Post-Operative Pain and Mechanical Allodynia Following Non-Surgical Root Canal Treatment Using the GentleWave System: A Randomized Controlled Trial

Abstract

Abstract Introduction: Cleaning and shaping is accomplished to allow delivery of irrigants and medicaments to the apical portion of the root canal system. Clinical success depends upon accessing and disinfecting bacteria in this zone. Standard treatment involves irrigation with sonic/ultrasonic activation. The GentleWave System (GWS; Sonendo, Inc, Laguna Hills, CA) combines irrigant delivery with multisonic activation. This randomized clinical trial aimed to determine whether irrigation with the GentleWave system will significantly decrease the incidence and severity of postoperative pain and mechanical allodynia following endodontic treatment in patients with symptomatic apical periodontitis compared to standard endodontic treatment. Methods: Patients used a numeric rating scale to record their pain level at the 6-hour time point before treatment. An occlusal force meter numerical reading was recorded at maximal bite force prior to feeling pain on the symptomatic tooth and maximal bite force on the contralateral tooth to assess mechanical allodynia. All participants were randomly divided into 2 groups and were blind to the treatment they received. All treatment was completed in two visits. The standard (control) group received endodontic treatment with conventional side-vented needle irrigation and passive ultrasonic activation. The second group received treatment with the GWS. Following treatment, patients used a numeric rating scale to record their pain level at 6, 24, 72, and 168 hours and mechanical allodynia was reassessed at the second visit. Results: 80% of standard treatment patients reported post-operative sensitivity at 24 hours with the mean value of intensity being 25 (95% CI: 16, 34) on the NRS, 65% of GWS patients reported post-operative sensitivity at 24 hours with a mean intensity value of 21 (95% CI: 12,30) on the NRS. By one-week post treatment 40% of patients in both groups reported at least some degree of pain, with the mean intensity being 8 (95% CI: 0,8) in the standard group and 6 (95% CI: 0,14) in the GWS. In this study, the average increase in bite force from visit 1 to visit 2 for the standard treatment group was 118 mPa (95% CI: 46-189) and 98 (95% CI: 20-175). Conclusions: There was no statistically significant difference in the incidence or intensity of postoperative pain between treatment groups. When considering mechanical allodynia, the average increase in bite force from visit 1 to visit 2 between groups was not statistically significant. However, both groups reported a statistically significant decrease in pain with time and increase in bite force between visits.