The effect of steam sterilization on plaster casting material.
Plaster-impregnated gauze was autoclaved as a preventative measure against infection. The mechanical properties and the hardening time of casts made with autoclaved plaster were investigated by measuring flexural yield stress and flexural modulus of elasticity. A cantilever bending test was used to determine the time required to harden. The average yield stress in bending was reduced by an average of 8% and the modulus of elasticity was unchanged by the steam sterilization. The time required for the plaster splint to harden was increased by a factor of 5.6 after steam sterilization. Although the reduction in the yield strength was not prohibitive, the increase in hardening time was unacceptable. The use of gas sterilization is recommended when a sterile cast is necessary because gas sterilization does not increase hardening time.
D002370:Casts, Surgical; D006358:Hot Temperature; D013242:Sterilization; D013314:Stress, Mechanical