Fracture Resistance of Sintered Monolithic Zirconia Dioxide in Different Thermal Units

Abstract

The purpose of this study was to compare the fracture strength of monolithic zirconium dioxide subjected to a sintering process in two different furnaces: InFire HTC Speed and CEREC SpeedFire. Methods: Forty restorations were designed and machined using a computer aided design/computer aidded machine (CAD/CAM) system. The restorations were randomly assigned to two groups of 20 samples each, Group 1 for the SpeedFire furnace (fast sintering) and Group 2 for the InFire furnace (slow sintering). Each of the crowns was subjected to a maximum compression load recorded in Newtons (N) and a displacement control with a speed of 1 mm/min. Results: Group 1 presented an average of 1222.8 N and a standard deviation of 136.91 N. Group 2 obtained a mean of 1068.5 N and a standard deviation of 316.39 N. Conclusions: There were no significant differences between the two groups, and the mechanical strength of the material was not affected, which would imply a saving of clinical and laboratory time when performing rapid sintering on monolithic translucent zirconium dioxide restorations. However, rapidly sintered restorations have limited reliability.

Mechanical Properties of Translucent Zirconia: An In Vitro Study

“…These can be used without the porcelain coating, thus resulting in being directly exposed to the oral cavity. Even if the influence of sintering protocols onto the mechanical characteristics of the monolithic zirconia restorations was deeply investigated and reported [58][59][60][61][62], we do not consider it in the present study and used a standard procedure. In 2010, Jung et al [63] analysed the effect of full zirconia restorations (Zirkonzahn Prettau) and feldspathic ceramics against dental enamel in a chewing simulator for 240,000 cycles.…”

Comparative Fracture Resistance Analysis of Translucent Monolithic Zirconia Dioxide Milled in a CAD/CAM System

“…However, other authors concluded that there was no significant difference between the two groups, and the mechanical strength of the material was not affected, which would imply clinical and laboratory time savings when performing rapid sintering on translucent monolithic zirconium dioxide restorations. However, rapidly sintered restorations have limited reliability, depending on the case [44].…”

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

“…All samples were subjected to a thermocycling process; in total, 5000 [ 6 ] cycles were used to estimate five years of oral conditions. Thermocycling was programed with temperature extremes of 5 °C and 55 °C in distilled water (residence time: 25 s; pause time: 10 s) and performed on the computerized thermocycling unit (Thermocycler™, SD Mechatronik, Westerham, Germany).…”

“…The emphasis on esthetics in dental restorations has concomitantly driven the rapid evolution of metal-free ceramic materials [ 1 , 2 ], used and valued for their outstanding mechanical and optical properties regarding dental restorations [ 3 , 4 , 5 , 6 ]. As an example, lithium silicate-based (SL) glass ceramics designed for dental CAD/CAM systems have been introduced in the market [ 7 ].…”