Abstract
In some commercial acrylic denture base resins, alkylmethacrylates, such as ethylmethacrylate or butylmethacrylate, have been added to methylmethacrylate to control the dough time.This study invstigated the effect of adding alkylmethacrylates on the viscoelastic properties and the impact strength.Test specimens were prepared both by the conventional heat-curing method and by heat-pressure welding of polymers.The storage modulus and loss modulus in the temperature range from 20 to 140℃ were measured, and the glass transition temperature(T_g)was determined.Furthermore, the values of impact energy were measured using an izod impact test at a temperature of 23℃.Increasing the amount of ethylmethacrylate or butylmethacrylate added to methylmethacrylate caused a decrease in the storage modulus, the loss modulus and the impact strength.In particular, the impact strength decreased markedly.These results suggest that it is preferable to reduce the volume of alkylmethacrylates added to control the dough time of denture base resin.
