The effects of hollow microsphere fillers on density and impact strength of denture base resins

The addition of 20 vol% and 40 vol% filler significantly (p less than 0.05) reduced the density and impact strength of the denture base resin when compared with resin without filler. There was no significant difference in the density or impact strength between 20 vol% and 40 vol% filled specimens. Desiccation significantly (p less than 0.05) decreased the density and impact strength of denture base resin regardless of the presence or amount of filler added. The addition of microsphere filler decreased the denture base resin density by 8% to 9%, which may not reduce the weight of prostheses enough to be clinically significant. The impact strength was reduced by approximately 30%.