The use of diffuse laser photonic energy and indocyanine green photosensitiser as an adjunct to periodontal therapy.

Light-activated chemical therapy - generally known as photodynamic therapy (PDT) - has been developed within medicine, to allow the use of an applied agent (photosensitiser) that could be activated using laser photonic energy, leading to the destruction of target cellular structures. In clinical dentistry, PDT has been utilised within a wide scope of topical application in endodontic, periodontal and oral epithelial pathology where specifically, anti-bacterial action may prove useful. Underlying the complex and multi-factorial aetiology, periodontal disease remains of essentially-bacterial origin and anti-bacterial PDT (aPDT) has been investigated as an adjunctive to other periodontal treatment therapies. Of several topically-applied photosensitisers, one agent, indocyanine green, may be activated using a diode laser wavelength (810 nm) that is commonly-available in clinical dental practice, to provide generalised bacteriocidal effect. Unlike antibiotics and antibacterial mouthwashes, the mode of action appears to be nonspecific to bacterial species and is linked to cell death through a process of oxidative stress. Additionally, indocyanine green has otherwise low toxicity to non-target host tissue and dental restorative materials. This paper explores the background to this therapy, its position within the broader delivery of periodontal treatment and the specific application of indocyanine green in clinical dental practice.