Assuming that you are a military dentist…
What are some of the advantages that come with living on base?
Larger maintenance issues are taken care of for you (your essentially renting the place so if your roof leaks they fix it), short commute to work (not always the case for example if you are stationed somewhere like LA Air Force Base where housing is not collocated with the base/clinic but this may be really nice if you live in like Alaska with bad weather), close access to things like a free gym (again not always the case), the base golf course may be nearby, there is a community of military to provide support (if you deploy it will be nice to have support for your family and at the very least your stuff is safe and someone will likely mow your lawn), junior officers with families may be able to get more space than their BAH would allow off base depending on location (when I got to my first base as a 2Lt I could only afford a condo or a place in a less than desirable neighborhood but on base it was safe and would have gotten a house so if I had kids I probably would have lived on base because of space and the school for the kids - as a Capt probably a wash and higher ranks unless you are a commander with a designated house probably not going to get anything better than you could afford off base).
Are utilities included or do you pay for them separately?
Generally included
Are you able to get cable and internet service?
Yes you pay for you plan so can usually get what you want
If you eat on base, how expensive are the meals… Is there a large cafeteria/mess hall?
Officers are not usually permitted to eat in the mess/dining hall unless they are temporarily visiting for duty or for some sort of morale type thing if they are a commander. Other options are fast food and prices are the same as off base. The grocery store on base is something there is often a misconception as well, the food is not free, but is often name brand things at discounts but personally I shop sales at Safeway/Ralphs or get generic and it is cheaper.