Nickel-chromium stainless steel can be found everywhere in our lives, including the utensils used in life, etc. Nickel-chromium alloy porcelain teeth is the use of sintering method in nickel-chromium alloy underlying crown surface porcelain, generally lingual edge with 0.5mm metal edge revealed, in the case of tight bite occlusal surface is not porcelain, made of metal occlusal surface. Such porcelain teeth have been used for 30 to 40 years, occasionally oral mucosal allergy, urticaria, but has not been found to have a direct relationship with hematuria. If chronic urticaria, allergic rhinitis, hematuria and other symptoms are found, it is recommended to go to the appropriate hospital department for further examination in order to exclude other causative factors. The indications for removal and redoing of nickel-chromium porcelain teeth are generally the redness and inflammation of the gums caused by the incompatibility of the cervical edge of the porcelain crown, the chipping of the porcelain on the adjacent surface so that there is a gap between the two adjacent teeth resulting in serious food impaction or the chipping of the porcelain on the lip of the front teeth affecting the aesthetics. If in wearing nickel-chromium porcelain teeth immediately after the mucositis, hives, allergic rhinitis and really can not find other reasons, can also consider removing, and then wear a period of temporary plastic teeth, observe whether the symptoms are eliminated, if confirmed for metal allergy can be changed to all-porcelain restorations.