Can this toothpaste keep your teeth white after a dentist visit?

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: 1. Healthy 55 subjects 2. Subjects of caucasian ethnicity 3. Subjects aged between 18 and 65 years (extremes included) 4. Subjects clinically showing stains on teeth (due to smoking, tea, coffee, wine or other food that typically stain teeth) 5. Subjects having at least one natural teeth or central superior incisors (tooth 11 and 21) with color shade at the inclusion ≥12 and ≤30 according to R20 Bleaching shade guide 6. Subjects registered with National Health Service (NHS) 7. Subjects certifying the truthfulness of the personal data disclosed to the Principal Investigator or designated personnel 8. Subjects able to understand the language used in the investigation center and the information given by the Principal Investigator or designated personnel 9. Subjects able to respect the instructions given by the Principal Investigator or designated personnel as well as able to respect the study constraints and specific requirements 10. Subjects who commit not to change their daily routine or lifestyle during the study 11. Subjects on stable pharmacological therapy (except for the pharmacological therapy in the non-inclusion criteria) for at least one month without any changes expected or planned during the study 12. Subjects informed about the test procedures who have signed a consent form and privacy agreement Exclusion Criteria: 1. Subjects who do not meet the inclusion criteria. 2. Subjects with all affection which could interfere with the interpretation of the results of the study 3. Subjects planning toothcare during the study period, using dental apparatus 4. Subjects using dental prosthesis affecting the central superior incisors, with generalized tooth recession, malocclusion or overlapping teeth in the anterior region, with presence of caries, with dental abscess or untreated gum disease, with central superior incisor (tooth 11 or 21) evaluated and filled and who performed whitening treatments less than 6 months before the study begin 5. Subjects with any acute, chronic, or progressive disease or condition that may interfere with the study data or that the Principal Investigator considers dangerous to the subject or incompatible with the requirements of the study 6. Subjects participating or planning to participate in other clinical trials 7. Subjects who participated in a similar study without respecting an adequate washout period (at least one month) 8. Subjects that have intolerances or allergies to ingredients of the study product 9. Subjects under pharmacological treatments that are considered incompatible with the study requirement by the Principal Investigator 10. Subjects who are currently using products with the same activity as the study product, or who haven't observed an adequate washout period (at least one month) 11. Subjects admitted to a health or social facility 12. Subjects planning a hospitalization during the study 13. Subjects not able to be contacted in case of emergency 14. Subjects deprived of freedom by administrative or legal decision or under guardianship 15. Subjects who have or have had a history of alcohol or drug addiction 16. Subject breastfeeding, pregnant or not willing to take necessary precautions to avoid pregnancy during the study (for the women of childbearing potential).