TENSILE BOND STRENGTH OF POLYVINYL SILOXANE IMPRESSIONS BONDED TO A CUSTOM TRAY AS A FUNCTION OF DRYING TIME .1.

Time-dependent bond strength studies of two polyvinyl siloxane impress ion materials to acrylic resin disks with their respective adhesives w ere studied to determine the optimal time for maximum bond strength. S ix groups were tested with varying adhesive dry times of 0, 7, 15, and 60 minutes and 8 and 24 hours before testing. The results indicated t hat the bond strength of the adhesive increased at least twofold from time zero to 7 minutes adhesive dry time and peaked at 60 minutes for one of the materials and at 8 hours for the other. Bond strengths incr eased rapidly to the 15-minute test interval and then seemed to platea u. Both materials exhibited decreased adhesive bond strengths at 24 ho urs.