Light-activated therapies have been used in medicine for decades, and one targeted approach—photodisinfection therapy—is gaining attention in dentistry for treating progressive gum disease (periodontitis).
This form of antimicrobial photodynamic therapy can selectively eliminate harmful, inflammation-causing bacteria beneath the gumline without contributing to antibiotic resistance, offering a useful adjunct to conventional periodontal care.
Below is an overview of what photodisinfection is, how it works, who may benefit, and what to expect from the treatment.
What is photodisinfection?
Photodisinfection is an antimicrobial photodynamic treatment that combines a photosensitizing solution with a nonthermal laser. The solution binds to bacteria and, when activated by the laser, produces reactive oxygen species that destroy microbial cells. Because it is not an antibiotic, photodisinfection does not promote antimicrobial resistance, even with repeated use.
In dental settings, photodisinfection is used as an adjunct to scaling and root planing (SRP) to target the biofilm and bacteria residing below the gumline. One widely used system for periodontal photodisinfection is Periowave™ by Ondine Biomedical, which has regulatory approval in multiple jurisdictions.
How does photodisinfection work?
During the procedure, a clinician applies a blue photosensitizing dye, typically methylene blue, directly into each periodontal pocket. The dye preferentially binds to bacterial cell walls—more rapidly to Gram-negative bacteria, which are commonly implicated in periodontal disease.
A nonthermal diode laser is then applied to activate the dye. Activation triggers a localized oxidative reaction that damages and kills the bacteria bound to the dye while sparing many beneficial Gram-positive species that support a healthy oral microbiome. When combined with mechanical debridement (SRP), photodisinfection can significantly reduce pocket depths, bleeding, and inflammation.
Importantly, because the mechanism relies on localized photochemical reactions rather than systemic antibiotics, it does not contribute to the development of antibiotic-resistant organisms.
Who can benefit from photodisinfection treatment?
Photodisinfection is indicated as an adjunctive therapy for patients with chronic periodontitis and for managing inflammation around dental implants (peri-implantitis). It may be particularly helpful in cases where conventional therapy alone has not achieved adequate control of infection and inflammation.
How photodisinfection treats gum disease
When used in combination with SRP, photodisinfection has been shown in clinical studies to enhance reductions in pocket depth, bleeding on probing, and signs of inflammation. Because advanced gum disease can lead to gum recession and bone loss—changes that are difficult or impossible to reverse—early and effective control of the infection is important.
Standard care often involves periodic SRP and, in some stubborn cases, systemic antibiotics. Photodisinfection offers an alternative or adjunct that can more selectively target pathogenic bacteria without depleting beneficial oral microbes, helping preserve the oral microbiome’s natural defenses.
Multiple applications of photodisinfection have also been associated in some studies with reductions in systemic inflammatory markers such as C-reactive protein (CRP), which links oral inflammation to broader systemic health concerns.
Scientific evidence
Clinical trials and reviews have examined the adjunctive effect of antimicrobial photodynamic therapy in periodontitis and peri-implantitis. These studies evaluate outcomes such as pocket depth reduction, bleeding, microbiological shifts, and short-term clinical improvements when photodisinfection is added to conventional periodontal therapy.
- Systematic and evidence reviews discussing antimicrobial photodynamic therapy for periodontitis and peri-implantitis.
- Multicenter clinical trials comparing SRP alone to SRP combined with photodisinfection.
- Randomized and controlled studies assessing clinical and microbiological outcomes after adjunctive photodynamic therapy.
Photodisinfection therapy: what to expect
A typical photodisinfection procedure for periodontitis follows these steps:
- First, the clinician performs scaling and root planing to remove plaque, calculus, and endotoxins from below the gumline. Local anesthetic is commonly used for SRP.
- If excessive bleeding is present, the clinician may delay the photodisinfection session for a short interval (often around two weeks) to allow initial healing. Otherwise, the photodisinfection can sometimes proceed immediately after SRP.
- The photosensitizing dye is gently applied into each periodontal pocket one at a time.
- A nonthermal diode laser is directed into the pocket for a specified duration (commonly around one minute) to activate the dye and achieve antimicrobial action.
- In severely infected areas, additional applications may be performed during the visit.
Contraindications & side effects
Photodisinfection has a favorable safety profile. There are no widely reported systemic side effects or established contraindications, and it is generally considered safe for pregnant or lactating patients. As with any clinical procedure, patients should discuss their individual medical history and any concerns with their dentist or periodontist prior to treatment.
Other health benefits of photodisinfection
Variations of photodisinfection have been explored in other clinical areas, including:
- Postoperative infection control in nasal surgery
- Treatment of chronic rhinosinusitis
- Disinfection of endotracheal or ventilator tubing
- Support of wound and burn healing
- Investigational uses related to reducing perinatal transmission risks
As research continues, photodisinfection remains an attractive, non-antibiotic option for targeted antimicrobial therapy in the oral cavity and beyond.