ObjectiveTo compare the application of impression made with machine mixed silicone rubber and alginate on fixed partial denture. MethodsThe fixed prosthesis oral cavity repair patients were continuously enrolled who visited the department of Oramaxillofacial Surgery of West China Stomatology Hospital, Sichuan University form June 2010 to January 2011. They were randomly divided into two groups (machine mixed silicone rubber group and alginate group). After conventional row for teeth, both materials were used to make impression. Then, bubble condition and its grade caused by dental impression were evaluated. Statistical analysis has performed using SPSS 15.0. ResultsA total of 50 fixed prosthesis oral cavity repair patients were included, of which, 25 were in the machine mixed silicone rubber group and 25 in the alginate group. Compared with alginate, the impression made with machine mixed silicone rubber was higher of grade (Z=-3.890, P < 0.001), smoother (t=4.196, P < 0.001), higher precision than the alginate group. ConclusionCompared with alginate, the mixed silicone rubber for making oral fixed prosthesis machine impression is higher in precision, clearer in the gum line, which is good for late production of denture.