Influence of surface treatments before staining on the wear resistance of a hybrid ceramic

Abstract

The extrinsic characterization (EC) or staining through pigments and glaze application on the surface of ceramic restorations promotes individualization and esthetics. Two surface treatment protocols are proposed for the polymer infiltrated ceramic (PIC, Vita Enamic, Vita Zahnfabrik). However, the question is whether these treatments can have their number of steps reduced and how relevant the glaze layer is over EC. Thus, the present study aims to evaluate the surface wear resistance of the PIC stained and stained+glaze using four different surface treatments prior to the EC. The hybrid ceramic blocks will be sliced through a Diamond Blade wafering machine (Isomet 1000, Precision Sectioning Saw, Buehler, Lake Bluff, Illinois, 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. Then the samples will be divided into eight groups according to the factors "surface treatment" (polishing+silanization, etching with 5% hydrofluoric acid+silanization, sandblasting with aluminum oxide particles+silanization or the use of a self-etching silane) and "staining technique" (stain or stain+glaze). After that, the samples will be submitted to surface roughness analysis and different wear tests: 1) three-body wear simulating the presence of food bolus and antagonist (pH 7, 15 N, 1Hz), and 2) toothbrushing simulation with the presence of toothpaste (2.45 N, 180 brushings/minute). The surfaces will be evaluated by profilometry (Ra) for the EC wear detection during predetermined intervals of 1, 3, 7, 20 and 40 days for three-bory wear and 50,000, 100,000 and 150,000 cycles for toothbrushing wear. The ceramic surfaces without and with EC and after wear tests will be inspected by Scanning Electron Microscopy (SEM). The amount of surface wear by both simulations will be analyzed by pertinent statistical analysis. SEM analyzes will be analyzed qualitatively. The results will be discussed according to relevant literature. (AU)