There are not too many diseases you really have a danger of contracting solely by kissing.  Mononucleosis is the only other common one I can think of right now...being a medical student.  Just be careful...look for obvious signs (boils, cold sores...[oooo, scary!].  Brush your teeth.  Keep your mouth clean.  When your done with a provider, if you feel the need, brush again, gargle with Listerine, etc.  Seriously, ethyl alcohol at 70% or greater is extremely bactericidal (that means "germ deadly").  So, rip out your oral mucosa with some Bacardi 151, if you're so inclined.  Viruses, you're going to have a harder time with...but most of them are delicate...so, my best advice is to stay clean as possible.