GITAM Dental College and Hospital, Visakhapatnam, India.
Clin Oral Investig. 2023 Oct;27(10):5805-5812. doi: 10.1007/s00784-023-05192-y. Epub 2023 Aug 16.
The aim of the present study was to comparatively evaluate the mechanical wear of adhesives used in bonded retainers.
Eighty mandibular acrylic teeth were included in the study that were divided into 4 different groups based upon the composite used. Each acrylic tooth was bonded with a retainer wire and composite of their respective group (Heliosit, Restofill, Tetric-N-flow, and Filtek Z350 XT). These bonded acrylic teeth were subjected to 3D scan in order to evaluate the volume and surface area of the composite. The 3D scans were recorded using MEDIT 3D scanner. After evaluating, the samples were subjected to brushing with the aid of a custom-made brushing simulator using a toothbrush with soft bristles and toothpaste slurry. The samples were subjected to 1 hr of brushing. These samples were again subjected to 3D scans to evaluate (post-test volume and surface area) and underwent statistical analysis.
The results showed the Heliosit group exhibited the highest mean volume (1.76 mm) and surface area (4.81 mm) difference between the pre-test and post-test values whereas the least mean volume difference (1.10 mm) and surface area difference (3.21 mm) were seen in the Tetric-N-flow group.
All the four composites underwent change in the mean surface area and volume after being subjected to brushing, suggesting that the composites routinely used for bonding fixed bonded lingual retainers are subjected to changes due to abrasion. The Heliosit group, which showed least filler loading among the 4 composites, exhibited least resistance to wear, whereas the Tetric-N-flow group which had highest filler loading among the composites exhibited highest resistance to wear.
The most crucial phase during orthodontic treatment is the retention phase. This phase is responsible for the long-term results of the treatment. The retainers that are placed in the oral cavity are subjected to changes due to oral environment, chemical changes, and mechanical changes. These changes have a direct effect on the retainers, which tend to alter their properties. Thus, the effects of these changes are to be studied thoroughly.
本研究旨在比较评估用于粘结保持器的胶粘剂的机械磨损。
本研究纳入了 80 颗下颌丙烯酸牙齿，根据使用的复合材料将其分为 4 个不同组。每个丙烯酸牙齿都用保持器线和相应组的复合材料（Heliosit、Restofill、Tetric-N-flow 和 Filtek Z350 XT）粘结。这些粘结的丙烯酸牙齿用 MEDIT 3D 扫描仪进行 3D 扫描，以评估复合材料的体积和表面积。记录 3D 扫描后，使用定制的带有软毛牙刷和牙膏糊的刷牙模拟器对样本进行刷牙。样本刷牙 1 小时。再次对这些样本进行 3D 扫描以评估（测试后体积和表面积）并进行统计分析。
结果显示，Heliosit 组在预测试和后测试值之间表现出最高的平均体积（1.76mm）和表面积（4.81mm）差异，而 Tetric-N-flow 组表现出最小的平均体积差异（1.10mm）和表面积差异（3.21mm）。
所有四种复合材料在经受刷牙后，平均表面积和体积均发生变化，表明用于粘结固定舌侧保持器的复合材料由于磨损而发生变化。在这四种复合材料中，Heliosit 组的填料加载量最低，表现出的耐磨性最低，而 Tetric-N-flow 组的填料加载量最高，表现出的耐磨性最高。
正畸治疗过程中最关键的阶段是保持阶段。这个阶段是治疗长期效果的关键。放置在口腔内的保持器会受到口腔环境、化学变化和机械变化的影响而发生变化。这些变化直接影响保持器，使其特性发生变化。因此，需要彻底研究这些变化的影响。
