Effect of Gloves and Sufactants on impression Material Setting Inhibition

Setting inhibition of three Poly(vinyl siloxane) [PVS] impression materials was studied after the impressed surface was rubbed with latex gloves treated with various surfactants. Setting inhibition of PVS has been reported when the mix remains in sustained contact with certain gloves. Under standardized conditions, a glass slab was rubbed for 30 seconds with two types of gloves (powdered & powder-free), each subjected to 3 different combinations of surfactants (wet; soap/rinsed; rubbing alcohol), and an untreated control group. After drying, 3 auto-mixed PVS materials were dispensed onto the treated surfaces at 20 & 37 degrees C, resulting in 960 specimens, in 48 experimental groups (n=20). Samples were removed from the slab at the manufacturer's recommended setting time, and rated as either set, or inhibited if any PVS residue remained. A Chi Square analysis was used to evaluate the data. Two materials (Affinis, Coltene / Whaledent and Aquasil, L.D. Caulk / Dentsply) exhibited no inhibition under any of the testing conditions. The third material (Extrude, Kerr) exhibited significant setting inhibition in selected groups ranging from 40 - 95% of tested specimens (p<.05). For all three PVS materials, temperature significantly influenced setting time (p<.05). The results suggest that the use of these natural latex gloves will not result in setting inhibition with these PVS materials. One of the tested PVS materials was inhibited when the latex gloves had been exposed to rubbing alcohol.