A Comparison Between Two Root-End Preparation Techniques in Human Cadavers

By Wuchenich G, Meadows D, Torabinejad M.

Date: 01/1994
Journal: JOE

Purpose:

Compare ultrasonic and bur root end cavity preparations with regard to retention, cleanliness, and root canal parallelism.

Materials/Methods:

  • N= 20 anterior teeth from 2 cadavers
  • Teeth were instrumented and obturated with gutta percha and sealer. A flap was raised and root end preparations were performed on each root. Retropreps were done with 45 degree bevel.
  • Teeth were separated into 2 groups:
  • Group 1 – (10) retroprep w/ inverted cone bur.
  • Group 2 – (10) retroprep w/ Ultrasonic (Carr tip).
  • The teeth were extracted, sectioned longitudinally, and examined with SEM for cleanliness of cavities and the direction of preparations in relationship to the canal.

Results:

  • Ultrasonic preps had more parallel walls, walls that followed the canals more and deeper depths for retention. The minimum depth was 2.5 mm.
  • Bur preps averaged 1 mm depth and were oblique to long axis of tooth.
  • Dentinal walls of preps with ultrasonics showed more open dentinal tubules and minimal debris layer compared to bur group.

Clinical Significance:

Ultrasonics allow for deeper, more parallel, and cleaner root end preparations that follow the canal system more accurately when compared to root end preparations with burs.