Laser-welded vs soldered nonprecious alloy dental bridges: A comparative study

Abstract

The high cost of gold alloy has caused the dental profession to begin substituting nonprecious alloy for the framework in porcelain fused to metal bridges. Especially in long‐span bridges it may be advantageous to make multiple castings and then join them for a better fit. As opposed to the highly successful soldering of gold, soldered nonprecious alloy bridges have a great failure rate in the mouth. Removal of and remaking of the bridges is thus the result. This study compares nonprecious units that have been laser‐welded with those conventionally soldered. Seven identical bridges of three units were cast in a popular alloy composed of 74–78% nickel, 12–15% chromium, 4–6% molybdenum, and 1·8% maximum beryllium. One served as a control, while the remaining six were all cut in the same place. Of these, three were soldered with a gas oxygen torch. The other three were welded with a Nd‐YAG laser. Better and stronger joints unlikely to fracture in the mouth were found with the leser‐welded specimen.