Impact of root canal shaping using TruNatomy on postoperative pain and operative torque generation: a randomized clinical trial.

Background: TruNatomy instruments promises a more conservative alternative to conventionally used instruments. They are claimed by the manufacture to decrease the amount of debris extrusion as well as the torque generated during instrumentation, potentially resulting in lower post-operative discomfort and a safer more convenient experience for the patient and clinician.

Aim: To compare the effect of canal shaping using TruNatomy (TN) rotary system to RaCe (RC) rotary system on post-operative pain in necrotic maxillary bi-rooted premolars, while simultaneously inspecting the real-time dynamic forces produced during instrumentation.

Methods: In this parallel group superiority trial, following power calculation, 40 patients diagnosed with pulp necrosis in asymptomatic bi-rooted maxillary premolars were recruited and randomly allocated into two equal groups (n = 20) according to the instrumentation system used. Treatment was completed in a one visit for all cases. Pain levels were recorded immediately before RCT and at 6,12,24,48, 72 h, and 1-week post RCT using mVAS. The number of analgesics taken if any was also recorded. Operative torque generated during root canal preparation as well as the time taken for the instrument to reach the working length were simultaneously recorded during instrumentation. Outcome data was statistically analyzed using Shapiro Wilk test, independent t test, Mann-Whitney U, Chi square, Fisher exact tests, spearman's correlation coefficient. Significance level (α) was set at 0.05.

Results: There was no statistically significant difference between pain scores in the test groups at all time points measured (P > .05). No significant different was also recorded in terms of number of analgesics taken (P > .05). Mean torque, average peak torque and maximum torque values showed no statistically significant difference as well, however the instrumentation time was significantly shorter for the TN Group (P < .05). A moderate significant positive correlation was found between the instrumentation time and generated operative torque.

Conclusion: TN and RC rotary instruments resulted in similar and acceptable levels of post-operative pain in cases of asymptomatic necrotic teeth. However, TN rotary system combined torque and instrumentation time values suggest an overall higher cutting efficiency and potentially a better safety profile as compared to RC rotary system.

Trial Registration: ClinicalTrials.gov identifier: NCT04616469; registration date (10/08/2020).