Effect of Low-Intensity Electrical Stimulation on External Apical Root Resorption and Periodontal Indices Following En-Masse Retraction of Upper Anterior Teeth in Young Adults: A Randomized Controlled Trial

Abstract

Objective: To evaluate external apical root resorption (EARR) and periodontal indices during en-masse retraction of maxillary anterior teeth stimulated with low-intensity electrical currents. Trial Design: A two-arm randomized controlled trial. Methods: Young adult patients who visited the Department of Orthodontics at Damascus University between November 2023 and March 2024 and met predefined inclusion criteria were randomly allocated into two groups using block randomization. The study included 34 patients, with 17 assigned to the electrically stimulated en-masse retraction (ESER) group and 17 to the conventional en-masse retraction (CER) group. The force for the en-masse retraction technique in both groups was 250 g per side. The force was applied through bilateral closed-coil nickel-titanium springs anchored to an orthodontic mini-screw on each side. In the ESER group, each upper anterior tooth was subjected to a continuous electrical stimulation of 15–20 µA for 5 h daily, utilizing an intraoral removable electrical stimulation device. EARR was assessed using digital panoramic radiographs. Four periodontal indices were also used to assess periodontal status. Blinding was confined to data analysis. Results: Thirty-four patients (26 females and 8 males) were analyzed with a mean age of 21.12 ± 2.41 years. At the end of the en-masse retraction phase, no significant difference in EARR was observed between the two groups (p > 0.05). The observed root resorption in the ESER and CER ranged between 0.27 and 0.64 and 0.32 and 0.71 mm, respectively. Also, insignificant differences were found in all periodontal indices studied at all measurement points between the two groups (p > 0.05). Conclusions: Low-intensity electrical stimulation had no significant effect on root resorption during the en-masse retraction of the six upper anterior teeth. Both groups exhibited comparable slight root resorption without any significant difference between them. Additionally, low-intensity electrical stimulation did not affect the periodontal status during en-masse retraction. Trail Registration: Clinical Trials database (NCT06873490).