Table 2.

General data of the three included trials: study design, type of fixed reconstruction, number of investigated subjects, and defined outcome(s)

No.	Study (year)	Study design	Type of reconstruction	Number of subjects	Outcome
1.	Batisse et al. (2014)	RCT - crossover design - double-blinded - without follow-up	A1. Tooth-borne crowns - n = 10: monolithic LS2 - n = 10: metal-ceramic (gold-alloy)	8 patients [10 crowns]: randomized treatment sequence	Esthetics: - patients & operators preference.
2.	Batson et al. (2014)	RCT - 3-armed design - non-blinded - without follow-up	A1. Tooth-borne crowns - n = 10: monolithic LS2 - n = 10: monolithic ZrO2 - n = 12: metal-ceramic (gold-alloy)	22 patients [32 crowns]: 3 randomized groups	Marginal discrepancy / precision: - micro-computed tomography; Quality of soft tissue response: - gingival crevicular fluid rates.
3.	Joda & Bragger (2016)	RCT - 2-armed design - non-blinded - without follow-up	B1. Implant-supported crowns - n = 10: monolithic LS2 - n = 10: ZrO2 coping veneered	20 patients [20 implant-crowns]: 2 randomized groups	Feasibility testing; Time-efficiency: - clinical & technical workflows.

LS2 lithium disilicate, ZrO2 zirconium dioxide