Photobiostimulation as a modality to accelerate orthodontic tooth movement

Nanotechnology for Dentistry: Prospects and Applications

In the XXI century, application of nanostructures in oral medicine has become common. In oral medicine, using nanostructures for the treatment of dental caries constitutes a great challenge. There are extensive studies on the implementation of nanomaterials to dental composites in order to improve their properties, e.g., their adhesive strength. Moreover, nanostructures are helpful in dental implant applications as well as in maxillofacial surgery for accelerated healing, promoting osseointegration, and others. Dental personal care products are an important part of oral medicine where nanomaterials are increasingly used, e.g., toothpaste for hypersensitivity. Nowadays, nanoparticles such as macrocycles are used in different formulations for early cancer diagnosis in the oral area. Cancer of the oral cavity-human squamous carcinoma-is the sixth leading cause of death. Detection in the early stage offers the best chance at total cure. Along with diagnosis, macrocycles are used for photodynamic mechanism-based treatments, which possess many advantages, such as protecting healthy tissues and producing good cosmetic results. Application of nanostructures in medicine carries potential risks, like long-term influence of toxicity on body, which need to be studied further. The introduction and development of nanotechnologies and nanomaterials are no longer part of a hypothetical future, but an increasingly important element of today's medicine.

The effect of intra-oral LED device and low-level laser therapy on orthodontic tooth movement in young adults: A randomized controlled trial

INTRODUCTION

This randomized controlled clinical trial aimed to assess the effect of LED⁵ and LLLT⁶ in a three-arm parallel setting.

METHODS

Sixty patients who needed the maxillary first premolar extraction were allocated to three groups using the stratified block randomization method. In the LED group, a custom-made device with a wavelength of 640nm and a power density of 40 mW/cm² was used 5min/day. In the laser group, Ga Al As⁷ laser with a wavelength of 810nm and a power of 100 mW was used on days 0, 3, 30, and 60 each time for 18seconds. Patients in the control group received placebo treatment as the laser group protocol, using a coated light cure device. Models were made at baseline and monthly until the end of the retraction. The rate of canine retraction was the primary outcome, while canine rotation and pain were secondary outcomes. The final data were anonymous for the outcome assessor and statistical consultant. Data were analyzed per protocol using a linear mixed model.

RESULTS

The rate of canine retraction significantly increased by 60.8% in the laser group, while it increased not significantly by 26% in the LED group compared with the control group. There was no significant difference among the groups in terms of tooth rotation and pain.

CONCLUSIONS

LLLT can accelerate orthodontic tooth movement (OTM). LED with the present setting couldn't increase the rate of OTM. LLLT and LED did not affect canine rotation or pain.

TRIAL REGISTRATION

IRCT20120220009086N4. On 1 June 2019 was retrospectively registered.

Effect of light-emitting diode-mediated photobiomodulation on extraction space closure in adolescents and young adults: A split-mouth, randomized controlled trial

INTRODUCTION

This split-mouth trial aimed to examine the effects of light-emitting diode (LED)-mediated photobiomodulation compared with no photobiomodulation on maxillary canine distalization.

METHODS

Twenty participants (10 males and 10 females; aged 11-20 years) requiring bilateral extraction of maxillary first premolars were included from the Sydney Dental Hospital waiting list. After premolar extractions, leveling, and alignment, canines were retracted on 0.020-in stainless steel wires with coil springs delivering 150 g of force to each side. Each patient's right side was randomly assigned to experimental or control using www.randomisation.com, and allocation concealment was performed with sequentially numbered, opaque, sealed envelopes. The experimental side received 850 nm wavelength, 60 mW/cm² power, continuous LED with OrthoPulse device (Biolux Research Ltd, Vancouver, British Columbia, Canada) for 5 min/d. For the control side, the device was blocked with opaque black film. Patients were reviewed at 4-week intervals for force reactivation and intraoral scanning over 12 weeks. The primary outcome was the amount of tooth movement, and secondary outcomes were anchorage loss and canine rotation, all measured digitally. Blinding for study participants and the treating clinician was not possible; however, blinding was done for the measurements by deidentifying the digital scans. Linear mixed models were implemented for the data analysis.

RESULTS

Nineteen participants concluded the study. Data analysis showed that the treatment × time interaction was not significant, suggesting no difference in space closure (unstandardized regression coefficient [b], 0.12; 95% confidence interval [CI], -0.05 to 0.29; P = 0.17), canine rotation (b, 0.21; 95% CI, -0.82 to 1.25; P = 0.69), and anchorage loss (b, -0.01, 95% CI, -0.28 to 0.26, P = 0.94). No harms were noted.

CONCLUSIONS

Daily 5-minute application of LED did not result in clinically meaningful differences during extraction space closure compared with no LED application.

REGISTRATION

Australian New Zealand Clinical Trials Registry (ACTRN12616000652471).

PROTOCOL

The protocol was not published before trial commencement.

FUNDING

This research was funded by the Australian Society of Orthodontists Foundation for Research and Education.

The red-light emitting diode irradiation increases proliferation of human bone marrow mesenchymal stem cells preserving their immunophenotype

PURPOSE

For effective clinical application of human bone marrow mesenchymal stem cells (hBM-MSCs), the enhancement of their proliferation in vitro together with maintaining the expression of their crucial surface antigens and differentiation potential is necessary. The present study aimed to investigate the effect of light-emitting diode (LED) irradiation on hBM-MSCs proliferation after two, five, or nine days post-irradiation.

MATERIALS AND METHODS

The hBM-MSCs were exposed to the LED light at 630 nm, 4 J/cm², and power densities of 7, 17, or 30 mW/cm². To assess the cell proliferation rate in the sham-irradiated and irradiated samples the cells metabolic activity and DNA content were determined. The number of apoptotic and necrotic cells in the samples was also evaluated. The expression of the crucial surface antigens of the hBM-MSCs up to nine days after irradiation at 4 J/cm² and 17 mW/cm² was monitored with flow cytometry. Additionally, the potential of hBM-MSCs for induced differentiation was measured.

RESULTS

When the metabolic activity was assayed, the significant increase in the cell proliferation rate by 31 and 50% after the irradiation with 4 J/cm² and 17 mW/cm², respectively, was observed at day five and nine when compared to the sham-irradiated cells (p < .05). Similarly, DNA content within the irradiated hBM-MSCs increased by 31 and 41% at day five and nine after the irradiation with 4 J/cm² and 17 mW/cm² in comparison to the sham-irradiated cells. LED irradiation did not change the expression of the crucial surface antigens of the hBM-MSCs up to nine days after irradiation at 4 J/cm² and 17 mW/cm². At the same experimental conditions, the hBM-MSCs maintain in vitro their capability for multipotential differentiation into osteoblasts, adipocytes, and chondrocytes.

CONCLUSION

Therefore, LED irradiation at a wavelength of 630 nm, energy density 4 J/cm², and power density 17 mW/cm² can effectively increase the number of viable hBM-MSCs in vitro.