SURFACE CHARACTERISTICS OF POLYETHER AND ADDITION SILICONE IMPRESSIONMATERIALS AFTER LONG-TERM DISINFECTION

It has been demonstrated that short-term disinfection can affect the s urface properties of impression materials. This study evaluated advanc ing contact angle, receding contact angle, imbibition and mass loss of a polyether impression material, and two different viscosities of an addition silicone impression material after long-term immersion disinf ection (18 hours). The brand names of the impression materials tested were Impregum F, Extrude Extra, and Extrude Wash, and all were tested by use of the Wilhemy technique; first, for the nondisinfected state, which served as controls, and then after 1 and 18 hours of disinfectio n in a full-strength solution of acid glutarldehyde. Weight changes be fore and after the disinfection process were also measured to detect w eight loss and mass change over time. Ah materials exhibited some degr ee of imbibition. Polyether lost 0.4% mass in air, which indicated los s of a volatile component. Polyether and addition silicone were both r elatively hydrophobic and could be disinfected with acid glutaraldehyd e for up to 18 hours without affecting wettability.