There is no scientific evidence that Keselu makes teeth yellow. Keserol is a lubricant, the main ingredient is glycerin, is a topical drug for constipation, mainly to relieve the symptoms of constipation, and does not have the effect of getting rid of yellow teeth. Yellow teeth may be exogenous discoloration of the teeth, such as long-term use of some special mouthwash, will cause tooth staining, such as fluorosis, tetracycline teeth, etc.; may also be endogenous discoloration of the teeth, such as pulp bleeding, dentin demyelination. To treat yellowing of teeth, first of all, we should avoid consuming medicines or supplies that cause yellowing of teeth, treat the corresponding primary diseases, and for the teeth that have been discolored, we can choose different methods such as bleaching method, cold light whitening of teeth, and restoration method to repair them. Therefore, yellowing of teeth should be treated with scientific methods, and the use of corkscrew is not recommended.