Multiple PDT sessions with chlorin-e6 and LL-37 loaded-nanoemulsion provide limited benefits to periodontitis in rats

BACKGROUND

The combination of photodynamic therapy (PDT) and LL-37 has never been tested in an animal study and our research team background suggests this strategy might be a promising alternative to intensify periodontitis resolution. This study aimed to assess the effects of multiple sessions of PDT with chlorin-e6 conjugated to the antimicrobial peptide LL-37 loaded nanoemulsion, as adjunctive therapy in experimental periodontitis in rats.

METHODS

Experimental periodontitis was induced in 81 rats. After disease establishment, animals were assigned to three groups: SRP (scaling and root planning); SRP + 1PDT, SRP followed by a single PDT session; SRP + 4PDT (n = 27), SRP followed by four PDT sessions at 0, 24, 48 and 72 h after SRP. Animals were subjected to euthanasia at 7, 14 and 28 days, and samples were submitted to osteoclast quantification, immunological and microtomography analysis.

RESULTS

All treatments resulted in significant periodontal improvements and there was no significant difference between the groups in both local inflammatory response and healing process. Minimal adjunctive effects could be found for the combined therapy in terms of cytokine levels (IL-1β and IL-10), with no statistical significance. However, the number of TRAP-positive osteoclasts per mm of alveolar bone linear surface for the group treated with PDT sessions was significantly lower than those treated with SRP only.

CONCLUSIONS

Multiple PDT sessions with chlorin-e6 and LL-37 nanoemulsion as an adjunct to scaling and root planning reduced the presence of osteoclast in the local site but did not contribute towards bone regeneration and IL-1β and IL-10 levels.

Effectiveness of antimicrobial photodynamic therapy in the treatment of peri-implantitis: systematic review and meta-analysis

The purpose of this study was to evaluate the current scientific evidence on the effectiveness of antimicrobial photodynamic therapy (aPDT) as an adjunctive treatment to mechanical debridement in the treatment of peri-implantitis. The Preferred Reporting Items for Systematic Reviews and Meta-analyses was followed. A protocol was registered in the International Prospective Registry of Systematic Reviews (PROSPERO #CRD42022361684). The search was carried out in seven databases, with no restrictions regarding language or year of publication. Our work included studies that compared clinical periodontal parameters between individuals treated with mechanical debridement associated with aPDT and a control group of patients who had undergone mechanical debridement alone. Study selection, data extraction, and risk of bias assessment (RoB 2.0) were performed by two review authors. Meta-analysis was performed. The mean difference (MD) and a 95% confidence interval (CI) were provided. Four hundred and seven-four studies were identified, of which five studies were included. The meta-analysis demonstrated that aPDT adjunctive to mechanical debridement in subjects with peri-implantitis resulted in greater reduction in probing depth 3 months after treatment than among subjects receiving treatment with mechanical debridement. Most of the included studies exhibit a low risk of bias. Adjunctive aPDT to mechanical debridement contributes to the improvement of peri-implant clinical parameters in individuals with peri-implantitis, in particular probing depth.

The adjunctive use of antimicrobial photodynamic therapy, light-emitting-diode photobiomodulation and ozone therapy in regenerative treatment of stage III/IV grade C periodontitis: a randomized controlled clinical trial

OBJECTIVES

To assess the short-term efficacy of multiple sessions of antimicrobial photodynamic therapy (aPDT), light-emitting-diode (LED) photobiomodulation, and topical ozone therapy applications following surgical regenerative treatments on clinical parameters, patient-centered outcomes, and mRNA expression levels of VEGF, IL-6, RunX2, Nell-1, and osterix in gingival crevicular fluid samples in patients with stage III/IV, grade C periodontitis.

MATERIALS AND METHODS

Forty-eight systemically healthy patients were assigned into four groups to receive adjunctive modalities with regenerative periodontal surgical treatment. A 970 ± 15 nm diode laser plus indocyanine-green for aPDT group, a 626 nm LED for photobiomodulation group, and topical gaseous ozone were applied at 0, 1, 3, and 7 postoperative days and compared to control group. The clinical periodontal parameters, early wound healing index (EHI), and postoperative patients' morbidity were evaluated. The mRNA levels of biomarkers were assessed by real-time polymerase chain reaction.

RESULTS

No significant difference in the clinical parameters except gingival recession (GR) was identified among the groups. For group-by-time interactions, plaque index (PI) and probing pocket depths (PD) showed significant differences (p = 0.034; p = 0.022). In sites with initial PD > 7 mm, significant differences were observed between control and photobiomodulation groups in PD (p = 0.011), between control and aPDT, and control and photobiomodulation groups in CAL at 6-month follow-up (p = 0.007; p = 0.022). The relative osterix mRNA levels showed a statistically significant difference among the treatment groups (p = 0.014).

CONCLUSIONS

The additional applications of aPDT and LED after regenerative treatment of stage III/IV grade C periodontitis exhibited a more pronounced beneficial effect on clinical outcomes in deep periodontal pockets.

Gold core@CeO2 halfshell Janus nanocomposites catalyze targeted sulfate radical for periodontitis therapy

The sulfate radical (SO4•-), known for its high reactivity and long lifespan, has emerged as a potent antimicrobial agent. Its exceptional energy allows for the disruption of vital structures and metabolic pathways in bacteria that are usually inaccessible to common radicals. Despite its promising potential, the efficient generation of this radical, particularly through methods involving enzymes and photocatalysis, remains a substantial challenge. Here, we capitalized on the peroxidase (POD)-mimicking activity and photocatalytic properties of cerium oxide (CeO2) nanozymes, integrating these properties with the enhanced concept of plasma gold nanorod (GNR) to develop a half-encapsulated core@shell GNRs@CeO2 Janus heterostructure impregnated with persulfate. Under near-infrared irradiation, the GNRs generate hot electrons, thereby boosting the CeO2's enzyme-like activity and initiating a potent reactive oxygen species (ROS) storm. This distinct nanoarchitecture facilitates functional specialization, wherein the heterostructure and efficient light absorption ensured continuous hot electron flow, not only enhancing the POD-like activity of CeO2 for the production of SO4•- effectively, but also contributing a significant photothermal effect, disrupting periodontal plaque biofilm and effectively eradicating pathogens. Furthermore, the local temperature elevation synergistically enhances the POD-like activity of CeO2. Transcriptomics analysis, as well as animal experiments of the periodontitis model, have revealed that pathogens undergo genetic information destruction, metabolic disorders, and pathogenicity changes in the powerful ROS system, and profound therapeutic outcomes in vivo, including anti-inflammation and bone preservation. This study demonstrated that energy transfer to augment nanozyme activity, specifically targeting ROS generation, constitutes a significant advancement in antibacterial treatment.

A win-win platform: Stabilized black phosphorous nanosheets loading gallium ions for enhancing the healing of bacterial-infected wounds through synergistic antibacterial approaches

Bacterial infection is the most common complication in wound healing, highlighting an urgent need for the development of innovative antibacterial technologies and treatments to address the growing threats posed by bacterial infections. Black phosphorus nanosheets (BPNSs), as a promising two-dimensional nanomaterial, have been utilized in treating infected wounds. However, BP's limited stability restricts its application. In this study, we enhance BP's stability and its antibacterial properties by anchoring gallium ions (Ga3+) onto BP's surface, creating a novel antibacterial platform. This modification reduces BP's electron density and enhances its antibacterial capabilities through a synergistic effect. Under near-infrared (NIR) irradiation, the BP/Ga3+ combination exerts antibacterial effects via photothermal therapy (PTT) and photodynamic therapy (PDT), while also releasing Ga3+. The Ga3+ employ a 'Trojan horse strategy' to disrupt iron metabolism, significantly boosting the antibacterial efficacy of the complex. This innovative material offers a viable alternative to antibiotics and holds significant promise for treating infected wounds and aiding skin reconstruction.

Evaluating the potency of laser-activated antimicrobial photodynamic therapy utilizing methylene blue as a treatment approach for chronic periodontitis

Chronic periodontitis is a ubiquitous inflammatory disease in dental healthcare that is challenging to treat due to its impact on bone and tooth loss. Conventional mechanical debridement has been challenging in eliminating complex subgingival biofilms. Hence, adjunctive approaches like low-level laser antimicrobial photodynamic therapy (A-PDT) utilising methylene blue (MB) have been emerging approaches in recent times. This review evaluates the latest research on the use of MB-mediated A-PDT to decrease microbial count and enhance clinical results in chronic periodontitis. Studies have shown the interaction between laser light and MB generates a phototoxic effect thereby, eliminating pathogenic bacteria within periodontal pockets. Moreover, numerous clinical trials have shown that A-PDT using MB can reduce probing depths, improve clinical attachment levels, and decrease bleeding during probing in comparison to traditional treatment approaches. Notably, A-PDT shows superior antibiotic resistance compared to conventional antibiotic treatments. In conclusion, the A-PDT using MB shows promise as an adjunctive treatment for chronic periodontitis. Additional research is required to standardize treatment protocols and assess long-term outcomes of A-PDT with MB in the treatment of periodontitis.

Photodynamic therapy adjuvant to non-surgical periodontal therapy: Systematic review of randomized clinical trials

OBJECTIVES

To systematically evaluate randomised controlled trials (RCTs) on whether adjuvant application of antimicrobial photodynamic therapy (aPDT) through the technique of irradiation in the external region of the periodontal pocket with optic-fibre tip offers benefits to scaling and root planning (SRP).

METHODS

Five databases were searched by two independent reviewers according to pre-specified eligibility criteria up to April 2023. No restrictions regarding date of publication, language and minimum follow-up period were imposed. The Cochrane Collaboration's Risk of Bias tool (RoB 2.0) was used for quality appraisal and Grading of Recommendations, Assessment, Development and Evaluation for assessing the certainty of evidence.

RESULTS

A total of 1388 publications were identified and reviewed for eligibility. Four of them fulfilled the inclusion criteria. The sample consisted of a total of 83 patients with periodontitis. In these, 330 periodontal sites were evaluated. The clinical findings of the majority of the included studies demonstrated that patients who received the association of aPDT + RAR with the protocol evaluated here, obtained clinical results similar to patients who received only the SRP alone. In none of the evaluated RCTs, clinical advantages were observed that would categorise this aPDT protocol as superior to conventional treatment.

CONCLUSION

Applying aPDT after SRP with external irradiation of the periodontal pocket does not seem to result in any clinical benefit compared to the use of SRP alone in patients with periodontitis.

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.

Superhydrophobic Tipped Antimicrobial Photodynamic Therapy Device for the In Vivo Treatment of Periodontitis Using a Wistar Rat Model

Limited options exist for treatment of periodontitis; scaling and root planing (SRP) are not sufficient to eradicate P. gingivalis and the resulting inflammatory disease. Chlorhexidine (CHX), used as an adjuvant to SRP, may reduce bacterial loads but leads to pain and staining, while evidence for its efficacy is lacking. Antibiotics are effective but can lead to drug-resistance. The rising concern of antibiotic resistance limits the future use of this treatment approach. This study evaluates the efficacy of a novel superhydrophobic (SH) antimicrobial photodynamic therapy (aPDT) device as an adjuvant to SRP for the treatment of periodontitis induced in a Wistar rat in vivo model relative to CHX. The SH-aPDT device comprises an SH silicone rubber strip coated with verteporfin photosensitizer (PS), sterilized, and secured onto a tapered plastic optical fiber tip connected to a red diode laser. The superhydrophobic polydimethylsiloxane (PDMS) strips were fabricated by using a novel soluble template method that creates a medical-grade elastomer with hierarchical surface roughness without the use of nanoparticles. Superhydrophobicity minimizes direct contact of the PS-coated surface with bacterial biofilms. Upon insertion of the device tip into the pocket and energizing the laser, the device generates singlet oxygen that effectively targets and eliminates bacteria within the periodontal pocket. SH-aPDT treatment using 125 J/cm2 of red light on three consecutive days reduced P. gingivalis significantly more than SRP-CHX controls (p < 0.05). Clinical parameters significantly improved (p < 0.05), and histology and stereometry results demonstrated SH-aPDT to be the most effective treatment for improving healing and reducing inflammation, with an increase in fibroblast cells and extracellular matrix and a reduction in vascularization, inflammatory cells, and COX-2 expression. The SH-aPDT approach resulted in complete disease clearance assessed 30 days after treatment initiation with significant reduction of the periodontal pocket and re-formation of the junctional epithelium at the enamel-cementum junction. PS isolation on a SH strip minimizes the potential for bacteria to develop resistance, where the treatment may be aided by the oxygen supply retained within the SH surface.

Clinical and Radiographic Outcomes of Adjunctive Photodynamic Therapy for Treating Peri-Implant Mucositis Among Cigarette Smokers and Diabetics: A Systematic Review and Meta-Analysis

Objective: This systematic review aimed to assess the influence of antimicrobial photodynamic therapy (aPDT) as an adjunct to mechanical debridement (MD) on peri-implant clinical and radiographic outcomes among cigarette smokers and diabetics with peri-implant mucositis (piM). Methods: Randomized controlled trials, assessing the clinical and radiographic parameters of aPDT versus MD alone among smokers and diabetics with piM, were included in the study. Meta-analyses were conducted to calculate the standard mean difference with a 95% confidence interval. The methodological quality of the included studies was assessed utilizing the modified Jadad quality scale. Results: The meta-analyses found statistically significant differences between the impact of adjunct aPDT and MD alone on the peri-implant plaque index (PI), probing depth (PD), and bleeding on probing among smokers and diabetics with piM at the final follow-up visit. However, no significant differences were found between the impact of adjunct aPDT and MD alone on the peri-implant crestal bone loss among smokers and diabetics with piM at the final follow-up. Conclusions: The application of aPDT as an adjunctive to MD demonstrated improved scores of the peri-implant clinical parameters among smokers and diabetics with piM in comparison with MD alone.

Influence of Smoking on Periodontal and Implant Therapy: A Narrative Review

BACKGROUND

smoking is considered the most modifiable risk factor for periodontal disease.

OBJECTIVE

the aim of this narrative review is to emphasize the effect of smoking on periodontal and implant therapy.

METHODS

The authors reviewed the literature reporting the clinical outcomes of smoking on periodontal surgical and nonsurgical treatment. The impact of smoking on implant therapy and sinus lifting procedures were also reviewed.

RESULTS

Periodontal and implant therapy outcomes are adversely affected by smoking. Smokers respond less favorably to periodontal therapy and periodontal flap procedures as compared to nonsmokers. Clinical outcomes for smokers are 50-75% worse than for nonsmokers. Studies reveal that smokers experience a significantly lower reduction in pocket depth compared to nonsmokers as well as less bone growth after treating infra-bony defects with guided tissue regeneration. The relative risk of implant failure is significantly higher in patients who smoke 20 cigarettes or more per day compared to nonsmokers. Additionally, smoking has also been shown to increase postoperative wound dehiscence and infection rates following sinus floor elevation. Longitudinal studies on smoke cessation have shown a reduction in bone loss and probing depths for periodontitis patients after cessation compared to those who smoke.

CONCLUSION

Smoking cessation can reduce probing depths and improve clinical attachment after nonsurgical periodontal therapy. There is insufficient evidence regarding the effect of smoking on peri-implantitis, as well as the loss of implants in the long-term.

Influence of periodontal surgery on the subgingival microbiome-A systematic review and meta-analysis

OBJECTIVE

The objective of this systematic review and meta-analysis was to evaluate the effect of periodontal surgery on the subgingival microbiome.

BACKGROUND

Periodontitis is a chronic inflammation of the tooth supporting tissues caused by the dysbiosis of the subgingival biofilm. It is managed through different non-surgical and surgical treatment modalities. Recent EFP S3 guidelines recommended performing periodontal surgery as part of Step 3 periodontitis treatment after Step 1 and Step 2 periodontal therapy, with the aim to achieve pocket closure of persisting sites. Changes in the sub-gingival microbiome may explain the treatment outcomes observed at different time points. Various microbiological detection techniques for disease-associated pathogens have been evolved over time and have been described in the literature. However, the impact of different types of periodontal surgery on the subgingival microbiome remains unclear.

METHODS

A systematic literature search was conducted in Medline, Embase, LILACS and Cochrane Library supplemented by manual search (23DEC2019, updated 21APR2022).

RESULTS

From an initial search of 3046 studies, 28 were included according to our specific inclusion criteria. Seven microbiological detection techniques were used to analyse disease-associated species in subgingival plaque samples: optical microscope, culture, polymerase chain reaction (PCR), checkerboard, enzymatic reactions, immunofluorescence and 16S gene sequencing. The included studies exhibited differences in various aspects of their methodologies such as subgingival plaque sample collection or treatment modalities. Clinical data showed a significant decrease in probing pocket depths (PPD) and clinical attachment loss (CAL) after periodontal surgery. Microbiological findings were overall heterogeneous. Meta-analysis was performed on a sub-cohort of studies all using checkerboard as a microbiological detection technique. Random effect models for Treponema denticola (T. denticola), Porphyromonas gingivalis (P. gingivalis) and Tannerella forsythia (T. forsythia) did not show a significant effect on mean counts 3 months after periodontal surgery. Notably, Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans) showed a significant increase 3 months after periodontal surgery. 16S gene sequencing was used in one included study and reported a decrease in disease-associated species with an increase in health-associated species after periodontal surgery at 3 and 6 months.

CONCLUSION

This systematic review has shown that the effect of periodontal surgery on the changes in subgingival microbiome is heterogeneous and may not always be associated with a decrease in disease-associated species. The variability could be attributed to the microbiological techniques employed for the analysis. Therefore, there is a need for well-designed and adequately powered studies to understand how periodontal surgery influences the subgingival microbiome and how the individual's microbiome affects treatment outcomes after periodontal surgery.

Efficacy of surgical periodontal treatment with and without photobiomodulation in the treatment of severe periodontitis: An evaluation of periodontal, microbiological, and cytokine levels

AIM

To compare the efficacy of surgical periodontal treatment (SPT) alone and PDT-assisted surgery in participants with severe periodontitis MATERIAL AND METHODS: The present clinical trial was completed by 64 participants (n=32 each). The selection was made according to predefined inclusion and exclusion criteria. Patients in group A were treated with SPT only and participants in group B were treated with SPT adjunct to PDT. Microbiological assessment of P.Gingivalis; T. Forsythia and T.Denticola were evaluated using cultural analysis and periodontal parameters plaque score (PSc), bleeding on probing (BoP) periodontal depth (PD), and clinical attachment loss (CAL) at baseline and post-treatment at 6 months and 12 months were performed. The gingival crevicular fluid (GCF) was collected for the estimation of IL-1β and tumor necrosis factor-alpha (TNF-α) using an enzyme-linked immunosorbent assay (ELISA). For intra-group comparison and post hoc correction, Student's t-test along with Bonferroni was used. For the difference between follow-ups, an analysis of variance (ANOVA) multiple rank tests were incorporated.

RESULTS

The mean age of participants in the SPT group was 55.25±4.6yrs. Whereas, participants treated with PDT adjunct to SPT were 54.88±3.6yrs. Periodontal parameters (BoP, PD, PSc, CAL) showed no significant difference at baseline. At 6 months and 12 months follow-up, a significant difference in all parameters (BoP, PD, PSc, and CAL) was found in participants treated with SPT alone and PDT adjunct to SPT (p<0.05). Inflammatory biomarkers at 6-month and 12-month follow-ups, a statistically significant difference in the level of biomarkers (IL-1β and TNF-α) were observed in both groups from baseline (p<0.05). However, at baseline, no significant difference was noted in both groups (p> 0.05). The microbiological assessment showed a significant drop in the bacterial count in participants treated with both regimes i.e., SPT alone and PDT adjunct to SPT.

CONCLUSION

Photodynamic therapy (PDT) adjunct to surgical periodontal treatment (SPT) in severe periodontitis improves microbiological and periodontal parameters and lowers the level of proinflammatory cytokines.

Clinical applications of antimicrobial photodynamic therapy in dentistry

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.

Influence of antimicrobial photodynamic therapy with different pre-irradiation times on children's dental biofilm: randomized clinical trial

PURPOSE

Photodynamic therapy (PDT) is effective in reducing pathogenic microorganisms in the oral cavity and in preventing dental diseases. This study evaluated the pre-irradiation time using PDT (diode laser associated with 0.01% methylene blue) to decrease the number of microorganisms in the visible plaque in permanent teeth.

METHODS

This randomized clinical trial included 108 homologous lower permanent first molars (36 and 46) with biofilm from 54 children aged six to 12 years. PDT was performed (0.01% methylene blue photosensitizer/therapeutic laser-InGaAIP), according to the following protocols: Group 1, biofilm collection of the distal area of the lingual surface of 36 µm before PDT; group 2, mesial area of the lingual surface of 36 µm 1 min after PDT; group 3, area of the lingual surface of 46 µm before PDT; and group 4, mesial area of the lingual surface of 46 µm 5 min after PDT.

RESULTS

After statistical analysis, significant differences were observed between the groups (p = 0.000). In groups 2 and 4, the number of bacteria tended to decrease, with a more evident bacterial reduction in group 4.

CONCLUSIONS

Pre-irradiation reduced the number of colony-forming units of mature bacterial biofilms in vivo. A time of 5 min resulted in a greater reduction in the number of colony-forming units.

CLINICAL TRIAL REGISTRATION

ReBEC Identifier: RBR-6bqfp3; Date of Register: March 2nd, 2020. Retrospectively Registered.

Randomized and Controlled Clinical Studies on Antibacterial Photodynamic Therapy: An Overview

The emergence of drug-resistant bacteria is considered a critical public health problem. The need to establish alternative approaches to countering resistant microorganisms is unquestionable in overcoming this problem. Among emerging alternatives, antimicrobial photodynamic therapy (aPDT) has become promising to control infectious diseases. aPDT is based on the activation of a photosensitizer (PS) by a particular wavelength of light followed by generation of the reactive oxygen. These interactions result in the production of reactive oxygen species, which are lethal to bacteria. Several types of research have shown that aPDT has been successfully studied in in vitro, in vivo, and randomized clinical trials (RCT). Considering the lack of reviews of RCTs studies with aPDT applied in bacteria in the literature, we performed a systematic review of aPDT randomized clinical trials for the treatment of bacteria-related diseases. According to the literature published from 2008 to 2022, the RCT study of aPDT was mostly performed for periodontal disease, followed by halitosis, dental infection, peri-implantitis, oral decontamination, and skin ulcers. A variety of PSs, light sources, and protocols were efficiently used, and the treatment did not cause any side effects for the individuals.

Evaluation of antimicrobial photodynamic therapy with acidic methylene blue for the treatment of experimental periodontitis

OBJECTIVE

To investigate the security and effectiveness of antimicrobial photodynamic therapy (aPDT) with a citric acid-based methylene blue (MB) on the periodontal repair following the treatment of ligature-induced experimental periodontitis (EP) in rats.

MATERIAL AND METHODS

Were used 120 male rats, randomly divided into 4 experimental groups (n = 30): no treatment (NT), SRP alone (SRP), SRP plus aPDT using conventional MB pH 7.0 (aPDT-pH7), SRP plus aPDT using acidic MB pH 1.0 (aPDT-pH1). EP was induced at day 0 by the placement of a ligature around the mandibular left first molars. Ten animals per group/period were euthanized at 14, 22 and 37 days. Histopathological, histometric (percentage of bone in the furcation [PBF]) and immunohistochemical (for tartrate-resistant acid phosphatase [TRAP] and osteocalcin [OCN]) analyses were performed. Data were statistically analyzed.

RESULTS

aPDT-pH1 showed the highest PBF as compared with the other treatments. Collectively, tissues' reaction to both dyes were controlled and healthy for the periodontium. Both aPDT protocols reduced the extent and intensity of the local inflammatory response, reduced the alveolar bone resorption, and promoted a better structural arrangement of the connective tissue as compared with SRP. TRAP expression was downregulated while OCN expression was upregulated by aPDT as compared with SRP alone.

CONCLUSION

Our data implicate that the novel MB pH 1.0 is as safe as the conventional MB for use in aPDT and raises its additional benefit of increasing the amount of alveolar bone in the furcation.

Efficacy of Adjunctive Antimicrobial Photodynamic Therapy to Mechanical Debridement in the Treatment of Peri-implantitis or Peri-implant Mucositis in Smokers: A Systematic Review and Meta-analysis

This systematic review and meta-analysis aimed to determine whether adjunctive use of antimicrobial photodynamic therapy (a-PDT) in peri-implant diseases improves clinical outcomes in smokers. An electronic search was performed in MEDLINE (through PubMed), Scopus, Cochrane Library, Embase, Web of Science and Google Scholar. The primary outcome measures were bleeding on probing (BOP) and pocket depth (PD). Plaque index (PI) was the secondary outcome. Four RCTs, (188 participants) comprised of 118 cigarette smokers, 38 E-cig smokers and 32 water pipe smokers with follow-up periods ranged from 6 weeks to 6 months were recruited. All trials applied diode laser in one session with wavelengths ranged from 660 to 670 nm. There was a significant difference between mechanical debridement (MD)+a-PDT and MD alone groups in PD (WMD = -1.26 mm, 95% CI: -2.19 to -0.32, P = 0.01) and PI (WMD = -10.60%, 95% CI: -14.46 to -6.74, P < 0.001) at 3-month follow-up. However, a great amount of heterogeneity was observed (PD: χ² = 199.19, I² = 98%, P < 0.001 and PI: χ² = 25.63, I² = 84.4%, P < 0.001). Due to methodological heterogeneity and small number of studies, this systematic review was unable to reach conclusive evidence in regards of adjunctive a-PDT efficacy in improving clinical parameters in smokers.

Comparative effects of different phenothiazine photosensitizers on experimental periodontitis treatment

AIM

The aim of the present study was to compare the effects of the phenothiazine photosensitizers methylene blue (MB), toluidine blue-O (TBO) and butyl toluidine blue (BuTB) in antimicrobial photodynamic therapy (aPDT), as adjuvant therapy to scaling and root planing (SRP) in the treatment of experimental periodontitis (EP) in rats.

MATERIAL AND METHODS

120 Wistar rats underwent ligation around the lower left molar. After seven days, the ligature was removed. The animals were separated into the following groups (n = 15): EP, no treatment; SRP, SRP and irrigation with saline solution; MB, SRP and deposition of MB; TBO, SRP and deposition of TBO; BuTB, SRP and deposition of BuTB; MB-aPDT, SRP and aPDT with MB; TBO-aPDT, SRP and aPDT with TBO and; BuTB-aPDT, SRP and aPDT with BuTB. The aPDT session was performed after SRP, with deposition of the photosensitizer and irradiation with a diode laser (DL; InGaAlP, 660 nm, 40 mW, 60 s, 2.4 J). Histological and histometric analysis was performed.

RESULTS

BuTB-aPDT group had a lesser extent of the inflammatory process compared to the EP, SRP, MB and TBO at all experimental periods (p < 0.05). At 15 days, the aPDT treated groups had a greater bone tissue structure than groups EP and SRP (p < 0.05) The BuTB showed lower Alveolar Bone Loss (ABL) compared to the TBO-aPDT group at 30 days (p < 0.05).

CONCLUSION

aPDT using the photosensitizer BuTB proved to be the adjuvant therapy that most favored the reduction of inflammatory infiltrate in the furcation area and ABL.

Did Omics change periodontal therapy?

The starting point for defining effective treatment protocols is a clear understanding of the etiology and pathogenesis of a condition. In periodontal diseases, this understanding has been hindered by a number of factors, such as the difficulty in differentiating primary pathogens from nonpathogens in complex biofilm structures. The introduction of DNA sequencing technologies, including taxonomic and functional analyses, has allowed the oral microbiome to be investigated in much greater breadth and depth. This article aims to compile the results of studies, using next-generation sequencing techniques to evaluate the periodontal microbiome, in an attempt to determine how far the knowledge provided by these studies has brought us in terms of influencing the way we treat periodontitis. The taxonomic data provided, to date, by published association and elimination studies using next-generation sequencing confirm previous knowledge on the role of classic periodontal pathogens in the pathobiology of disease and include new species/genera. Conversely, species and genera already considered as host-compatible and others less explored were associated with periodontal health as their levels were elevated in healthy individuals and increased after therapy. Functional and transcriptomic analyses also demonstrated that periodontal biofilms are taxonomically diverse, functionally congruent, and highly cooperative. Very few interventional studies to date have examined the effects of treatment on the periodontal microbiome, and such studies are heterogeneous in terms of design, sample size, sampling method, treatment provided, and duration of follow-up. Hence, it is still difficult to draw meaningful conclusions from them. Thus, although OMICS knowledge has not yet changed the way we treat patients in daily practice, the information provided by these studies opens new avenues for future research in this field. As new pathogens and beneficial species become identified, future randomized clinical trials could monitor these species/genera more comprehensively. In addition, the metatranscriptomic data, although still embryonic, suggest that the interplay between the host and the oral microbiome may be our best opportunity to implement personalized periodontal treatments. Therapeutic schemes targeting particular bacterial protein products in subjects with specific genetic profiles, for example, may be the futuristic view of enhanced periodontal therapy.

Assessment and Characterization of Some New Photosensitizers for Antimicrobial Photodynamic Therapy (aPDT)

The novelty of this study consists on the formulation and evaluation of five complex experimental natural photosensitizers (PS): gel with oregano essential oil (O), gel with methylene blue (AM), gel with a mixture of essential oils (Thieves-H), gel with arnica oil and curcuma extract (CU) and gel with frankincense essential oil (T), used as photosensitizing agents (PS) in antimicrobial photodynamic therapy (aPDT) in the control of microbial biofilm in oral cavity. The experimental PS were characterized by gas chromatography-mass spectrometry (GC-MS), Fourier-transform infrared spectroscopy (FTIR), UV-Vis spectroscopy, cytotoxicity assay, antimicrobial effect and scanning electron microscopy (SEM). The IR spectra of the experimental PS with essential oils exhibit absorption bands due to the presence of water and glycerol in high quantities. The studied compounds had a reduced cytotoxic effect on cell cultures. The lowest cytotoxic effect was observed in experimental PS with oregano essential oil and methylene blue PS. Essential oils with proven antibacterial capabilities used in experimental PS confer antibacterial activity to the gels in which they are incorporated, an activity that may be more efficient use of a PDT therapy. Single bacteria were detected mainly by SEM after 12 h, while aggregate bacteria and micro colonies dominated the samples at 48 h.

Photonic Therapy in Periodontal Diseases an Overview with Appraisal of the Literature and Reasoned Treatment Recommendations

Recent reviews and meta-analyses of the literature over the past quarter-century have failed to provide enough evidence to prove or disprove the actual utility of photonic therapy in periodontitis, alone or adjunctive to conventional approaches. This apparent paradox has been explained by the many physical, molecular, biological, anatomical, and technical variables of photonic treatments, which can differ in light-emitting devices (laser or LED), wavelengths, irradiation power and modes, clinical objectives, follow-up times, disease grading, and assessment methods. This multi-faceted, controversial scenario has led practitioners to underestimate the actual potential of photonic therapy in periodontal diseases. In this critical appraisal of the literature, we have briefly summarized the main photonic therapies and instruments used in Periodontology, highlighting their main characteristics and limitations. Then, we have tried to identify and discuss the key methodological issues which can have an impact on the outcome of photonic therapies. Our main goal was to identify the best parameters, settings, and methodologies to perform effective periodontal photonic treatments and to extrapolate some recommendations for clinical use. Should these recommendations find a consensus among periodontologists and be adopted in future clinical studies, they will hopefully contribute to dissipate the present confusion and uncertainty on this complex matter.

Novel nanotechnology and near-infrared photodynamic therapy to kill periodontitis-related biofilm pathogens and protect the periodontium

OBJECTIVE

Periodontal tissue destruction and tooth loss are increasingly a worldwide problem as the population ages. Periodontitis is caused by bacterial infection and biofilm plaque buildup. Therefore, the objectives of this study were to: (1) develop a near-infrared light (NIR)-triggered core-shell nanostructure of upconversion nanoparticles and TiO₂ (UCNPs@TiO₂), and (2) investigate its inhibitory effects via antibacterial photodynamic therapy (aPDT) against periodontitis-related pathogens.

METHODS

The core β-NaYF₄:Yb³⁺,Tm³⁺ were synthesized via thermal decomposition and further modified with the TiO₂ shell via a hydrothermal method. The core-shell structure and the upconversion fluorescence-induced aPDT treatment via 980nm laser were studied. Three periodontitis-related pathogens Streptococcus sanguinis (S. sanguinis), Porphyromonas gingivalis (P. gingivalis) and Fusobacterium nucleatum (F. nucleatum) were investigated. The killing activity against planktonic bacteria was detected by a time-kill assay. Single species 4-day biofilms on dentin were tested by live/dead staining, colony-forming units (CFU), and metabolic activity.

RESULTS

The hexagonal shaped UCNPs@TiO₂ had an average diameter of 39.7nm. UCNPs@TiO₂ nanoparticles had positively charged (+12.4mV) surface and were biocompatible and non-cytotoxic. Under the excitation of NIR light (980nm), the core NaYF₄:Yb³⁺,Tm³⁺ UCNPs could emit intense ultraviolet (UV) light, which further triggered the aPDT function of the shell TiO₂ via energy transfer, thereby realizing the remarkable antibacterial effects against planktons and biofilms of periodontitis-associated pathogens. NIR-triggered UCNPs@TiO₂ achieved much greater reduction in biofilms than control (p<0.05). Biofilm CFU was reduced by 3-4 orders of magnitude via NIR-triggered aPDT, which is significantly greater than that of negative control and commercial aPDT control groups. The killing efficacy of UCNPs@TiO₂-based aPDT against the three species was ranked to be: S. sanguinis<F. nucleatum=P. gingivalis. Metabolic activities of biofilms were also greatly reduced via NIR-triggered aPDT (p<0.05).

SIGNIFICANCE

Upconversion fluorescence-based aPDT achieved strong inhibiting effects against all three species of periodontitis-related pathogens. This novel nanotechnology demonstrated a high promise to inhibit periodontitis, with exciting potential to combat other oral infectious diseases such as deep endodontic infections.

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.

Scope of antimicrobial photodynamic therapy in Orthodontics and related research: A review

BACKGROUND

The aim of the present study was to comprehensively review indexed literature regarding the potential role of antimicrobial photodynamic therapy (aPDT) in Orthodontics.

METHODS

Indexed databases were searched up to and including January 2019 using the following key words: (a) antimicrobial photodynamic therapy; (b) antimicrobial photodynamic chemotherapy; (c) orthodontic; and (d) orthodontics. Original (clinical and experimental) studies, case-reports, and case-series were included. Letters to the Editor, commentaries and review articles were excluded.

RESULTS

Out of the 29 studies identified in the initial search, 4 studies were processed for data extraction. Three studies were randomized clinical trials performed in humans and 1 study was experimental. Results from 2 studies showed that aPDT is effective in the treatment of gingival inflammation in patients undergoing orthodontic therapy (OT). One study showed that oral decontamination can be successfully performed using aPDT among patients undergoing OT. Results of the experimental study showed that aPDT helps in surface decontamination of orthodontic instruments.

CONCLUSION

There is insufficient evidence in indexed literature to justify the potential role of aPDT in OT. Hence, further studies are required in this regard.