Quality of root canal fillings performed by undergraduate dental students on single-rooted teeth

Root canal therapy is an accepted and successful form of tooth conservation. Educational guidelines require dental schools to ensure that their graduates are competent on graduation at performing root canal therapy. The aim of this investigation was to assess the technical quality of root canal fillings placed by undergraduate students in single-rooted teeth.

A total of 100 radiographs of root canal fillings placed by undergraduate students in single-rooted teeth were examined under even illumination in a darkened room using x2 magnification. These were graded as 'adequate', where the root canal filling was within 2 mm of the radiographic apex, 'under-filled', where the root canal filling was >2 mm from the radiographic apex, and 'over-filled', where the root canal filling was extruded beyond the radiographic apex. The presence of voids, fractured instruments, and root perforations were also noted.

All teeth were obturated with gutta-percha and sealer (Roth Cement), using a cold lateral condensation technique. Of 100 teeth, 10% (n = 10) had voids. Of the remainder, 70% (n = 63) were judged to be 'acceptable', 21% (n = 19) were 'under-filled', and 9% (n = 8) were 'over-filled'. There was no evidence of fractured instruments or root perforations in any root filling examined.

The quality of root canal fillings placed in single-rooted teeth by undergraduate dental students at the University Dental School and Hospital, Cork was acceptable (63% of root fillings placed in single rooted teeth were graded as 'adequate'). The probable reasons for this are multi-factorial, but may be linked to the amount of pre-clinical and clinical teaching in endodontics at the University Dental School and Hospital, Cork. It should be remembered that factors other than radiographic quality/evidence must be considered when determining the outcome of root canal therapy.