All the toothpastes discussed so far include sodium lauryl sulfate (SLS) as a surfactant. It's what gives the toothpastes their pleasant foaminess. Some people find that it irritates their mouths, however, contributing to the incidence of canker sores or other mouth discomfort. Another problem dentists frequently encounter is sensitive teeth - teeth that hurt when touched by hot or cold food or drink.
A lot of things can cause canker sores and sensitive teeth, but most toothpastes designed for sensitive mouths and teeth don't include SLS, which can dry the gums and lining of the mouth. Some toothpastes for sensitive teeth made by Sensodyne and Rembrandt also contain potassium nitrate, an ingredient that can alleviate tooth sensitivity. Dentists say that some patients only need to use a toothpaste for sensitive teeth for a month or two, while others need to stay with it indefinitely.
For patients with sensitive teeth, quite a few dentists recommend Sensodyne toothpastes, which don't contain xylitol but do contain fluoride plus potassium nitrate (5%) to reduce sensitivity. Dr. Vu Le recommends Sensodyne Pronamel (*Est. $5.50 for 4 oz.) , which also reduces one of the main causes of sensitivity, acid erosion of tooth enamel. Nor does it contain SLS, though a few users reviewing Pronamel toothpaste at Drugstore.com report that it irritates their gums anyway. Users also give it mixed reviews for taste and texture. This particular Sensodyne toothpaste isn't on the ADA-approved list. Sensodyne Fresh Impact (*Est. $4.50/4 oz.) does carry their seal, but contains SLS, which can irritate some mouths.
Rembrandt Extra Gentle Mint (*Est. $7/3 oz.) does not contain SLS, and does contain xylitol in addition to fluoride. The RDA isn't specified, but it contains aluminum hydroxide to boost stain removal. None of the Rembrandt toothpastes are on the ADA list, but the Extra Gentle toothpaste, also called Rembrandt Classic Canker Sore Extra Gentle, gets positive reviews from 70 users rating it at Drugstore.com - far more than most toothpastes reviewed there. Rembrandt Classic Sensitive (*est. $7/3 oz.) contains potassium nitrate to combat sensitivity, but sweetens with saccharin and sorbitol rather than xylitol and contains methylparaben - a preservative that quite a few experts suggest avoiding.
The more expensive Squigle Enamel Saver (*Est. $8/4 oz.) isn't on the ADA list either. It doesn't have potassium nitrate and isn't designed for sensitive teeth, but it does have 36 percent xylitol - more xylitol than most toothpastes boast. The toothpaste's name stems from its low abrasiveness; the RDA is only 44. Squigle Enamel Saver earns very positive user-written reviews at Amazon.com, and several detailed single-product reviews also recommend it.
Tom's of Maine Natural Clean & Gentle SLS-free (*Est. $4/5.2 oz.) has less xylitol but costs about half as much. It also has only mild abrasiveness, with an RDA in the 40s. It uses glycyrrhizin, a natural ingredient derived from licorice, for foaming. According to Dr. Weil, this ingredient is also a natural anti-inflammatory and a useful treatment for mouth sores.