## 1 Introduction  
The orthodontic bracket's bonding to enamel using resin-composite adhesives should provide high enough bond strengths to withstand unintentional failure [1; 2]; moreover, debonding after treatment must also produce no enamel damage [1; 3]. The design of the orthodontic bracket base is vital in obtaining a clinically adequate strong bond to the tooth enamel [4; 5; 6]. The strength of the bracket's bond to the enamel has been extensively investigated resulting in the establishment of various factors influencing the bond strength, including conditioning procedures of the enamel, masticatory strengths, adherent procedures, and bracket-correlating factors (such as the size of the brackets, bracket base design, and material of the bracket base) [2; 4; 5; 6; 7; 8]. Earlier studies showed that the failure of the bracket bond usually happens at the adhesive/bracket base interface [1; 6]. The differences in metal bracket base design have improved the bracket base interface's micro-interlocking mechanism, enabling successful adhesive retention to the base. Moreover, the combination with adhesive penetrance properties to etched enamel ensures a clinically good bond strength [1; 6; 9]. In addition, different mechanical retentive and chemical treatments have been applied to the bracket base in an effort to enhance the adhesive retention to the base [1; 10; 11]. Bonding systems for ceramic brackets rely on mechanical retention rather than chemical retention. The latter method has resulted in excessively high bond strengths, resulting in enamel surface fracture during the debonding procedure [12; 13; 14; 15]. Subsequently, manufacturers favored mechanical retention mechanisms for orthodontic attachments. This evolution in ceramic bracket design enabled adequate adhesion to the resin/composite interface and, thus, to the enamel, subsequently leading to safe debonding [12; 13; 14]. Ceramic brackets are composed of monocrystalline or polycrystalline materials [12]. These aesthetically acceptable tooth-colored brackets are safe for magnetic resonance imaging (MRI) and exhibit superior biocompatibility. These brackets have been utilized successfully for over 30 years [12; 13]. Contemporary orthodontics is experiencing significant growth due to the development of digital technologies such as cone-beam computed tomography (CBCT), intraoral scanning, three-dimensional (3D) photography, computer-aided design, and computer-aided manufacturing (CAD/CAM), affecting diagnosis, treatment planning, and orthodontic treatment process [12; 13; 14]. Additive manufacturing (3D printing) is a new technique that permits the fabrication of metallic and nonmetallic parts directly from the CAD file. In this technique, the CAD file is sliced into thin sheets, and each sheet is built on top of the previous sheet until the final part is produced [12; 16]. For example, 3D-printed brackets are now designed and fabricated using CAD and 3D printing technology [16]. Customized bracket design and fabrication provide specific and individualized bracket base characteristics, which in turn ensure an improved match to the tooth surfaces. This characteristic in itself promotes good adhesion properties [17]. The 3D-printed bracket thus has the appearance and morphology to meet the specific clinical requirements [16]. There is a continual search to embrace effective and efficient orthodontic treatment. One such development is 3D printing technology, which is considered a likely approach to grant higher-quality orthodontic treatment by diminishing chair time, treatment time, and discomfort and achieving better treatment outcomes [16; 18]. [PERSON], [PERSON] et al. [16] compared the shear bond strength (SBS) and the adhesive remnant index (ARI) amongst 3D custom-printed lithium disilicate orthodontic brackets, stainless-steel orthodontic brackets, and three types of clear ceramic orthodontic brackets, and found no significant differences in SBS values amongst the groups. Moreover, in a recent study, [PERSON] et al.