Molecular Analysis of the Antibacterial Effects of Photodynamic Therapy in Endodontic Surgery: A Case Series

Development of photodynamic therapy in treating oral diseases

The morbidity of oral disorders, including gingivitis, caries, endodontic-periodontal diseases, and oral cancer, is relatively high globally. Pathogenic cells are the root cause of many oral disorders, and oral therapies depend on eradicating them. Photodynamic therapy (PDT) has been established as a potential and non-invasive local adjuvant treatment for oral disorders. PDT consists of three essential components: photosensitizer (PS), a light source with a certain wavelength, and oxygen dissolved in the cells. These three components can interact to cause damage to proteins, lipids, nucleic acids, and other biological components within diseased tissues. Herein, we aimed to provide a detailed understanding of PDT and how it can treat oral diseases. Concerns about PDT and potential remedies are also a factor. PDT has been shown in numerous clinical studies to be an efficient supplementary therapy that can reduce pathogenic cells. The PDT has great potential for dental applications, including treating bacterial and fungal infections during root canal therapy and preventing oral cancer, potentially malignant disorders, periodontitis, dental caries, and peri-implant disorders. Although PDT has been promoted as having significant potential and utility in dentistry, more clinical research must be conducted before being used broadly.

Comparative Evaluation of Sodium Hypochlorite Gel Penetration Using Er,Cr:YSGG Laser and Passive Ultrasonic Activation After Apicoectomy: An In Vitro Study with Confocal Laser Scanning Microscopy

Background: Lasers from the erbium family have been investigated to activate irrigation with sodium hypochlorite (NaOCl), improving the disinfection depth of the dentinal tubules of the root canal walls during root canal treatment. However, the possibility of laser-activated irrigation (LAI) in retro-cavity preparation has not been investigated to the date. The aim of our experimental study is to evaluate the efficacy of NaOCl gel penetration inside the dentinal tubules when activated during retro-cavity preparation, comparing passive ultrasonic activation (PUI) and Er,Cr:YSGG LAI. Materials and Methods: Fifty extracted mature single-root human teeth were divided into four groups (control, PUI, and two LAI groups with different NaOCl concentrations). After conventional endodontic treatment and root end resection, NaOCl gel (impregnated with rhodamine dye for confocal laser scanning microscopy (CLSM) analysis) was applied and activated according to the study group. The penetration index and mean penetration length were measured using computer software. Results: Both penetration index and mean penetration length were found to have increased in the PUI group compared to the control samples. However, LAI had a better penetration that was statistically significant compared to both the PUI and control groups. The difference in NaOCl concentration in the laser groups did not affect the penetration values. Conclusions: Within the limitations of our in vitro study using NaOCl gel activation in the retro-cavity after apicectomy, Er,Cr:YSGG LAI significantly enhanced NaOCl gel penetration capacity compared to PUI, regardless of its concentration. LAI can enhance its penetration in a safe way, avoiding its extrusion to the surrounding periapical tissues.

Outcome of curcumin-based photodynamic therapy in endodontic microsurgery: A case report

INTRODUCTION

Persistent apical periodontitis after root canal treatment may require surgical retreatment when non-surgical options are ineffective or impractical due to anatomical challenges or iatrogenic errors. Endodontic microsurgery (EMS) is a precise technique that aims to overcome extraradicular biofilm and root morphology issues. Photodynamic therapy (PDT) is an emerging supplementary disinfection approach that utilizes a photosensitizer agent and light to eliminate microorganisms through oxidative reactions.

REPORT

A 60-year-old male with persistent apical periodontitis in a left maxillary first molar underwent non-surgical root canal retreatment followed by surgical reintervention due to anatomical complexities. During surgery, PDT was performed using a novel curcumin-based photosensitizer agent. After the procedure, the tooth was retrofilled with bioceramic cement, and photobiomodulation was applied to enhance tissue healing. One year post-surgery, the patient exhibited complete periradicular repair and remained asymptomatic.

DISCUSSION

EMS is considered a last resort to salvage an endodontically treated tooth and has shown moderate success rates. PDT has demonstrated promise in improving periapical healing and reducing microorganisms. In this case, curcumin, diluted with 2 % chlorhexidine gel, served as an effective photosensitizer agent with antimicrobial properties. Moreover, performing photobiomodulation aided in cell recovery and reduced postoperative discomfort.

CONCLUSION

The proposed EMS treatment protocol with PDT using curcumin yielded positive outcomes in this case report. Further randomized clinical trials are necessary to assess the efficacy of this approach in EMS. Additionally, further research on curcumin-based photosensitizer agents encapsulated in nanoparticles and enhanced antimicrobial agents is recommended to refine this treatment protocol for routine use.

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.

The role of the light source in antimicrobial photodynamic therapy

Antimicrobial photodynamic therapy (APDT) is a promising approach to fight the growing problem of antimicrobial resistance that threatens health care, food security and agriculture. APDT uses light to excite a light-activated chemical (photosensitiser), leading to the generation of reactive oxygen species (ROS). Many APDT studies confirm its efficacy in vitro and in vivo against bacteria, fungi, viruses and parasites. However, the development of the field is focused on exploring potential targets and developing new photosensitisers. The role of light, a crucial element for ROS production, has been neglected. What are the main parameters essential for effective photosensitiser activation? Does an optimal light radiant exposure exist? And finally, which light source is best? Many reports have described the promising antibacterial effects of APDT in vitro, however, its application in vivo, especially in clinical settings remains very limited. The restricted availability may partially be due to a lack of standard conditions or protocols, arising from the diversity of selected photosensitising agents (PS), variable testing conditions including light sources used for PS activation and methods of measuring anti-bacterial activity and their effectiveness in treating bacterial infections. We thus sought to systematically review and examine the evidence from existing studies on APDT associated with the light source used. We show how the reduction of pathogens depends on the light source applied, radiant exposure and irradiance of light used, and type of pathogen, and so critically appraise the current state of development of APDT and areas to be addressed in future studies. We anticipate that further standardisation of the experimental conditions will help the field advance, and suggest key optical and biological parameters that should be reported in all APDT studies. More in vivo and clinical studies are needed and are expected to be facilitated by advances in light sources, leading to APDT becoming a sustainable, alternative therapeutic option for bacterial and other microbial infections in the future.

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.

How can biophotonics help dentistry to avoid or minimize cross infection by SARS-CoV-2?

Biophotonics is defined as the combination of biology and photonics (the physical science of the light). It is a general term for all techniques that deal with the interaction between biological tissues/cells and photons (light). Biophotonics offers a great variety of techniques that can facilitate the early detection of diseases and promote innovative theragnostic approaches. As the COVID-19 infection can be transmitted due to the face-to-face communication, droplets and aerosol inhalation and the exposure to saliva, blood, and other body fluids, as well as the handling of sharp instruments, dental practices are at increased risk of infection. In this paper, a literature review was performed to explore the application of Biophotonics approaches in Dentistry focusing on the COVID-19 pandemic and how they can contribute to avoid or minimize the risks of infection in a dental setting. For this, search-related papers were retrieved from PubMED, Scielo, Google Schoolar, and American Dental Association and Centers for Disease Control and Prevention databases. The body of evidence currently available showed that Biophotonics approaches can reduce microorganism load, decontaminate surfaces, air, tissues, and minimize the generation of aerosol and virus spreading by minimally invasive, time-saving, and alternative techniques in general. However, each clinical situation must be individually evaluated regarding the benefits and drawbacks of these approaches, but always pursuing less-invasive and less aerosol-generating procedures, especially during the COVID-19 pandemic.

Dens invaginatus: clinical implications and antimicrobial endodontic treatment considerations

Dens invaginatus or dens in dente is a developmental dental anomaly resulting from an invagination of the enamel organ into the dental papilla during odontogenesis. Radiographically, it is usually seen as a radiolucent invagination surrounded by a radiopaque area (enamel) limited to the tooth crown or extending into the root. Because the invagination is opened to the oral cavity, it can retain saliva, food remnants, and bacteria. In conditions that the enamel lining of the invagination is naturally absent or lost due to caries, bacterial cells and products can diffuse from the invagination through the dentin tubules to reach the pulp and cause disease. Management of teeth with dens invaginatus include preventive sealing or filling of the invagination, or, if the pulp is affected, therapeutical options include vital pulp therapy, nonsurgical root canal treatment, apexification or regenerative endodontic procedures, periradicular surgery, intentional replantation, or extraction. It is recommended that the invagination be always approached, regardless of the type of dens invaginatus. The root canal should be treated whenever the pulp is irreversibly inflamed or necrotic. Endodontic management of teeth with dens invaginatus is often tricky because of its anatomical complexity, and special and customized strategies should be devised. This review discusses the endodontic implications of this anomaly and the current treatment recommendations based on anatomic, pathologic, and technologic considerations.

Antimicrobial and Antibiofilm Properties of Bioceramic Materials in Endodontics

Microbes are prevalent in the root canals of necrotic teeth, and they are the cause of primary and post-treatment apical periodontitis. Bacteria can dwell within the infected root canal system as surface-adherent biofilm structures, which exhibit high resistance to antimicrobial agents. Bioceramic materials, with their biocompatible nature and excellent physico-chemical properties, have been widely used in dental applications, including endodontics. This review focuses on the application of bioceramic technology in endodontic disinfection and the antibiofilm effects of endodontic bioceramic materials. Different bioceramic materials have shown different levels of antibiofilm effects. New supplements have emerged to potentially enhance the antibiofilm properties of bioceramics aiming to achieve the goal of microbial elimination in the root canal system.

Adjunctive use of antimicrobial photodynamic therapy in the surgical treatment of periapical lesions: a case series

BACKGROUND

Antimicrobial photodynamic therapy (aPDT) is being used in endodontics to improve orthograde root canal disinfection as an adjunct to standard treatments. Conversely, evidence concerning the application of aPDT in retrograde endodontic surgery is limited. Thus, the aim of the present study was to provide additional data regarding the use of aPDT in the surgical endodontic treatment of periapical lesions.

METHODS

A total of 25 consecutive patients presenting teeth with periapical radiolucency eventually associated with clinical signs and symptoms of apical periodontitis were included. Following access flap completion, osteotomy, mechanical debridement, root apical third resection, and preparation of the root-end cavity, aPDT was applied to decontaminate the surgical site using phenothiazine chloride dye at a concentration of 10 mg/mL and irradiation with a hand-held 100-mW diode laser with a wavelength of 660 ± 10 nm. At the latest follow-up visit, healing was evaluated as successful, uncertain, or failure according to well-established clinical and radiological criteria.

RESULTS

Overall, 31 periapical lesions were treated with aPDT. Healing proceeded uneventfully. The mean follow-up time was 36.19 months, with times ranging from 12 to 85 months. A total of 25 (80.65%) cases were classified as successful, 5 (16.13%) as uncertain, and only one (3.22%) as failure. Irrespective of the treatment outcome, all treated teeth were still functional, with no symptoms reported by the patients.

CONCLUSION

aPDT as an adjunctive treatment modality in the surgical endodontic treatment of periapical lesions showed promising medium-term results associated with preservation of all diseased teeth.

The effectiveness of the supplementary use of the XP-endo Finisher on bacteria content reduction: a systematic review and meta-analysis

Objectives

This systematic review evaluated the efficacy of the supplementary use of the XP-endo Finisher on bacteria content reduction in the root canal system.

Materials and Methods

In-vitro studies evaluating the use of the XP-endo Finisher on bacteria content were searched in four databases in July 2020. Two authors independently screened the studies for eligibility. Data were extracted, and risk of bias was assessed. Data were meta-analyzed by using random-effects model to compare the effect of the supplementary use (experimental) or not (control) of the XP-endo Finisher on bacteria counting reduction, and results from different endodontic protocols were combined. Four studies met the inclusion criteria while 1 study was excluded from the meta-analysis due to its high risk of bias and outlier data. The 3 studies that made it to the meta-analysis had an unclear risk of bias for at least one criterion.

Results

No heterogeneity was observed among the results of the studies included in the meta-analysis. The study excluded from the meta-analysis assessing the bacteria counting deep in the dentin demonstrated further bacteria reduction upon the use of the XP-endo Finisher.

Conclusions

This systematic review found no evidence supporting the supplementary use of the XP-endo Finisher on further bacteria counting the reduction in the root canal.

Photodynamic Therapy in Endodontics: A Helpful Tool to Combat Antibiotic Resistance? A Literature Review

BACKGROUND

Antibiotic resistance has become a growing global problem where overprescription is a contributing factor for its development. In the endodontics field, complementary treatments, such as antimicrobial photodynamic therapy (aPDT), have been described to eliminate residual bacteria from the root canal space and reduce complications. The aim of this review is to describe the literature evidence up to now regarding the advantages, efficiency, and clinical outcomes of this therapy in endodontics as a possible tool to combat antibiotic resistance.

METHODS

A review of the literature from 2010 to 2021 was carried out using the PubMed and Web of Science databases. Two steps were taken: First, articles were compiled through the terms and MeSH terms "Photochesdmotherapy" and "endodontics." Then, a second search was conducted using "photodynamic therapy" and "antibiotic resistance" or "drug resistance, microbial."

RESULTS

A total of 51 articles were included for evaluation: 27 laboratory studies, 14 reviews, and 10 clinical studies. Laboratory studies show that aPDT achieves significant bacterial elimination, even against antibiotic-resistant species, and is also effective in biofilm disruption. Clinical studies suggest that aPDT can be considered a promising technique to reduce bacterial complications, and reviews about the issue confirm its advantages.

CONCLUSION

The benefits of aPDT in reducing complications due to its antibacterial effects means a possible decrease in systemic antibiotic prescription in endodontics. In addition, it could be an alternative to local intracanal antibiotic therapy, avoiding the appearance of possible antibiotic resistance, as no bacterial resistance with aPDT has been described to date.

Effect of Photodynamic Therapy on Postoperative Pain in Posterior Teeth with Symptomatic Apical Periodontitis

This study aimed to evaluate the impact of photodynamic therapy (PDT) after root canal preparation on pain relief in posterior teeth presenting with symptomatic apical periodontitis (SAP). A visual analog scale (VAS) was completed by the patients which registered their pain perception as none (0), mild (1-3), moderate (4-7), or severe (8-10). Only patients who registered moderate or severe pain were included. Seventy patients were allocated to two groups (n=35): a control group (CG) without the PDT application and an intervention group with PDT application (PG). The same chemo-mechanical preparation was achieved in both groups. In the PG, 150 µM methylene blue (MB)Please remove the underline was placed inside the canal for 2 minutes and a 660 nm wavelength laser was applied through a fiber for 3 minutes (100 mW, 600 J/cm², total 18J). The patients were asked to register their pain perception in the VAS document after 24-h, 72-h, and 1-week intervals. The number of tablets taken for pain relief was also recorded. The Mann-Whitney, Students T-test and Fisher´s exact tests were used for statistical analysis (P < .05). After 1 week, 32 patients in the CG and 33 in the PG returned their VAS cards. The PG resulted in lower pain levels after the 24-hour interval (median 0) than the CG (median 2); there was no difference between both groups at 72-h and 1-week intervals. The decrease in pain was higher in the PG at all time-intervals when compared to the CG. There was no difference in the mean number of tablets taken for pain relief (P > .05). Within the limitations of this study, it can be concluded that PDT was efficient in decreasing pain in teeth presenting with SAP. There was no difference observed after 72 hours and there was no impact on the intake of pain relief medication.

Dual antibacterial behavior of a curcumin–upconversion photodynamic nanosystem for efficient eradication of drug-resistant bacteria in a deep joint infection

The curcumin–upconversion photodynamic nanosystem exhibits dual antibacterial behavior for MRSA-induced periprosthetic joint infection under NIR irradiation.