Effect of Luting Cement and Convergence Angle of the Preparation on the Internal Fit of Zirconia Restorations

Andrés Sánchez-Monescillo; Carlos González-Serrano; José González-Serrano; João Malta Barbosa; Carlos López-Suárez; Sillas Duarte Jr

doi:10.3390/ma14247858

Effect of Luting Cement and Convergence Angle of the Preparation on the Internal Fit of Zirconia Restorations

Materials (Basel). 2021 Dec 18;14(24):7858. doi: 10.3390/ma14247858.

Authors

Andrés Sánchez-Monescillo¹, Carlos González-Serrano², José González-Serrano³, João Malta Barbosa⁴, Carlos López-Suárez⁵, Sillas Duarte Jr¹

Affiliations

¹ Norris Dental Science Center, Division of Restorative Sciences, Herman Ostrow School of Dentistry, University of Southern California, 925 W 34th St, DEN 311, Los Angeles, CA 90089, USA.
² IDIBO Research Group, Stomatology Department, School of Health Sciences, Rey Juan Carlos University, Av. de Atenas, S/N, Alcorcón, 28922 Madrid, Spain.
³ ORALMED Research Group, Department of Dental Clinical Specialities, School of Dentistry, Complutense University of Madrid, Plaza Ramón y Cajal s/n, 28040 Madrid, Spain.
⁴ Department of Biomaterials and Biomimetics, New York University College of Dentistry, 345 E 24th St, New York, NY 10010, USA.
⁵ ICAPE Research Group, Department of Conservative Dentistry and Buccofacial Prosthesis, School of Dentistry, Complutense University of Madrid, Plaza Ramón y Cajal, s/n, 28040 Madrid, Spain.

Abstract

The objective was to evaluate the effect of luting agents and the preparation design on the internal fit of zirconia restorations. Sixty dies were prepared and divided in occlusal convergence angle of 6° (OC6) and 12° (OC12). CAD/CAM zirconia copings were fabricated (Lava All-Ceramic System). A zinc phosphate cement (ZPC); a glass ionomer cement (GIC); and a resin cement (RC) were studied. Specimens were sectioned and coping/die discrepancies were evaluated through Stereoscopic Microscopy. A closer fit was observed in OC12 when compared to OC6 (p < 0.001). For OC6 no significant differences were observed in between ZPC, GIC, and RC (p > 0.05). For OC12, a significantly closer fit was recorded on the ZPC subgroup when compared to the GIC subgroup (p < 0.001). Preparations of 12 degrees demonstrated a closer internal fit when compared to 6 degrees. Preparations of 12 degrees achieved better internal fit values with ZPC (Fortex) followed by RC (RelyX Unicem), and GIC (Ketac Cem). No differences were found when comparing different luting agents over 6° degrees preparations.

Keywords: cement; coping; internal fit; luting cement; occlusal convergence; preparation angle; preparation design; restoration; zirconia.