Effect of Low-Level Laser Therapy on Spontaneous and Chewing Pain Associated With Orthodontic Elastomeric Separator Placement

Effect of 635-nm Low-Level Laser Therapy on Spontaneous and Chewing Pain After Orthodontic Elastomeric Separator Placement: A Split-mouth Randomized Controlled Trial

The objective of this study is to determine the efficacy of LLLT at a wavelength of 635 nm on:

• Spontaneous pain between laser and placebo group with the placement of orthodontic elastomeric separators.
• Chewing pain between laser and placebo group with the placement of orthodontic elastomeric separators Study design: Randomized Controlled Trial (split-mouth study). Setting: Department of Orthodontics, Foundation University College of Dentistry & Hospital (FUCD&H).

Duration of study: Six months after approval of synopsis. Sample size: 80 By using WHO calculator the sample size is 80, 40 sample in each group.

Sampling method: Purposive sampling.

Data Collection Procedure:

• Permission has been taken and already submitted from the Ethical Committee of Foundation University College of Dentistry & Hospital (FUCD&H), for the study.
• An informed written consent of the patient will be obtained on consent form. (Annexure-A)
• Patients reporting to orthodontic department of FUCD&H for orthodontic treatment fulfilling the inclusion criteria in our sample will be selected after history, clinical examination & radiographic evaluation.
• Four elastomeric separators will be placed by an orthodontic resident, using dental floss, for the first permanent molars (distal and mesial), either on maxillary or mandibular arches with a split mouth study design.
• Allocation of quadrant will be randomized by simple randomization method in which experimental side will be randomly allocated to the patient and opposite side of the same patient will act as control.
• Diode laser of 635 nm, in direct contact with a power output of 100mW in pulsed wave mode will be used on the experimental side. The laser will be applied bucally and lingually on two points: mucosa adjacent to the mesial and distal contact points of the permanent first molar, for 20 s each.
• The vertical level of laser application will be approximately at the center of the root with the fiber tip of the laser placed nearly perpendicular in close contact with the gingival tissue.
• For the placebo quadrant, a similar procedure will be carried out but with no laser irradiation, without the patient's knowledge.
• After 24 hours, patients will return to the clinic and receive the laser irradiation on the same quadrant.
• After placing the elastomeric separators, patients will be given a pain questionnaire for 7 days, gathering data on the age, gender, and the involved jaw (maxilla or mandible). Patients will be instructed to record spontaneous pain as well as pain on chewing, and mark their level of pain on a VAS. They will be asked to mark the pain level for both jaws immediately at hour 0 (before laser irradiation), after 6, 24, and 30 h, and on the days 3, 4, 5, 6, and 7.
• All the procedural observation will be carried out by the trainee researcher himself, under the supervision of his Supervisor.
• Patient will submit the VAS to the trainee researcher on day 8.

Study Overview

• Status: Completed
• Conditions: Pain; Orthodontics; Chewing Function; Low Level Laser Therapy; Visual Analog Scale
• Intervention / Treatment: Device: Low Level Laser Therapy; Device: Control

Detailed Description

Objective:

To determine the efficacy of LLLT at a wavelength of 635 nm on:

• Spontaneous pain between laser and placebo group with the placement of orthodontic elastomeric separators.
• Chewing pain between laser and placebo group with the placement of orthodontic elastomeric separators

MATERIALS AND METHODS:

Study design: Randomized Controlled Trial (split-mouth study). Setting: Department of Orthodontics, Foundation University College of Dentistry & Hospital (FUCD&H).

Duration of study: Six months after approval of synopsis. Sample size: 80 By using WHO calculator the sample size is 80, 40 sample in each group, level of significance 5 %, power of test 90 %, Population standard deviation = 1.95510, group 1 mean(S.D) 3.00 ± 2.31, group 2 mean(S.D ) 1.58 ± 1.60.

Sampling method: Purposive sampling.

Sample selection:

Inclusion criteria:

• Both male and female patients.
• 15-30 years of age.
• Healthy and complete dentition including permanent second molars.
• Good oral hygiene (absence of generalized calculus deposits assessed clinically).

Exclusion criteria:

• Patients on pain killers or anti-inflammatory medication.
• Spacing between molars and premolars.
• History of diabetes mellitus, epilepsy or any other medical condition.
• Ongoing periodontal disease.
• Past history of orthodontic treatment.

Data Collection Procedure:

• Permission has been taken and already submitted from the Ethical Committee of Foundation University College of Dentistry & Hospital (FUCD&H), for the study.
• An informed written consent of the patient will be obtained on consent form. (Annexure-A)
• Patients reporting to orthodontic department of FUCD&H for orthodontic treatment fulfilling the inclusion criteria in our sample will be selected after history, clinical examination & radiographic evaluation.
• Four elastomeric separators will be placed by an orthodontic resident, using dental floss, for the first permanent molars (distal and mesial), either on maxillary or mandibular arches with a split mouth study design.
• Allocation of quadrant will be randomized by simple randomization method in which experimental side will be randomly allocated to the patient and opposite side of the same patient will act as control.
• Diode laser of 635 nm, in direct contact with a power output of 100mW in pulsed wave mode will be used on the experimental side. The laser will be applied bucally and lingually on two points: mucosa adjacent to the mesial and distal contact points of the permanent first molar, for 20 s each.
• The vertical level of laser application will be approximately at the center of the root with the fiber tip of the laser placed nearly perpendicular in close contact with the gingival tissue.
• For the placebo quadrant, a similar procedure will be carried out but with no laser irradiation, without the patient's knowledge.
• After 24 hours, patients will return to the clinic and receive the laser irradiation on the same quadrant.
• After placing the elastomeric separators, patients will be given a pain questionnaire for 7 days, gathering data on the age, gender, and the involved jaw (maxilla or mandible). Patients will be instructed to record spontaneous pain as well as pain on chewing, and mark their level of pain on a VAS. They will be asked to mark the pain level for both jaws immediately at hour 0 (before laser irradiation), after 6, 24, and 30 h, and on the days 3, 4, 5, 6, and 7.
• All the procedural observation will be carried out by the trainee researcher himself, under the supervision of his Supervisor.
• Patient will submit the VAS to the trainee researcher on day 8.

Data Analysis Procedure:

Data will be coded and analyzed using SPSS version 24.0. Mean and Standard deviation will be calculated for quantitative variables. Frequency and percentages will be calculated for qualitative variables. Independent samples t tests will be applied to compare the mean pain scores between the experimental and the placebo sides for spontaneous and pain on chewing. P value will be set at 0.05 with a 95% confidence interval. Value less than 0.05 will be considered significant.

• Study Type: Interventional
• Enrollment (Actual): 80
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Pakistan
  • Federal
    • Islamabad, Federal, Pakistan, 44000
      • Foundation University Islamabad

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Healthy and complete dentition including permanent second molars. • Good oral hygiene (absence of generalized calculus deposits assessed clinically).

Exclusion Criteria:

• Patients on pain killers or anti-inflammatory medication.
• Spacing between molars and premolars.
• History of diabetes mellitus, epilepsy or any other medical condition.
• Ongoing periodontal disease.
• Past history of orthodontic treatment.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Single Group Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Low Level Laser Therapy; Effect of LLLT on pain associated with separator placement	Device: Low Level Laser Therapy; • Diode laser of 635 nm, in direct contact with a power output of 100mW in pulsed wave mode will be used on the experimental side. The laser will be applied bucally and lingually on two points: mucosa adjacent to the mesial and distal contact points of the permanent first molar, for 20 s each
Placebo Comparator: Control Group; No Therapy provided	Device: Control; No therapy given

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Spontaneous and chewing pain between laser and placebo group with the placement of orthodontic elastomeric separators with Visual Analogue Scale (VAS)	• After placing the elastomeric separators, patients will be given a pain questionnaire for 7 days, gathering data on the age, gender, and the involved jaw (maxilla or mandible). Patients will be instructed to record spontaneous pain as well as pain on chewing, and mark their level of pain on a VAS. They will be asked to mark the pain level for both sides immediately at hour 0 (before laser irradiation), after 6, 24, and 30 hours, and on the days 3, 4, 5, 6, and 7.	pain level for both sides immediately at hour 0 (before laser irradiation), after 6, 24, and 30 hours , and on the days 3, 4, 5, 6, and 7.

Collaborators and Investigators

• Sponsor: Foundation University Islamabad

Publications and helpful links

General Publications

• 1. Shi Q, Yang S, Jia F, Xu J. Does low level laser therapy relieve the pain caused by the placement of the orthodontic separators? a meta-analysis. Head Face Med. 2015;11(1):1-9. 2. Ortega SM, Gonçalves ML, da Silva T, Horliana AC, Motta LJ, Altavista OM, Olivan SR, Dos Santos AE, Martimbianco AL, Mesquita-Ferrari RA, Fernandes KP. Evaluation of the use of photobiomodulation following the placement of elastomeric separators: protocol for a randomized controlled clinical trial. J of Med. 2019;98(43). 3. Marini I, Bartolucci ML, Bortolotti F, Innocenti G, Gatto MR, Bonetti GA. The effect of diode superpulsed low-level laser therapy on experimental orthodontic pain caused by elastomeric separators: a randomized controlled clinical trial. Lasers Med Sci. 2015;30(1):35-41. 4. Kim WT, Bayome M, Park JB, Park JH, Baek SH, Kook YA. Effect of frequent laser irradiation on orthodontic pain: a single-blind randomized clinical trial. Angle Orthod. 2013;83(4):611-6. 5. Tamgonda S, Reddy YM, Raj KP, Reddy R, Dharamdeep G. Effect of Low Level Laser Therapy: A Novel Approach to Diminish Pain Associated With Elastomeric Separators. Annals of International Med and Dent Research. 2019;5(6):38.

Study record dates

Study Major Dates

• Study Start (Actual): June 2, 2022
• Primary Completion (Actual): January 15, 2023
• Study Completion (Actual): January 15, 2024

Study Registration Dates

• First Submitted: March 31, 2026
• First Submitted That Met QC Criteria: June 11, 2026
• First Posted (Actual): June 16, 2026

Study Record Updates

• Last Update Posted (Actual): June 16, 2026
• Last Update Submitted That Met QC Criteria: June 11, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Keywords: Orthodontics; Orthodontic Pain; Elastomeric separators; Chewing Pain; Spontaneous pain
• Additional Relevant MeSH Terms: Neurologic Manifestations; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Pain; Therapeutics; Laser Therapy; Phototherapy; Low-Level Light Therapy
• Other Study ID Numbers: FUCD-Ortho- 2603

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Privacy Reasons

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No