# Which of the following locations would a perforation demonstrate the BEST prognosis?  A. Floor of pulp chamber  B. Coronal 1/3 of root  C. Middle 1/3 of root  D. Apical 1/3 of root      The correct answer is D. Apical third of root.    Apical perforations occur through the apical foramen or the body of the root to form  a new canal.   The more apical the perforation, the more favorable the prognosis for the tooth. (except for the coronal perforations)