TL;DR - No
The term you probably want to be using when googling for this sort of thing is "Enlargement Transitional Provisions". There's lots of information on it all on this section of Europa.eu
In short, the UK applied transitional provisions against workers from Romania and Bulgaria for the maximum period of time allowed under the rules, but these expired after December 2013. You can find more on that in this news article, and this UK Parliament briefing paper. With the lifting of those restrictions, Romanians and Bulgarians no longer need work permits of similar for the UK, everything is the same as for any other EU citizen wanting to move and work in the UK.
There are restrictions on benefits, which may well get stricter in the near future based on current political discussions, but no longer any on working