Fracture durability of restored functional cusps on maxillary nonvital premolar teeth

Palatal cusps of nonvital maxillary premolar teeth were restored with a coronal-radicular restoration of posterior composite resin (Occlusin), amalgam (Tytin), or cermet (Chelon-Silver). Mean fracture strength values were: 370 lb for intact premolar teeth, 266 lb for amalgam, 215 lb for posterior composite resin, and 132 lb for cermet. From this in vitro study it can be suggested that for selected endodontically treated maxillary premolar teeth, the dentist can use acid-etch-retained posterior composite resin or pin-retained high copper amalgam material for a definitive coronal-radicular restoration. The use of cermet for this purpose is contraindicated.