Table 1. Data extraction and analysis of the studies included in this systematic review.

CAD-CAM: computer-aided design-computer-aided machining; PLV: porcelain laminate veneer; SEM: scanning electron microscopy

Journal, year	Author	Type of preparation	Type of porcelain	Cementation	Adaptation device	Fabrication technique	Follow up	Type of the study	Result
Journal of Dentistry, 2012	Lin et al. [6]	Full veneer and traditional veneer	Leucite-reinforced ceramic veneer and conventional sintered feldspathic porcelain veneer	Clear self-cured acrylic resin	Keyence digital microscope at 200×	CAD-CAM and conventional feldspathic	-	In vitro	Traditional veneers designed with ProCAD porcelain demonstrated lesser horizontal gaps
Journal of Dentistry, 2012	Aboushelib et al. [7]	Incisal lap preparation	Ceramic laminate veneers	Resin cement	SEM and stereomicroscope	CAD-CAM and pressed PLVs	60 days	In vitro	Pressable ceramic laminate veneers exhibited superior marginal fidelity, uniform and thinner cement film thickness, and lesser microleakage in contrast to machinable ceramic veneers
Journal of Prosthodontics, 2013	Jha et al. [8]	Window preparation	Refractory die technique, low-fusing feldspathic porcelain (IPS e. max Ceram), and lithium disilicate-reinforced glass ceramic (IPS e. max Press)	Dual-cure composite resin	SEM at 200× magnification	Conventional feldspathic and pressing technique	Seven days and three months	In vivo	Veneers of both groups showed a comparable marginal fidelity at the microscopic level at seven days and three months after cementation
Dental Research Journal, 2016	Ghaffari et al. [9]	Incisal overlap preparation	Feldspathic laminate system (Du Ceram LFC) and in Ceram laminate veneer	Hueless glue	Stereomicroscope at 46× magnification	Refractory die technique and slip cast technique	-	In vitro	PLVs fabricated with Inceram had a marginal gap within an acceptable range
Journal of Prosthetic Dentistry, 2018	Al-Dwairi et al. [10]	Full veneer preparation	Feldspathic glass ceramic, fine structure feldspar ceramic	Composite resin cement and variolink – N	SEM at 200× magnification	Pressed PLVs and CAD-CAM milling	-	In vitro	No statistically significant difference was found in gap measurements
Journal of Prosthodontics, 2017	Yuce et al. [11]	Incisal overlap preparation	Nano-fluor apatite glass ceramic	Adhesive luting cement	Light optical microscopy at 40× magnification	CAD-CAM (cerec) and heat-pressed (E. Max press)	6, 12, 18, and 24 months	In vivo	Marginal and internal adaptation of veneers were similar and within clinically acceptable ranges