The in vitro effect of Antimicrobial Photodynamic Therapy on dental microcosm biofilms from partially erupted permanent molars: A pilot study

The effects of low-level laser therapy and photodynamic therapy on oral health of fixed orthodontics patients. A systematic review and meta-analysis

Objective To investigate the effect of low-level laser and photodynamic therapy on the oral health, and periodontal tissue of fixed orthodontic patients and the effect of using photobiomodulation methods compared to routine plaque removal methods and the amount of plaque in fixed orthodontic patients. Method and materials First, the title and summary of related articles were collected by using the search strategy electronic databases PUBMED, EMBASE, Cochrane's CENTRAL, Scopus, ISI and all the articles that were published from the beginning to February 2023 were evaluated. The title, abstracts and full texts of all the relevant studies were reviewed respectively, and those meeting the criteria were entered into our study. Finally, the quality of the studies was examined and the results of the studies were pooled by means of random effects inverse variance meta-analysis. Results Eighteen randomized studies, conducted between 2015 and December 2022, were selected for meta-analysis. Five studies were conducted as split-mouth, twelve as parallel-group, and one as a cross-over design. Among the studies, five examined the effects of low-level laser therapy and twelve assessed the effects of photodynamic therapy. The meta-analysis revealed that photodynamic therapy significantly reduced probing depth compared to scaling (MD=-0.2 mm, P<0.001), though the difference does not seem to be clinically significant. But no significant differences between photodynamic therapy and scaling or low-level laser therapy and control groups in terms of plaque index, or bleeding on probing, gingival crevicular fluid volume, gingival recession, clinical attachment loss, bacterial load and concentrations of inflammatory substances across multiple follow-up periods. Conclusion Moderate evidence indicates that photodynamic therapy (PDT) is comparable to conventional methods in improving oral health, as measured by periodontal indices, inflammatory proteins, bacterial colonies, and white spot lesions, making it a suitable alternative. Limited evidence suggests low-level laser therapy (LLLT) may improve oral health, particularly addressing caries, but further research is needed.

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.

Application of Photodynamic Therapy in Pediatric Dentistry: Literature Review

Microbiological control of dental pathologies presents a significant clinical challenge for dental surgeons, particularly considering drug-resistant microorganisms. To address this issue, Antimicrobial Photodynamic Therapy (PDT) has emerged as an effective and complementary technique for microbial reduction. This therapy involves the application of a photosensitizer dye (PS) either topically or systemically, followed by exposure to low-power lasers with appropriate visible light wavelengths. PDT has found a valuable place in dentistry across various specialties, including surgery, periodontics, endodontics, dentistry, implantology, orthodontics, and pediatrics. In the realm of pediatric dentistry, managing microorganisms during dental treatments has become a major challenge. Considering its promising results and ease of application, Photodynamic Therapy presents an interesting alternative for clinical practice. However, it is important to note that specific protocols must be followed for each application, encompassing the type of photosensitizer, concentration, pre-irradiation time, light type, wavelength, energy, power, and mode of light delivery. Researchers have been steadily refining these protocols to facilitate PDT's integration into clinical practice. The objective of this review is to describe in which procedures and oral health problems in children PDT can be applied. In this sense, we list what the literature brings about the possibilities of applying PDT in a pediatric dentistry clinic.

Smart dental materials for antimicrobial applications

Smart biomaterials can sense and react to physiological or external environmental stimuli (e.g., mechanical, chemical, electrical, or magnetic signals). The last decades have seen exponential growth in the use and development of smart dental biomaterials for antimicrobial applications in dentistry. These biomaterial systems offer improved efficacy and controllable bio-functionalities to prevent infections and extend the longevity of dental devices. This review article presents the current state-of-the-art of design, evaluation, advantages, and limitations of bioactive and stimuli-responsive and autonomous dental materials for antimicrobial applications. First, the importance and classification of smart biomaterials are discussed. Second, the categories of bioresponsive antibacterial dental materials are systematically itemized based on different stimuli, including pH, enzymes, light, magnetic field, and vibrations. For each category, their antimicrobial mechanism, applications, and examples are discussed. Finally, we examined the limitations and obstacles required to develop clinically relevant applications of these appealing technologies.

Does potassium iodide help in the microbial reduction of oral microcosm biofilms after photodynamic therapy with methylene blue and red laser?

OBJECTIVE

To evaluate the efficacy of methylene blue (MB)-mediated antimicrobial photodynamic therapy (aPDT) doped with potassium iodide (KI) against oral microcosms biofilms cultured in dentin.

METHODS

A saliva-glycerol stock formed from pooled human saliva was diluted in McBain artificial saliva with 1% sucrose (1:1), inoculated on bovine dentin blocks, and refreshed daily for 5 days. The biofilms were divided (n = 9/group) and treated with 0.9% NaCl (C), 0.2% chlorhexidine (CX), 0.01% MB + low-power laser 15 J, 88 mW, 180 s (PL), and 0.01% MB + 50 mM KI + laser (PKIL). Serial dilution was performed, and cellular viability (CFU/mL) was evaluated for total microorganisms, total lactobacilli, total streptococci, and S. mutans. Additional biofilms were cultured and treated (n = 4) for biomass determination (%BMR). The microscopic structure of the biofilms was observed by SEM. One-way ANOVA and Tukey tests were conducted (α=5%).

RESULTS

Total microorganisms and total streptococci significantly reduced in biofilms treated with CX and PKIL when compared to C, but the CX, PKIL, and PL treatments did not differ from each other. Total lactobacilli and S. mutans showed a significant reduction in the CX, PL, and PKIL groups when compared to C, but with no difference between them. Biomass analysis showed a significantly reduction for CX and PKIL compared to C. SEM micrographs showed noticeable changes in bacterial membrane integrity for the PKIL and CX groups.

CONCLUSION

The addition of KI to methylene blue-mediated aPDT in microcosm biofilms was effective in reducing oral microorganisms, but the effect was group dependent.

Photodynamic Therapy for Treatment of Disease in Children—A Review of the Literature

Photodynamic therapy is a mode of treatment whereby local irradiation of an administered photosensitizer with light of a specific wavelength generates cytotoxic reactive oxygen species. Despite the upward trend in the popularity of this method in adults, it is not yet commonly used in the treatment of children. Due to certain limitations, underdeveloped treatment regimens and potential side effects, the use of photodynamic therapy in the pediatric population is still in the initial phases of evaluation in clinical trials. Method: This study is a review of articles in English from the databases PubMed and Web of Science retrieved by applying the search term “photodynamic therapy in children” from 2000–2020. Results: Based on the literature review, we analyze selected pediatric clinical cases in which photodynamic therapy was used for treatment in children. Examples of photodynamic therapy for treatment of dermatological diseases, diseases of the mucosa of the upper respiratory tract, halitosis, eye diseases and brain tumors are described. The paper describes the effectiveness of anti-cancer photodynamic therapy, including its use in antibacterial therapy. Conclusions: The results of the analysis suggest the potential of photodynamic therapy for the treatment of various diseases in children.

Strategies toward development of antimicrobial biomaterials for dental healthcare applications

Several approaches for elimination of oral pathogens are being explored at the present time since oral diseases remain prevalent affecting approximately 3.5 billion people worldwide. Need for antimicrobial biomaterials in dental healthcare include but is not restricted to designing resin composites and adhesives for prevention of dental caries. Constant efforts are also being made to develop antimicrobial strategies for clearance of endodontic space prior root canal treatment and for treatment of periimplantitis and periodontitis. This article discusses various conventional and nanotechnology-based strategies to achieve antimicrobial efficacy in dental biomaterials. Recent developments in the design and synthesis of antimicrobial peptides and antifouling zwitterionic polymers to effectively lessen the risks of antimicrobial drug resistance are also outlined in this review. Further, the role of contemporary strategies such as use of smart biomaterials, ionic solvent-based biomaterials and quorum quenchers incorporated biomaterials in the elimination of dental pathogens are described in detail. Lastly, we mentioned the approach of using polymers to print custom-made three-dimensional antibacterial dental products via additive manufacturing technologies. This review provides a critical perspective on the chemical, biomimetic, and engineering strategies intended for developing antimicrobial biomaterials that have the potential to substantially improve the dental health.

Antimicrobial photodynamic therapy mediated by methylene blue coupled to β-cyclodextrin reduces early colonizing microorganisms from the oral biofilm

OBJECTIVE

To test the effect of antimicrobial photodynamic therapy (A-PDT) on the oral biofilm formed with early colonizing microorganisms, using the photosensitizer methylene blue coupled with β-cyclodextrin nanoparticles and red light sources laser or LED (λ =660 nm).

METHODS

The groups were divided into (n = 3, in triplicate): C (negative control, 0.9 % NaCl), CX (positive control, 0.2 % chlorhexidine), P (Photosensitizer/Nanoparticle), L (Laser), LED (light-emitting diode), LP (Laser + Photosensitizer/Nanoparticle) and LEDP (LED + Photosensitizer/Nanoparticle). A multispecies biofilm composed ofS. gordonii, S. oralis, S. mitis, and S. sanguinis was grown in microplates containing BHI supplemented with 1% sucrose (w/v) for 24 h. Light irradiations were applied with a laser at 9 J for 90 s (320 J/cm²), or with LED, at 8.1 J for 90 s (8.1 J/cm²). The microbial reduction was assessed by counting viable biofilm microorganisms in selective culture media, before and after the treatments. Data normality was assessed by the Shapiro-Wilk test, and the results were submitted to Kruskal-Wallis analysis, followed by Dunn's test, with a significance level of 5%.

RESULTS

The groups LP and LEDP were able to significantly reduce the biofilm microorganism counts by as much as 4 log₁₀ times compared to the negative control group (p < 0.05) and did not statistically differ from the positive control group (CX) (p > 0.05).

CONCLUSION

The A-PDT mediated by encapsulated β-cyclodextrin methylene blue irradiated by Laser or LED was effective in the microbial reduction of multispecies biofilm composed of early colonizing microorganisms.

Effects of Antibiotics Versus Repeated Applications of Photodynamic Therapy as an Adjunctive Treatment for Periodontitis: A Systematic Review and Meta-Analysis

Objective: Although multiple applications of antimicrobial photodynamic therapy (aPDT) and antibiotics (AB) have been proved to have a biomodulatory effect, no systematic review has exclusively compared the effectiveness as an adjunct to scaling and root planning (SRP). This study sought to systematically compare the clinical efficacy of repeated antimicrobial photodynamic therapy (RaPDT) with that of the systemic administered AB as an alternative approach to SRP in treating periodontitis. Methods: In this systematic review, two independent reviewers searched PubMed, Embase, and CENTRAL databases. The primary outcomes assessed were bleeding on probing (BOP), probing pocket depth (PPD), and clinical attachment level (CAL). Results: Five randomized clinical trials were included after screening 457 records. Results revealed that when patients from all studies were categorized based on their baseline CAL, AB demonstrated significant benefits over RaPDT in the improvement of PPD [weighted mean differences (WMD) = -0.36, 95% confidence interval (CI) = -0.71 to -0.02, p < 0.05] in the patients with severe periodontitis (CAL baseline ≥5 mm) 3-month postoperatively, and CAL (WMD = -0.57, 95% CI = -1.11 to -0.04, p < 0.05) at 6-month observation. Nevertheless, AB failed to show significant benefits over RaPDT, when CAL baseline <5 mm in terms of clinical parameters. Conclusions: RaPDT may represent an alternative approach to SRP in treating slight-to-moderate periodontitis cases (CAL <5 mm), whereas AB remain a main therapy for treating severe periodontitis (CAL ≥5 mm).

Effect of Photodynamic Therapy on Microorganisms Responsible for Dental Caries: A Systematic Review and Meta-Analysis

The aim of this study was to perform a systematic review of the literature followed by a meta-analysis about the efficacy of photodynamic therapy (PDT) on the microorganisms responsible for dental caries. The research question and the keywords were constructed according to the PICO strategy. The article search was done in Embase, Lilacs, Scielo, Medline, Scopus, Cochrane Library, Web of Science, Science Direct, and Pubmed databases. Randomized clinical trials and in vitro studies were selected in the review. The study was conducted according the PRISMA guideline for systematic review. A total of 34 articles were included in the qualitative analysis and four articles were divided into two subgroups to perform the meta-analysis. Few studies have achieved an effective microbial reduction in microorganisms associated with the pathogenesis of dental caries. The results highlight that there is no consensus about the study protocols for PDT against cariogenic microorganisms, although the results showed the PDT could be a good alternative for the treatment of dental caries.

The effectiveness of curcumin-mediated antimicrobial photodynamic therapy depends on pre-irradiation and biofilm growth times

BACKGROUND

The aim of this study was to determine the influence of distinct pre-irradiation times (PIT) of curcumin on the effectiveness of antimicrobial photodynamic therapy (aPDT) against intact dentin caries biofilms grown for 3 or 5 days.

METHODS

The microcosm biofilms grew on non-fluorescent glass blocks immersed in McBain medium with 1% sucrose, using microaerophilic conditions at 37 °C for 3 or 5 days. The biofilms were treated by the association of 600 μmol.L^-1 curcumin using different pre-irradiation times (1, 2 or 5 min) combined with 0 or 75 J.cm^-2 blue LED. Then, the vitality of biofilms was determined by confocal scanning laser microscopy (CSLM), after being stained with the mixture of ethidium bromide and fluorescein diacetate. Statistical analysis was performed by two-way ANOVA and post-hoc Tukey tests, after arcsine transformation (P < 0,05).

RESULTS

In comparison to control, curcumin alone (PIT = 5 min) and all combinations of curcumin and LED reduced significantly the vitality of 3-day biofilms. Distinctly, only curcumin plus LED using PITs of 2 or 5 min were effective in reducing the vitality of 5-day biofilms.

CONCLUSION

Curcumin-mediated aPDT significantly decreased the vitality of intact dentin caries microcosms grown during 3 or 5 days, although successful treatments of 5-day biofilms required longer PITs in comparison to their counterparts.