1. Torque Control

2. Torque Control Predefined torque values are based on new instruments!
Used NiTi files have 50-60% decreased resistance to fracture after use with high-torque motors. Gamborini 2001
Predefined torque values on some motors are > than the fracture limit of the NiTi file. Gamborini 2001
Handpieces have different degrees of effectiveness, which affects torque values on files. Gamborini 2001

3. Influence of torque control motors and the operator's proficiency w/ ProTaper NiTi Yared G, Bou Dagher F, Kulkarni K. OOOOE 2003
To evaluate the influence of 2 electric torque control motors and operator experience with ProTaper NiTi on the incidence of deformation and separation of instruments.
Preclinical training in the use of the PT technique at rpm is crucial to prevent instrument separation and deformation.
High torque control motor is safe with the experienced operator.

4. Advantages and disadvantages of new torque-controlled endodontic motors and low-torque NiTi rotary instrumentation. Gambarini G. Aust Endod J. 2001
Advantages:
reduced pressure/force required
computer-controlled electronics
allows for fine adjustment of torque values
improved tactile awareness
new ‘mental’ awareness
> resistance to cyclic fatigue
reduces rate of fracture rotary files

5. Advantages and disadvantages of new torque-controlled endodontic motors and low-torque NiTi rotary instrumentation. Gambarini G. Aust Endod J. 2001
Disdvantages:
< cutting efficiency
slower instrument advancement
increases time of debridement procedure

6. Cyclic fatigue of nickel-titanium rotary instruments after clinical use with low- and high-torque endodontic motors. Gambarini G. J Endod. 2001
investigated the cyclic fatigue resistance
high vs. low torque electric motors
Profile NiTi: .06/25, .06/20, and .04/25
A = 10 new instruments (control)
B = 20 used instruments, high-torque motor
C = 20 used instruments, low-torque motor

7. Cyclic fatigue of nickel-titanium rotary instruments after clinical use with low- and high-torque endodontic motors. Gambarini G. J Endod. 2001
group A (new) instruments exhibited significantly higher values of rotation-to-breakage cycles
Statistically higher resistance to cyclic fatigue was noted for group C (low-torque) in all sizes compared with group B
the use of endodontic motor with lower torque values reduced cyclic fatigue of nickel-titanium rotary instruments.