Abstract
In part 1, we have reported the reduction of thickness in forming and the deformation under static loading in 10 kinds of the sheet type and 4 kinds of the molding type mouthguard materials. In this paper the shock absorptive ability of their materials were investigated by drop-ball test. The steel ball (64.2 g in weight and 25.0 mm in diameter) was dropped on the materials on the steel table from 200 mm height. Shock wave was picked up by an accelerometer and the magnitude of the shock waves were measured by FFT analyzer.
The results were as follows:
1. In the sheet type materials, the thick group showed higher shock absorptive abilities thanthe thin group.
2. In the molding type materials, thick specimen showed higher shock absorptive abilities in each materials. Molteno soft showed the highest and Molteno hard and Elastomer showed the lowest shock absorptive abilities in each thicknesses.
3. With the results of thickness and deformation in part 1, it is suggested that the thin group in the sheet type and less than 3.0 mm of Molteno soft, less than 2.0 mm of Molteno regular, less than 1.0 mm of Molteno hard and Elastomer in the molding type are not suitable for custom-made mouthguar material
