Q. I was troubled with recurrent canker sores for a while. The only thing that had changed was my toothpaste. I wanted whiter teeth, so I was using whitening toothpastes.
I got canker sores when there was sodium lauryl sulfate (SLS) in the toothpaste. As soon as I switched to toothpaste without SLS, the mouth sores went away.
A. Many readers report that if they avoid toothpaste with SLS, mouth ulcers are less troublesome. Nevertheless, a randomized controlled trial of SLS-free toothpaste did not result in a change in outbreaks. It did cut healing time and reduce pain (Oral Diseases, Oct. 2012).