Influence of Different Thicknesses of Monolithic Crowns Made from Different Resin-Bonded Glass Ceramic on Their Load-bearing Capacity (An in vitro Comparative Study)


  • Azad R. Abdalla Conservative Department, College of Dentistry, University of Sulaimani, Kurdistan Region, Iraq. Author
  • Abdulsalam R. Al-Zahawi Conservative Department, College of Dentistry, University of Sulaimani, Kurdistan Region, Iraq. Author



Celtra Duo, Fracture Resistance, Lithium Disilicate E.max, Thermocycling


Objective: To investigate the load-bearing capacity of the full-coverage crowns made from lithium disilicate glass-ceramic LDGC (IPS e.max®, Ivoclar Vivadent) and 10% zirconia reinforced lithium silicate glass ceramic ZLS (Dentsply DeTrey) with different thicknesses.

Methods: Forty resin dies with supporting bases were duplicated from two prepared typodont teeth for all-ceramic crowns as a maxillary first molar. Forty crowns corresponding to each die were prepared and then they were divided into four groups: Group I (n 10) made from ZLS with a restoration thickness of (1.0 mm occlusally and 1.0 mm radially) and Group II (n 10) made from LDGC with a restoration thickness of (1.0 mm occlusally and 1.0 mm radially), and Group III (n 10) made from ZLS (1.5 mm occlusally and 1.5mm radially) and Group IV (n 10) made from LDGC (1.5 mm occlusally and 1.5 radially). All crowns were fabricated by chair side CEREC CAD/CAM and crystallized with Speed fire Dentsply Furness. The virolink resin cement (VariolinkII, Ivoclar Vivadent) was used to bond the crowns to the corresponding dies.  All samples were thermo-cycled (10000 cycles between 5c and 55c) and tested for fracture resistance using a Universal testing machine at 0.5 mm/minute speed until failure. ANOVA and Tukey HSD test were used to compare the fracture resistance between groups.

Results: The result demonstrates that the fracture resistance means and SD of ZLS with different thicknesses ranged from 572 N ± 122.002 to 1171±217.432 N, and those of LDGC with different thicknesses ranged from 625 N ±151.676 N to 845 N ±388.222 N.

Conclusions: The fracture resistance increased with increasing crown thickness using different glass-ceramic materials.


Gracis S, Thompson VP, Ferencz JL, Silva NR, Bonfante EA. A new classification system for all-ceramic and ceramic-like restorative materials. Int J Prosthodont. 2015;28(3):227-35.

Helvey GA. Classification of dental ceramics. Inside Continuing Education. 2013;13:62-8.

McLaren EA, Figueira J. Updating classifications of ceramic dental materials: a guide to material selection. Compendium. 2015;36(6):400-6.

Denry I. How and when does fabrication damage adversely affect the clinical performance of ceramic restorations?. Dent Mater. 2013;29(1):85-96.

Zhang Y, Kelly JR. Dental ceramics for restoration and metal veneering. Dent Clin North Am. 2017;61(4):797-819.

Traini T, Sinjari B, Pascetta R, Serafini N, Perfetti G, Trisi P, et al. The zirconia-reinforced lithium silicate ceramic: lights and shadows of a new material. Dent Mater J. 2016;35(5):748-55.

Volpato C, Philippi A, Petter C, Fredel M. Ceramic materials and color in dentistry: INTECH Open Access Publisher; 2010.

Rinke S, Pabel AK, Rödiger M, Ziebolz D. Chairside fabrication of an all-ceramic partial crown using a zirconia-reinforced lithium silicate ceramic. Case Rep Dent. 2016;2016:1354186.

Lawson NC, Bansal R, Burgess JO. Wear, strength, modulus and hardness of CAD/CAM restorative materials. Dent Mater. 2016;32(11):e275-e83.

Abdulkader KF, Elnaggar GAE, Kheiralla LS. Shear bond strength of cemented zirconia-reinforced lithium silicate ceramics (Celtra Duo) with two surface treatments (in vitro study). J Adhes Sci Technol. 2021;35(1):35-51.

Choi S, Yoon H-I, Park E-J. Load-bearing capacity of various CAD/CAM monolithic molar crowns under recommended occlusal thickness and reduced occlusal thickness conditions. J Adv prosthodont. 2017;9(6):423-31.

Nawafleh N, Hatamleh M, Elshiyab S, Mack F. Lithium disilicate restorations fatigue testing parameters: a systematic review. J Prosthodont. 2016;25(2):116-26.

Kim JH, Lee S-J, Park JS, Ryu JJ. Fracture load of monolithic CAD/CAM lithium disilicate ceramic crowns and veneered zirconia crowns as a posterior implant restoration. Implant Dent. 2013;22(1):66-70.

Yu T, Wang F, Liu Y, Wu T, Deng Z, Chen J. Fracture behaviors of monolithic lithium disilicate ceramic crowns with different thicknesses. RSC advances. 2017;7(41):25542-8.

Pires LA, Novais PM, Araújo VD, Pegoraro LF. Effects of the type and thickness of ceramic, substrate, and cement on the optical color of a lithium disilicate ceramic. J Prosthet Dent. 2017;117(1):144-9.

Al-Akhali M, Chaar MS, Elsayed A, Samran A, Kern M. Fracture resistance of ceramic and polymer-based occlusal veneer restorations. J Mech Behav Biomed Mater. 2017;74(1):245-50.

Kasem AT, Ellayeh M, Özcan M, Sakrana AA. Three-year clinical evaluation of zirconia and zirconia-reinforced lithium silicate crowns with minimally invasive vertical preparation technique. Clin Oral Investig. 2022;27(4):1577-88.

Stappert CF, Guess PC, Chitmongkolsuk S, Gerds T, Strub JR. All-ceramic partial coverage restorations on natural molars. Masticatory fatigue loading and fracture resistance. Am J Dent. 2007;20(1):21.

Al-Zarea BK. Maximum bite force following unilateral fixed prosthetic treatment: a within-subject comparison to the dentate side. Med Princ Pract. 2015;24(2):142-6.

Waltimo A, Könönen M. Bite force on single as opposed to all maxillary front teeth. Eur J Oral Sci. 1994;102(6):372-5.

Zarone F, Ruggiero G, Leone R, Breschi L, Leuci S, Sorrentino R. Zirconia-Reinforced Lithium Silicate (ZLS) mechanical and biological properties: a literature review. J Dent. 2021;109(1):103661.

Sahebi S, Giti R, Sherafati A. The effect of aging on the fracture resistance of different types of screw-cement-retained implant-supported zirconia-based restorations. PLoS One. 2022;17(6):e0270527.

Morresi AL, D'Amario M, Capogreco M, Gatto R, Marzo G, D'Arcangelo C, et al. Thermal cycling for restorative materials: does a standardized protocol exist in laboratory testing? A literature review. J Mech Behav Biomed Mater. 2014;29(1):295-308.

Diniz V, Prado PHCO, Rodrigues JVM, Monteiro JB, Zucuni C, Valandro LF, et al. Ceramic firing protocols and thermocycling: Effects on the load-bearing capacity under fatigue of a bonded zirconia lithium silicate glass-ceramic. J Mech Behav Biomed Mater. 2020;110(1):103963.

Bajraktarova-Valjakova E, Korunoska-Stevkovska V, Kapusevska B, Gigovski N, Bajraktarova-Misevska C, Grozdanov A. Contemporary dental ceramic materials, a review: chemical composition, physical and mechanical properties, indications for use. Open Access Maced J Med Sci. 2018;6(9):1742-55.

Elsaka SE, Elnaghy AM. Mechanical properties of zirconia reinforced lithium silicate glass-ceramic. Dent Mater. 2016;32(7):908-14.

Schwindling FS, Rues S, Schmitter M. Fracture resistance of glazed, full-contour ZLS incisor crowns. J Prosthodont Res. 2017;61(3):344-9.

Seydler B, Rues S, Müller D, Schmitter M. In vitro fracture load of monolithic lithium disilicate ceramic molar crowns with different wall thicknesses. Clin Oral Investig. 2014;18:1165-71.

Magne P, Carvalho AO, Bruzi G, Giannini M. Fatigue resistance of ultrathin CAD/CAM complete crowns with a simplified cementation process. J Prosthet Dent. 2015;114(4):574-9.

Rekow ED, Harsono M, Janal M, Thompson VP, Zhang G. Factorial analysis of variables influencing stress in all-ceramic crowns. Dent Mater. 2006;22(2):125-32.



How to Cite

Influence of Different Thicknesses of Monolithic Crowns Made from Different Resin-Bonded Glass Ceramic on Their Load-bearing Capacity (An in vitro Comparative Study). (2023). Sulaimani Dental Journal, 10(3), 7.