The computer-designed substructure is milled either from presintered zirconia blanks (soft milling) followed by densely sintering or from fully sintered blanks (hard milling) in hot isostatic pressed (HIP) zirconia.

Zirconia is a high-strength ceramic material with high fracture toughness, chemical inertness, and decent aesthetic properties, which is used mainly as a core material for single and multiunit fixed dental prostheses (FDPs) and abutments [3, 4].

The high fracture resistance of zirconia is due to the ability of the material to transform from one structural phase to another, when exposed to stress.

According to a systematic review, the 5-year survival rate for zirconia FDPs is 90.1% [16].

However, the 5-year survival rates may range from 74.7% to 100% [11, 20].

A few studies have been published on the clinical performance of zirconia restorations.

For single crowns, Groten and Huttig have presented a 2-year survival rate of 98% [6]. found a survival rate of 88.8% for 205 crowns [7], Güncü et al.

The introduction and rapid development of computer-aided design and computer-aided manufacturing (CAD/CAM) technology in prosthetic dentistry have been highly evident in the last decade.

Combined with a search for new materials with aesthetic, biocompatible, and high-strength properties, this has contributed to the increasingly frequent use of dental ceramics in general and yttria-stabilized tetragonal zirconia polycrystals (Y-TZP, hereafter called zirconia) in particular [1, 2].

Case records from 151 patients (59 men, mean age 58, and 92 women, mean age 58) were analysed.

They were treated with a total of 184 zirconia FDPs, and the distribution between the three clinics was 39, 56, and 89 FDPs.

The three-year cumulative success and survival rates (CSR) were 82.3% and 95.2%, respectively. Ceramic-veneered zirconia is a promising alternative to metal-ceramic FDPs, even in the posterior area.

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