Photodynamic antimicrobial chemotherapy has an overt killing effect on periodontal pathogens? A systematic review of experimental studies

A novel investigational preclinical model to assess fluence rate for dental oral craniofacial tissues

OBJECTIVE

Photodynamic Therapy (PDT) and Photobiomodulation (PBM) are recognized for their potential in treating head and neck conditions. The heterogeneity of human tissue optical properties presents a challenge for effective dosimetry. The porcine mandible cadaver serves as an excellent model and has several similarities to human tissues of the dental oral craniofacial complex. This study aims to validate a novel modeling system that will help refine PDT and PBM dosimetry for the head and neck region.

METHODS AND MATERIALS

Light transmission was analyzed through several tissue combinations at distances of 2 mm to 10 mm. Maximum light fluence rates (mW/cm2) were compared across tissue types to reveal the effects of tissue heterogeneity.

RESULTS

The study revealed that light fluence is affected by tissue composition, with dentin/enamel showing reduced transmission and soft tissue regions exhibiting elevated values. The porcine model has proven to be efficient in mimicking human tissue responses to light, enabling the potential to optimize future protocols.

CONCLUSION

The porcine mandible cadaver is a novel model to understand the complex interactions between light and tissue. This study provides a foundation for future investigations into dosimetry optimization for PDT and PBM.

Periodontal disease in down syndrome: Predisposing factors and potential non-surgical therapeutic approaches

BACKGROUND

Periodontal diseases (PDs) have been documented to be significantly more prevalent and severe in patients with Down syndrome (DS). Different immunological and microbiological factors contributed to predisposing these patients to progressive and recurrent PDs.

AIM

The aim of this review was to investigate the altered immunological responses and oral microbiota disorders as well as focus on adjunctive non-surgical methods for the treatment of PDs and its applicability in patients with DS.

MATERIAL AND METHODS

A literature review was conducted addressing the following topics: (1) the altered immunological responses, (2) orofacial disorders related to DS patients, (3) oral microbiota changing, and (4) adjunctive non-surgical treatment and its efficacy in patients with DS.

RESULTS

Due to the early onset of PDs in children with DS, the need for prompt and effective treatment in these patients is essential.

DISCUSSION AND CONCLUSION

So, investigating underlying factors may open a new window to better understand the pathology of PDs in DS people and thus, find better strategies for treatment in such group. Although non-surgical treatments such as photodynamic therapy and probiotic consumption represented acceptable outcomes in different examined patients without DS, data about the application of these convenience and no need for local anesthesia methods in patients with DS is limited.

Photoinactivation and Photoablation of Porphyromonas gingivalis

Several types of phototherapy target human pathogens and Porphyromonas gingivitis (Pg) in particular. The various approaches can be organized into five different treatment modes sorted by different power densities, interaction times, effective wavelengths and mechanisms of action. Mode 1: antimicrobial ultraviolet (aUV); mode 2: antimicrobial blue light (aBL); mode 3: antimicrobial selective photothermolysis (aSP); mode 4: antimicrobial vaporization; mode 5: antimicrobial photodynamic therapy (aPDT). This report reviews the literature to identify for each mode (a) the putative molecular mechanism of action; (b) the effective wavelength range and penetration depth; (c) selectivity; (d) in vitro outcomes; and (e) clinical trial/study outcomes as these elements apply to Porphyromonas gingivalis (Pg). The characteristics of each mode influence how each is translated into the clinic.

Combatting Antibiotic Resistance Using Supramolecular Assemblies

Antibiotic resistance has posed a great threat to human health. The emergence of antibiotic resistance has always outpaced the development of new antibiotics, and the investment in the development of new antibiotics is diminishing. Supramolecular self-assembly of the conventional antibacterial agents has been proved to be a promising and versatile strategy to tackle the serious problem of antibiotic resistance. In this review, the recent development of antibacterial agents based on supramolecular self-assembly strategies will be introduced.

Efficacy of antimicrobial photodynamic therapy (aPDT) for nonsurgical treatment of periodontal disease: a systematic review

Although the standard treatment for periodontal disease is based on scaling and root planing (SRP), the use of antimicrobial photodynamic therapy (aPDT) has been studied as a complement to obtain better clinical results. The purpose of this study was to evaluate the effect of aPDT as adjuncts to SRP, compared with SRP alone, on clinical parameters of chronic periodontal patients. Only randomized controlled trials with at least 3-month follow-ups, of SRP alone and in association with aPDT, were included. The MEDLINE (PubMed), Google Scholar, and LILACS databases were searched for articles published up to July 2020. Random-effects meta-analyses were conducted for clinical attachment level (CAL) and probing pocket depth (PPD) change after treatment. Of 141 potentially relevant papers, 22 were included. The association between SRP and aPDT promoted a significant CAL gain and PPD reduction. Periodontal treatment was partially improved by aPDT, and a favorable effect of indocyanine green-mediated aPDT was observed, and high concentrations of phenothiazine chloride presented clinical improvement as well.

Clinical and microbiological effects of adjunctive photodynamic diode laser therapy in the treatment of chronic periodontitis: A randomized clinical trial

Background. Conventional mechanical debridement alone cannot eliminate bacteria and their products from periodontal pockets. Adjunctive therapies improve tissue healing through detoxification and bactericidal effects. Photodynamic therapy (PDT) is a non-invasive treatment procedure that involves the use of a dye as a photosensitizer to attach to the target cell and be activated by a photon of an appropriate wavelength. This study aimed to assess the effectiveness of PDT in treating periodontitis as an adjunct to scaling and root planing.

Methods. Fifteen subjects with chronic periodontitis were treated randomly with scaling and root planing (SRP), followed by a single PDT (test) or SRP (control) episode alone. Full-mouth plaque index (PI), sulcus bleeding index (SBI), probing depth (PD), and clinical attachment level (CAL) were assessed at baseline and 1-month and 3-month intervals. Microbiological evaluation of Porphyromonas gingivalis (Pg) in subgingival plaque samples was performed using a commercially available real-time polymerase chain reaction.

Results. The results revealed a significant difference in PI, SBI, PD, CAL, and microbiological parameters between the groups one and three months after treatment.

Conclusion. A combination of PDT and SRP gave rise to a significant improvement in clinical and microbiological parameters in patients with chronic periodontitis.

Do Lasers Have an Adjunctive Role in Initial Non-Surgical Periodontal Therapy? A Systematic Review

(1) Background: dental lasers have numerous applications for periodontal therapy which include surgical procedures of soft tissue and osseous structures, and non-surgical treatments such as pathogen reduction, removal of surface accretions, and photobiomodulation. The aim of this review was to evaluate the scientific literature to ascertain whether lasers have a beneficial role when used adjunctively in initial non-surgical periodontal therapy. (2) Methods: A PubMed search was performed specifically for randomized clinical trials where a dental laser was used adjunctively for initial periodontal therapy on human patients published from January 2010–April 2020. The first search identified 1294 eligible studies. After additional criteria and filters were applied, 20 manuscripts were included in this review. (3) Results: The chosen manuscripts reported on investigations into initial therapy for patients diagnosed with chronic periodontitis. After periodontal charting, conventional instrumentation such as hand and ultrasonic scaling was performed on all patients in the studies, and then a test group or groups of patients were treated adjunctively with a laser. That adjunctive laser group’s periodontal findings showed various degrees of improved health compared to the group treated with only conventional methods. (4) Conclusion: This systematic review found that 70% of the included studies reported significantly better outcomes in certain clinical parameters, but no improvement in others. The remaining 30% of the manuscripts reported no significant difference in any of the measurements. With consideration to correct parametry, lasers have an adjunctive role in initial non-surgical periodontal therapy.

Antimicrobial photodynamic therapy mediated by methylene blue in surfactant vehicle on periodontopathogens

BACKGROUND

Periodontal disease (PD) is a chronic inflammatory disease caused by the presence of microbial biofilm. The aim of this study was to evaluate antimicrobial effect of antimicrobial photodynamic therapy (A-PDT) mediated by methylene blue (MB) in monomer form on A. actinomycetemcomitans and P. gingivalis.

METHODS

A. actinomycetemcomitans ATCC 29523 and P. gingivalis ATCC 33577 were cultured on anaerobic jars at 37 °C for 48 h, and we tested APDT in the presence of 0.25% sodium dodecyl sulfate (SDS) in phosphate-buffered saline (PBS) or in PBS alone. APDT was carried out with 100 μM MB under laser radiation (PhotolaseIII, DMC, Brazil) at ʎ =660 nm and parameters as following (P =100 mW; I =250 mW/cm², and doses of 15, 45 and 75 J/cm²).

RESULTS

Following A-PDT, PBS groups of A. actinomycetemcomitans presented 4 Logs of microbial death after 5 min irradiation. However, there was no bacterial reduction in SDS groups. On the other hand, P. gingivalis was sensitive to APDT in the presence of 0.25% SDS with 2 logs reduction from dark toxicity.

CONCLUSION

The presence of 0.25% SDS can lead to different responses depending on the different microbial species.