Getting a seat in All India Quota (government) will be very difficult with this score. You can try your state counselling, and from your profile I am assuming your home state to be Andhra Pradesh. To be honest, the cut off for government dental colleges in Andhra Pradesh was also very high (401-407 marks). You can apply in the counselling for private dental colleges in AP, but their cut off too was 420+ marks.

Another option would be management seats in other states