Question:
If a woman’s teeth are looking awful because they have turned black, will it be allowed for her to get them clean by a male dentist?
Answer: حامدا ومصليا ومسلما
To have her teeth cleaned by a non-mahram male will not be permissible since it is simply for beautification.
(Hazrat Mufti) Ahmed Khanpuri (May Allah preserve him)
Mahoodul Fatawa 5/672-673