Inventor held back by false teeth (5)
I believe the answer is:
tesla
'inventor' is the definition.
(scientist Nikola Tesla)
'held back by false teeth' is the wordplay.
'back by' says the letters should be written in reverse.
'held' indicates a hidden word.
'alset' is hidden within 'false teeth'.
'alset' written backwards gives 'TESLA'.
(Other definitions for tesla that I've seen before include "Inventive sort" , "American scientist" , "Inventor" , "Physicist" , "Physics unit" .)