Effects of Antimicrobial Photodynamic Therapy in the Treatment of Periodontal Disease in Adults

Abstract

Periodontal disease is a chronic inflammatory condition affecting the supporting tissues of the teeth, and is considered one of the leading causes of tooth loss in adults. Its development is associated with the presence of subgingival bacterial biofilm and the host's immunoinflammatory response. Although conventional treatment based on scaling and root planing is widely used and effective, there is growing interest in complementary therapies that enhance microbial elimination and promote better clinical outcomes. Among these approaches, Antimicrobial Photodynamic Therapy (aPDT) has gained prominence by combining a photosensitizer with a specific light source, generating reactive oxygen species capable of destroying pathogenic microorganisms without causing tissue damage.

Several studies demonstrate that aPDT can significantly reduce bacterial counts, especially of periodontal pathogens such as *Porphyromonas gingivalis*, *Tannerella forsythia*, and *Treponema denticola*. Furthermore, the effects of the therapy include reduced probing depth, clinical improvement in periodontal attachment, and decreased bleeding on probing, especially when used as an adjunct to conventional mechanical treatment. aPDT also presents advantages such as a lower risk of bacterial resistance, absence of systemic adverse effects, and minimally invasive application, making it a promising alternative, especially for patients with restrictions on antibiotic use or in cases of refractory periodontitis.

However, the effectiveness of the therapy depends on factors such as the type of photosensitizer used, the power of the light source, the application protocol, and the patient's initial periodontal condition. Despite the positive results reported in the literature, there is still significant variability between studies, suggesting the need for standardization of the methods employed. Photodynamic therapy tends to show better results when repeated in multiple sessions and integrated into a comprehensive therapeutic plan. In adults, especially those with a history of rapid disease progression, aPDT can contribute to deeper microbial control and a more stable periodontal inflammatory process. Considering its safety and potential to enhance the effects of scaling and root planing, antimicrobial photodynamic therapy has proven to be an effective tool in the management of periodontal disease. While it does not yet replace traditional mechanical approaches, it stands out as a therapeutic complement that can improve clinical outcomes, reduce resistant pathogens, and promote a healthier periodontal environment in the long term. Future research should focus on standardized protocols, understanding the cellular mechanisms involved, and evaluating long-term clinical outcomes to consolidate its routine use in dental practice.