Surface quality of Cerec CAD/CAM ceramic veneers treated with four different polishing systems

To achieve satisfactory aesthetic appearance of ceramic veneers food debris retention and plaque formation, resulting in possible irritation of surrounding tissues, should be avoided. It is, therefore, necessary to decrease the roughness of ceramic surfaces as much as possible. The aim of this study was to evaluate surface roughness of ceramic veneers after polishin15038787 g with four different techniques.

Twenty veneers were fabricated using Cerec 2 CAD/CAM method (Sirona AG, Bensheim, Germany) from Cerec VITA MARK II ceramic blocks (Vita Zahnfabrik, Bad Säckingen, Germany) and cemented onto prepared extracted teeth. Veneers were divided into 4 groups of 5 specimens and polished with 4 different techniques: 1. Sof-lex discs grit 150, 360, 600, 1200 (3M, St. Paul, MN, USA); 2. Hawe brushes (Hawe Neos Dental, Bioggio, Switzerland); 3. Hawe brushes and diamond paste Diabrill (Oralia Dental GmbH, Kostanz, Germany); 4. Politip-P rubber cups (Vivadent, Schaan, Liechtenstein). Surface profile was measured using Perthometer Perthen S8P 4.5 (Feinprüf Perthen GmbH, Goettingen, Germany) profilometer.

Data were analysed using ANOVA with Tukey HSD test.

Sof-lex discs revealed significant statistical differences for Rz, Ra, Rk, Rpk values (p=0.0002) (Rz=2.92 mm; Ra=0.462 mm; Rk=1.098 mm; Rpk=0.472 mm). Values for Rvk were statistically significant only for rubber cups with diamond paste (p=0,002) (Rvk 4=3.04 mm). Rvk values for all other techniques were not statistically significant (Rvk 1=1.148 mm; Rvk 2=1.936 mm; Rvk 3=2.18 mm).

The best surface smoothness was achieved with Sof-lex discs polishing system. All other methods are clinically acceptable. Selection of polishing technique should be made according to geometric construction of the polishing instrument and possibility of reaching various restoration areas with the polishing instrument.