Microbial Composition of Oral Biofilms after Visible Light and Water-Filtered Infrared a Radiation (VIS+wIRA) in Combination with Indocyanine Green (ICG) as Photosensitizer

Lima

Journal of Periodontology

et al. 2023

BackgroundProspective studies have reported conflicting results regarding the adjunctive effect of antimicrobial photodynamic therapy (aPDT) on clinical and microbiological parameters in individuals under periodontal maintenance therapy (PMT). This study aimed to evaluate the clinical and microbiological adjunctive effects of aPDT using indocyanine green (ICG) in residual sites with probing depth (PD) ≥5 mm during PMT in comparison with scaling and root planing (SRP) alone.MethodsA split‐mouth randomized controlled clinical trial was conducted with 24 individuals in a PMT program. Contralateral quadrants with eligible residual sites were randomly assigned to either SRP + aPDT (test group) or SRP alone (control). aPDT included ICG dye and diode laser (909 nm) performed together with SRP and repeated 15 days after. Periodontal clinical parameters, periodontal inflamed surface area (PISA) index, and subgingival biofilm samples were collected at baseline (T1), 3 (T2), and 6 months later (T3). Microbiological analyses were performed by quantitative real‐time polymerase chain reaction.ResultsSignificant improvements were observed in all clinical and microbiological parameters in both groups from T1 to T3. However, no significant differences were observed regarding plaque index, PD, and clinical attachment level. Test group showed significantly greater reductions in bleeding on probing (BOP), PISA index, and Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans levels, when compared with controls.ConclusionsBoth treatments resulted in significant clinical periodontal improvements, but with no significant differences between groups except from inflammation parameters. aPDT using ICG resulted in significant reductions in BOP and PISA index, as well as in P. gingivalis and A. actinomycetemcomitans levels.

Section: Discussionmentioning

confidence: 99%

Adjunctive effects of photodynamic therapy using indocyanine green in residual pockets during periodontal maintenance therapy: A split‐mouth randomized controlled trial

Lima

Journal of Periodontology

et al. 2023

“…To verify the CHX-induced adaptions in biofilm building capacity and cross-resistance to antibiotics, studies should be conducted with a larger number of different oral bacterial species, whereby including oral bacterial strains from patients who underwent intensive CHX therapy could add some new insights to this topic. Nevertheless, although CHX appears to retain its biofilm-reducing effect, the use of alternative compounds such as photodynamic therapy or natural compounds should be considered to avoid antimicrobial resistance in the future [ 53 , 54 ].…”

Section: Discussionmentioning

confidence: 99%

Antibiotic Resistance of Selected Bacteria after Treatment of the Supragingival Biofilm with Subinhibitory Chlorhexidine Concentrations

et al. 2022

Due to increasing rates of antibiotic resistance and very few novel developments of antibiotics, it is crucial to understand the mechanisms of resistance development. The aim of the present study was to investigate the adaptation of oral bacteria to the frequently used oral antiseptic chlorhexidine digluconate (CHX) and potential cross-adaptation to antibiotics after repeated exposure of supragingival plaque samples to subinhibitory concentrations of CHX. Plaque samples from six healthy donors were passaged for 10 days in subinhibitory concentrations of CHX, while passaging of plaque samples without CHX served as control. The surviving bacteria were cultured on agar plates and identified with Matrix-assisted Laser Desorption/Ionization-Time of Flight-Mass spectrometry (MALDI-TOF). Subsequently, the minimum inhibitory concentrations (MIC) of these isolates toward CHX were determined using a broth-microdilution method, and phenotypic antibiotic resistance was evaluated using the epsilometertest. Furthermore, biofilm-forming capacities were determined. Repeated exposure of supragingival plaque samples to subinhibitory concentrations of CHX led to the selection of oral bacteria with 2-fold up to 4-fold increased MICs toward CHX. Furthermore, these isolates showed up to 12-fold increased MICs towards some antibiotics such as erythromycin and clindamycin. Conversely, biofilm-forming capacity was decreased. In summary, this study shows that oral bacteria are able to adapt to CHX, while also decreasing their susceptibility to antibiotics.

“…The combination of visible light and water-filtered infrared-A (VIS + wIRA) has been investigated as a novel light source to fulfill the mentioned aims. Studies have shown that applying VIS + wIRA significantly reduced the amount of periodontal and intra-radicular bacteria ( Karygianni et al, 2014 ; Al-Ahmad et al, 2016 ; Burchard et al, 2020 ). These light sources increase the oxygen partial pressure in the target tissue without overheating the external tissue layers ( Jung and Grune, 2012 ; Künzli et al, 2013 ).…”

Section: Antimicrobial Photodynamic Therapy In Periodontitismentioning

confidence: 99%

Clinical applications of antimicrobial photodynamic therapy in dentistry

et al. 2023

Given the emergence of resistant bacterial strains and novel microorganisms that globally threaten human life, moving toward new treatment modalities for microbial infections has become a priority more than ever. Antimicrobial photodynamic therapy (aPDT) has been introduced as a promising and non-invasive local and adjuvant treatment in several oral infectious diseases. Its efficacy for elimination of bacterial, fungal, and viral infections and key pathogens such as Streptococcus mutans, Porphyromonas gingivalis, Candida albicans, and Enterococcus faecalis have been investigated by many invitro and clinical studies. Researchers have also investigated methods of increasing the efficacy of such treatment modalities by amazing developments in the production of natural, nano based, and targeted photosensitizers. As clinical studies have an important role in paving the way towards evidence-based applications in oral infection treatment by this method, the current review aimed to provide an overall view of potential clinical applications in this field and summarize the data of available randomized controlled clinical studies conducted on the applications of aPDT in dentistry and investigate its future horizons in the dental practice. Four databases including PubMed (Medline), Web of Science, Scopus and Embase were searched up to September 2022 to retrieve related clinical studies. There are several clinical studies reporting aPDT as an effective adjunctive treatment modality capable of reducing pathogenic bacterial loads in periodontal and peri-implant, and persistent endodontic infections. Clinical evidence also reveals a therapeutic potential for aPDT in prevention and reduction of cariogenic organisms and treatment of infections with fungal or viral origins, however, the number of randomized clinical studies in these groups are much less. Altogether, various photosensitizers have been used and it is still not possible to recommend specific irradiation parameters due to heterogenicity among studies. Reaching effective clinical protocols and parameters of this treatment is difficult and requires further high quality randomized controlled trials focusing on specific PS and irradiation parameters that have shown to have clinical efficacy and are able to reduce pathogenic bacterial loads with sufficient follow-up periods.