Farrington, T and Coward, T and Onambele-Pearson, G and Taylor, RL and Earl, P and Winwood, K (2015)The effect of model inclination during fabri- cation on mouthguard calliper-measured and CT scan-assessed thickness

Aim: Excessive material thinning has been observed in the production of custom-made mouthguards in a number of studies, due to production anomalies that may lead to such thinning. This study investigated the effect of thinning material patterns of custom made mouthguards when the anterior angulation of dental model was increased during the thermoforming process. Materials & Methods: A total of 60 samples of mouthguard blanks were thermoformed on identical maxillary models under four anterior inclination conditions (n=4×15); control 0°, 15°, 30°, and 45° . Each mouthguard sample was measured, using an electronic calliper gauge, at 3 anatomical points (anterior labial sulcus, posterior occlusion and posterior lingual). Mouthguards were then CT scanned to give a visual representation of the surface thickness. Results: Data showed a significant difference (p < 0.005) in the anterior mouthguard thickness between the four levels of anterior inclination, with the 45° inclination producing the thickest mouthguards, increasing the mean anterior thickness by 75% (2.8mm, SD: 0.16) from the model on a flat plane (1.6mm, SD: 0.34). Anterior model inclination of 30o and 45o inclinations increased consistancies between the thickest and thinnest mouthguards in the anterior region of these sample groups. Conclusion: This study highlights the importance of standardising the thermoforming process, as this has a significant effect on the quality and material distribution of the resultant product. In particular, greater model inclination is advised as this optimises the thickness of the anterior sulcus of the mouthguard which may be more prominently at risk from sportrelated impact.