The deadline for applications to study dentistry, medicine and Oxford/Cambridge is the 15th of October, so you will be best to start filling out your application straight after you do your AS exams. Organisation is good. You will need to choose your universities and do the UKCAT exam if they require it (I think most will next year). This will be between June and September, but it is better to get it out of the way earlier rather than later. Work experience, try to find NHS work experience as universities like this a lot (from what they told me at open days). Start organising your work experience now, because then you can get doing it and do lots. I did it once per week for 5 months in private practice which really helped and a week in NHS and a day in an orthodontist's. Get to some university open days (Dentistry isn't too bad, there are only 14 unis that do it). You will only be able to apply for 4 dentistry courses and you use your fifth option to apply for an insurance course (if you don't get on) like biomedicine or chemistry or something. Don't worry about writing your personal statement for this insurance course, they understand that people who want to be dentists apply for other things as well and understand you are academically able.