Pure White spot on tooth. On the sides.

I never seen these white patches or spot in any of my tooth. I have been flossing regularly before. I have been dealing with right lower jaw and neck pain since may and I am not flossing at all since may. I am brushing once a day. I extracted upper right wisdom tooth, did one root canal on lower right first  molar. Just had temporary crown today. I am not using that side to eat since I have jaw pain. I noticed some white spot or patches in my teeth recently. It's been there for a month and not going away with brushing. I see that spot only on tooth next to wisdom tooth removal and tooth next to the root canaled tooth. So, I have white patches on second upper molar and lower premolar. It's pure white in color and it's on edges /sides of the tooth. Not able to scrub it while brushing. How to remove these? What to do for this? I never had like this before. Seeing this after my dental work done and am not using that side at all to chew food. And not brushing so heavily on that side.