## 1 Introduction  
Restorative dentistry aims to reconstruct natural tooth structures both aesthetically and functionally. Increasing demand for restorations that have excellent aesthetics and higher durability has led to the development of alternative material solutions for indirect restorations such as veneer, inlay, onlay, and crown. Thanks to the developments in digital technology and the integration of these developments into dentistry, computer-aided design and computer-aided manufacturing (CAD/CAM) systems have been commonly used in the fabrication of dental restorations [1]. The advantages of CAD/CAM systems include free design, customized manufacture, quick chair time, infection control by removing laboratory processes, and excellent accuracy [2]. For dental accessories, including surgical, restorative endodontic dentistry, prosthetics, and orthodontics, digital technology has been increasingly used in clinical applications [3]. Improvements in technology have led to the emergence of novel materials for CAD/CAM restorations, including glass ceramics, zirconia, and composites, offering clinicians a variety of mechanical and optical features [4]. While CAD/CAM technology was until recently associated with subtractive manufacturing or milling, restorations can now be produced digitally with additive manufacturing or three-dimensional (3D) printing technology [5]. Both CAD/CAM technologies are based on the basic principle that the restorations are digitally designed with the information received from the patient using a CAD software program, and this information is saved as standard Tessellation language (STL) files [6]. In the milling technique, this document is transferred to a computer-controlled machine and restorations are produced from blocks using milling tools [7; 8]. The processing principle of the 3D printing method can be expressed as the opposite of milling production [9]. The document file data are transferred to the 3D printer and the restorations are printed layer by layer. Various 3D printing technologies are applied for the production of dental restorations. Stereolithography (SLA) and direct light processing (DLP) technology are popularly used [10; 11]. An SLA 3D printer uses an ultraviolet laser light source to polymerize the photosensitive resin. By repeating the curing process on each printed layer, layer-by-layer polymerization is performed, and the 3D model is completed [10]. Although DLP technology is similar to SLA, a DLP printer has digital micro-mirrors under the resin tank, and all layers of the resin are polymerized in a single exposure, which makes DLP faster than SLA. In this way, the production time of the DLP technique is significantly shorter than that of SLA [12; 13]. Composite resins or glass ceramics, such as feldspathic ceramics, lithium disilicate glass ceramics, or leucite-reinforced glass ceramics, are used as CAD/CAM milled materials in the manufacturing of indirect restorations [14; 15]. In recent years, novel resin-matrix milled indirect restorative materials containing varying amounts of composite resin and ceramic components in the same material have been developed to integrate the beneficial characteristics of composite resin and glass ceramic [16]. Vita Enamic, also called PICN, is the first resin-ceramic material developed for a CAD/CAM application. Vita Enamic, also known as polymer-infiltrated ceramic, consists of a feldspar ceramic structure of 86% that has been enhanced with Al\({}_{2}\)O\({}_{3}\) particles, SiO\({}_{2}\) particles, Na\({}_{2}\)O particles, and K\({}_{2}\)O particles in a urethane dimethacrylate (UDMA) and tri-ethylene-glycol-dimethacrylate (TEGDMA) polymer matrix (14%). This material's partially sintered ceramic particles are infiltrated with a low-viscosity polymer under high pressure and high temperature [17]. Cerasmart 270 resin is a nanoceramic block that consists of nanometer-sized ceramic fillers dispersed into the polymer matrix [18].