ABSTRACT
BACKGROUND: The use of low-level laser therapy is growing in the field of dentistry especially in orthodontics to speed up tooth movement and in implantology to aid osseointegration. In these dental applications, the laser energy needs to penetrate through the periodontium to the target site to stimulate photobiomodulation. The percentage of energy loss when laser is transmitted through the periodontium has not been previously studied. With the use of an 808-nanometer diode laser, the aim was to investigate the percentage loss of laser energy when transmitted through the periodontium to the extraction socket. METHODS: The percentage energy loss of an 808-nm diode laser through the periodontium was measured in 27 tooth sockets by using a specifically designed photodiode ammeter. RESULTS: For each millimeter of increased bone thickness there was 6.81% reduction in laser energy (95% confidence interval, 5.02% to 8.60%). The gingival thickness had no statistically significant effect on energy penetration. CONCLUSION: Energy penetration depends markedly on bone thickness and is independent of gingival thickness. PRACTICAL IMPLICATIONS: To the best of the authors' knowledge, this study is one of the first to investigate laser penetration through the periodontium. Evidence from this study showed that laser energy penetration through the periodontium is markedly affected by bone thickness but less so by gingival thickness. Clinicians need to be aware of the biological factors that could affect laser energy penetration to the target site and adjust their laser dosages accordingly. These findings may guide dental practitioners in selecting the appropriate laser dosage parameters for low-level laser therapy.
Subject(s)
Gingiva , Periodontium , Pilot Projects , Tooth Movement Techniques , Tooth SocketABSTRACT
Background: The effect of low-level laser therapy (LLLT) on accelerating orthodontic tooth movement has been extensively studied; however, there is limited knowledge on the use of LLLT on orthodontic root resorption. Objective: To investigate the effect of LLLT on orthodontically induced inflammatory root resorption (OIIRR) and to compare the difference between pulsed and continuous LLLT on OIIRR. Trial design: Double-blind, single-centre 3-arm parallel split-mouth randomized controlled trial. Participants: Twenty adolescent patients who required bilateral maxillary first premolar (MFP) orthodontic extractions were recruited from the Sydney Dental Hospital between October 2014 and December 2014. Intervention: All MFPs were tipped buccally for 28 days to induce OIIRR. The experimental premolars (n = 20) received LLLT and the control premolars (n = 20) received placebo-laser on days 0, 1, 2, 3, 7, 14, and 21. Ten experimental premolars received LLLT via continuous delivery and 10 received pulsed delivery. Laser parameter: AlGaAs diode laser of 808 nm wavelength, 0.18 W power, 1.6 J per point, and duration of 9s for continuous mode and 4.5 s for pulsed mode. Outcome: The difference in root resorption crater volume between LLLT and placebo-laser and continuous or pulsed laser delivery after 28 days. Randomization: Randomization was computer-generated, with allocation concealment by opaque sequentially numbered sealed envelopes. Blinding: The participants and operator were blinded. Results: Eighty-eight patients were screened and 20 patients were randomized. Forty premolars were analysed. LLLT resulted in 23 per cent less root resorption compared to the placebo (P = 0.026). Pulsed laser delivery resulted in 5 per cent less root resorption than continuous; however, this was not statistically significant (P = 0.823). No harm was observed. Conclusion: Teeth treated with LLLT had less total root resorption than placebo-laser. Furthermore, there was minimal difference between pulsed or continuous delivery of LLLT. Trial Registration: Clinical Trials Registry (ACTRN12616000829415). Protocol: The protocol was not published before trial commencement.
