In vitro considerations in the production of dimensionally accurate earmoulds. II. The earmould material.
In the first part of this work, the accuracy of impression materials was studied. In the present paper, the dimensional accuracy of a range of hard and soft polymeric earmould materials was studied and found to be a function of choice of material, processing equipment, curing cycle, time after processing, and choice and storage time of impression material. It was noted that generally speaking the overall shrinkage of a two-stage specimen is approximately equal to the sum of the impression shrinkage plus processing shrinkage. Clinical trials are now being conducted to assess the real ear performance of earmoulds as a function of material accuracy and flexibility.
Biomaterials Science Unit, University of Manchester, Lancashire, England.
E C
EC
Combe
M
M
Nolan
D000179:Acrylates; D006310:Hearing Aids; D066298:In Vitro Techniques; D011108:Polymers; D012828:Silicones; D013997:Time Factors
D000179:Acrylates; D011108:Polymers; D012828:Silicones