Inclusion Criteria:  Aged between 18-70 years old Good general health Could attend the clinical examinations during the 4 week study period Possessing >20 natural permanent teeth that were uncrowned or heavily filled with restorative materials, excluding third molars Having a whole-mouth mean tooth stain score of more than 1.5 according to the Lobene index.  Exclusion Criteria:  Severe oral diseases, chronic disease or allergic to the trial products Advanced periodontal diseases Females who are pregnant or lactating Taking part in other clinical trials Taking part in orthodontic treatment or wearing removable denture Fluorosis or tetracycline teeth Receiving prophylaxis during the previous 3 months or tooth whitening treatment during the past 6 months.