Not having had dealings with UKBA for some time, I can't say for sure, but it set the SCAM alarm buzzing in my head - the English is all wrong - even if writing to your friend, at least the english would be correct, one would hope. As mentioned, she really need to get in touch with the BDA, & possibly the UKBA - if there is a shortage of dentists, the profession will be listed as in need with UKBA & they can advise her of what to do - failing those 2 organisations, the Visa agency in UAE or the Consulate may be able to advise, but she needs to steer clear of the cowboys who wrote to her.
1 other minor thing to consider is her training / experience - we had a similar situation in nursing - we had lots of nurses who'd worked in UAE, BUT had to undertake an adaptation programme before registration in the UK, but even if this is the case, the BDA / UKBA will be able to advise her.
Best of luck to her - we need NHS dentists in the UK!!