Photodynamic therapy as an alternative treatment for disinfection of bacteria in oral biofilms

Developments in low level light therapy (LLLT) for dentistry

OBJECTIVES

Low level light/laser therapy (LLLT) is the direct application of light to stimulate cell responses (photobiomodulation) in order to promote tissue healing, reduce inflammation and induce analgesia. There have been significant studies demonstrating its application and efficacy at many sites within the body and for treatment of a range of musculoskeletal injuries, degenerative diseases and dysfunction, however, its use on oral tissues has, to date, been limited. The purpose of this review is to consider the potential for LLLT in dental and oral applications by providing background information on its mechanism of action and delivery parameters and by drawing parallels with its treatment use in analogous cells and tissues from other sites of the body.

METHODS

A literature search on Medline was performed on laser and light treatments in a range of dental/orofacial applications from 2010 to March 2013. The search results were filtered for LLLT relevance. The clinical papers were then arranged to eight broad dental/orofacial categories and reviewed.

RESULTS

The initial search returned 2778 results, when filtered this was reduced to 153. 41 were review papers or editorials, 65 clinical and 47 laboratory studies. Of all the publications, 130 reported a positive effect in terms of pain relief, fast healing or other improvement in symptoms or appearance and 23 reported inconclusive or negative outcomes. Direct application of light as a therapeutic intervention within the oral cavity (rather than photodynamic therapies, which utilize photosensitizing solutions) has thus far received minimal attention. Data from the limited studies that have been performed which relate to the oral cavity indicate that LLLT may be a reliable, safe and novel approach to treating a range of oral and dental disorders and in particular for those which there is an unmet clinical need.

SIGNIFICANCE

The potential benefits of LLLT that have been demonstrated in many healthcare fields and include improved healing, reduced inflammation and pain control, which suggest considerable potential for its use in oral tissues.

Photoelimination of Streptococcus mutans with two methods of photodynamic and photothermal therapy

BACKGROUND

Increasing resistance of oral pathogens to conventional antibacterial agents has resulted to find alternative therapies to overcome resistance development problems; hence this in vitro study was carried out to investigate the efficacy of photoelimination of Streptococcus mutans with two methods of photodynamic and photothermal therapy.

METHODS

Standard Suspensions of S. mutans were treated in two groups of photodynamic therapy with Toluidine blue O and Rhadachlorin(®) and photothermal therapy by EmunDo(®) and their individual light sources, then Bacterial suspension from each treatment was subcultured on the surface of Mueller-Hinton agar plates and bacterial growth was assessed. The results were analyzed by analysis of variance and Tukey test (p<0.05).

RESULTS

After treatments significant reduction of S. mutans viability in planktonic culture was observed in both groups of photodynamic and photothermal therapy with no priority.

CONCLUSION

Photoelimination can be a novel modality in the eradication of S. mutans colonies in near future.

Photodynamic Therapy (PDT) Utilizing Multiple Light Sources Significantly Improves Clinical Efficacy and Subject Satisfaction with a Review of PDT Mechanisms of Action

Introduction:

Many topically applied devices and medicaments have been developed to give hope to people who want to reduce the signs of visible aging. All modalities have benefits and risks, and no single modality produces complete resolution of photoaging. Although approved by the US Food and Drug Administration for treatment of epithelial neoplasia, photodynamic therapy (PDT) is also reported to produce significant benefits in reducing photoaging. The goal of this study was to determine if clinical response and subject satisfaction can be improved for PDT while reducing downtime and increasing activation of the photosensitizer.

Materials and Methods:

In a regimen administered monthly for 3 treatments, 14 subjects participated in a prospective intervention pilot trial using an 830 nm light-emitting diode (LED), a 540 nm advanced fluorescence technology laser, a 570 nm advanced fluorescence technology laser, and a 633 nm LED. The photoactivation phase was initiated with the 830 nm LED 10 minutes after application of 20% 5-aminolevulinic acid, followed by each modality in listed order. Baseline global extrinsic aging scores were compared with scores 1 month after the final treatment. Subject satisfaction scores were also obtained 1 month after the final treatment.

Results:

Twelve subjects completed this trial. The global extrinsic aging score improved from a baseline of 3.3 to 1.0. Of these 12 subjects, 10 (84%) indicated that they were satisfied or very satisfied with the results 1 month after completion of the treatment.

Conclusions:

This photodynamic therapy regimen is very effective while being better tolerated and involving less downtime. The treatment can also be completed in a shorter time than regimens requiring a longer incubation time.