Shock Absorption of Mouthguard Materials

Influence of Temperature Conditions and Shore Hardne-ss on Shock Absorption

Abstract

Purpose: To consider changes in the physical properties of mouthguard materials with the change of temperature, shock-absorbing examination and Shore hardness measurement of existing MG materials and other elastic materials were carried out.
Methods: Both examinations were done under two temperature conditions: at room temperature (25deg;C) and simulated intraoral temperature (37deg;C). In addition, a comparative study of the relation between Shore hardness and shock absorption of the materials was made. A self-made drop impact machine was used for the shock-absorbing examination. The thickness of a sample was assumed to be 3mm. The loading was applied by dropping 3 kinds of steel ball, ∅ 10mm (4.0g), ∅ 15mm (13.7g), and ∅ 20mm (32.6g) from a height of 60cm. The shock absorption of all materials was compared by the maximum impact force. Shore hardness was measured based on the JIS standard.
Results: The shock absorption of each material showed a different tendency depending on the loading condition. Furthermore, the shock absorption of the same material showed different results depending on the temperature condition. Shore hardness measurements tended to show low values with the condition of 37deg;C for all materials.
Conclusion: From the relation between shock absorption and Shore hardness, it was confirmed that there is a correlation between hardness and the maximum impact force in the materials that showed shock absorption by elastic deformation. Some materials showed high shock absorption compared with existing MG materials.