Frequently, bonded restorations are not inserted into the patients' mouths until a few days after air brushing in the laboratory. By that time the reactive bonds of the metal surface may have undergone saturation by air during storage or by saliva components during try-in. This in turn, might result in a loss of bond strength. According to the present in vitro study it is possible to bond NPM alloy restorations with Panavia Ex several days after air brushing with corundum. The bond strength after up to 150 days of storage in water is approx. 25 N/mm2 and thus clearly above the clinical minimum requirements of 10 N/mm2 (internal enamel strength). After contamination with saliva, restorations must be air brushed again before bonding.