Abstract
Regardless the materials properties, the vast majority of ceramic restorations require an individualization through the extrinsic characterization (EC) called staining. The present study aims to evaluate the wear resistance of different monolithic ceramics. High translucent zirconia (YZ HT), zirconia reinforced lithium silicate (ZLS), polymer infiltrated ceramic (PIC) and feldspathic ceramic (VMII) from Vita Zahnfabrik will be sliced through a cutting machine (Isomet 1000, Precision Sectioning Saw, Buehler, Lake Bluff, Illinois, USA) with diamond disk (Series 15LC Diamond Blade wafering, Buehler, USA) under constant water irrigation. Afterwards, the specimens will be polished with # 600 sandpaper and cleaned in an ultrasonic bath with isopropyl alcohol for 5 minutes. The ZLS and YZ HT samples will be crystallized/sintered in specific ovens. Then, the samples will be extrinsically characterized according to the manufacturer's recommendation and then submitted to surface roughness analysis and different wear simulation tests: 1) three-body wear simulating the presence of food bolus and antagonist (pH 7, 15 N, 1Hz) and 2) simulation of toothbrushing with the presence of toothpaste (2.45 N, 180 brushings per minute). Before the wear simulation and during predetermined intervals of 1, 3, 7, 20 and 40 days for the three-body wear and 50,000, 100,000 and 150,000 cycles for the brushing test, the surface will be evaluated through profilometry (Ra, Rz e RSm) to detect wear of the EC layer. The surfaces with EC, without EC and with wear will be inspected by Scanning Electron Microscopy (SEM). Dispersive Energy Spectroscopy (EDAX) will be performed for chemical evaluation of the presence of EC on surfaces during wear intervals. The amount of wear by both simulations will be analyzed by statistical analysis. SEM and EDAX analysis will be interpreted qualitatively. The results will be discussed according to relevant literature. (AU)
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