The Effectiveness of Low-level Laser Therapy in Orthodontic Retention for Periodontal-compromised Patients
Condition: Orthodontics; Periodontal Diseases
MeSH terms: Periodontal Diseases
Study type: Interventional

Summary: 
      The aim of the study is to evaluate the effects of low-level laser therapy (LLLT) on patients
      with chronic periodontitis during a post-orthodontic period for 12 months. Following aspects
      will be assessed: 1. Effects on tooth stability maintenance and bone remodeling. 2. Effects
      on periodontal inflammation status. 3. Effects on cervical dentin sensitivity and quality of
      life. The study design is a randomised controlled trail. To eliminate any bias, the
      investigator will initially hypothesis there is no significant difference in the
      aforementioned aspects between teeth retained with an adjunctive LLLT strategy and those
      retained in a conventional regimen.
    

Detailed description: 
      The study design is a randomised split-mouth design based on the result of investigator's
      pilot study. Thirty-five non-smoking Ethnic Chinese patients (male and female, age: 25-65
      years) with chronic periodontitis will be recruited. The teeth in experimental group will
      receive LLLT during orthodontic retention period for 12 months, while the teeth in the
      control (placebo) group will not receive laser therapy. Orthodontic occlusal indices will be
      measured to explore LLLT's role in maintaining tooth stability. The effects of LLLT on
      periodontal inflammation status will be evaluated by assessing clinical periodontal
      parameters and the levels of supra-gingival and sub-gingival bacteria. The effects of LLLT on
      bone remodelling will be explored by testing the biochemical biomarkers in gingival
      crevicular fluid (GCF). Cone-beam computed tomography will also be used to provide clinical
      evidence of periodontal status and bone remodelling. Possible effects of LLLT on patient's
      quality of life will be investigated via validated questionnaires, subjective assessment of
      tooth sensitivity, and objective measurement of bite force.
    

Intervention name(s): low-level laser therapy; orthodontic retention
Intervention type(s): Device; Other
Intervention description(s): LLLT will be performed by a diode gallium-aluminum-arsenide (Ga-Al-As) laser with a 940-nm wavelength (Ezlase; Biolase Technology Inc., Irvine, CA) and delivered by a quadrant-sized probe which cover the region from the central incisor to the first molar on the test side. The laser probe will be 1 cm from the soft tissue around the test tooth at the gingival margin and alveolar mucosa covering the root area using a setting of 800 milliwatt in a continuous wave. Each tooth will receive 30 seconds of exposure, with no more than 8.6 J/cm2 of energy delivered. In addition, a spot-size laser probe will be applied for 30 seconds 5 mm from the cervical dentin with an output power of 700 milliwatt to reduce tooth sensitivity.; All participants included will wear fixed lingual retainer and removable retainers in the post-orthodontic retention period and their previous orthodontic treatment will be carried out by one operator using preadjusted appliances with bonded 0.022×0.028-inch2 brackets/buccal tubes and 0.014-inch Nickel Titanium (NiTi) archwires as the first archwires.
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Triple (Participant, Care Provider, Outcomes Assessor)
Primary purpose: Treatment
Keywords: low-level laser therapy; orthodontic retention; periodontal disease