A comparison of six impression syringes

Five manually operated, and one air-activated, syringes were evaluated and compared. When used with polyether or polysulfide, some disposable syringes were found to require in excess of 100 pounds of force to operate. The metal reusable syringe required only 13 and 21 pounds, respectively, with the same materials; the air-activated syringe required none. There was no significant difference among the syringes with regard to bubble entrapment during impression making. There was a significant difference found in this regard among the five experienced dentists. The air-activated syringe was most easily controlled, as evidenced by the significantly smaller number of tracing errors made with it.