Application of Different Wavelengths of LED Lights in Antimicrobial Photodynamic Therapy for the Treatment of Periodontal Disease

Abstract

Therapeutic light has been increasingly used in clinical dentistry for surgical ablation, disinfection, bio-stimulation, reduction in inflammation, and promotion of wound healing. Photodynamic therapy (PDT), a type of phototherapy, has been used to selectively destroy tumor cells. Antimicrobial PDT (a-PDT) is used to inactivate causative bacteria in infectious oral diseases, such as periodontitis. Several studies have reported that this minimally invasive technique has favorable therapeutic outcomes with a low probability of adverse effects. PDT is based on the photochemical reaction between light, a photosensitizer, and oxygen, which affects its efficacy. Low-power lasers have been predominantly used in phototherapy for periodontal treatments, while light-emitting diodes (LEDs) have received considerable attention as a novel light source in recent years. LEDs can emit broad wavelengths of light, from infrared to ultraviolet, and the lower directivity of LED light appears to be suitable for plaque control over large and complex surfaces. In addition, LED devices are small, lightweight, and less expensive than lasers. Although limited evidence exists on LED-based a-PDT for periodontitis, a-PDT using red or blue LED light could be effective in attenuating bacteria associated with periodontal diseases. LEDs have the potential to provide a new direction for light therapy in periodontics.

The Effect of Photodynamic Therapy on Enterococcus spp. and Its Application in Dentistry: A Scoping Review

“…Since the mechanism of action of PDT requires the simultaneous presence of the photosensitizer compound, molecular oxygen, and visible light, PDT can easily be applied to the oral cavity. Using red or blue LED light, PDT for periodontitis can effectively attenuate bacteria associated with periodontal diseases [ 98 ]. Dentists already have devices that emit light at specific wavelengths that can be easily applied to activate PSs on exposed oral cavity surfaces in the presence of oxygen [ 8 ].…”

“…Therefore, improving the effectiveness of PDT for E. faecium and E. faecalis will depend on multiple variables, such as the selected PS and its concentration, the wavelength at which the PS is activated, the power output of the lamp used, and the irradiation time, among others. For example, riboflavin or curcumin can be activated by using curing resin devices that emit light at wavelengths between 430 and 480 nm with powers close to 1200 mW/cm 2 [ 98 ]. Thus, multiple PSs have been studied as treatment alternatives, with phenothiazine derivatives such as toluidine blue (TBO) and methylene blue (MB) being highlighted as the most effective.…”

“…Opposite to the good results yield by phenothiazine derivatives, curcumin did not show significant photosensitizer activity, even in combination with TBO or MB. Another drawback of curcumin is that its low solubility in water limits its elimination [ 51 , 52 ], although its low wavelength maximum absorption, close to 405 nm, makes it suitable for blue-light-emitting dental devices [ 98 ].…”