Small potential cavity what to do?

Hi guys, I am 27m, dentist once a year, never had a filling, am very good with oral hygiene, last check up a couple of months ago was excellent but I have noticed a small black dot on maybe one or 2 of my teeth at the back, potential stage 1 cavity?

What can I do the help/prevent these from getting worse, strange as dentist said nothing but like I say, you have to get a light on the back to notice.

Thoughts on duraohat fluoride toothpaste and xylitol

Gum?