
if the filling that exists in the top of the tooth is large, and if this newly discovered
decay is extensive, the
tooth may need a crown after the
decay is cleaned out and the cavity filled. remember that the more "filling" a tooth has, the more prone to fracture it is. when teeth do fracture, sometimes they cannot be restored at all, so placing a crown befoe that happens is oftentimes prudent if the fillings are large.