Aim: To compare the dimensional accuracy of the addition silicone in impressions obtained in one and two steps.
Materials and methods: Using a main model with four props of implants (A, B, C, D) 50 impressions took with addition silicone, 25 in one step and 25 in two steps. The plastering were done one hour after polymerized the silicone. Obtained the models of plaster, carried out eight measurements for each one to evaluate the dimensional accuracy of every technique.
Results: the obtained information compared by means of T of Test not rhyming couplet. Two of eight measurements showed a statistically significant difference for the distance oclusal between props of implants, with p = 0,002 for A-B and p = 0,003 for A-C.
Conclusion: Both technologies support his dimensional accuracy and are clinical accepted. There is major dimensional accuracy in the capture of impressions with the technique of two times on having evaluated the distance between props.