The authors reach the following conclusion as the result of the examination on the physical properties of vinyl silicone impression materials in comparison with those of other elastomers.
1) The materials are slightly late in the beginning time of setting, but quick in the setting finish, as compared with the condensation typed silicone.
2) The materials are excellent in dimensional stability, as compared with other elastomers.
3) The materials are not only excellent in elasticity, but very small in permanent deformation, as compared with other elastomers.
4) From the results shown above, it is presumed that the materials show preferable impression accuracy even in the case a large undercut is necessary.
