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Purpose This investigation compared the Vickers hardness and microstructures of four recently marketed, palladium‐based alloys for metal‐ceramic restorations.

Materials and Methods Wax patterns simulating copings for maxillary central incisors were invested in a fine‐grained, carbon‐free, phosphate‐bonded investment. Following burnout, the palladium alloys were fused with a gas‐oxygen torch, centrifugally cast, and bench‐cooled. Representative castings were embedded in transparent metallographic resin and sectioned to yield two mirror‐image specimens. The specimens were evaluated in either the as‐cast condition or following heat treatment simulating the firing cycles for Vita VMK porcelain. Vickers hardness measurements (n = 50) were made using a 1‐kg load, and photomicrographs of polished and etched specimens were obtained with a scanning electron microscope.

Results The measured …