[Bond between wash elastomers and putty silicones]

Areas of elastomeric impression materials are deformed when impressions are removed from undercuts in the mouth. Bond strength between low and high viscosity impression materials is considered to be higher than the adhesion between impression material and teeth or gum (up to 50 N/cm2). Otherwise failure of impression may be due to failure of the bond between putty and wash elastomers. Bond strength of condensation putty and wash silicones was evaluated at about 70 N/cm2. Bond of putty and addition-cured wash silicones failed at about 130 N/cm2. Bond strength decreased to 34 N/cm2, when putty material was contaminated with saliva and dried before adding the wash elastomer. When putty silicones were rinsed and dried after contamination with saliva bond strength increased up to 80-90% that of fresh probes.