According to the Academy of General Dentistry, competitive swimmers may be at risk for developing yellowish-brown or dark-brown stains on their teeth.
Athlete swimmers who are swimming more then six hours a week are exposing their teeth to large amounts of chemically treated water. Water which contains chemical additives like antimicrobials, which give the water a higher pH than saliva, causing salivary proteins to break down quickly and form organic deposits on swimmer’s teeth.
The result is swimmer’s calculus, hard, brown tartar deposits that appear predominantly on the front teeth. Swimmers who notice the stains should talk to their dentist and perhaps increase their dental visits to three or four times a year.