Ok just looked at ucas course finder, for dentistry, selected 3 random unis, they need:
It seems they want 3 A Levels and 1 AS minimum - AAB offer for your A2 level, Chem + Bio must be at A grade. Some don't need the AS Level. At least some also require "UK Clinical Aptitude Test (UKCAT)"
They all seem to require interview to be accepted, also one mentioned at least 2 weeks dental work experience/shadowing. It's a 5 year course.
Pharmacy:
3 A2 or 3A2 + 1 AS Level, depending on where you go. Some specify UCAS points (320 the 1 i saw)
All that's specified is Chemistry (B or above) and one other science (which includes physics, biology and maths).
Basically you'd be wise doing 3 of the sciences (which always includes maths) and something else (History, English Literature) if you liked.
I'm either extremely helpful or extremely bored.