Tooth material (7)
I believe the answer is:
dentine
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">tooth material</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for dentine that I've seen before include "bony material" , "Tooth material" , "Tin need (anag.)" , "Substance of which teeth are mainly composed" , "which forms tooth" .)