Endo 101: Access

A 50-year-old lady presents to clinic with chief complaint "I need a new filling in the lower right".  Root canal has been done in her home country without symptoms for several years.  Exam reveals that the tooth #31 has DO composite.  The mesial portion of the restoration has chipped (Fig.1: black arrowhead).  There is 2nd caries in the distal margin (white arrowhead).  Percussion reveals minimal tenderness.  Crown is recommended.  In addition to the post (P) and core (C), what is special about this case?

In fact, there is a separated file in the mesial canal (Fig.2: S).  The related problem is that the mesial portion of the pulpal roof is not removed (arrowheads).  The access to the pulp is limited (Fig.3: red lines), particularly to the mesial canal.  The file must have been bent twice (pink line in an S shape) before separation.  By comparison, the access to the pulp of another lower 2nd molar is sufficient (Fig.4 red lines) and the file is bent only once (pink line).

Xin Wei, DDS, PhD, MS 1st edition 09/24/2012, last revision 09/24/2012