I can't say whether the risk of acquiring HIV, if exposed, is elevated after the sort of dental procedure you describe. If this has been studied or any data are available, I am unaware of it. I don't know what you mean by "naked gum"; if there was an open sore, the risk might be elevated, but if the gum had healed over, there shouldn't be a problem. Even with open lesions on th bums, if there is any increased risk at all, it is a good bet to be small. Obviously I cannot diagnose the rash you describe, but it does not sound suspicious for HIV infection or any other STD. Anyway, if you are concerned, have another HIV test. Enough time has gone by so that you can rely on a negative result.
Good luck-- HHH, MD
You should focus instead on the fact that neither man ejaculated into your mouth; this bodes well for you. Even if both were HIV+, most research indicatest that the HIV contained in precum (if there was any precum involved), is in such small amounts that it is difficult for it to survive the hostile environment of the mouth (your saliva would block some of the HIV's power to infiltrate your gums.) Three researchers I read about online -- Susan Buchbinder, Kimberly Page-Schafer, and Jeff Klausner -- did a lot of research into HIV and oral sex. They said that transmission via oral sex without ejaculation is exceedingly rare, even to the one giving a blowjob. The dental work increases the risk a little in theory, and there would be increased risk if either of the two Chilean men had another STD that could have been producing pus or other ulcering, canchrous effects. But these are small increases added to an extremely low risk in the first place.
Jeff Klausner, who has a column on gay.com, said that his advice was for men "to enjoy oral sex and get tested once a year." That's how low the risk of oral sex is, regarding HIV. You could choose to get tested once for these episodes, and then keep on doing oral sex and get tested again in a year for everything.
Thank you doctor for your comment, and thank you also to the second poster. I am sorry for being unclear about 'naked gum'. By that I meant that because the tooth had been filed away the gum 'socket' was exposed - eg the area of the gum where the tooth had previously been. However, it was two days later so I would expect it to have healed by this time, and certainly not to be like a fresh sore. I don't recall any blood when I touched it for example, or even any pain. Also neither man had ejaculated in my mouth so hopefully that helps my case, so to speak.