Can low-power laser treatment or gentle electrical nerve stimulation reduce pain after orthodontic wires are fitted?
| ISRCTN | ISRCTN56942915 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN56942915 |
| Sponsor | University of Health Sciences Türkiye |
| Funder | Health Sciences University Hamidiye Scientific Research Projects Coordination Unit |
- Submission date
- 10/08/2026
- Registration date
- 14/08/2026
- Last edited
- 11/08/2026
- Recruitment status
- No longer recruiting
- Overall study status
- Completed
- Condition category
- Oral Health
Plain English summary of protocol
Background and study aims
Fixed orthodontic wires can cause pain, especially during the first two days after they are fitted. This study looked at whether low-level laser therapy (LLLT) or transcutaneous electrical nerve stimulation (TENS) could reduce this pain without medication.
Who could participate?
Patients aged 14–20 years with permanent teeth and mild crowding in both dental arches could take part. Patients with systemic or neurological diseases, poor oral or periodontal health, impacted or missing teeth, or current use of pain-relieving or anti-inflammatory medication were excluded.
What did the study involve?
Participants were randomly assigned to three groups. Group A received LLLT at week 1 and TENS at week 5. Group B received the same treatments in the opposite order. Group C received dummy LLLT at week 1 and dummy TENS at week 5.
Treatment was applied to the right side, while the left side was left untreated for comparison. Participants rated pain on both sides using a scale from 0 to 100 immediately after treatment and at 2, 4, 6, 12, 24 and 48 hours.
What were the possible benefits and risks?
The treatments might have reduced pain, but a direct benefit was not guaranteed. Both treatments were non-invasive. TENS could cause temporary tingling or discomfort, and any unwanted effects were recorded.
Where was the study run?
The study was carried out at the Orthodontic Clinic of Sultan 2. Abdülhamid Han Training and Research Hospital in Istanbul, Türkiye.
When did the study take place?
Recruitment took place between September 2020 and March 2021. Follow-up was completed in April 2021.
Who funded the study?
The study was funded by the University of Health Sciences Türkiye, Scientific Research Projects Coordination Unit (project number 2021/009).
Who was the main contact?
Dr Neslihan Karaoğlan
dr.dt.neslihankaraoglan@gmail.com
Contact information
Principal investigator, Public, Scientific
Dental Clinic, University of Health Sciences Türkiye, Sultan II. Abdülhamid Han Training and Research Hospital
Kadıköy
34668
Türkiye
 ORCID ID |
0000-0002-1077-0768 |
|---|---|
| Phone | +90 5426641954 |
| bolenlerneslihan@gmail.com |
Public, Scientific, Principal investigator
University of Health Sciences, Hamidiye Faculty of Dentistry
Kadıköy
34668
Türkiye
| ersin.yildirim@sbu.edu.tr |
Study information
| Primary study design | Interventional |
|---|---|
| Allocation | Randomized controlled trial |
| Masking | Blinded (masking used) |
| Control | Placebo |
| Assignment | Crossover |
| Purpose | Supportive care |
| Participant information sheet | 50064 Parent_Guardian_Informed_Consent_Form_EN.pdf |
| Scientific title | Low-level laser therapy and transcutaneous electrical nerve stimulation for pain control after fixed orthodontic archwire placement: a randomized clinical trial |
| Study objectives | |
| Ethics approval(s) |
Approved 10/07/2020, University of Health Sciences Hamidiye Clinical Research Ethics Committee (University of Health Sciences, Mekteb-i Tıbbiye-i Şahane (Haydarpaşa) Campus, Selimiye Mahallesi, Tıbbiye Caddesi No: 38, Üsküdar, Istanbul, 34668, Türkiye; +90 2167779021; hamidiye.kaek@sbu.edu.tr), ref: Protocol reference: 20-76; approval number: 2020.07.10-66 |
| Health condition(s) or problem(s) studied | Pain following fixed orthodontic archwire placement in adolescents and young adults with mild dental crowding. |
| Intervention | After confirmation of eligibility and written informed consent, 81 participants were randomly allocated in a 1:1:1 ratio to three intervention sequences using sex-stratified, computer-generated permuted blocks and sequentially numbered, opaque, sealed envelopes. All participants received 0.018 × 0.025-inch fixed metal brackets. During period 1 (week 1), immediately after placement of a 0.016-inch round nickel–titanium archwire, Group A received active low-level laser therapy (LLLT), Group B received active transcutaneous electrical nerve stimulation (TENS), and Group C received sham LLLT. During period 2 (week 5), immediately after placement of a 0.016 × 0.016-inch rectangular nickel–titanium archwire, Group A received active TENS, Group B received active LLLT, and Group C received sham TENS. LLLT was delivered using a Solase diode laser (Lazon Laser, Shenyang, China) at 976 nm and 0.5 W in continuous mode through a 1 cm² biostimulation tip. Treatment was applied for 15 seconds per tooth (7.5 J per point; 7.5 J/cm²) at one vestibular point corresponding to the middle third of each root, with the tip in contact with the gingival mucosa. TENS was delivered using a Medelsan device (Istanbul, Türkiye) with a 200-μs pulse width at 50 Hz for 20 minutes. Extraoral 5 × 5 cm electrodes were positioned near the premolar roots immediately below the zygomatic bone for the maxilla and near the mental foramen for the mandible. Participant-specific stimulation amplitudes were not retained. The right side was the fixed application side and the left side was the untreated contralateral comparator. Sham LLLT used the same device placement and application procedure without laser emission. Sham TENS used the same electrode placement and duration without electrical current. Pain was recorded separately for the application and contralateral sides for 48 hours after each intervention period. |
| Intervention type | Device |
| Phase | Not Applicable |
| Drug / device / biological / vaccine name(s) | Solase multifunctional dental diode laser (Lazon Laser, Shenyang, China), Medelsan transcutaneous electrical nerve stimulation (TENS) device (Medelsan, Istanbul, Türkiye) |
| Primary outcome measure(s) |
|
| Key secondary outcome measure(s) |
|
| Completion date | 28/04/2021 |
Eligibility
| Participant type(s) | |
|---|---|
| Age group | Mixed |
| Lower age limit | 14 Years |
| Upper age limit | 20 Years |
| Sex | All |
| Target sample size at registration | 72 |
| Total final enrolment | 81 |
| Key inclusion criteria | 1. Male or female participants aged 14–20 years 2. Permanent dentition 3. Dental crowding of 2–4 mm in both the maxillary and mandibular arches 4. No previous orthodontic treatment |
| Key exclusion criteria | 1. Presence of a systemic or neurological disease 2. Use of analgesic or anti-inflammatory medication at enrolment 3. Impacted or missing teeth, except for third molars 4. Requirement for additional anchorage reinforcement 5. Poor oral hygiene 6. Presence of periodontal disease |
| Date of first enrolment | 15/09/2020 |
| Date of final enrolment | 20/03/2021 |
Locations
Countries of recruitment
- Türkiye
Study participating centres
Results and Publications
| Individual participant data (IPD) Intention to share | Yes |
|---|---|
| IPD sharing plan | De identified individual participant data will be available from the corresponding author upon reasonable request, subject to institutional approval and applicable ethical and data-protection requirements. |
Study outputs
| Output type | Details | Date created | Date added | Peer reviewed? | Patient-facing? |
|---|---|---|---|---|---|
| Participant information sheet | Adult | 11/08/2026 | No | Yes | |
| Participant information sheet | Child | 11/08/2026 | No | Yes | |
| Participant information sheet | Parent/guardian | 11/08/2026 | No | Yes |
Additional files
- 50064 Adult_Informed_Consent_Form_EN.pdf
- Adult
- 50064 Parent_Guardian_Informed_Consent_Form_EN.pdf
- Parent/guardian
- 50064 Child_Assent_Form_EN.pdf
- Child
Editorial Notes
11/08/2026: Trial's existence confirmed by University of Health Sciences Hamidiye Clinical Research Ethics Committee.
