Assessment of safety and efficacy of antimicrobial photodynamic therapy for peri-implant disease

Photodynamic therapy alone or in combination to counteract bacterial infections

INTRODUCTION

Antibacterial photodynamic therapy presents a promising alternative to antibiotics, with potential against multidrug-resistant bacteria, offering broad-spectrum action, reduced resistance risk, and improved tissue selectivity.

AREAS COVERED

This manuscript reviews patent literature in the field of antibacterial photodynamic therapy through the period of 2019-2023. All data are from the US and European patent databases and SciFinder.

EXPERT OPINION

Antibacterial photodynamic therapy (PDT) is an appealing approach for treating bacterial infections, especially biofilm-related ones, by releasing reactive oxygen species (ROS) upon light activation. Its success is driven by a growing variety of photosensitizers (PSs) with tailored properties, like water solubility, controllable surface charge, and ROS generation efficiency. Among them, Aggregation Induced Emission (AIE)-type PSs are promising, demonstrating enhanced efficacy when aggregated in biological environments. However, the penetration of pristine PSs into bacterial biofilms within deep tissues or complex anatomical regions is limited, reducing their antibacterial effectiveness. To address this, nanotechnology has been integrated into antibacterial PDT to synthesize various nano-PSs. This adaptability allows seamless integration with other antimicrobial treatments, offering a comprehensive approach to combat localized infections, especially in dentistry and dermatology. By combining PSs with complementary therapies, antibacterial PDT offers a multifaceted strategy for effective microbial control and management.

Clinical and Radiographic Outcomes of Adjunctive Phototherapy Versus Antibiotic Therapy Against Peri-Implant Diseases: A Systematic Review and Meta-Analysis

Background: Peri-implantitis, an inflammatory condition in implant tissues, requires bacterial eradication and implant surface decontamination, with aPDT as a helpful surgical adjunct. Objective:This project was designed to investigate the effect of antibiotic therapy versus aPDT, as adjuncts to conventional mechanical debridement (MD), on the peri-implant clinical and/or radiographic parameters among patients with peri-implant diseases. Methods: A comprehensive search was conducted across electronic databases, including PubMed, Scopus, and Web of Science, up to and including April 2023, without any restriction on the language and year of publication, focusing the following research question: "Does adjunctive aPDT improve the peri-implant clinical and/or radiographic parameters in treating peri-implant diseases compared to antibiotic therapy?" Statistical analysis was performed on peri-implant clinical [plaque index (PI), probing depth (PD), and bleeding on probing (BOP)] and radiographic parameters [marginal bone loss (MBL)]. The study included six randomized controlled trials and one clinical (nonrandomized) study. Results: The systematic review findings indicate that the application of aPDT as an adjunct to MD is equally effective as adjunctive antibiotic therapy in improving peri-implant clinical parameters and radiographic parameters in patients with peri-implant diseases. Only two studies were classified as having a low risk of bias (RoB), two were assessed as having an unclear RoB, and the remaining three studies were determined to have a high RoB. However, the meta-analysis results revealed no statistically significant difference in peri-implant PI, PD, and MBL scores between patients treated with adjunct aPDT or adjunct antibiotic therapy. Notably, there was a statistically significant difference favoring adjunct aPDT in peri-implant BOP values compared to the control group. Conclusions: Despite the limited number of included studies and the significant heterogeneity among them, the findings suggest that aPDT yields comparable peri-implant clinical and radiographic outcomes to adjunctive antibiotic therapy, as adjuncts to MD, for the potential treatment of peri-implant diseases.

Diagnosis and Treatment of Periimplant Mucositis and Periimplantitis: An Overview and Related Controversial Issues

Periimplant mucositis and periimplantitis are common complications of dental implant. This article provides a comprehensive overview of the 2017 World Workshop's new definition, clinical and radiographic presentation, pathogenesis, risk factors, and classification of periimplant diseases. Also, the authors discuss various types of instruments, materials, and techniques commonly used for treatment of nonsurgical and surgical periimplantitis. Lastly, the authors include some controversial topics surrounding this subject.

Manganese Amplifies Photoinduced ROS in Toluidine Blue Carbon Dots to Boost MRI Guided Chemo/Photodynamic Therapy

The contrast agents and tumor treatments currently used in clinical practice are far from satisfactory, due to the specificity of the tumor microenvironment (TME). Identification of diagnostic and therapeutic reagents with strong contrast and therapeutic effect remains a great challenge. Herein, a novel carbon dot nanozyme (Mn-CD) is synthesized for the first time using toluidine blue (TB) and manganese as raw materials. As expected, the enhanced magnetic resonance (MR) imaging capability of Mn-CDs is realized in response to the TME (acidity and glutathione), and r1 and r2 relaxation rates are enhanced by 224% and 249%, respectively. In addition, the photostability of Mn-CDs is also improved, and show an efficient singlet oxygen (1 O2 ) yield of 1.68. Moreover, Mn-CDs can also perform high-efficiency peroxidase (POD)-like activity and catalyze hydrogen peroxide to hydroxyl radicals, which is greatly improved under the light condition. The results both in vitro and in vivo demonstrate that the Mn-CDs are able to achieve real-time MR imaging of TME responsiveness through aggregation of the enhanced permeability and retention effect at tumor sites and facilitate light-enhanced chemodynamic and photodynamic combination therapies. This work opens a new perspective in terms of the role of carbon nanomaterials in integrated diagnosis and treatment of diseases.

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.

Surgical reconstruction of peri-implantitis with adjunctive antimicrobial photodynamic therapy: A case report with 5-year follow-up

BACKGROUND

Peri-implantitis poses a significant challenge in dental implantology due to its potential to result in the loss of supporting tissue around dental implants. Surgical reconstruction is often recommended for intrabony defects, accompanied by various adjunctive therapies, such as antimicrobial photodynamic therapy (aPDT), for bacterial decontamination. However, the long-term efficacy of such treatments remains unclear.

METHODS

This clinical report presents a case of peri-implantitis management in a healthy 55-year-old male using guided bone regeneration principles and surface decontamination via aPDT. The patient exhibited peri-implantitis with probing pocket depths (PPD) of 7 mm at buccal sites, 5 mm at palatal sites, and significant bone loss around implant #12. The reconstructive approach involved preservation of the existing implant and following a non-submerged healing protocol. The surgical phase included meticulous debridement, chemical detoxification with hydrogen peroxide, and aPDT using a 670 nm diode laser with methylene blue as the photosensitizer. Xenogenic bone graft and a resorbable collagen membrane were applied and the patient was followed up to through a 5-year period.

RESULTS

Postsurgery the patient exhibited normal healing, and long-term follow-up at 5 years showed reduced PPD (2 mm buccally, 3 mm mid-palatally), complete intrabony defect fill, and stable bone levels, indicating successful treatment.

CONCLUSIONS

This case report demonstrates the potential long-term success of a reconstructive approach with adjunctive aPDT in peri-implantitis management. However, it highlights the need for standardized protocols and further clinical trials to establish the clinical benefits of aPDT in surgical reconstruction of peri-implantitis defects, serving as valuable pilot data for future research.

HIGHLIGHTS

Why is this case new information? Provides a rare 5-year insight into peri-implantitis intrabony defect reconstruction, offering extended success and outcomes not frequently documented. Demonstrates the efficacy of aPDT with a 670-nm diode laser in achieving successful long-term outcomes, contributing valuable evidence to existing literature.Keys to successful management of this case: Success involves initial non-surgical debridement followed by a reconstructive strategy, incorporating guided bone regeneration and surface decontamination via aPDT. Long-term success hinges on patient compliance with routine oral hygiene, emphasizing the importance of adherence to preventive measures post-reconstruction to minimize recurrence risk.What are the primary limitations to success in this case? Variability in photosensitizer uptake, and potential risks such as tissue damage and bacterial resistance pose challenges to the effectiveness of aPDT. The existing literature on aPDT in peri-implantitis treatment lacks standardization in methodology, laser parameters, and follow-up durations, making it challenging to establish a universally accepted protocol.

Antimicrobial photodynamic therapy for the treatment of oral infections: A systematic review

Oral infection is a common clinical symptom. While antibiotics are widely employed as the primary treatment for oral diseases, the emergence of drug-resistant bacteria has necessitated the exploration of alternative therapeutic approaches. One such modality is antimicrobial photodynamic therapy (aPDT), which utilizes light and photosensitizers. Indeed, aPDT has been used alone or in combination with other treatment options dealing with periodontal disease for the elimination of biofilms from bacterial community to achieve bone formation and/or tissue regeneration. In this review article, in addition to factors affecting the efficacy of aPDT, various photosensitizers, the latest technology and perspectives on aPDT are discussed in detail. More importantly, the article emphasizes the novel design and clinical applications of photosensitizers, as well as the synergistic effects of chemical and biomolecules with aPDT to achieve the complete eradication of biofilms and even enhance the biological performance of tissues surrounding the treated oral area.

Consensus Report of the Technical-Scientific Associations of Italian Dental Hygienists and the Academy of Advanced Technologies in Oral Hygiene Sciences on the Non-Surgical Treatment of Peri-Implant Disease

BACKGROUND

The recent publication of the new classification of periodontal and peri-implant disease has given clear indications on the parameters to be taken into consideration to correctly diagnose the different phases of these diseases. To date, however, there are no equally clear indications on the treatments to be implemented to solve these diseases. The objective of this Consensus Report is to provide guidance for the non-surgical management of peri-implant mucositis and peri-implantitis. For the drafting of the consensus, the most recent scientific literature was analysed.

MATERIALS AND METHODS

A group of 15 expert Italian dental hygienists were selected by the Italian technical-scientific societies (AIDI, UNID and ATASIO) and, starting from the literature review, they formulated indications according to the GRADE method (Grading of Recommendations, Assessment, Development, and Evaluation, a tool for rating the quality of evidence, used to draw up systematic reviews and clinical guidelines) on the treatment of peri-implant mucositis, peri-implantitis and on management of the various implanting surfaces.

CONCLUSIONS

in accordance with the international literature, non-surgical therapy alone can resolve peri-implant mucositis, but not peri-implantitis. Several adjunctive therapies have been considered and some appear to be helpful in managing inflammation.

The Application of Antimicrobial Photodynamic Therapy (aPDT) in the Treatment of Peri-Implantitis

Background

This literature review evaluates the mechanisms and efficacy of different types of antimicrobial photodynamic therapy (aPDT) for treating peri-implantitis by reviewing existing experimental studies to provide guidance for the clinical application of antibacterial photodynamic therapy (aPDT) in oral implants.

Materials and Methods

From February 2001 to February 2021, we have collected 152 randomized controlled trials of aPDT for peri-implantitis by searching the experimental studies and clinical trials published in PubMed, Embase, Web of Science, and Google Scholar databases via online search. After screening the retrieved literature, we finally selected 10 statistically significant literature for evaluation and review.

Results

Compared with the traditional nonsurgical treatment of peri-implantitis, the aPDT was superior to the traditional mechanical irrigation treatment group in terms of periodontal indexes PD, BOP, PLI, and postoperative effect, and the difference was statistically significant (P < 0.05). Furthermore, the combination of the aPDT and other treatments shows the synergistic antibacterial effect, signifying better clinical effect in many aspects (P < 0.05). In these 10 papers, by comparing the probe depth (PD), bleeding on probing (BOP), synosteosis, and periodontal pathogenic bacteria detection, etc., obtained after treating peri-implantitis by application of the antimicrobial photodynamic therapy, and using the SPSS data analysis software for statistical data processing, we found that the antimicrobial photodynamic therapy combined with other periodontal treatments has a more prominent postoperative effect. Meanwhile, the antibacterial photodynamic therapy with targeted action of photosensitizer has strong specificity to some bacteria, while the synthetic photosensitize for antibacterial photodynamic therapy can show good inactivation effect on broad-spectrum periodontal anaerobes without side effect.

Conclusion

The experimental studies and clinical data of antibacterial photodynamic therapy for treating peri-implantitis show a good postoperative treatment effect. In addition, it did not develop resistance due to the use of antibiotic drugs. Owing to multiple advantages from combining antibacterial photodynamic therapy and other treatments, it is applicable for clinical treatment.