katie,
yes, dental school is very competitive just like medical school. about a ~50% acceptance rate each year just like medical school. However the curriculum in dental school is much, much more demanding. The first two years you are doing the same stuff as medical students, plus dental stuff like laboratories and lectures. At U.Washington the medical students go to class around 4 hours a day. However, the dental students are in class/lab/etc from 7:30am-5pm. Some schools even have labs until midnight somenights. Yes, the gpa's are not as high as medical school with ave acceptance between 3.3-3.5, but it is much more demanding. If you are thinking that dental school will be easier to get into than medical school, or if you changed your mind from medicine for whatever reason do your research. You need to do research....nothing makes me more upset than random pre-meds asking if dental school is easier. It isn't. SDN is a great source for advice but people need to do their own research. Go to AMCAS and ADEA websites and see the grade trends and other stuff.
About your recommendation question. Most schools require 3. Some schools want 3 science, others 2 science and one non-science, and others want dentist and science and non-science. So get as many as you can...GOOD recommendations not vague ones stating you did good in the class and dental school is for you. The dental ADcom can see right through a person if they have passion or not. you need experience too..dental experience. Clinical is good, but you need dental experience observing, helping out. Hope this helps.
DesiDentist