An in vitro study of 45 teeth compared the failure loads of endodontically treated teeth restored with pin and amalgams, Para-Post dowel and composite, and glass ionomer/amalgam alloy coronal-radicular buildups. The following conclusions were made. The Para-Post and composite buildups exhibited the highest mean failure load, 35.3 kg. The mean failure load for pin and amalgam buildups was 27.9 kg. Glass ionomer/amalgam alloy coronal-radicular buildups exhibited the lowest mean failure load, 14.1 kg. Restoration of endodontically treated anterior teeth with glass ionomer/amalgam alloy coronal-radicular buildups is contraindicated.