Effectiveness of low-intensity electrical current in accelerating the en-masse retraction of the upper anterior teeth following first-premolar extraction in young adult patients with Class II division 1 malocclusion: A randomized controlled clinical trial.

INTRODUCTION: Many efforts have been made to shorten fixed appliance orthodontic treatment time by accelerating the rate of tooth movement. Low-intensity electrical stimulation (LIES) is one of the proposed physical methods that has not yet been well studied in the medical literature. This study aimed to evaluate the effectiveness of LIES in accelerating orthodontic tooth movement in cases of en-mass retraction of the upper anterior teeth. METHODS: Patients who attended the Department of Orthodontics at the Faculty of Dentistry, University of Damascus, between September 2019 and February 2021, for treatment were carefully checked. All patients who met the eligibility criteria were invited to participate in this RCT. Young adult patients having class II division I malocclusion were equally and randomly assigned into the low-intensity electrical stimulation group (LIES), and traditional en-masse retraction group (TRAD). The mini-implants assisted en-masse retraction technique was used to close the extracted upper first premolar spaces in both groups. NiTi closed coil springs (250g/side) were used. Electrical stimulation of 15-20µA for each tooth was applied on the upper anterior teeth using a recently developed intraorally removable device in the LIES group. The primary outcome was the en-masse retraction rate, the secondary outcomes were changes in the first molar position, intermolar width, and intercanine width. These outcomes were measured on the digital photographs of the maxilla cast using the Image J program. Two-sample t-test with Bonferroni's correction was utilized to explore any significant differences between the two groups in all studied variables. RESULTS: Of the 168 patients examined by the researcher, 38 patients with Class II division I malocclusion (30 females and 8 males; mean age: 21.1±2.31 years) were finally recruited in this RCT. The overall en-masse retraction rate was significantly greater in the LIES group compared to the TRAD group (1.02±0.08, 0.73±0.04mm/month respectively; P<0.001). In addition, the monthly rate of space closure was significantly greater in this group at all evaluation times (P<0.001). A small increase was noted in the intercanine width (1.60±0.27, and 1.65±0.33mm respectively). Negligible changes were noted in the first molar positions and intermolar width, with insignificant differences between the two groups. CONCLUSIONS: LIES according to the protocol applied in this trial accelerated the upper anterior teeth en-masse retraction rate by approximately 28% compared to the traditional en-masse retraction method. While this acceleration was statistically significant, may not have substantial clinical implications. REGISTRATION: This trial protocol was registered in the Clinical Trials database (ClinicalTrials.gov NCT05350280).

Patient-reported outcomes during accelerating the en-masse retraction of the upper anterior teeth using low-intensity electrical stimulation: a randomized controlled trial.

BACKGROUND: Low-intensity electrical stimulation (LIES) is considered a relatively recent technology that has received little attention in orthodontics as a method of acceleration. This study aimed to evaluate patient-reported outcome measures when LIES is used to accelerate the en-masse retraction of the upper anterior teeth. MATERIALS AND METHODS: The sample consisted of 40 patients (8 males, 32 females; mean age 21.1 ± 2.3 years), with Class II division I malocclusion who required extraction of the first premolars to retract upper anterior teeth. They were randomly assigned to the LIES group (n = 20) and the conventional en-masse retraction group (CER; n = 20). Patient responses regarding pain, discomfort, burning sensation, swelling, chewing difficulty, speech difficulty, and painkillers' consumption were recorded at these nine assessment times: 24 h (T1), 3 days (T2), and 7 days (T3) after force application, then in the second month after 24 h (T4), 3 days (T5), and 7 days (T6) of force re-activation, and finally after 24 h (T7), 3 days (T8), and 7 days (T9) of force re-activation in the third month. RESULTS: The mean values of pain perception were smaller in the LIES group than those in the CER group at all assessment times with no statistically significant differences between the two groups except during the second and third months (T5, T6, T8, and T9; P < 0.005). However, discomfort mean values were greater in the LIES group with significant differences compared to CER group during the first week of the follow-up only (T1, T2, and T3; P < 0.005). Burning sensation levels were very mild in the LIES group, with significant differences between the two groups at T1 and T2 only (P < 0.001). Speech difficulty was significantly greater in the LIES group compared to CER group at all studied times (P < 0.001). High levels of satisfaction and acceptance were reported in both groups, without any significant difference. CONCLUSION: Both the LIES-based acceleration of en-masse retraction of upper anterior teeth and the conventional retraction were accompanied by mild to moderate pain, discomfort, and chewing difficulty on the first day of retraction. These sensations gradually decreased and almost disappeared over a week after force application or re-activation. TRIAL REGISTRATION: ClinicalTrials.gov, ClinicalTrials.gov, NCT05920525. Registered 17 June 2023 - retrospectively registered, http://clinicaltrials.gov/study/NCT05920525?term=NCT05920525&rank=1 .

Effect of Fluoride Release on Enamel Demineralization Adjacent to Orthodontic Brackets.

INTRODUCTION AND AIM: This study aimed to evaluate the ability of fluoride-releasing adhesives to inhibit enamel demineralization surrounding orthodontic brackets. METHODS: Two groups of 40 sound human premolars were sectioned mesio-distally. The halves were varnished, and orthodontic brackets were bonded with different adhesive materials. An area 1 mm wide surrounding the brackets was left exposed. Each specimen was immersed daily in a pH cycle for 28 days. In the second group, the specimens were exposed daily to a fluoride solution (250 ppm F-) at 37°C. The fluoride release from different groups was measured. Quantitative light-induced fluorescence (QLF) was used to quantify fluorescence loss of enamel surfaces adjacent to the brackets. Results were statistically analyzed using ANOVA at (p<0.05). RESULTS: Fluoride released from the three fluoride-releasing adhesives was significantly higher (p<0.001) in the group with daily fluoride exposures than in the group without fluoride exposures. Enamel adjacent to brackets bonded with Fuji Ortho LC, Ketac Cem, and Dyract Cem showed significantly less (p<0.001) changes in (ΔQ) value (less demineralization) than enamel bonded with Transbond, the control adhesive material. CONCLUSIONS: Using fluoride-releasing adhesives significantly reduced the level of demineralization adjacent to orthodontic brackets.