Note last fragment of amalgam in type of bear's tooth (8)
I believe the answer is:
premolar
'tooth' is the definition.
(premolar is a kind of tooth)
'note last fragment of amalgam in type of bear's' is the wordplay.
'note' becomes 're' (**).
'last fragment of' says to take the final letters.
'in' indicates putting letters inside.
'type of bear' becomes 'polar' (I've seen this before).
The final letter of 'amalgam' is 'm'.
're'+'m'='rem'
'rem' placed within 'polar' is 'PREMOLAR'.
(Other definitions for premolar that I've seen before include "Type of tooth" , "Grinder" , "Tooth -- real romp (anag)" .)