fafooden,
if you only have 2 months, that cuts out a lot of possible topics. You could do a wound healing study, but that would require access to an animal facility and persons experianced with a model. You could always do something microbiologically related: in vitro s. mutans, lactobacillis etc. studies (vary their diet, etc), something with perio disease related bacteria. If you need ideas on general topics in dental research, check out some online (or paper) issues of JADA or another dental journal - you can link to it from ada.org Oh, and there're always materials research topics...
Good luck!
p.s. are you an undergrad or is this predoctoral project? Where do you go to school?