The aim of this study was to evaluate in vitro a new protocol for removing intraradicular retainers from multirooted teeth applying ultrasonic vibration.
mandibular molars were endodontically treated to receive cast
intraradicular retainers, which were distributed into the following 4
groups: group 1: control without a slot and without ultrasound, group 2:
control with a slot and without ultrasound, group 3: ultrasonic
vibration in the core without a slot, and group 4: ultrasonic vibration
in the core with a slot. After the intraradicular retainers were
cemented with zinc phosphate, ultrasonic vibration was applied for
1 minute. The test specimens were then submitted to the traction test in
the universal testing machine at a speed of 1 mm/min. The maximum
traction force required to remove the intraradicular retainer was
recorded in newtons, and the data were statistically analyzed using
analysis of variance and the Tukey-Kramer test (P < .05).
results showed statistically significant differences among the groups
tested (group 1 = 234.34 N, group 2 = 201.67 N, group 3 = 139.57 N, and
group 4 = 83.23 N). The lowest mean value of traction force recorded was
when ultrasonic vibration was applied on the core with a slot.
a slot in the core and the ultrasound application on all surfaces and
inside the slot reduced the force required for removing intraradicular
metal retainers from multirooted teeth cemented with zinc phosphate.