Comparative Study of the Influence of Heat Treatment on Fracture Resistance of Different Ceramic Materials Used for CAD/CAM Systems

Abstract

The aim of this study was to compare the influence of heat treatment on fracture resistance (FR) of different ceramic materials used for CAD/CAM systems. Methods: Eighty monolithic restorations were designed using the same parameters and milled with a CAD/CAM system (CEREC SW 5.0, PrimeMill, Dentsply-Sirona™, Bensheim, Germany), forming five study groups: Group 1 (n = 10), CEREC Tessera (Dentsply-Sirona™, Bensheim, Germany) crystallized (CCT), Group 2 (n = 10), CEREC Tessera uncrystallized (UCT), Group 3 (n = 20), Emax-CAD (Ivoclar Vivadent, Schaan, Liechtenstein) (CEC), Group 4 (n = 20), Vita Suprinity (Vita Zahnfabrik, Bad Säckingen, Germany) (CVS), and Group 5 (n = 20) Cameo (Aidite, Qinhuangdao, China) (CC). Results: The average FR was similar for CCT, CC, and CEC at above 400 N, while CVS and UCT had the lowest values at 389,677 N and 343,212 N, respectively. Conclusion: Among the three ceramic materials that exhibited an FR above 400 N, CCT was considered the first recommended choice for CAD/CAM systems. This material not only demonstrated the highest FR but also exhibited outstanding consistency in the related measurements without the presence of outliers. Although the CC material showed high FR, its high dispersion revealed inconsistencies in the repetitions, suggesting caution in its use.

Thermal Influence on the Mechanical Properties of CAD/CAM Ceramics: A Systematic Review

“…This discrepancy highlights the importance of material sensitivity to variations in the thermal protocol, suggesting that indiscriminate increases in time and temperature do not necessarily guarantee improvements in desired mechanical properties. This was demonstrated by Ordonez et al who analyzed and compared in a recent study the FS of four CAD/CAM glass ceramics, showing that the AHT of CEREC Tessera at 760 • C for 2 min obtained the best results of 437,462 ± 69.17 MPa [58].…”

Effect of Glazing Protocol on the Surface Roughness and Optical Properties of Lithia-Based Glass-Ceramics

“…These properties are crucial for determining the material's suitability for different dental applications. According to a few data from the literature, some aspects can be summarized below to compose the final idea that materials that share a clinical indication can behave very differently (Table 7) in the same condition [40][41][42][43].…”

“…Lithium disilicate -LD PS e.max CAD, Ivoclar 14.1 [41] 402.9 ± 78.4 [4] 434.96 ± 88.01 [40] 14.1 [41] 6.63 ± 0.21 [42] 103 [43] Advanced Lithium Disilicate -ALD Tessera Blocks, Sirona 21.4 [41] 282.1 ± 64.4 [4] 437.46 ± 69.17 [40] 21.4 [41] 7.37 ± 0.19 [42] 103 [43] Author Contributions:…”