunnett’s T3 test. The results showed that the highest mean flexural strength was from Group 4 Tessera (540.52 ± 143.33 MPa). For microhardness, the highest mean was from Group 1 Mazic Claro (667.70 ± 9.41 HV). Within the four groups, statistically significant difference is noted for flexural strength and microhardness. As a conclusion, Tessera demonstrated significantly higher flexural strength than IPS emax and Cameo. Mazic and Tessera demonstrated significantly higher microhardness than IPS emax and Cameo. All materials tested were above the threshold of 300 MPa.

Keywords: CAD/CAM; flexural strength; lithium disilicate; microhardness; microstructure

Abstrak

Litium disilikat kerap digunakan dalam rawatan pergigian disebabkan sifat mekanikal dan estetiknya yang memberangsangkan. Paten IPS emax CAD tamat tempoh membawa kepada kemunculan variasi lain. Walau bagaimanapun, data dan kajian mengenai sifat mekanikal CAD/CAM litium disilikat baru-baru ini adalah terhad dan ia memerlukan kajian demi menyediakan bukti saintifik untuk menyokong penggunaan hariannya. Matlamat kajian ini adalah untuk membandingkan sifat mekanikal blok CAD/CAM litium disilikat daripada empat jenama berbeza. Empat jenama CAD/CAM litium disilikat telah dikaji; IPS emax, Mazic Claro, Cameo dan Tessera. Spesimen (n = 10) disiapkan mengikut dimensi; untuk kekuatan lentur (16 × 4 × 1.2 mm) dan ujian mikrokekerasan (15 × 13 × 2 mm). Satu spesimen daripada setiap jenama dianalisis untuk struktur mikro, komposisi unsur dan pengedaran sebelum dan selepas rawatan haba menggunakan Mikroskop Elektron Pengimbasan dan spektroskopi sinar-x penyebaran Tenaga. Ujian kekuatan lentur tiga mata (n=10) dan ujian mikrokekerasan (n=10) telah dilakukan. Data dianalisis menggunakan ANOVA sehala dan ujian pasca hoc T3 Dunnett. Keputusan menunjukkan purata kekuatan lenturan tertinggi adalah daripada Kumpulan 4 Tessera (540.52 ± 143.33 MPa). Untuk kekerasan mikro, min tertinggi ialah daripada Kumpulan 1 Mazic Claro (667.70 ± 9.41 HV). Dalam empat kumpulan, perbezaan ketara secara statistik dicatatkan untuk kekuatan lentur dan kekerasan mikro. Secara kesimpulan, Tessera menunjukkan kekuatan lenturan yang lebih tinggi daripada IPS emax dan Cameo. Mazic dan Tessera menunjukkan kekerasan mikro yang lebih tinggi daripada IPS emax dan Cameo. Semua bahan yang diuji melebihi ambang 300 MPa.

Kata kunci: CAD/CAM; kekerasan mikro; kekuatan lentur; litium disilikat; struktur mikro

RUJUKAN

Al-Thobity, A.M. & Alsalman, A. 2021. Flexural properties of three lithium disilicate materials: An in vitro evaluation. The Saudi Dental Journal 33(7): 620-627.

Aurélio, I.L., Prochnow, C., Guilardi, L.F., Ramos, G.F., Bottino, M.A. & May, L.G.  2018. The effect of extended glaze firing on the flexural fatigue strength of hard- machined ceramics. The Journal of Prosthetic Dentistry 120(5): 755-761.

Braly, A., Darnell, L., Mann, A., Teaford, M. & Weihs, T. 2007. The effect of prism orientation on the indentation testing of human molar enamel. Archives of Oral Biology 52(9): 856-860.

CEREC Tessera^TM: Advanced Lithium Disilicate. 2021. chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/https://www.dentsplysirona.com/content/dam/flagship/sv-se/products/restorative/NORTH-BROCHURE-CEREC-TESSERA.pdf

Cuy, J.L., Mann, A.B., Livi, K.J., Teaford, M.F. & Weihs, T.P. 2002. Nanoindentation mapping of the mechanical properties of human molar tooth enamel. Archives of Oral Biology 47(4): 281-291.

Denry, I. & Holloway, J. 2004. Effect of post‐processing heat treatment on the fracture strength of a heat‐pressed dental ceramic. Journal of Biomedical Materials Research Part B: Applied Biomaterials 68B(2): 174-179.

Denry, I., Holloway, J., & Tarr, L. 1999. Effect of heat treatment on microcrack healing behaviour of a machinable dental ceramic. Journal of Biomedical Materials Research 48(6): 791-796.

Elsaka, S.E. & Elnaghy, A.M. 2016. Mechanical properties of zirconia reinforced lithium silicate glass-ceramic. Dental Materials 32(7): 908-914.

Etman, M. 2013. Wear properties of dental ceramics. In Non-metallic Biomaterials for Tooth Repair and Replacement, edited by Vallittu, P. Woodhead Publishing. pp. 161-193.

Fonzar, R.F., Carrabba, M., Sedda, M., Ferrari, M., Goracci, C. & Vichi, A. 2017. Flexural resistance of heat-pressed and CAD-CAM lithium disilicate with different translucencies. Dental Materials 33(1): 63-70.

Guazzato, M., Albakry, M., Ringer, S.P. & Swain, M.V. 2004. Strength, fracture toughness and microstructure of a selection of all-ceramic materials. Part I. Pressable and alumina glass-infiltrated ceramics. Dental Materials 20(5): 441-448.

Hallmann, L., Ulmer, P. & Kern, M. 2018. Effect of microstructure on the mechanical properties of lithium disilicate glass-ceramics. Journal of the Mechanical Behaviour of Biomedical Materials 82: 355-370.

Hirao, K. & Tomozawa, M. 1987. Dynamic fatigue of treated high‐silica glass: Explanation by crack tip blunting. Journal of the American Ceramic Society 70(6): 377-382.

Huang, S., Li, Y., Wei, S., Huang, Z., Gao, W. & Cao, P. 2017. A novel high-strength lithium disilicate glass-ceramic featuring a highly intertwined microstructure. Journal of the European Ceramic Society 37(3): 1083-1094.

ISO 2015. 6872: 2015. Dentistry-Ceramic Materials. Helsinki: Suomen Standardoimisliitto.

Ivoclar Vivadent. 2011. IPS e. max CAD Scientific Documentation. In: Lichtenstein.

Kang, S.H., Chang, J. & Son, H.H. 2013. Flexural strength and microstructure of two lithium disilicate glass ceramics for CAD/CAM restoration in the dental clinic. Restorative Dentistry & Endodontics 38(3): 134-140.

Kumar, A., Chakrabarti, A., Shekhawat, M.S. & Molla, A.R. 2019. Transparent ultra- low expansion lithium aluminosilicate glass-ceramics: Crystallization kinetics, structural and optical properties. Thermochimica Acta 676: 155-163.

Leung, B.T., Tsoi, J.K., Matinlinna, J.P. & Pow, E.H. 2015. Comparison of mechanical properties of three machinable ceramics with an experimental fluorophlogopite glass ceramic. The Journal of Prosthetic Dentistry 114(3): 440-446.

Li, D., Guo, J., Wang, X., Zhang, S. & He, L. 2016. Effects of crystal size on the mechanical properties of a lithium disilicate glass-ceramic. Materials Science and Engineering: A 669: 332-339.

Lien, W., Roberts, H.W., Platt, J.A., Vandewalle, K.S., Hill, T.J. & Chu, T.M. 2015. Microstructural evolution and physical behavior of a lithium disilicate glass- ceramic. Dental Materials 31(8): 928-940.

Lubauer, J., Belli, R., Peterlik, H., Hurle, K. & Lohbauer, U. 2022. Grasping the lithium hype: Insights into modern dental lithium silicate glass-ceramics. Dental Materials 38(2): 318-332.

Quinn, G.D., Sparenberg, B.T., Koshy, P., Ives, L.K., Jahanmir, S. & Arola, D.D. 2009. Flexural strength of ceramic and glass rods. Journal of Testing and Evaluation 37(3): 222-244.

Quinn, J., Sundar, V. & Lloyd, I.K. 2003. Influence of microstructure and chemistry on the fracture toughness of dental ceramics. Dental Materials 19(7): 603-611.

Riquieri, H., Monteiro, J.B., Viegas, D.C., Campos, T.M.B., de Melo, R.M. & Saavedra, G.d.S.F.A. 2018. Impact of crystallization firing process on the microstructure and flexural strength of zirconia-reinforced lithium silicate glass- ceramics. Dental Materials 34(10): 1483-1491.

Ritzberger, C., Apel, E., Höland, W., Peschke, A. & Rheinberger, V.M. 2010. Properties and clinical application of three types of dental glass-ceramics and ceramics for CAD-CAM technologies. Materials 3(6): 3700-3713.

Schweitzer, F., Spintzyk, S., Geis-Gerstorfer, J. & Huettig, F. 2020. Influence of minimal extended firing on dimensional, optical, and mechanical properties of crystalized zirconia-reinforced lithium silicate glass ceramic. Journal of the Mechanical Behavior of Biomedical Materials 104: 103644.

Sedda, M., Vichi, A., Del Siena, F., Louca, C. & Ferrari, M. 2014. Flexural resistance of Cerec CAD/CAM system ceramic blocks. Part 2: Outsourcing materials. American Journal of Dentistry 27(1): 17-22.

Serbena, F., Mathias, I., Foerster, C. & Zanotto, E. 2015. Crystallization toughening of a model glass-ceramic. Acta Materialia 86: 216-228.

Serbena, F.C. & Zanotto, E.D. 2012. Internal residual stresses in glass-ceramics: A review. Journal of Non-crystalline Solids 358(6-7): 975-984.

Zarone, F., Ferrari, M., Guido Mangano, F., Leone, R. & Sorrentino, R. 2016. “Digitally oriented materials”: Focus on lithium disilicate ceramics. International Journal of Dentistry 2016(1): 9840594.

Zhang, P., Li, X., Yang, J. & Xu, S. 2014. The crystallization and microstructure evolution of lithium disilicate-based glass-ceramic. Journal of Non-crystalline Solids 392: 26-30.

*Pengarang untuk surat-menyurat; email: yotumdental@um.edu.my