Abstract: Objective To study the effects of monomer released from four kinds of temporary crown materials on DNA damage of buccal mucosa cells. Methods The experimental animal models was established with prosthesis of temporary crowns on dog' s teeth, using chemical-curing acylate resin, heat-curing resin, DMG-TEMP resin and Shofu SWIFT-TEMP resin. The buccal mucosa cells in the corresponding areas were collected and its DNA damage was detected by comet assay in five different periods. Results The residual monomer released from chemical-curing resin and heat-curing resin resulted in significant comet cells percentages of buccal mucosa cells (P<0.01) during the forepart period after temporary crowns were worn. The comet cells percentage of buccal mucosa cells in DMG-TEMP resin group and Shofu SWIFT-TEMP resin group both remained steady at a low level, without significant difference(P>0.05). Conclusions The chemical-curing and heat-curing resin crowns resulted in significant DNA damage of buccal mucosa cells in the corresponding areas during the forepart period after temporary crowns were worn, while DMG-TEMP resin and Shofu SWIFT-TEMP resin crowns did not.