Color and glaze: Effects of repeated firings

Four commercially available porcelains were applied to 108 specimens of five precious and one nonprecious alloys. Porcelains applied to these specimens were subjected to repeated firings up to nine times to compare shade and glaze. The results were as follows:o1.Repeated firings, up to nine times, do not noticeably effect the shade of porcelain.2.Repeated firings may cause reduction and loss of autoglaze in porcelain.3.Porcelain manufacturers' recommendations for selection of alloy do not improve the color nor the autoglazing of porcelain bonded to metal.