Saliva contamination and resin bonding of etched metal retainers.

This study was performed to determine how preapplication of unfilled resin and subsequent saliva contamination would affect the shear strength of the etched-metal resin-bonded retainer. There was no significant difference in the shear strength of the metal-resin bond among experimental groups when the metal retainer was bonded in the routine manner, when unfilled resin was applied and allowed to polymerize before bonding of filled resin, or when saliva contamination occurred before the addition of filled resin. Preapplication of unfilled resin to etched metal retainers may serve as a means of protecting the etched metal surface for routine try-in of "Maryland bridges" before final cementation.