Effect of the anteroposterior position of the model on fabricated mouthguard thickness: Part 2 Influence of sheet thickness and material

Bando

2019

Self Cite

Background/Aim Wearing a mouthguard during sports reduces the risk of dental injury via absorbing impact forces, and the effectiveness and safety of the mouthguard are closely linked to the mouthguard material and thickness. The aim of this study was to clarify the suppression effect of the thickness reduction of the mouthguard when changing the moving distance of the model forward in a stepwise manner. Materials and Methods Ethylene‐vinyl acetate sheets of 4.0 mm thick and a vacuum forming machine were used. The working model was placed at a position 40 mm from the front of the forming unit. The sheet was softened until it sagged 15 mm, and the sheet frame was lowered and covered the model. The model was then pushed from the back to move it forward, and the vacuum was switched on. The model was moved 10 (MP‐10), 20 (MP‐20), or 30 mm (MP‐30). The control model was not moved. The thickness after formation was measured with a specialized caliper. Differences in the mouthguard thickness caused by the forming conditions were analyzed by one‐way ANOVA and Bonferroni's multiple comparison tests. Results Significant differences were observed between the control and each MP condition (P < 0.01). Reduction rate of the thickness decreased as the moving distance of the model increased. In particular, the thickness difference depending on the forming conditions was greater at the labial site. The reduction rate of MP‐30 was 33.8 ± 0.8% smaller than that of the control. Conclusion The thickness reduction in mouthguards was mitigated by moving the model forward just before vacuum forming. The reduction was smaller as the moving distance of the model increased. This study suggested that moving the model 20 mm or more forward just before vacuum forming could secure the labial thickness of 3 mm or more.

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

“…The sheet thickness after formation was measured with a specialized caliper (21–111, YDM Co.) that can measure up to 1/10 mm . The spring in the caliper was removed.…”

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Movement of model position just before vacuum forming to ensure mouthguard thickness: Part 2 Effect of model moving distance

Bando

2019

Self Cite

Thermoforming technique for suppressing reduction in mouthguard thickness: Part 2 Effect of model height and model moving distance

Bando

2020

Self Cite

Background/Aim Wearing a mouthguard reduces the risk of sports‐related injuries, but the material and thickness of the mouthguard have a substantial impact on its effectiveness and safety. The aim of this study was to establish a thermoforming technique in which the model position is moved just before formation to suppress the reduction in thickness. The aim of this study was to assess the effects of model height and model moving distance on mouthguard thickness. Materials and Methods Ethylene‐vinyl acetate sheets of 4.0 mm thick and a vacuum forming machine were used. Three hard plaster models were trimmed so that the height of the anterior teeth was 25 mm, 30 mm and 35 mm. Model position (MP) 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. The model was then pushed from behind to move it forward, and the vacuum was switched on. The model was moved at distances of 20 mm, 25 mm or 30 mm whereas a control model was not moved. Thickness after formation was measured with a specialized caliper. Differences in mouthguard thickness due to model height and moving distance were analysed by two‐way ANOVA and Bonferroni's multiple comparison tests. Results Sheet thickness decreased as the model height increased. Each MP condition was significantly thicker than the control in each model. There was no significant difference among MP conditions except for the buccal surface. Conclusions Moving the model forward by 20 mm or more just before formation is useful to secure the labial thickness of the mouthguard. This thermoforming technique increased the thickness by 1.5 times or more compared with the normal forming method, regardless of model height.

Fabrication method to maintain mouthguard thickness regardless of the model angle

Bando²

2020

Self Cite

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. Materials and methods: 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. Results: 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. Conclusions: 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.