Blue Light Photodynamic Therapy With Curcumin and Riboflavin in the Management of Periodontitis: A Systematic Review

Potential of using medicinal plant extracts as photosensitizers for antimicrobial photodynamic therapy

Antimicrobial photodynamic therapy (APDT) is a promising approach to overcome antimicrobial resistance. However, for widespread implementation of this approach, approved photosensitizers are needed. In this study, we used commercially available preparations (Calendulae officinalis floridis extract, Chamomillae recutitae floridis extract, Achillea millefolii herbae extract; Hypericum perforatum extract; Eucalyptus viminalis folia extract) as photosensitizers for inactivation of gram-negative (Pseudomonas aeruginosa) and gram-positive (Staphylococcus aureus) bacteria. Spectral-luminescent analysis has shown that the major chromophores are of chlorophyll (mainly chlorophyll a and b) and hypericin nature. The extracts are efficient generators of singlet oxygen with quantum yield (γΔ) from 0.40 to 0.64 (reference compound, methylene blue with γΔ = 0.52). In APDT assays, bacteria before irradiation were incubated with extracts for 30 min. After irradiation and 24 h of incubation, colony-forming units (CFU) were counted. Upon exposure of P. aeruginosa to radiation of 405 nm, 590 nm, and 660 nm at equal energy dose of 30 J/cm2 (irradiance - 100 mW/cm2, exposure time - 5 min), the most pronounced effect is observed with blue light (>3 log10 reduction); in case of S. aureus, the effect is approximately equivalent for light of indicated wavelengths and dose (>4 log10 reduction).

Reduction of Multispecies Biofilms on an Acrylic Denture Base Model by Antimicrobial Photodynamic Therapy Mediated by Natural Photosensitizers

OBJECTIVES

The aim of this study is to investigate the antimicrobial efficacy of antimicrobial photodynamic therapy (PDT) using natural photosensitizers (curcumin, riboflavin, and phycocyanin) and light-emitting diode (LED) irradiation against multispecies biofilms in an acrylic denture base model.

MATERIALS AND METHODS

Forty-five acrylic specimens were fabricated using heat-curing acrylic resin. The specimens were then infected with a mixed culture of bacterial and fungal species (including Streptococcus mutans, Streptococcus sanguinis, Candida albicans, and Candida glabrata) for 4 days. The acrylic discs were divided into nine groups, with each group containing five discs: control, 0.2% chlorhexidine, 5.25% sodium hypochlorite, curcumin, riboflavin, phycocyanin alone or along with LED. After treatment, the number of colony-forming units (CFUs) per milliliter was counted. In addition, the extent of biofilm degradation was assessed using the crystal violet staining method and scanning electron microscopy.

RESULTS

All experimental groups exhibited a significant reduction in colony numbers for both bacterial and fungal species compared to the control (p < 0.001). The PDT groups exhibited a statistically significant reduction in colony counts for both bacteria and fungi compared to the photosensitizer-only groups.

CONCLUSIONS

The results of this in vitro study show that PDT with natural photosensitizers and LED devices can effectively reduce the viability and eradicate the biofilm of microorganisms responsible for causing denture infections.

Bactericidal Effect of Different Photochemical-Based Therapy Options on Implant Surfaces-An In Vitro Study

Objectives: Photochemical systems are frequently recommended as an adjuvant treatment option in peri-implantitis therapy. The aim of the present study was to evaluate the efficacy of these treatment options, as well as a novel curcumin-based option, in a biofilm model on implants. Methods: Eighty dental implants were inoculated with an artificial biofilm of periodontal pathogens and placed in peri-implant pocket models. The following groups were analyzed: I, photodynamic therapy (PDT); II, PDT dye; III, curcumin/DMSO + laser; IV, curcumin/DMSO only; V, dimethyl sulfoxide (DMSO) only; VI, photothermal therapy (PTT); VII, PTT dye; VIII, control. After treatment, remaining bacterial loads were assessed microbiologically using quantitative real-time polymerase chain reaction analysis. Results: The PDT, PTT, and DMSO treatment methods were associated with statistically significant (p < 0.05) improvements in germ reduction in comparison with the other methods and the untreated control group. The mean percentage reductions were as follows: I (PDT) 93.9%, II (PDT dye) 62.9%, III (curcumin/DMSO + laser) 74.8%, IV (curcumin/DMSO only) 67.9%, V (DMSO) 89.4%, VI (PTT) 86.8%, and VII (PTT dye) 66.3%. Conclusions: The commercially available PDT and PTT adjuvant treatment systems were associated with the largest statistically significant reduction in periopathogenic bacteria on implant surfaces. However, activation with laser light at a suitable wavelength is necessary to achieve the bactericidal effects. The use of curcumin as a photosensitizer for 445 nm laser irradiation did not lead to any improvement in antibacterial efficacy in comparison with rinsing with DMSO solution alone.

[Effectiveness of curcumin as photodynamic therapy for endodontic procedures: a narrative review]

Introduction

Endodontic therapy is performed by biomechanical preparation and intracanal medication; however, residual bacteria can be compromised due to their ability to adhere to the root canal walls. Therefore, photodynamic therapy has gained popularity because of its good ability to prevent and eradicate microbial infections by using a light-activated dye. Objective: Analyze and to update the information on the effect of curcumin in photodynamic therapy in root canal treatment.

Material and Methods

A literature search was carried out in PubMed/MEDLINE, Scopus, Ebsco, Science Direct, and LILACS databases using the keywords "curcumin", "turmeric", "photodynamic", "photochemotherapy", "photoradiation", "photoactivated disinfection", "root canal disinfection", "root canal therapy", "endodontics" in both Spanish and English, from 2018 to 2023.

Results

Information from the last five years was collected with the aim of updating the study topic. 749 articles were examined using inclusion and exclusion criteria, of which only 50 met these criteria and were analyzed. Current studies show the effects of therapy on the contamination of the root canal biofilm with E. faecalis, demonstrating that photoactivated curcumin promotes the disruption of the biofilm and reduction of Colony-Forming Units.

Conclusions

Curcumin as a photosensitizer demonstrates a potential antibacterial effect significantly decreasing the viability of microbial cells and the vitality of biofilms.

Application of photosensitive dental materials as a novel antimicrobial option in dentistry: A literature review

The formation of dental plaque is well-known for its role in causing various oral infections, such as tooth decay, inflammation of the dental pulp, gum disease, and infections of the oral mucosa like peri-implantitis and denture stomatitis. These infections primarily affect the local area of the mouth, but if not treated, they can potentially lead to life-threatening conditions. Traditional methods of mechanical and chemical antimicrobial treatment have limitations in fully eliminating microorganisms and preventing the formation of biofilms. Additionally, these methods can contribute to the development of drug-resistant microorganisms and disrupt the natural balance of oral bacteria. Antimicrobial photodynamic therapy (aPDT) is a technique that utilizes low-power lasers with specific wavelengths in combination with a photosensitizing agent called photosensitizer to kill microorganisms. By inducing damage through reactive oxygen species (ROS), aPDT offers a new approach to addressing dental plaque and associated microbial biofilms, aiming to improve oral health outcomes. Recently, photosensitizers have been incorporated into dental materials to create photosensitive dental materials. This article aimed to review the use of photosensitive dental materials for aPDT as an innovative antimicrobial option in dentistry, with the goal of enhancing oral health.

Evaluation of Sterify Gel as an Adjunctive Treatment to Scaling and Root Planing in Promoting Healing of Periodontal Pockets: A Split-Mouth Randomized Controlled Trial

Background

Periodontal disease is a common infectious disease that leads to the destruction of tooth-supporting structures. Current treatments, such as scaling and root planing (SRP), have limitations in deep and complex pockets, and antibiotic use carries the risk of resistance. Sterify Gel, a medical device composed of polyvinyl polymers, hydroxytyrosol, nisin, and magnesium ascorbyl phosphate, offers a new approach to periodontal care. This study aims to evaluate the safety and efficacy of Sterify Gel as an adjunctive treatment to SRP in promoting the healing of periodontal pockets.

Methods

The study includes 34 patients with moderate to advanced chronic periodontal disease. Randomization assigned one site for SRP alone (control) and the other site for SRP with Sterify Gel (treatment). Periodontal parameters were evaluated at baseline, 1, 2, and 3 months after treatment bacterial contamination was assessed through quantitative PCR at baseline and 3 months after treatment. Statistical analysis was conducted using ANOVA and Wilcoxon test.

Results

Treatment with Sterify Gel and SRP demonstrated significant improvements in pocket depth, gingival recession, and clinical attachment level compared with SRP alone. Bleeding and plaque indexes, pain perception, tooth mobility, and furcations showed no significant differences between the two groups. The treatment group showed a reduction in bacterial contamination at 3 months.

Conclusions

Sterify Gel in combination with SRP shows the potential for improving periodontal health by promoting healing and reducing periodontal pockets. It may offer benefits in preventing bacterial recolonization and reducing reliance on antibiotics.

Clinical and radiographic peri-implant outcomes with riboflavin loaded Poly-L-glycolic acid nanoparticles incorporated in aloe-vera gel treating peri-implantitis in chronic hyperglycemic patients

AIM

The objective of the current study was to compare the effectiveness of antimicrobial photodynamic therapy (PDT) versus Poly-L-glycolic acid nanoparticles loaded riboflavin incorporated in aloe vera gel (PGA/RF/AV) on periimplant parameters and bacterial counts in chronic hyperglycemic patients having periimplantitis.

METHODS

One hundred and two diabetic patients undergoing mechanical debridement (MD) were equally divided into three groups: Group 1: PGA/RF/AV+ MD, Group 2: PDT + MD, and Group 3: MD alone. Periimplant parameters [Bleeding on probing (BoP), probing depth (PD), plaque index (PI), marginal bone level (MBL)] were recorded in all three groups. Periimplant plaque samples were studied to record the levels of Tannerella forsythia (Tf) and Porphyromonas gingivalis (Pg). The recordings were taken at baseline, 3 months and 6 months post treatment.

RESULTS

All three groups showed a reduction in severity of periimplantitis measured in terms of PD, PI, MBL and BoP. A statistically significant reduction in PD, PI and MBL was found in patients in Group 2 whereas participants of Group 1 were found to have a significant decrease in BoP. A statistically significant decline in the numbers of both the bacterial species was seen in Group 2 at the three-month follow-up whereas at the six-month follow-up, a statistically significant reduction was observed in treatment Group 2 in the levels of Tf species only.

CONCLUSION

Riboflavin-loaded nanocarrier incorporated in aloe vera gel showed greater clinical efficacy than PDT alone in the treatment of periimplantitis in chronic hyperglycemic individuals.

Evaluation of the effect of photodynamic therapy with Curcumin and Riboflavin on implant surface contaminated with Aggregatibacter actinomycetemcomitans

BACKGROUND

Peri-implantitis is a destructive inflammatory disease affecting both hard and soft tissues of the osseointegrated implant and causing bone loss and envelope surrounding the implant. The study aimed at evaluating the effect of Photodynamic therapy with Curcumin and Riboflavin on the level of decontamination of implant surface impregnated with Aggregatibacter actinomycetemcomitans (A.a) biofilm.

MATERIALS AND METHODS

In this experimental and laboratory study, 42 implants (4.3 mm in diameter and 8 mm in length) were infected with A.a. bacterial suspension. Then, the implants carrying A.a biofilm were randomly divided into seven groups (n = 6). The groups included: 1- a negative control group (without treatment), 2- a positive control group of Chlorhexidine 0.12 %, 3- a Curcumin (5 mg/ ml) group, 4- a Riboflavin (0.5 %) group, 5- an LED irradiation group (390-480 nm), 6- a photodynamic therapy with Curcumin group, and 7- a photodynamic therapy with Riboflavin group. Then, the implants were sonicated and the amount of CFU/mL of each sample was calculated. One-way ANOVA and Tamhane tests were used to analyze the data.

RESULTS

The lowest mean number of colonies of A.a (CFU/ mL) were seen in the following groups, respectively: the positive control group of Chlorhexidine 0.12 %, the photodynamic therapy with Curcumin group, the photodynamic therapy with Riboflavin group, the Curcumin (5 mg/ ml) group, the Riboflavin (0.5 %) group, the LED radiation group, and the negative control group. The use of photodynamic therapy with Curcumin significantly reduced the number of colonies of A.a (CFU/ mL) in comparison with the photodynamic therapy with Riboflavin group (p = 0.004), the Riboflavin group (p = 0.045), the LED radiation group (p = 0.012), and the negative control group (p = 0.007).

CONCLUSION

aPDT with Curcumin and LED can reduce A.a biofilm on implant surfaces and can be used as a safe and non-invasive disinfection method to reduce A.a biofilm on implant surfaces.

Antimicrobial photodynamic therapy with erythrosine and blue light on dental biofilm bacteria: study protocol for randomised clinical trial

INTRODUCTION

The objective is to investigate the effect of antimicrobial photodynamic therapy (aPDT) mediated by erythrosine and a blue light-emitting diode (LED) in the reduction of bacteria in dental biofilm.

METHODS AND ANALYSIS

This clinical trial will be conducted with 30 patients who have biofilm, but without the presence of periodontal pockets, and who are being treated at the Dental Clinic of Universidade Metropolitana de Santos. A split-mouth model will be used (n=30), with group 1 control (conventional treatment) and group 2 (conventional treatment and aPDT). The bicarbonate jet will be used to remove dental biofilm in both groups. The treatment will be carried out in one session. aPDT will be performed before cleaning/prophylaxis, only in group 2. Participants will rinse with the photosensitiser erythrosine (diluted to 1 mM) for 1 min of pre-irradiation time, so that the drug can stain all the bacterial biofilm. Then, the D-2000 LED (DMC) will be applied, emitting at a wavelength of ʎ=470 nm, radiant power of 1000 mW, irradiance of 0.532 W/cm2 and radiant exposure of 63.8 J/cm2. Irradiation will be performed until the biofilm of the cervical region is illuminated for 2 min/point (4 cm2). The microbiological examination will be performed from samples of supragingival biofilm collected from the gingival sulcus. Collection will be performed in each experimental site before irradiation, immediately after the irradiation procedure and after the prophylaxis. Colony-forming units will be counted and the data will be submitted for statistical analysis for comparison of pretreatment and post-treatment results and between groups (conventional X aPDT).

ETHICS AND DISSEMINATION

This study has been approved by the Ethics Committee of Universidade Metropolitana de Santos under process number 66984123.0.0000.5509. Results will be published in peer-reviewed journals and will be presented at conferences.

TRIAL REGISTRATION NUMBER

NCT05805761.

Antimicrobial Resistance: Is There a 'Light' at the End of the Tunnel?

In recent years, with the increases in microorganisms that express a multitude of antimicrobial resistance (AMR) mechanisms, the threat of antimicrobial resistance in the global population has reached critical levels. The introduction of the COVID-19 pandemic has further contributed to the influx of infections caused by multidrug-resistant organisms (MDROs), which has placed significant pressure on healthcare systems. For over a century, the potential for light-based approaches targeted at combatting both cancer and infectious diseases has been proposed. They offer effective killing of microbial pathogens, regardless of AMR status, and have not typically been associated with high propensities of resistance development. To that end, the goal of this review is to describe the different mechanisms that drive AMR, including intrinsic, phenotypic, and acquired resistance mechanisms. Additionally, the different light-based approaches, including antimicrobial photodynamic therapy (aPDT), antimicrobial blue light (aBL), and ultraviolet (UV) light, will be discussed as potential alternatives or adjunct therapies with conventional antimicrobials. Lastly, we will evaluate the feasibility and requirements associated with integration of light-based approaches into the clinical pipeline.

In vitro antifungal activity of curcumin mediated by photodynamic therapy on Sporothrix brasiliensis

BACKGROUND

Sporothrix brasiliensis is a pathogenic dimorphic fungus that affects humans and animals causing sporotrichosis. The treatment of this disease with conventional antifungals commonly results in therapeutic failures and resistance. Therefore, this study aimed to evaluate the in vitro effect of curcumin (CUR) mediated by photodynamic therapy (PDT) in its pure state and incorporated into pharmaceutical formulation in gel form, on the filamentous and yeast forms of S. brasiliensis.

METHODS

Cells from both forms of the fungus were treated with pure curcumin (PDT-CUR). For this, CUR concentrations ranging from 0.09 to 50 μM were incubated for 15 min and then irradiated with blue LED at 15 J/cm². Similarly, it was performed with PDT-CUR-gel, at lower concentration with fungistatic action. After, a qualitative and quantitative (colony forming units (CFU)) analysis of the results was performed. Additionally, reactive oxygen species (ROS) were detected by flow cytometry. Results PDT with 0.78 μM of CUR caused a significant reduction (p < 0.05) in cells of the filamentous and yeast form, 1.38 log10 and 1.18 log10, respectively, in comparison with the control. From the concentration of 1.56 μM of CUR, there was a total reduction in the number of CFU (≥ 3 log10). The PDT-CUR-gel, in relation to its base without CUR, presented a significant reduction (p < 0.05) of 0.83 log10 for the filamentous form and for the yeast form, 0.72 log10. ROS release was detected after the PDT-CUR assay, showing that this may be an important pathway of death caused by photoinactivation. Conclusion PDT-CUR has an important in vitro antifungal action against S. brasiliensis strains in both morphologies.

Using Antimicrobial Photodynamic Therapy with Ultrasound Devices and Bioactive Glasses as a Combined Approach for Treating Dentin Caries Lesions

Novel approaches for caries lesion removal and treatment have been proposed. This study evaluates the combined use of an experimental ultrasound, aPDT (antimicrobial photodynamic therapy) and bioactive glasses on the removal, decontamination and remineralization of dentin caries lesions. A biological model created with a duo species biofilm (Streptococcus mutans and Lactobacillus acidophilus) was used for the development of a caries-like lesion over the dentin for 7 days. Bovine dentin specimens (4 × 4 × 2 mm) were randomized according to the following caries removal techniques: bur (BUR) or ultrasound (ULT), decontamination (with or without aPDT) and remineralization materials (45S5 or F18 bioactive glasses). The following different groups were investigated: caries lesion (control); sound dentin (control); BUR; BUR + aPDT; ULT; ULT + aPDT; BUR + 45S5, BUR + F18; ULT + 45S5; ULT + F18; BUR + aPDT + 45S5; BUR + aPDT + F18; ULT + aPDT + 45S5; and ULT + aPDT + F18. Transverse microradiography (TMR), cross-sectional microhardness (CSH), FT-Raman spectroscopy and confocal microscopy (CLSM) were performed. A two-way ANOVA and Tukey's test were used (α = 0.05). (3) Results: The TMR revealed a lesion depth of 213.9 ± 49.5 μm and a mineral loss of 4929.3% vol.μm. The CSH increases as a function of depth, regardless of the group (p < 0.05). Removal with BUR (24.40-63.03 KHN) has a greater CSH than ULT (20.01-47.53 KHN; p < 0.05). aPDT did not affect the CSH (p > 0.05). No difference was observed between 45S5 or F18 (p > 0.05), but a change was observed for ULT (p > 0.05). The FT-Raman shows no differences for the phosphate (p > 0.05), but a difference is observed for the carbonate and C-H bonds. The CLSM images show that aPDT effectively inactivates residual bacteria. A combination of ULT, aPDT and bioactive glasses can be a promising minimally invasive treatment.

The Effect of Different Output Powers of Blue Diode Laser along with Curcumin and Riboflavin against Streptococcus mutans around Orthodontic Brackets: An In Vitro Study

OBJECTIVES

The aim of the present study was to determine the effects of antimicrobial photodynamic therapy (aPDT) using the blue diode laser (BDL) with different output powers and the photosensitizers riboflavin and curcumin on reducing the number of Streptococcus mutans around orthodontic brackets.

MATERIALS AND METHODS

A total of 36 orthodontic brackets were contaminated with S. mutans and randomly assigned to 12 groups as follows: control, riboflavin alone, riboflavin + BDL with an output power of 200, 300, 400, or 500 mW, and curcumin alone, curcumin + BDL with an output power of 200, 300, 400, or 500 mW, and 0.2% chlorhexidine (CHX-positive control). Orthodontic brackets were irradiated with a BDL (wavelength 445 nm) at a power density of 0.4-1.0 W/cm2 for 30 s. All orthodontic brackets were examined under a stereomicroscope at 10× magnification. Mean colony-forming units (CFUs)/mL were measured before and after treatment. A one-way analysis of variance with Tukey's post hoc test was performed to compare CFU/mL between groups.

RESULTS

CHX and curcumin plus BDL with an output power of 500 mW had the highest reduction in S. mutans colony numbers (p < 0.001). The curcumin groups were more effective than the riboflavin groups. Riboflavin alone and riboflavin + BDL with an output power of 200 mW showed no significant difference from the control group (p = 0.99 and 0.74, respectively).

CONCLUSION

Our results suggest that aPDT using curcumin as a photosensitizer plus BDL with an output power of 500 mW and a power density of 1.0 W/cm2 at a wavelength of 445 nm can effectively reduce colonies of S. mutans around stainless steel brackets.

Challenges and opportunities for improving the druggability of natural product: Why need drug delivery system?

Bioactive natural products (BNPs) are the marrow of medicinal plants, which are the secondary metabolites of organisms and have been the most famous drug discovery database. Bioactive natural products are famous for their enormous number and great safety in medical applications. However, BNPs are troubled by their poor druggability compared with synthesis drugs and are challenged as medicine (only a few BNPs are applied in clinical settings). In order to find a reasonable solution to improving the druggability of BNPs, this review summarizes their bioactive nature based on the enormous pharmacological research and tries to explain the reasons for the poor druggability of BNPs. And then focused on the boosting research on BNPs loaded drug delivery systems, this review further concludes the advantages of drug delivery systems on the druggability improvement of BNPs from the perspective of their bioactive nature, discusses why BNPs need drug delivery systems, and predicts the next direction.

Improving antimicrobial activity against endodontic biofilm after exposure to blue light-activated novel curcumin nanoparticle

New therapies involving natural products and nanobiotechnology open additional perspectives to reduce endodontic infections. Curcumin is a natural polyphenol extracted from the dry rhizome of curcuma long Linn with therapeutic properties for application in nanobiotechnology and as a photosensitizer for photodynamic therapy. This study aimed to synthesize a novel polymeric nanoparticle of poly (lactic-co-glycolic acid) (PLGA) loaded with curcumin (NP+Cur), and evaluate its antimicrobial activity against endodontic biofilms. Additionally, its biocompatibility using oral keratinocytes was assessed. The polymeric NP+Cur was prepared by the nanoprecipitation method. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were calculated for the three endodontic bacteria (Enterococcus faecalis, Streptococcus oralis and Actinomyces viscosus). Antibacterial activity of NP+Cur against single- and multispecies biofilm pre-formed on the botton 24-well plate and into dentin tubules of bovine teeth were evaluated by colony forming units and confocal laser scanning microscopy. The pre-irradiation time was 5 min followed by exposure to blue light-emitting diode at 450 nm for the photodynamic treatment. Cell viability using oral keratinocytes was assessed by Alamar Blue assay. MIC and MBC showed antibacterial activity of NP+Cur against endodontic bacteria. A treatment of pre-formed biofilms of endodontic bacteria with NP+Cur also significantly decreased bacterial viability. The concentration of 325 μg/mL of photoactivated NP+Cur was the one that most reduced the viability of the endodontic bacteria evaluated. Regarding biocompatibility, NP+Cur 325 μg/mL and pure nanoparticles showed a cell viability greater than 80%. The novel polymeric nanoparticles loaded with curcumin may be a promising adjunct use to treatment of endodontic infections.

The in vitro effect of antimicrobial photodynamic therapy with toluidine blue and indocyanine green on microleakage of class V cavities

INTRODUCTION

Considering the importance of disinfecting dentin and enamel after cavity preparation and the possible effect of disinfection methods on induction of various reactions in the tooth structure the aim of the present study was to evaluate microleakage of composite resin restoration after disinfecting the prepared dentin and enamel surface with antimicrobial photodynamic therapy (aPDT) with toluidine blue (TBO) and indocyanine green (ICG).

MATERIALS AND METHODS

Standard class V cavities were prepared on buccal surface of 71 human premolar teeth. The samples were randomly divided into 3 groups based on disinfection method: Group 1: conventional disinfection method with Phosphoric acid 37% as the control; Group 2: aPDT with TBO and diode laser with wavelength of 635 nm; Group 3: aPDT with ICG and diode laser with wavelength of 808 nm. All the cavities were restored with composite resin (3M™ Filtek™ Z250). After thermocycling and immersing in 0.5% basic fuchsin, the samples were prepared for microleakage evaluation under a stereomicroscope. Data was analyzed with Kruskal-Wallis and Wilcoxon signed-rank tests at P < 0.05.

RESULTS

There were no significant differences in the microleakage of occlusal and gingival margins between the TBO and control groups (P > 0.05). Also, the microleackage of occlusal margins between groups was not significantly different (P > 0.05) but microleackage of gingival margins of ICG group was lower than two other groups in a meaningful way (P < 0.05).

CONCLUSION

Photodynamic therapy with ICG as disinfecting agent in cavity preparations before composite resin restorations decreases the microleackage of gingival margins.

The Potential Application of Natural Photosensitizers Used in Antimicrobial Photodynamic Therapy against Oral Infections

Oral health problems and the emergence of antimicrobial resistance among pathogenic bacterial strains have become major global challenges and are essential elements that negatively affect general well-being. Antimicrobial photodynamic therapy (APDT) is based on a light source and oxygen that activates a nontoxic photosensitizer, resulting in microbial destruction. Synthetic and natural products can be used to help the APDT against oral microorganisms. The undesirable consequences of conventional photosensitizers, including toxicity, and cost encourage researchers to explore new promising photosensitizers based on natural compounds such as curcumin, chlorella, chlorophyllin, phycocyanin, 5-aminolevulinic acid, and riboflavin. In this review, we summarize in vitro studies describing the potential use of APDT therapy conjugated with some natural products against selected microorganisms that are considered to be responsible for oral infections.

Cytotoxicity of root canal irrigating solutions and photodynamic therapy using curcumin photosensitizer

BACKGROUND

Photodynamic therapy (PDT) has shown satisfactory antibacterial effects. However, few information regarding the cytotoxicity potential of PDT using curcumin as a photosensitizer (PS) on fibroblasts are found. The aim of this in vitro study was to evaluate the cytotoxicity of root canal irrigating solutions and photodynamic therapy with curcumin PS on the L-929 cell line.

METHODS

Healthy mouse skin fibroblast cells were distributed into the following 7 experimental groups: G1 - culture medium DMEM (control group); G2 - 0.9% sodium chloride; G3 - 2.5% sodium hypochlorite (NaOCl); G4 - 5% NaOCl; G5 - PDT with curcumin PS at 500 mg/L + blue LED; G6 - PDT with curcumin PS at 750 mg/L + blue LED; and G7 - PDT with curcumin PS at 1000 mg/L + blue LED. All experimental groups which underwent PDT action were submitted to blue LED for 4 minutes, with a wavelength of 480 nm and energy fluency of 75 J/cm². The cultures were maintained under standard cell culture conditions (37°C, 100% humidity, 5% CO₂). Cell viability analysis was performed using the colorimetric method to evaluate the periods of 6, 24, and 48 hours. Data were subjected to the Kruskal-Wallis test, followed by the Dunn test to compare groups and Friedman test to compare periods (α = 0.05).

RESULTS

When comparing the periods, no significant differences were observed for any of the experimental groups analyzed (p > 0.05), except for the NaOCl_2.5 group that exhibited higher cell viability at 6 hours compared to the period of 48 hours (p = 0.0489). In the comparisons of the experimental groups, there were no statistically significant differences between the control group compared to all disinfection protocols, regardless of the period evaluated (p > 0.05), except for the PDT + C₁₀₀₀ group that showed lower cell viability (p < 0.05).

CONCLUSIONS

PDT with curcumin at 1000 mg/L was cytotoxic on L-929 fibroblast cell culture. However, laser-activated curcumin at a concentration of 500 mg/L presented no influence on L-929 fibroblast cell viability in in vitro conditions.

Photodynamic Therapy with Natural Photosensitizers in the Management of Periodontal Disease Induced in Rats

This study aims to investigate the effect of new natural photosensitizers (PS) (based on oregano essential oil, curcuma extract, and arnica oil) through in vitro cytotoxicity and biological tests in rat-induced periodontal disease, treated with photodynamic therapy (aPDT). The cytotoxicity of PS was performed on human dental pulp mesenchymal stem cells (dMSCs) and human keratinocyte (HaCaT) cell lines. Periodontal disease was induced by ligation of the first mandibular molar of 25 rats, which were divided into 5 groups: control group, periodontitis group, Curcuma and aPDT-treated group, oregano and aPDT-treated group, and aPDT group. The animals were euthanized after 4 weeks of study. Computed tomography imaging has been used to evaluate alveolar bone loss. Hematological and histological evaluation showed a greater magnitude of the inflammatory response and severe destruction of the periodontal ligaments in the untreated group.. For the group with the induced periodontitis and treated with natural photosensitizers, the aPDT improved the results; this therapy could be an important adjuvant treatment. The obtained results of these preliminary studies encourage us to continue the research of periodontitis treated with natural photosensitizers activated by photodynamic therapy.