Table 1 Ceramic materials used in the study

ZLS (Celtra Duo)

Dentsply Sirona

Zirconium lithium silicate ceramic

SiO₂ (58%), P₂O₅ (5%), Al₂O₃ (1.9%), Li₂O (18.5%), ZrO₂ (10.1%), Tb₄O₇ (1%), and CeO₂ (2%)

Mill and polish: 210 MPa

Mill and fire: 370 MPa

Zr (DD BIO ZX²)

Dental Direkt

High-translucent zirconium oxide ceramic

ZrO₂ + HfO₂ + Y₂O₃ (> 99%), Y₂O₃ (< 6%), Al₂O₃ (≤ 0.15%), and other oxides

1100–1250 MPa