Alnuaimy Noor S, Alhuwaizi Akram F
Department of Orthodontics, College of Dentistry, University of Baghdad, Baghdad, Iraq.
J Orthod Sci. 2025 Mar 25;14:2. doi: 10.4103/jos.jos_75_24. eCollection 2025.
Retention preserves the optimal esthetic and functional positions of teeth following the termination of active orthodontic treatment. Conventional stainless-steel multistrand fixed retainers have limitations and drawbacks, mainly related to retainer failure.
Nano-ceramic hybrid resin (SprintRay OnX) was employed to fabricate new, customized three-dimensional (3D)-printed lingual retainers, and their debonding forces and failure modes were evaluated.
Pairs of premolars were embedded in acrylic blocks. Fifty acrylic blocks were divided into five groups, including three different cross-sections of customized 3D-printed wires- round (1 mm), oval (1 × 1.5 mm), and semi-elliptical (1 × 1.5 mm)- and comparative stainless steel multistrand retainers (G and H and Respond). Retainers were bonded to the teeth using Transbond™ LR Light Cure Adhesive. The models were stored in distilled water for 24 hours, simulating the wet intraoral conditions. Debonding forces and failure modes were then evaluated. A vertical debonding force was applied to the interdental area of the bonded retainer. Post-retainer debonding failure mode was examined under a stereomicroscope (×10 magnification).
Semi-elliptical 3D-printed retainers yielded the highest debonding forces, followed by oval 3D-printed retainers, twisted G and H retainers, round 3D-printed retainers, and Respond retainers. The debonding forces of oval and semi-elliptical 3D-printed retainers did not differ significantly. The 3D-printed retainer groups presented predominantly cohesive failure due to the strong adhesion between the 3D-printed resin and adhesive.
Oval and semi-elliptical 3D-printed retainers exhibited favorable debonding forces.
保持是在主动正畸治疗结束后维持牙齿最佳美观和功能位置的方法。传统的不锈钢多股固定保持器存在局限性和缺点，主要与保持器失败有关。
采用纳米陶瓷混合树脂（SprintRay OnX）制作新型定制三维（3D）打印舌侧保持器，并评估其脱粘力和失败模式。
将成对的前磨牙嵌入丙烯酸块中。50个丙烯酸块分为五组，包括三种不同横截面的定制3D打印丝材——圆形（1毫米）、椭圆形（1×1.5毫米）和半椭圆形（1×1.5毫米）——以及对比的不锈钢多股保持器（G和H以及Respond）。使用Transbond™ LR光固化粘合剂将保持器粘结到牙齿上。模型在蒸馏水中储存24小时，模拟口腔内湿润条件。然后评估脱粘力和失败模式。对粘结保持器的牙间隙区域施加垂直脱粘力。在立体显微镜（×10放大倍数）下检查保持器脱粘后的失败模式。
半椭圆形3D打印保持器产生的脱粘力最高，其次是椭圆形3D打印保持器、麻花状G和H保持器、圆形3D打印保持器以及Respond保持器。椭圆形和半椭圆形3D打印保持器的脱粘力无显著差异。由于3D打印树脂与粘合剂之间的强粘附力，3D打印保持器组主要呈现内聚性失败。
椭圆形和半椭圆形3D打印保持器表现出良好的脱粘力。
