EXP: As used materials,

・ Dental alginate impression product (SiO₂: Diatomite) (Algiace Z, DENTSPLY International Inc., Tokyo, Japan)

・ Chalk (CaCO₃) (Dustless chalk, Nihon Rikagaku Industry Co., Ltd., Kawasaki, Japan)

CON: As a control,

・ Diatomite (SiO₂) (Wakkanai green factory Co., Ltd., Wakkanai, Japan)

・ CaCO₃reagent (Calcium carbonate, Wako Pure Chemical Industries, Ltd., Osaka, Japan)