I massage the muscles of my hands and wrists almost daily, especially the muscles by my thumbs because that is what bothers me the most. Wrapping cold clothes or ice packs around my hands and wrists some nights before bed has helped me also. If I feel any pain while working I will correct my ergonomics right away until the pain subsides and try to remember how my wrists were positioned that caused pain and find a better way to keep my wrists in a neutral position. I will also do finger and wrist stretches while working on patients and that helps some.
I have always been concerned about carpal tunnel. When I started having sore wrists, tingling I was checked for carpal tunnel and they said I was fine. I changed the diameter of my instruments, I have some thicker some thinner, that has helped me somewhat. I have been practicing 27 years. I was having symptoms about 10 years ago. It was also suggested to wear wrist splints at night when the symptoms were more consistent. I did not do this though. Talk to a specialist to get the best information for your situation.
Try using a Wrist Timer. You can purchase anywhere online. I bought mine from Posturedontics.