Akademik Veri Yönetim Sistemi
Clinical Dentistry and Research, cilt.39, sa.2, ss.49-55, 2015 (Hakemli Dergi)
Background and Aim: The aim of the study was to evaluate the
fracture resistance of roots after instrumentation with two nickeltitanium rotary systems at different working lengths.
Materials and Methods: One hundred-twelve human maxillary
two-rooted premolars were used. Teeth were divided into 2 main
groups according to their working lengths, (14 or 16 mm). Each group
was then assigned into 3 subgroups to be prepared with different
root canal instruments [ProTaper Universal (PTU), ProFile GT Series
X (GTX), and K-flexofiles] (n=16). The remaining teeth were used
as the control groups. The specimens were loaded vertically at 1
mm/min crosshead speed until root fracture occurred. Data were
evaluated statistically using Kruskal-Wallis and Mann Whitney U (p
< 0.001) tests.
Results: Fracture resistance of control groups were higher than
that of all experimental groups (p< 0.001). PTU+16 mm group
was found less resistant to fracture than other groups (p< 0.001)
whereas no statistically significant differences were found among
other experimental groups (p= 0.012).
Conclusion: Fracture resistance could decrease whilst the active
16 mm of the instrument is used inside the canal especially with
PTU rotary system in two-rooted maxillary premolars.