Table 2 Polishing methods and application procedures used with different CAD/CAM.
Material | Polishing System | Abbr | *Application procedure |
|---|---|---|---|
FC | Mechanical polishing | FC-M | Mechanical polishing: A ceramic polishing kit (EVE Diapol; EVE Ernst Vetter GmbH, Keltern, Germany) with 3 stages (blue rubber, pink rubber, white rubber) was used. A rotary tool at 10,000 rpm was applied at each stage for one minute. |
Glaze | FC-G | Traditional glaze: Universal Vita Akzent Plus (Vita Zahnfabrik, Bad Säckingen, Germany) was applied to the sample surfaces. Firing was applied using a Programat PS10 (Ivoclar Vivadent, Schaan AG, Liechtenstein) with an initial temperature of 400 °C, heat rise time 3 min, heat rise rate 45 °C/min, final temperature 840 °C, firing time 1 min, and vacuum application between 450 °C and 840 °C. | |
Mechanical polishing + Glaze | FC-MG | First, mechanical polishing with EVE Diapol, as in the FC-M group, followed by traditional glaze application, as in the FC-C group. | |
LDC | Mechanical polishing | LDC-M | Mechanical polishing with a ceramic polishing kit (same with the group FC-M) |
Glaze | LDC-G | Traditional glaze (same with the group FC-G) | |
Mechanical polishing + Glaze | LDC-MG | Mechanical polishing + traditional glaze (same with the group FC-MG) | |
RNC | Mechanical polishing | RNC-M | Mechanical polishing: A diamond polishing system (Sof-Lex Diamond Polishing System; 3 M ESPE St Paul, MN, USA) with four different grades of abrasive aluminum oxidecoated disks was applied in decreasing order of grits (in order: Coarse 100 μm, Medium 29 μm, Fine 14 μm, and Super Fine 8 μm) in the same direction for 15–20 s using a low-speed handpiece of equipment at 15.000 rpm. A new disc was used to polish each sample. |
Glaze | RNC-G | Light-curing glaze: Samples were sandblasted with 50 μm Al2O3 particles for 10 s at 2.5 bar pressure and ultrasonically cleaned in distilled water for 5 min. Silan (G-Multi Primer; GC Corporation; Tokyo, Japan) was applied to the samples’ surfaces for 30 s and air dried. Glaze material (Optiglaze; GC Corporation, Tokyo, Japan) was applied and LED cured (Bluephase 20i, Ivoclar Vivadent; Schaan, Liechtenstein) at 430 nm wavelength for 40 s. | |
Mechanical polishing + Glaze | RNC-GM | First, mechanical polishing with Sof-Lex Diamond Polishing System, as in the RNC-M group, followed by light-curing glaze application, as in the RNC-G group. |
