Takahashi Mutsumi, Araie Yoshiaki, Satoh Yoshihide, Iwasaki Shin-Ichi
Department of Physiology, The Nippon Dental University School of Life Dentistry at Niigata, Japan.
RITEC Limited Company, Osaka, Japan.
Dent Traumatol. 2017 Aug;33(4):288-294. doi: 10.1111/edt.12335. Epub 2017 Apr 26.
BACKGROUND/AIMS: Mouthguards can reduce the risk of sports-related injuries such as tooth fracture or avulsion, but the sheet material and thickness have a large effect on their efficacy and safety. The aim of this study was to investigate the effect of the continuous use of a vacuum-forming machine on mouthguard thickness.
Ethylene vinyl acetate sheets and olefin copolymer sheets were used for thermoforming with a vacuum-forming machine. The working model was trimmed to a height of 23 mm at the maxillary central incisor and 20 mm at maxillary first molar. During molding, the model was placed at the center of the vacuum unit. Three molding conditions were investigated (i) molding was carried out after the sag at the center of the softened sheet was 15 mm below the clamp (control); (ii) sheet heating started 5 minutes after the control, and molding in the same way as the control (AF5); and (iii) sheet heating started 10 minutes after the control, and molding in the same way as the control (AF10). Under each condition, vacuum forming was conducted for 30 seconds. Sheet thickness after fabrication was determined for the incisal edge, labial surface, cusp, and buccal surface using a special caliper accurate to 0.1 mm. The differences of the molding conditions on the thickness in each sheet material were analyzed by one-way analysis of variance and Bonferroni's multiple comparison tests.
For both sheet materials, significant differences between the control and AF5 were observed at all measurement points (P<.01), but not between the control and AF10. Compared with the control, AF5 was thinner and AF10 was a similar thickness.
The continuous use of a vacuum-forming machine led to a reduction in the thickness of the mouthguard. Intervals of 10 minutes are necessary to achieve consistent molding.
背景/目的：口腔保护器可降低与运动相关损伤的风险，如牙齿折断或脱落，但片材和厚度对其功效和安全性有很大影响。本研究的目的是探讨连续使用真空成型机对口腔保护器厚度的影响。
使用乙烯醋酸乙烯酯片材和烯烃共聚物片材通过真空成型机进行热成型。工作模型在上颌中切牙处修剪至23毫米高，在上颌第一磨牙处修剪至20毫米高。在成型过程中，将模型放置在真空单元的中心。研究了三种成型条件：（i）在软化片材中心下垂至夹具下方15毫米后进行成型（对照）；（ii）在对照开始5分钟后开始片材加热，并以与对照相同的方式成型（AF5）；（iii）在对照开始10分钟后开始片材加热，并以与对照相同的方式成型（AF10）。在每种条件下，进行30秒的真空成型。使用精确到0.1毫米的特殊卡尺测定制成后片材在切缘、唇面、牙尖和颊面的厚度。通过单因素方差分析和Bonferroni多重比较检验分析每种片材成型条件对厚度的差异。
对于两种片材，在所有测量点，对照与AF5之间均观察到显著差异（P<0.01），但对照与AF10之间未观察到显著差异。与对照相比，AF5更薄，AF10厚度相似。
连续使用真空成型机导致口腔保护器厚度降低。需要10分钟的间隔时间以实现一致的成型。
