Enhanced Force Systems for Efficient Maxillary Anterior Diastema Closure Using Clear Aligners: Evaluation of Attachments and Enhanced Structural Modifications

This study evaluates the biomechanical efficacy of clear aligners in closing anterior maxillary diastemas using enhanced force systems. While clear aligners offer esthetic and functional benefits, their predictability in controlling bodily movement and torque remains limited. This research investigates the effects of structural modifications, such as the addition of flowable resin to interdental embrasures and intrusive force application, on the force and moment characteristics during mesial bodily movement of maxillary central incisors. Experiments were conducted using 3D-printed maxillary models with a 6-axis force/torque sensor under controlled conditions. Four experimental groups were tested: Group 1 (0.3 mm mesial bodily shift), Group 2 (0.3 mm mesial shift + 0.1 mm intrusion), Group 3 (0.3 mm mesial shift with resin reinforcement), and Group 4 (0.3 mm mesial shift + 0.1 mm intrusion with resin reinforcement). The results showed that Groups 1 and 3 exhibited extrusive forces, while Groups 2 and 4 exhibited intrusive movement with minimized extrusion. Resin reinforcement significantly increased mesiodistal force application and reduced unwanted tipping and rotational moments, improving bodily movement efficiency. The addition of intrusive movement minimized extrusive forces but introduced a minor lingual inclination. The combination of both modifications provided the most controlled and efficient tooth movement. These results suggest that modifying clear aligners with localized structural enhancements can improve treatment predictability and efficiency. Clinically, the application of flowable resin enhancements offers a simple and effective approach to optimizing clear aligner therapy.