Damage to root dentin during retreatment procedures.

By Shemesh H, Roeleveld AC, Wesselink P, Wu M

Date: 04/2012
Journal: JOE

Purpose: to assess the influence of retreatment procedure on the appearance of defects on the root canal walls

Materials and Methods:

•N = 200 extracted mandibular premolars were standardized.

•4 groups (n= 50, average diameter was 0.7 mm)

•Teeth were examined to exclude presence of cracks.

•Group (1): left unprepared. Group (2-4): C/S with ProTaper to F4. Passive Ultrasonic was used at the end. All groups (2-4) were filled with lateral condensation (MAF= 40, spreader with controlled load 2 kg, AH26 sealer). oGroup (1): unprepared and no obturation.

oGroup (2): Prepared, obturated but no retreatment.

oGroup (3): Retreated with ProTaper retreatment files (D1, D2, D3) with chloroform.

oGroup (4): Retreated with H-files + chloroform.

•Part One: Evaluation under operating microscope. Part II: roots were sectioned horizontally and examined under stereomicroscope.

Most highlighted Results: 

  • Group (1): unprepared and no obturation: No defects
  • Group (2): prepared and obturated: almost 30% defects were found
  • Group (3): prepared and obturated, then retreated with ProTaper: almost 38 % defects were found
  • Group (4): prepared and obturated, then retreated with  H-file: almost 55% defects were found üGroups 3 and 4 were compared to group 2. No difference between groups 3 and 4

Clinical significance: The lower success noted in retreatment may be attributed to further damage to roots resulted from the procedure.