Feasibility of transgingival laser irradiation for antimicrobial photodynamic therapy

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

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.

Optimization of treatment and prevention of generalized periodontal diseases with the use of transgingival photoactived disinfection

The aim of the study is to develop protocols for the treatment and prevention of generalized periodontal disease using a nozzle that designed for transgingival photosensitizer activation. Methods. Analysis of available variants of irradiation nozzles for photoactivated disinfection. Circuit design and construction of authors’ irradiation nozzle for transgingival photosensitizer activation. Results. Based on the analysis of data, there was developed a nozzle design that allows treating periodontium areas within 4-6 teeth, evenly distributes the required power of laser radiation, and can be used in hard-to-reach areas of the oral cavity. Based on the above calculations, a nozzle for transgingival photosensitizer activation was created (jointly with Fotonika Plus, PE). To optimize the PAD procedure, there was created a protocol of transgingival photoactivated disinfection to be applied at the stage of professional oral hygiene, using the created irradiation nozzle NOU-9 of authors’ design, and diode 2 W laser LIKA-surgeon with a wavelength of 660 nm. The result is the accelerated procedure of transgingival photoactivated disinfection. Conclusions. The development of photoactivated disinfection technology allows supplementing the traditional treatment of generalized periodontal diseases. Studies of non-invasive, transgingival method of photosensitizer activation have recently become popular. This, in turn, carries a lower probability of cross-infection and less traumatization of periodontal tissues during the manipulation. The use of PAD cannot lead to resistance of the microflora in contrast to pharmacological antibacterial preparations. Carrying out PAD does not require any complex manual skills, the purchase of expensive equipment, provides an opportunity for widespread introduction of technology. The use of the therapeutic complex and protocols of PAD that were developed can significantly reduce the duration of the procedure, resulting in improved comfort for both the doctor and the patient. The NOU-9 irradiation nozzle allows reaching hard-to-reach areas of the oral cavity, distributing laser radiation efficiently and evenly on periodontal tissues. The LIKA-surgeon 2 W laser with a wavelength of 660 nm provides the operating parameters required to activate the photosensitizer. Due to low-intensity radiation, it is possible to enhance regenerative processes in the periodontium after traumatic intervention. Clinical studies on the antibacterial efficacy of the technology are ongoing

Laser-Assisted aPDT Protocols in Randomized Controlled Clinical Trials in Dentistry: A Systematic Review

BACKGROUND

Antimicrobial photodynamic therapy (aPDT) has been proposed as an effective alternative method for the adjunctive treatment of all classes of oral infections. The multifactorial nature of its mechanism of action correlates with various influencing factors, involving parameters concerning both the photosensitizer and the light delivery system. This study aims to critically evaluate the recorded parameters of aPDT applications that use lasers as the light source in randomized clinical trials in dentistry.

METHODS

PubMed and Cochrane search engines were used to identify human clinical trials of aPDT therapy in dentistry. After applying specific keywords, additional filters, inclusion and exclusion criteria, the initial number of 7744 articles was reduced to 38.

RESULTS

Almost one-half of the articles presented incomplete parameters, whilst the others had different protocols, even with the same photosensitizer and for the same field of application.

CONCLUSIONS

No safe recommendation for aPDT protocols can be extrapolated for clinical use. Further research investigations should be performed with clear protocols, so that standardization for their potential dental applications can be achieved.

Transgingival photodynamic therapy (tg-aPDT) adjunctive to subgingival mechanical instrumentation in supportive periodontal therapy. A randomized controlled clinical study

BACKGROUND

Recent data from preclinical studies and case series suggest that transgingival irradiation with diode lasers may represent a novel modality for antimicrobial photodynamic therapy (aPDT). However, at present, there is lack of data from controlled clinical studies on the use of transgingival antimicrobial photodynamic therapy (tg-aPDT) in the treatment of periodontitis.

OBJECTIVE

To evaluate the clinical effects of tg-aPDT used in conjunction with nonsurgical mechanical instrumentation during supportive periodontal therapy (SPT).

MATERIALS AND METHODS

Forty stage II and III periodontitis patients enrolled in SPT were randomly assigned to two groups of equal size. At baseline, study sites had to show sites with pocket probing depth (PPD) of ≥ 5 mm and Bleeding on Probing (BOP). Full mouth and site-specific Plaque-Index scores (PI), BOP, PPD, and Clinical Attachment Level (CAL) were recorded at baseline (BL), three months (3 M), and 6 months (6 M), respectively. The primary outcome variable was the change in the number of sites with BOP. Treatment was performed under local anaesthesia after random allocation to one of the following groups 1) Subgingival scaling and root planing (SRP) + tg-aPDT (test) or 2) SRP alone (control).

RESULTS

Thirty-nine patients completed the study. Full mouth PI and BOP improved over six month, however without statistically significant difference between the groups. At 6 M, BOP-levels were statistically significantly lower in test sites (25.0 %) compared to the control sites (65.0 %), (p < 0.025). PPD improved in both groups with comparable mean values at 3 M (PPD test: 5.21 ± 0.92 mm; PPD control: 4.45 ± 1.36 mm) and 6 M (PPD test: 5.11 ± 1.10 mm; PPD control: 4.35 ± 1.14 mm). Additionally, CAL slightly improved in both groups with comparable mean values at 3 M (CAL test: 6.79 ± 1.72 mm; CAL control: 5.30 ± 2.43 mm) and 6 M (CAL test: 6.26 ± 1.70 mm; CAL control: 5.50 ± 2.33 mm).

CONCLUSIONS

Within its limits, the present results appear to indicate that the use of tg-aPDT adjunctive to SRP may represent a new modality for controlling inflammation and further bleeding in residual periodontal pockets.