Effects of 6 Single-File Systems on Dentinal Crack Formation

By Pedullà E, Genovesi F, Rapisarda S, La Rosa GR, Grande NM, Plotino G, Adorno CG.

Date: 01/2017
Journal: JOE


Purpose: To compare the formation of micro-cracks after canal preparation performed with different single-file systems as One Shape, F6 SkyTaper, HyFlex EDM, WaveOne , Reciproc, and WaveOne Gold.

N=  84  human extracted mandibular central incisors (40–60 y)


•Teeth were selected and divided into 6 experimental groups (n = 12 teeth) and a control group (unprepared teeth):

  • One Shape (group 1)
  • F6 SkyTaper (group 2)
  • HyFlex EDM (group 3)
  • WaveOne (group 4)
  • Reciproc (group 5)
  • WaveOne Gold (group 6)
  • Roots were then sectioned at 3, 6, and 9 mm from the apex, and the surface was observed under a stereomicroscope

Most highlighted Results: 

  • No cracks were observed in the control group.
  • All the systems tested caused cracks, mainly in the apical section (3 mm). HyFlex EDM (33.3%) and WaveOne Gold (58.3%) showed fewer microcracks than other experimental groups (P < .01).
  • however, no significant difference was found between them in crack formation (P > .05).
  • There was no difference among the other experimental groups (P > .05).

Clinical significance:

The flexibility of nickel-titanium instruments because of heat treatment seems to have a significant influence on dentinal crack formation. Hy- Flex EDM and WaveOne Gold caused less microcracks than the other instruments tested.