So reading your previous questions, and this one, it seems like you have a real phobia of germs, or maybe STIs specifically?
In any case, there is no way to get any of these infections without having sexual activity. They are called sexually transmitted infections because you have to have sexual activity to get them. (Some are blood borne pathogens, and can be transmitted by sharing needles for drug use, too, but that didn't happen here, either.)
None of these infections can survive outside of a human body long enough to infect you through dental tools, or anything else - kitchen utensils, counters, bathrooms, door knobs, etc. The only way you'd get it is sexual activity.
Are you receiving any kind of treatment for your anxiety? You should talk to your doctor about it. There is good treatment available, and you deserve relief.