Cast metal resin-bonded dental restorations: Effect on the resin-to-metal bond of storage conditions before cementation

Abstract

Cast metal resin-bonded restorations are often stored in the laboratory or dental practice/office before they are fitted in the mouth. This study investigated the effect of the storage conditions of such restorations on the tensile bond strength of a resin cement. Sixty cylinders were cast in nickel-chromium alloy (Wiron 88). Their bonding surfaces were sandblasted, cleaned ultrasonically in distilled water, and air dried. Groups of 10 cylinders were stored for 10 days in an office environment as follows: in an open container, in a sealed polyethylene bag, in a plastic pot, in distilled water, or in acetone. A control group was used immediately for bonding. Each cylinder was bonded with a thin film of resin (Panavia Ex) to a freshly prepared disk of the same alloy. After 24 hours in water at 37 °C, the assembly was loaded under tension to failure. The results indicated that storage in an open container should be avoided and that restorations can best be protected by storage in distilled water.