Maii,
Here are some very simple answers to your questions. Hopefully these will provide a good reference and starting place for you.
1) The DAT. You may take it nearly any day of the year, and it is administered at Sylvan Learning Centers across the nation. To register for it, you will need to fill out a packet and mail it in. Once the ADA has received your registration, they will mail you a confirmation letter which also includes a phone number for you to call. By calling the phone number, you can reserve a testing day/time slot at one of the Sylvan Centers. The registration packet is also the place where you mark the schools which you want the ADA to send your DAT scores to. Although you have no advisor, your school might still receive DAT registration packets. If not, you can request them online or by phone. For more information on the DAT, you can go to the ADA website at <
http://www.ada.org/prof/ed/testing/dat.asp >
2. AADSAS. The application service for predental applicants is called AADSAS, and this is how you formally let schools know that you are applying to their program. AADSAS will collect your biographical information, letters of recommendation, personal statement, and official college transcripts. Once you have submitted these items to AADSAS, they will mail your file to the schools you have requested. AADSAS is available online in early June of each year. You can find out more about AADSAS by visiting this year's AADSAS website at <
http://www.adea.org/AADSAS/AADSAS_Main_Page.htm >. There you will find instructions for this year's applicants (they won't change much from year to year) as well as other information which will give you a feel for the application process.
3. Fees and supplemental materials. The AADSAS web page also has a downloadable document which lists the fees and other materials that dental schools require. Some schools want you to mail them a processing fee at the same time you submit your AADSAS application online -- and others will request the fee from you only at a later time. Many schools require secondary applications to be filled out, and these are sent to you after the schools have received your AADSAS application.
In summary, the dental school application is comprised of three large parts:
1. Your DAT test scores (which are sent to your chosen schools by the American Dental Association).
2. Your AADSAS application (which is sent to your chosen schools by the American Dental Education Association)
3. Supplemental materials (fees and other items which you are responsible for directly sending to the schools).
Hopefully this information is of some value to you. The websites I listed will have the requirements for registering for the DAT, and other information. You ought to plan on taking the DAT during the spring of your junior year, or the summer between your junior and senior years. That summer is also the optimal time to submit your AADSAS application online. The Fall of your senior year is when you will hear from schools regarding supplemental material and interviews, and Dec. 1 is the first date which schools may notify you of your acceptance (or denial). Many incoming classes are full by late March/early April.
Good luck with your pursuits, look these things over and let us know if we can be of any further help! I would also recommend that you observe a general dentist for a couple of hours to determine if you truly want to pursue dentistry. It would be horrible to fork out the $$ and time for the application process, only to find out that you dislike dentistry. After observing a general dentist, look at some specialists also. Welcome to SDN!