Effects of a solution of a succinic aldehyde on elastomeric impressions

This study investigates the effect of a 10 per cent solution of a succinic aldehyde on impressions of three representative elastomeric materials. For each material ten specimens were required for each of six immersion periods ranging from 10 min to 72 h at 23 degrees C and including immediate and delayed immersions. Control groups, each of five specimens, were investigated in air and water. The specimens were formed against a standard ruled block (ADA No. 18). Before and after immersion/storage the impression surface of each specimen was assessed, scored and measured to determine dimensional stability and any attenuation and loss of detail. The results indicate that following all immersion/storage periods there was no loss of detail. Whereas dimensional changes of c. -0.5 per cent and +1.0 per cent were observed for the addition and condensation cured silicones, respectively, after 72 h immersion in the solution, zero dimensional changes were observed following the recommended immersion period for sterilization (4 h). However, with the polyether impressions, a 4 per cent expansion occurred after 4 h in the test solution and 9 h in the aqueous control. No significant differences were found between data relating to immediate and delayed immersions. It is concluded that the immersions in the test solution had no effect on surface detail; only the silicone impressions exhibited acceptable dimensional stability during prolonged immersions (4-72 h) in the test solutions and aqueous control, and that the polyether specimens withstood immersion in the test solution for the 10-min period recommended for disinfection.