Department of Physiology, The Nippon Dental University School of Life Dentistry at Niigata, Niigata, Japan.
BANDO Dental Clinic, Ishikawa, Japan.
Dent Traumatol. 2021 Feb;37(1):131-137. doi: 10.1111/edt.12584. Epub 2020 Jul 11.
BACKGROUND/AIM: The safety and effectiveness of mouthguards depend on the sheet material and thickness. The aim of this study was to investigate the fabrication method for a mouthguard with appropriate thickness using a single sheet regardless of the model angle.
Mouthguards were thermoformed using 4.0 mm thick ethylene vinyl acetate sheets and a vacuum forming machine. The working models were three hard plaster models trimmed so that the angle of the anterior teeth to the model base was 90°, 100°, and 110°. The model position was 40 mm from the front of the forming unit. The sheet was softened until it sagged 15 mm, after which the sheet frame was lowered to cover the model. Next, the vacuum was turned on and held for 30 seconds for the control. Under the forming conditions in which the model position (MP) was moved, after the model was covered with the sheet, a scissors handle was positioned at the rear of the model and used to push it forward 20 mm, and then, the vacuum switch was turned on for 30 seconds. Six specimens were formed for each condition. Mouthguard thickness after formation was measured using a specialized caliper. The differences in mouthguard thickness due to forming conditions and model angle were analyzed.
The MP was significantly thicker than the control in each model (P < .01). The mouthguard thickness tended to decrease as the model angle increased. The average thickness of the labial surface in the MP was 3 mm or more and was not affected by the model angle.
This study suggested that the fabrication method in which moving the model forward by 20 mm just before formation could produce a mouthguard with approximately 3 mm thickness on the labial side with a single sheet regardless of the model angle.
背景/目的：防护牙套的安全性和有效性取决于片材的类型和厚度。本研究旨在探索一种方法，使用单一薄片材料，无论模型角度如何，都能制作出具有适当厚度的防护牙套。
使用 4.0 毫米厚的乙烯-醋酸乙烯共聚物片材和真空成型机对防护牙套进行热成型。工作模型是三个硬石膏模型，修整后使前牙与模型基底的角度分别为 90°、100°和 110°。模型位置距离成型单元前端 40 毫米。将片材软化至下垂 15 毫米，然后降低片材框架以覆盖模型。接着，打开真空并保持 30 秒作为对照。在模型位置（MP）移动的成型条件下，在片材覆盖模型后，将一把剪刀手柄置于模型后部并向前推动 20 毫米，然后打开真空开关保持 30 秒。每种条件下形成 6 个样本。使用专用卡尺测量成型后的防护牙套厚度。分析成型条件和模型角度对防护牙套厚度的影响。
在每个模型中，MP 都明显比对照更厚（P<.01）。随着模型角度的增加，防护牙套的厚度有变薄的趋势。MP 唇面的平均厚度为 3 毫米或更厚，不受模型角度的影响。
本研究表明，在成型前将模型向前移动 20 毫米的制作方法可以使用单一薄片材料，无论模型角度如何，都能在唇面制作出约 3 毫米厚的防护牙套。
