Great question, let me help you. There can be many reasons for thick ropey salivas. First, one of the most common reasons is dry mouth, believe it or not. Have a really dry mouth causes your salivary glands to secret a thick, ropey, stringy saliva. Dry mouth can be from medications, being a mouth-breather, history or radiation therapy in the jaw, and many other things. Second, many medications can have this as a side affect, especially antidepressant medication. Thirdly, thick saliva can be a result of dehydration, post nasal drip, allergies, upper respiratory and sinus infections
, and diabetes. If you've ever undergone chemotherapy, this can cause ropey saliva also. If you have any of the listed conditions, this would help explain your saliva, however if you do not, and you are certain that it is the toothpaste that is causing your thick saliva, then there either is an ingredient in the toothpaste, or the paste is giving you a dry mouth affect. I suggest that you try Crest Sensitivity
b/c it is similar to Sensodyne in that it's great for sensitive teeth, but it may not cause the stringy saliva issue you are having. I hope this helps! Please accept my answer if I've been helpful.