Safety and efficacy of NiTi rotary
instruments for gutta-percha removal
from curved canals 
- Suntaree Petchrungrusmee D.D.S., M.Sc. (Endodontics)
- Piyanee Panitvisai D.D.S., M.D.Sc. (Endodontics), Thai Board of Endodontics
Abstract :
Objective To compare the safety and efficacy of gutta-percha removal using NiTi rotary instruments
with eucalyptol versus hand files with eucalyptol.
Materials and methods Eighty-eight distobuccal root canals of maxillary molars with curvatures
ranging between 10° and 35° were instrumented using modified stepback technique and obturated with
gutta-percha and zinc oxide eugenol sealer. One week later, gutta-percha was removed using: Group
1-ProFile with eucalyptol and Group 2-H-file with eucalyptol. Safety of gutta-percha removal was
evaluated from the extent of canal deviation and loss of dentin. Canal deviation was evaluated by
comparing the angles of curvature before and after gutta-percha removal. Loss of dentin was evaluated
by comparing the ratios of root to root canal area before and after gutta-percha removal. Efficacy of
gutta-percha removal was evaluated by time of gutta-percha removal and cleanliness of the canal wall,
which was measured from percentage of remaining gutta-percha. Statistical analysis was performed
using Mann-Whitney U test at p < 0.05.
Results NiTi rotary instruments caused significantly greater loss of dentin than hand files in a buccolingual
direction, but not in a mesiodistal direction. However, the lost dentin was within 1/3 of root width.
NiTi rotary instruments removed gutta-percha significantly faster than hand files, with no significant
difference in cleanliness of root canals.
Conclusion NiTi rotary instruments used with eucalyptol are safe and able to remove gutta-percha in
curved canals no different from hand files with eucalyptol. However, the technique requires significantly
less amount of removal time.
(CU Dent J. 2011;34:117-128)
Keywords :
curved canals; gutta-percha removal; NiTi Rotary instruments