Stresses in the anchor crowns of a metal-ceramic bridge in model experiments

A four-unit principal model bridge was used. The stresses in the porcelain part of an anchor crown were analysed. When the middle of the span was loaded tensile stresses appeared in the outer surface of the porcelain and compressive ones in the interface. Greater stresses were found when the anchor crown was loaded itself. They were not critical, however, when the gold thickness was > 3 mm.