I think they just go down the waiting list. most schools rank.
and I don't think AADSAS notify schools after May 1st whether they double deposit or not. I think it's just that one time but I might be wrong....so it wouldn't matter if people double deposit after May 1st.
this is from AADSAS
Applicants holding positions at multiple institutions. Dental schools participating in AADSAS will report to AADSAS by May 1, the names and identification numbers of candidates who have paid a deposit and/or hold a position in their entering class. After May 5, AADSAS will report to each institution the names of candidates in their entering class who are holding acceptance(s) at additional institutions. Dental schools will have the option of rescinding an offer of admission to candidates who have paid deposits and are holding positions at multiple institutions. Dental schools with candidates holding multiple positions on May 1of the year of admission will give such candidates a minimum 15-day notice if they choose to withdraw them from the entering class. This policy will be evaluated every two years by the ADEA Section of Dental School Admissions Officers to assess its impact on applicants and dental schools and provide applicants a reasonable time-frame to complete their enrollment process.
good luck everyone! I just need something like this to keep me going and to stay optimistic. but yeah, i have other plans if i don't get off the waiting lists.