**2. Materials and Methods**

The study compared marginal misfit and surface micro-roughness of metal copings fabricated using Cast-LWT, CAD-CAM, SLM, and DLP-Cast.

## *2.1. Specimen Preparation*

An ivorine mandibular first molar (KaVo Dental, Fruehauf Drive, Charlotte, NC, USA) was prepared for metal ceramic crown with a high-speed airotor and diamond burs (NSK Co., Japan). Tooth reduction parameters included 2 mm occlusal and axial, two-plane reduction on buccal surface, a radial shoulder margin, and a taper of 6◦ using a milling machine. Preparation margins were finished with a chisel and smoothed with silicon impregnated burs (Rubberrized abrasives, Lasco Diamond Products, Chatsworth, CA, USA) (Figure 1). The prepared tooth surface was recorded using polyvinyl siloxane (PVS) impression material (Putty light technique) and the impression was verified. A replica

was prepared in wax and was casted using the lost wax technique in nickel-chrome alloy (Remanium, Dentauram GmbH & Co., Ispringen, Germany).

**Figure 1.** Representative image of the prepared tooth specimen. Prepared tooth (**A**) Occlusal, (**B**) Buccal.

Forty metal alloy copings were prepared in the study and divided into study groups according to the fabrication technique (n = 10): Casting-Lost wax technique (Cast-LWT) (control), CAD-CAM, Selective laser melting (SLM), and Digital light processing with casting (DLP CAST). The sample size in each group of the study was calculated by performing a power calculation utilizing data from a similar previous study [11].
