NOTHING. There is no magical way to prevent HIV transmission apart from wearing a condom consistently. HIV doesn't transmit through the mouth.
If you are this concerned about getting HIV and you are having intercourse regularly with partners whose HIV status is not known to you, talk to your doctor about PrEP.
why you said that HIV doesn't transmit through the mouth? unprotected oral sex can transmit HIV if there are cuts(even micro-tears?) inside the mouth or throats
Oral sex is NOT a realistic concern. It is a 0.001% risk, which is not statistically significant.
Again, if you are THAT concerned about HIV, especially from negligible risk events, you need to 1) talk to your doctor about PEP, and 2) perhaps talk to a therapist about your irrationally inflated concern about HIV.
No, that statistical incidence of transmission is for everyone, even those with mouth sores. No one gets HIV from oral sex regardless of their oral hygiene or mouth sores. It just does not happen.
Ok thank you for the answer, you are helping me a lot, I appreciate that.
unprotected oral sex can lead to other STDs such as Chlamydia, and they raise the risk for HIV as they make your immune system more vulnerable to any kind of virus, including HIV, am I right?
Reread. "No one gets HIV from oral sex regardless of their oral hygiene or mouth sores."
and 2) perhaps talk to a therapist about your irrationally inflated concern about HIV.