Backgrounds <p>Clear aligner therapy (CAT) depends on accurately fabricated and mechanically reliable attachments to optimize aligner retention and force delivery. Conventional attachments, produced via manual resin filling, are prone to operator variability, prolonged chair-side procedures, and inconsistent bonding outcomes. This study aimed to evaluate the feasibility of preformed 3D-printed attachments as a standardized alternative to conventional resin-based attachments.</p> Methods <p>Four types of attachment specimens were prepared: a ceramic-reinforced 3D-printed resin (Bego VarseoSmile Crown^Plus, BVSC), a universal nano-hybrid restorative resin (Z350), a flowable restorative resin (Z350L), and a common 3D-printed resin (CPR). Scanning electron microscopy (SEM) and Raman spectroscopy were used to characterize surface morphology and degree of conversion. Dimensional accuracy, water sorption, mechanical properties (elastic modulus, yield strength, bonding strength, wear resistance), and cytotoxicity were evaluated.</p> Results <p>Both 3D-printed resins demonstrated significantly higher dimensional accuracy and degree of conversion than conventional restorative resins (<i>P</i> &lt; 0.05). The BVSC group exhibited the best overall performance, showing superior dimensional stability, yield strength, bonding strength, and wear resistance compared with all other groups (<i>P</i> &lt; 0.05). No significant differences in cytotoxicity were observed among all tested materials (<i>P</i> &gt; 0.05).</p> Conclusions <p>Preformed attachments fabricated using ceramic-reinforced 3D-printed polymers demonstrated high manufacturing precision, favorable mechanical performance, and good biocompatibility. These findings support their feasibility as a standardized and reliable alternative to manually fabricated composite attachments in clear aligner therapy.</p>