Hi James
Not that I know re shortage of dental nurses, there are a batch of qualified nurses just hitting the market now after qualifying, but I presume you mean someone who has been in the industry a while?.
just a thought but have you approached -:
www.cavitydentalstaff.co.uk
, they cover most of the uk and have temp and permanent nurses on file, maybe able to help you.
Shame you are too far away I have 30 years on and off experience and am qualified, I could have helped.
hope you get sorted