Utilisation of antimicrobial photodynamic therapy as an adjunctive tool for open flap debridement in the management of chronic periodontitis: A randomized controlled clinical trial

Root surface biomodification in periodontal therapy: Biological rationale and clinical applications

Regenerative periodontal therapy aims to form new cementum, periodontal ligament, and alveolar bone, all sealed by gingival tissue. The root surface acts as the wound margin during this regeneration process. Root surface biomodification (root conditioning/root decontamination), therefore, seems instrumental in promoting surface decontamination and enhancing tissue attachment by removing the smear layer, exposing collagen fibrils, and facilitating blood clot formation and stabilization. This review attempted to provide an all-encompassing, evidence-based assessment of the role of root surface biomodification in regenerative periodontal therapy, particularly in intrabony defects, furcation defects, and root coverage procedures. The reviewed evidence suggested that root conditioning agents, whether used independently or in conjunction with bone graft materials, biological agents, membranes, or connective tissue grafts, do not offer any clinical advantage regarding clinical attachment gain. Thus, integrating chemical methods with the mechanical root instrumentation process does not necessarily contribute to superior clinical outcomes.

Toxicity evaluation of indocyanine green mediated photodynamic therapy

BACKGROUND

The aim of the study is to determine the cytotoxic, genotoxic and inflammatory effects of indocyanine green (ICG) mediated photodynamic therapy (PDT) in direct contact with L-929 mouse fibroblast cells and over a dentin barrier.

METHODS

Eight groups were evaluated; control (C), group with a dentin barrier (D), ICG applied directly on the cells (ICG), ICG applied over a dentin barrier (D-ICG), only laser applied (L), laser applied over a dentin barrier (D-L), ICG and laser applied directly on the cells (ICG-L), ICG and laser applied over a dentin barrier (D-ICG-L). Cell viability was evaluated via ATP Assay, DNA damage was evaluated via Comet Assay, and inflammatory markers IL-1β and TNF-α were assessed via ELISA test.

RESULTS

Cell viability decreased in group ICG (p<0.001). Cell viability decrease was higher in Group ICG-L (p<0.001). Cell viability decrease was lower in group D-ICG-L (p>0.05). Group L caused an increase in cell number (p<0.001). DNA damage was observed in ICG, D-ICG, and ICG-L groups (p<0.05). None of the groups displayed an increase of inflammatory markers IL-1β and TNF-α (p>0.05).

CONCLUSIONS

The presence of dentin between ICG and cells acted as a barrier and protected the cells. ICG-mediated PDT did not cause any cytotoxic, genotoxic or inflammatory effect. The use of ICG-mediated PDT for cavity disinfection is acceptable, but at this concentration its use in periodontal pocket disinfection is not recommended due to its cytotoxic and genotoxic properties.

The effect of photodynamic therapy in controlling the oral biofilm: A comprehensive overview

Several resistance mechanisms are involved in dental caries, including oral biofilms. An accumulation of bacteria on the surface of teeth is called plaque. Periodontitis and gingivitis are caused by dental plaque. In this review article, we aimed to review the studies associated with the application of photodynamic therapy (PDT) to prevent and treat various microbial biofilm-caused oral diseases in recent decades. There are several studies published in PubMed that have described antimicrobial photodynamic therapy (APDT) effects on microorganisms. Several in vitro and in vivo studies have demonstrated the potential of APDT for treating endodontic, periodontal, and mucosal infections caused by bacteria as biofilms. Reactive oxygen species (ROS) are activated in the presence of oxygen by integrating a nontoxic photosensitizer (PS) with appropriate wavelength visible light. By causing irreversible damage to microorganisms, ROS induces some biological and photochemical events. Testing several wavelengths has been conducted to identify potential PS for APDT. A standard protocol is not yet available, and the current review summarizes findings from dental studies on APDT.

A Novel Approach of Combining Methylene Blue Photodynamic Inactivation, Photobiomodulation and Oral Ingested Methylene Blue in COVID-19 Management: A Pilot Clinical Study with 12-Month Follow-Up

Coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 virus was first recognized in late 2019 and remains a significant threat. We therefore assessed the use of local methylene blue photodynamic viral inactivation (MB-PDI) in the oral and nasal cavities, in combination with the systemic anti-viral, anti-inflammatory and antioxidant actions of orally ingested methylene blue (MB) and photobiomodulation (PBM) for COVID-19 disease. The proposed protocol leverages the separate and combined effects of MB and 660nm red light emitted diode (LED) to comprehensively address the pathophysiological sequelae of COVID-19. A total of eight pilot subjects with COVID-19 disease were treated in the Bahamas over the period June 2021-August 2021, using a remote care program that was developed for this purpose. Although not a pre-requisite for inclusion, none of the subjects had received any COVID-19 vaccination prior to commencing the study. Clinical outcome assessment tools included serial cycle threshold measurements as a surrogate estimate of viral load; serial online questionnaires to document symptom response and adverse effects; and a one-year follow-up survey to assess long-term outcomes. All subjects received MB-PDI to target the main sites of viral entry in the nose and mouth. This was the central component of the treatment protocol with the addition of orally ingested MB and/or PBM based on clinical requirements. The mucosal surfaces were irradiated with 660 nm LED in a continuous emission mode at energy density of 49 J/cm2 for PDI and 4.9 J/cm2 for PBM. Although our pilot subjects had significant co-morbidities, extremely high viral loads and moderately severe symptoms during the Delta phase of the pandemic, the response to treatment was highly encouraging. Rapid reductions in viral loads were observed and negative PCR tests were documented within a median of 4 days. These laboratory findings occurred in parallel with significant clinical improvement, mostly within 12-24 h of commencing the treatment protocol. There were no significant adverse effects and none of the subjects who completed the protocol required in-patient hospitalization. The outcomes were similarly encouraging at one-year follow-up with virtual absence of "long COVID" symptoms or of COVID-19 re-infection. Our results indicate that the protocols may be a safe and promising approach to challenging COVID-19 disease. Moreover, due its broad spectrum of activity, this approach has the potential to address the prevailing and future COVID-19 variants and other infections transmitted via the upper respiratory tract. Extensive studies with a large cohort are warranted to validate our results.

Stimuli-Sheddable Nanomedicine Overcoming Pathophysiological Barriers for Potentiating Immunotherapy of Cancer

Immunotherapy displays potent potential for clinical cancer management by activating the protective immune response; however, the microenvironment of the immunosuppressive tumor restricts the efficiency of immunotherapies. Along with the complex pathophysiological barrier of the solid tumors, successful immunotherapeutic delivery remains a formidable challenge for conventional nanomedicine. Stimuli-sheddable nano vectors may facilitate the delivery of cargoes to tumors with minimal premature cargo leakage in blood circulation while enhancing the tumor penetration of nanomedicines by deshielding the polyethylene glycol (PEG) corona upon endogenous activity such as acidity, enzymes and glutathione, or external stimuli, such as laser irradiation. Throughout this study, researchers overviewed the recent advances of nanomedicine-based cancer immunotherapy using the stimuli-responsive deshielding nano vectors, which allowed researchers to integrate multiple therapeutic regimens for inducing immunogenic cell death. This aided in blocking the immune checkpoints, repolarizing the macrophages, and regulating the kynurenine metabolism. Furthermore, researchers discussed the critical issues in the development of stimuli-sheddable nanoimmunodulators, primarily aimed at speeding up their clinical translation. Finally, researchers provided novel perspectives for improving cancer management with the stimuli-sheddable nanomedicine.

Is antimicrobial photodynamic therapy an effective treatment modality for aggressive periodontitis? A systematic review of in vivo human randomized controlled clinical trials

BACKGROUND

Limitations of scaling and root planing (SRP) have directed research to utilize additional therapies to enhance conventional techniques. The present systematic review was conducted to evaluate and present a comprehensive overview on effectiveness of antimicrobial photodynamic therapy (aPDT) in the management of aggressive periodontitis (AgP).

METHODOLOGY

The PRISMA statement guidelines and Cochrane Collaboration recommendations were followed to conduct this systematic review. The review protocol is registered in PROSPERO (CRD 42019143316). A structured electronic and manual search strategy was implied to gather the relevant published data on in vivo human RCTs from their earliest records until 31st October 2019. Relevant data was extracted from the eligible studies, analysed and impartially appraised for its quality.

RESULTS

Eleven papers met the eligibility criteria and included in this review. The data on standardized study protocol, ideal photosensitizer (PS) dye-wavelength combination, optimal parameters was inconclusive and a high risk of bias in majority of the studies noted, which are fundamental in establishing a standardized and replicable protocol.

CONCLUSION

Ultimately researchers should conduct well-designed and robust RCTs performed by trained clinicians in order to determine the effectiveness of aPDT, if any, after acknowledging the drawbacks highlighted in this systematic review.

Effectiveness of antimicrobial photodynamic therapy as an adjunct to open flap debridement in patients with aggressive periodontitis

AIM

The aim of the present clinical trial was to evaluate the clinical efficacy of photodynamic therapy (PDT) as an adjunct to open flap debridement (OFD) in the treatment of generalized aggressive periodontitis (GAP).

MATERIALS AND METHODS

The subjects recruited for the study were divided into two groups: 'control group' received treatment through OFD, whereas the test participants were treated with OFD and adjunctive PDT. The clinical periodontal parameters were plaque index (PI), full mouth probing depth (FMPD) and full mouth relative attachment loss (FMRA). The microbial levels of Aggregatibacter actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg) and Tannarella forsythia (Tf) were analyzed. All parameters were assessed at baseline and 3 months.

STATISTICAL ANALYSIS

The observed values for all the parameters were reported in mean and standard deviation (mean ± SD). In order to analyse the mean values and inter-group comparisons, the Mann-Whitney U test was employed. The p-value was set at <0.05 to establish a significant difference among the reported values.

RESULTS

A statistically significant improvement for BOP was observed in PDT group in comparison to the control group at 3 months only (p < 0.05). A significant reduction in the microbiological levels for Aa, Pg and Tf in both the study groups was observed. However, no significant differences in microbial levels were observed at any time point when the control and test groups were compared to each other.

CONCLUSION

PDT in conjuction with OFD plays a significant role in reducing the microbial load and improving the clinical periodontal parameters in patients with GAP. Moreover, it is regarded as a safe treatment regimen as no side effects have been reported regarding its use in GAP.

Applications of Lasers in Refractory Periodontitis: A Narrative Review

OBJECTIVE

The purpose of the study is to evaluate the various lasers in dentistry and to investigate if it can be used for treatment of refractory periodontitis.

METHODS

The study followed partially the PRISMA guidelines as it is a narrative review. A number of articles were selected from a period of 1980 to 2020 from databases, PubMed, PubMed central, Cochrane and Scopus. Articles related to the effects of lasers on periodontitis both refractory and aggressive were investigated.

RESULTS

After reviewing the literature, 70 articles were found, related to application of lasers in periodontal diseases. Out of the 70, 11 articles pertained to the effect of laser for the treatment of Refractory and inflammatory periodontitis. 5 articles related to experimental animal models, one pertaining to in-vitro and six studies related to in-vivo in human cohorts.

DISCUSSION

It was found that lasers if used in controlled parameters by incorporating laser assisted treatment such as Photodynamic therapy and low level laser therapy can be of use as an adjunct therapy for treatment of refractory periodontitis. The use of different wavelengths in the initial and maintenance phase of periodontal disease plays a positive role. The presence of in-vitro and animal model studies is one of the limitation to this study. The available studies have shown marked reduction in inflammation and better clinical and microbiological parameters. The drawback of this study is the limited literature involving laser management for refractory periodontitis in human cohorts.

CONCLUSION

Different wavelengths of laser and choice of laser assisted periodontal treatment plays an important role in the overall progress and prognosis of periodontal disease activity.

Clinical efficacy of photodynamic therapy and laser irradiation as an adjunct to open flap debridement in the treatment of chronic periodontitis: A systematic review and meta-analysis

BACKGROUND

The aim of this systematic review and meta-analyses was to assess the quality of evidence and efficacy of antimicrobial photodynamic therapy (aPDT) and laser irradiation (LI) as an adjunct to open flap debridement (OFD) in the treatment of chronic periodontitis.

METHODS

Electronic searches were conducted in databases (MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials and Cochrane Oral Health Group Trials Register databases) up to March 2019. Randomized clinical trials (RCTs) comparing clinical efficacy of either aPDT and/or LI, placebo, or no treatment were included. Primary outcomes included clinical attachment level (CAL), while secondary outcomes were reduction in probing depth (PD) and gingival recession (GR) depth. The weighted mean differences (WMD) of outcomes and 95% confidence intervals (CI) for each variable were calculated using random effect model.

RESULTS

Six RCTs were included. For aPDT studies, the overall mean difference for CAL gain (WMD = -0.61, 95% CI = -1.22 to -0.016, P = .044) and PD reduction (WMD = -1.79, 95% CI = -3.44 to -0.14, P = .034) was significant between aPDT and OFD groups at follow-up. No significant overall mean difference was observed for GR depth (WMD = 0.02, 95% CI = -0.75 to 0.79, P = .95). For LI studies, none of the clinical periodontal parameters including CAL gain (WMD = 0.23, 95% CI = -0.09 to 0.55, P = .159, Figure 3A), PD reduction (WMD = 0.31, 95% CI = -0.67 to 1.31, P = .52, Figure 3B) and GR depth (WMD = -0.34, 95% CI = -2.47 to 1.78, P = .74, Figure 3C) were found to be significant between LI and OFD groups at follow-up.

CONCLUSION

With the limited data available, only aPDT as an adjunct to OFD showed superior results for clinical periodontal parameters compared to OFD alone in the treatment of chronic periodontitis. Further RCTs are warranted in order to obtain robust conclusions with regard to laser therapy.