An interventional study of photobiomodulation therapy and orthodontic fixed-appliance in Orthodontics and Root Resorption, sponsored by The University of Hong Kong. Active, not recruiting at 1 site in Hong Kong. Open to participants aged 18 Years to 35 Years. Per ClinicalTrials.gov, last updated 2026-06-24.
Sponsored by The University of Hong Kong · Not applicable, Interventional, and Prevention
The aim of this study is to investigate the effects of photobiomodulation therapy (PBM) on the dental and periodontal health of patients undergoing fixed-appliance orthodontic treatment, including orthodontically induced root resorption, orthodontic pain, space closing rate, and dental microbiome profile in dental plaques.
Photobiomodulation therapy (PBM) is a non-invasive, adjunctive medical treatment that has promising effects on various dental and oral conditions, including controlling inflammation, promoting wound healing, and relieving pain. While animal studies have explored PBM therapy in orthodontics for accelerating tooth movement, preventing root resorption, alleviating pain, and controlling periodontal inflammation, clinical studies with high-quality evidence remain limited. Therefore, a randomized controlled trial (RCT) will be conducted to investigate the effects of a portable PBM device on the dental and periodontal health of patients undergoing fixed-appliance orthodontic treatment. This two-arm RCT will be conducted with a triple-blinded and parallel study design in a 1:1 ratio. Fifty orthodontic patients will be recruited at the Prince Philip Dental Hospital following the eligibility criteria from Jan. 2024 to Jan. 2026 (24 months) and evenly distributed to the two arms. Randomization and allocation will be conducted by a statistician who will not participate in the intervention and outcome assessment process using computer software. Participants in the PBM group will be required to wear a PBM device, while those in the control group will receive a sham device with an identical appearance to the PBM device but without light irradiation. All participants must wear their assigned device daily for 8 minutes (4 minutes for the upper and lower dental arches each) after brushing their teeth during the process of fixed-appliance orthodontic treatment. The allocation sequences will be concealed in a batch of opaque envelopes. Patients and the outcome assessor will be blinded to the allocation sequence. This protocol is proposed in compliance with the Declaration of Helsinki and the ICH-Good Clinical Practice (GCP) Guideline. The study will be conducted and reported according to the Consolidated Standards of Reporting Trials (CONSORT) guideline. Written consent will be obtained from all subjects.
43 studies on the registry are indexed under Root Resorption; 9 are open to participants now.
This study's planned enrollment of 50 is above the median of 29 across 36 interventional studies indexed under Root Resorption.
Browse Root Resorption studies →The University of Hong Kong is the lead sponsor of 1,292 studies on the registry; 348 are open to participants now.
Of its 9 completed or terminated interventional studies of FDA-regulated products, 0 (0%) have results posted.
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Exclusion Criteria:
wear PBM device daily during the fixed-appliance orthodontic treatment
Device: photobiomodulation therapy · Other: orthodontic fixed-appliance
wear sham device daily during the fixed-appliance orthodontic treatment
Other: orthodontic fixed-appliance
Patients in the PBM group will be delivered a portable PBM device (PBM Healing Ortho) at the beginning of orthodontic treatment and will be instructed to use it daily at home for 8 minutes (4 min per arch) after tooth brushing.
All eligible patients will receive orthodontic treatment with a pre-adjusted fixed appliance (0.022'' × 0.028'' slot system, MBT, 3M Unitek) provided by the same practitioner. At the start of treatment, a cantilever auxiliary arch bent with a 0.017'' × 0.025'' Stainless Steel wire (3M Unitek) will be used to apply a 100 g intrusion force to the premolars that will be extracted in 3 months. All other teeth will undergo regular orthodontic treatment with a standard archwire protocol (0.014'' NiTi, 0.016'' NiTi, 0.018'' NiTi, 0.017'' × 0.025'' NiTi, 0.019'' × 0.025'' NiTi, and 0.019'' × 0.025'' SS, 0.019'' × 0.025'' TMA) for alignment, leveling, space closure, detailing, and finishing. For en masse retraction, a 150 g force will be applied by coil springs, allowing bracket slots to slide along the 0.019'' × 0.025'' SS.
Orthodontic-induced inflammatory root resorption (OIIRR)
Record OIIRR by calculating the volume of craters on the root surfaces of the extracted tooth using a standard micro-CT machine after 3 months following intrusions by cantilever auxiliary arch.
Time frame: baseline, 3 months after intrusive force loading
Orthodontic pain
Record orthodontic pain monthly since the beginning of regular orthodontic treatment by patients' self-registration on a 100-millimetre Visual Analogue Scale (VAS). 0 means "no pain", 100 means "worst pain", the higher the score, the more severe the pain. In addition, 5-millilitre unstimulated saliva samples will be collected from each participant with the same time scheme for evaluation of pain-related biomarkers.
Time frame: baseline, immediately after fixed appliance placement and immediately after adjustment every month during the first year of regular orthodontic treatment
Space closure by en masse retraction
Record the duration of the space closure by calculating the rate of tooth movement (mm/mo) with physically measurement. In addition, gingival crevicular fluid samples will be collected from the two space-neighbouring teeth to analyse bone-related biomarkers.
Time frame: every month from the start of space closure to the end of closure, taking into account the very slow closure of space, assessed up to 12 months
Microbiome profile in dental plaques
Samples of supragingival and subgingival plaques will proceed to 16S rRNA sequencing for analysis of microbiome profiles, and q-PCR for evaluating bacterial loads of some critical pathogens for dental caries and periodontitis.
Time frame: baseline, every 3 months from the start of regular orthodontic treatment to the end of treatment process
Started Jan 2024 (actual). Primary completion is estimated for Jun 2027, 40 months after the start.
Of 25 interventional studies with no phase under Root Resorption, half reached primary completion within 21 months of starting (the median), counting those still running; a quarter within 12 and three quarters within 41. This study's planned 40 months is above that.
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This study is active, not recruiting, as verified in Jun 2026. You cannot join it, but the record below documents what was studied.
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