## 1 Introduction  
The increasing popularity of removable clear aligners highlights the shifting priorities in orthodontic treatment toward aesthetics, convenience, and comfort [1]. Clear aligners are used more than ever and represent the result of new materials and technologies in the orthodontic field [2, 3]. Several brands of orthodontic aligners are continually being improved to achieve even more complex tooth movements [4, 5, 6, 7]. The choice of thermoplastic materials for aligners is crucial, as these materials need to be transparent, flexible, durable, biocompatible, and effective [3, 8]. Different materials, including polyethylene terephthalate glycol-modified (PET-G) and thermoplastic polyurethane (TPU), exhibit varying properties that affect aligner performance [9, 10]. Despite their advantages over traditional fixed appliances [11, 12, 13], clear aligners face challenges in achieving precise tooth movements [14]. Initially, aligners were limited to Class I crowding cases, avoiding enamel involvement with acid etching and maintaining its structural and optical properties [15, 16, 17]. However, when aligners expanded to more complex tooth movements in all three planes, using auxiliary elements (attachments) of composite resin bonded to the dental enamel became necessary [4, 18, 19, 20]. Composite attachments, typically 2-5 mm in size and over 1 mm in thickness, are mainly bonded to the labial surface of multiple teeth [21]. These attachments have a high surface-area-to-volume ratio, increasing their interaction with the oral environment [22]. Unlike traditional orthodontic brackets that are bonded using a sandwich pattern to reduce exposure to the oral cavity, aligner attachments are more exposed, increasing their reactivity with oral fluids and materials [22]. Attachments play a critical role in the efficacy of clear aligner therapy. Various factors such as position, conformation, size, and number of attachments influence the fitting of the aligner in the oral cavity [23; 24; 25]. A precise bonding protocol is also essential, as inaccurate adhesion can cause incorrect tooth movements that can affect the efficacy of the therapy [26]. In orthodontic bonding, adhesives interlock with the enamel and the bracket base, creating a robust bond with minimal edge exposure [27]. However, for aligner attachments, the significant thickness and frequent interaction with aligners during fitting and mastication result in larger exposed surfaces and higher susceptibility to masticatory stresses [22]. Thus, while aligners offer aesthetic and functional benefits, the attachments' exposure and stress factors present unique challenges compared to traditional brackets. The composite resin used is critical for effective tooth movement and treatment outcomes due to its superior aesthetics and adhesion properties [28]. In addition to preserving its characteristics inside the oral cavity during the entire orthodontic treatment, the light-cured composite resin must faithfully reproduce the virtually planned attachments by filling the reservoirs of the template [29; 30; 31]. Regarding the viscosity of adhesive materials, an equivalent level of accuracy has been demonstrated in the shapes and volumes of attachments using composite resins with different viscosities [32]. The clinical reproduction of the attachments on the teeth represents a critical step that must guarantee their integrity [33]. Nevertheless, clinicians carry out this protocol according to their preferences, risking not completely filling the reservoirs of the templates, with consequent defects in the shapes or volumes in the attachments, or overfilling, causing an overflow of composite resin around the auxiliary elements [33]. Therefore, this research aims to create an innovative operative procedure to optimize the shapes of the attachments during their clinical positioning. This protocol uses two types of templates, each with different structural characteristics and functions.