Introduction
Periodontitis
CELL INJURY, PERIODONTITIS, BACTERIAL RESISTANCE, DYSREGULATED HOST RESPONSE, PERIODONTITIS, INFLAMMATORY DISEASE
Periodontitis is a chronic multifactorial inflammatory disease initiated by a dysbiotic biofilm and mediated by a dysregulated host response. It is characterized by the progressive destruction of the supporting periodontal tissues [In this context, the use of lasers in combination with photosensitizer solutions, namely, antimicrobial photodynamic therapy (aPDT), has been proposed as an adjunct to conventional periodontal therapy to enhance the antibacterial effect and, thus, to improve clinical results especially in areas with difficult access. The goal of aPDT is to use a photosensitizer solution that once absorbed by bacteria is activated with a light irradiation, thereby producing reactive oxygen species, which injure bacteria without the risk of developing bacterial resistance [Due to the heterogeneity of proposed protocols and the conflicting results on their efficacy for the treatment of periodontitis, the evidence for adjunctive aPDT is as yet insufficient for clinical recommendation [The combined use of diode laser and indocyanine green (ICG) has been recently proposed for the adjunctive treatment of periodontitis. ICG is approved for use as a fluorescence perfusion dye and as a photosensitizer. In addition to oxidative attack, it has been reported to exert, in response to near-infrared lasers, a photothermal effect that causes cell injury related to the hyperthermic condition and deeper light penetration [Given the relevance of this topic and the existence of limited and heterogeneous data in the literature, the aim of the present randomized controlled trial (RCT) was to evaluate the clinical and microbiological adjunctive effects of repeated applications of ICG-aPDT as an adjunct to FMUD in the treatment of periodontitis.