Table 1.
Studies investigating the strength of monolithic zirconia crowns. Studies are presented in ascending chronological order.
| Authors | Zirconia system | Test type/Methodology | Results | |
|---|---|---|---|---|
| Beuer et al. (2012) [67] | - Zirlunaa | Fracture strength, molar crowns, loading in chewing simulator, crosshead-speed 0.5 mm min−1. | Higher strength of monolithic compared to veneered zirconia | |
| Zhang et al. (2012) [68] | - Lava | Chipping test (Vickers) on zirconia and glass-infiltrated monolithic zirconia molar crowns | Chipping resistance: glass-infiltrated monolithic zirconia crowns comparable to monolithic zirconia and significantly higher compared to veneered zirconia crowns | |
| - In-Ceram Zirconia YZ | ||||
| Sun et al. (2014) [69] | - Lava Frame (MZC) | Axial load, molar crowns of varying occlusal thickness (0.6–1.5 mm), crosshead speed of 0.5 mm min−1. | MZC exhibited higher fracture loads than MLC, LZC and MCC. The fracture resistance of MZC (1.0 mm) was equal to MCC. Doubling the monolithic zirconia core from 0.6 mm to 1.5 mm increased the fracture resistance system threefold. | |
| - IPS e.max Press (MLC) | Cementation with resin cement | |||
| - Layered zirconia crowns (LZC) | ||||
| - Metal ceramic crowns (MCC) | ||||
| Nakamura et al. (2015) [70] | - Lava Plus | Fracture strength, molar crowns cemented to composite dies, crosshead-speed 0.5 mm min−1 | The occlusal thickness significantly affected the fracture load, but not the axial thickness. Higher strength compared to monolithic lithium disilicate crowns. | |
| Zhang et al. (2016) [71] | - Lava Plus | Fracture strength, molar crowns cemented to composite dies, crosshead-speed 0.1 mm min−1. | The stiffer and stronger zirconia and lithium disilicate crowns afforded superior stress shielding of the tooth interior and inhibited crack initiation | |
| Sorrentino et al. (2016) [72] | - Aadva | Fracture test, axially loaded molar crowns of various thicknesses (0.5, 1, 1.5 and 2 mm), crosshead speed 1 mm min−1 | The occlusal thickness did not influence the fracture resistance and the mode of failure of the restorations. | |
| Schriwer et al. (2017) [73] | Soft machined | - Bruxzir | Fracture strength, axially loaded premolar crowns from hard and soft machined zirconia ceramics, crosshead speed 0.5 mm min−1 | The hard-machined Y-TZP crowns had the best margin quality and the highest load at fracture. The BX and the PZ group had statistically significant weaker load at fracture than the other groups. Margin defects affected negatively the load at fracture. |
| - ICE Zirkon | ||||
| - DD Bio ZX2 | ||||
| − NobelProcera | ||||
| Hard machined: | - Denzir Y-TZP | |||
| - Denzir Mg-PSZ | ||||
| Rohr et al. (2018) [74] | - VITA YZ T | Fracture strength, implant supported monolithic crowns, crosshead speed 1 mm min−1 | For uncemented crowns the initial fracture initiated from the internal surface, for cemented crowns from the loading point. VITA YZ T presented the highest flexural strength and fracture strength. Increased compressive strength of the cement was correlated to high fracture toughness, but not for monolithic zirconia. | |
| - VITA In-Ceram AL VITABLOCS | Crowns cemented with temporary, adhesive dual-cured cements cement and self-adhesive dual-cured cement. | |||
| - Mark II VITA ENAMIC | ||||
| - IPS e.max CAD | ||||
| Tsuyuki Y et al. (2018) [75] | - Adamant, Tokyo, Japan | Fracture strength, crosshead speed 1 mm min−1. | The presence of an occlusal groove decreased fracture strength but to a smaller degree when resin cement was used. The use of glass ionomer cement was associated with lower fracture strength. | |
| Different types of abutments fabricated with different depths of occlusal groove or abscesnce of groove. Evaluation of the effects of abutment morphology, crown thickness and cement type. | ||||
| Moilanen et al. (2018) [76] | - PSZ Prettau | Fracture strength, 45° angle to the long axis, crosshead speed 1 mm/min. | Cementation of the crown on a titanium base was correlated to higher fracture strength compared to direct cementation on the implant’s surface. | |
| - FSZ Prettau Anterior | A titanium base on the implant surface was evaluated with regard to its effect on the monolithic crown’s fracture strength. | |||
a
The composition of the materials presented in this and all the tables in the manuscript are presented in Table 5.