Effect of different polymerization techniques on dimensional stability of record bases.

In this study, discrepancies in the adaptation of the posterior borders of maxillary record bases to their casts were analyzed with five polymerization techniques: (1) bench curing, (2) curing under a coat of petroleum jelly, (3) curing in a monomer atmosphere, (4) curing under air pressure, and (5) curing under warm water and air pressure. Ten record bases were made with each of the five techniques and were tested immediately for dimensional accuracy. Measurements of adaptations were made at three points that represent the right and left crest of the ridge and midpalatal region with a measuring microscope equipped with a filar unit-measuring eyepiece. Dimensional changes were observed under all test conditions. The monomer atmosphere technique produced the least dimensional change when compared with other techniques.