Whilst the universities conduct a CRB/DBS check to ensure you are safe to go out on placement - it's also to screen for folk who have convictions that would prevent them from gaining paid employment upon qualifying. They also do not want to train/fund a 3 year course for someone when there is no gain for anyone involved at the end. Although it may be disappointing, the advantage is that you won't have to 'work your a*se' off for 3 years to find out.
With that in mind, I'd really suggest giving the admissions tutors a call and talk it through with them. Trust me, this will be a conversation they have had with many people and they'll be best placed to advise you. It'll also give you some practice at disclosing - if you are successful, you will still have to have this conversation with every new employer you have.
As has already been said, a criminal record is not an automatic exclusion. I write this post with a less than perfect history myself (my teens were spent rough sleeping and with documented run ins for soliciting and heroin use). I've also spent the last 10 years working "in the field" in jobs which all required a CRB check.
Individual circumstances are important. Honesty and transparency is essential!
Speak to those that can give you the answers you need to put your mind to rest. Go on, what are you waiting for?!
All the best