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Photobiomodulation (PBM) is a technique that harnesses non-ionizing light at specific wavelengths, triggering the modulation of metabolic pathways, engendering favourable biological outcomes that reduce inflammation and foster enhanced tissue healing and regeneration. PBM holds significant promise for bone tissue applications due to its non-invasive nature and ability to stimulate cellular activity and vascularization within the healing framework. Notwithstanding, the impact of PBM on bone functionality remains largely undisclosed, particularly in the absence of influencing factors such as pathologies or regenerative therapies. This study aims to investigate the potential effects of PBM using red (660 nm) (RED) and near-infrared (808 nm) (NIR) wavelengths within an ex vivo bone culture system - the organotypic embryonic chicken femur model. A continuous irradiation mode was used, administering a total energy dose of 1.0 J, at an intensity of 100 mW for 10 s, which was repeated four times over the course of the 11-day culture period. The primary focus is on characterizing the expression of pivotal osteoblastic genes, the maturation and deposition of collagen, and the formation of bone mineral. Exposing femora to both RED and NIR wavelengths led to a notable increase in the expression of osteochondrogenic transcription factors (i.e., SOX9 and RUNX2), correlating with enhanced mineralization. Notably, NIR irradiation further elevated the expression of bone matrix-related genes and fostered enhanced deposition and maturation of fibrillar collagen. This study demonstrates that PBM has the potential to enhance osteogenic functionality within a translational organotypic bone culture system, with the NIR wavelength showing remarkable capabilities in augmenting the formation and maturation of the collagenous matrix., Competing Interests: Declaration of Competing Interest The authors have no conflicts of interest relevant to this article., (Copyright © 2023. Published by Elsevier B.V.)

Dental caries is a multifactorial, non-communicable disease. Effective treatment options for minimally invasive removal of carious tissue include Papacarie Duo® gel and antimicrobial photodynamic therapy (aPDT). aPDT involves a combination of a light source and photosensitizer. Given that Papacarie Duo® contains a percentage of blue dye, this study aims to explore the antimicrobial potential of Papacarie Duo® when associated with a light source against Streptococcus mutans strains. The chosen light source was a low-power diode laser (λ = 660 nm, E = 3 J, P = 100 mW, t = 30 s). To assess antimicrobial capacity, planktonic suspensions of Streptococcus mutans were plated on Brain Heart Infusion Agar (BHI) to observe the formation of inhibition halos. The studied groups included methylene blue (0.005%), Papacarie Duo®, distilled water (negative control), 2% chlorhexidine (positive control), Papacarie Duo® + laser, and methylene blue (0.005%) + laser. Following distribution onto plates, each group was incubated at 37 °C for 48 h under microaerophilic conditions. Inhibition halos were subsequently measured using a digital caliper. The results showed that chlorhexidine had the greatest antimicrobial effect followed by the group of irradiated methylene blue and irradiated Papacarie Duo®. All experimental groups demonstrated antimicrobial potential, excluding the negative control group. The study concludes that Papacarie Duo® exhibits antimicrobial properties when associated with a low-power diode laser., (© 2024. The Author(s), under exclusive licence to Springer-Verlag London Ltd., part of Springer Nature.)

Introduction: The light-emitting diode (Led) in the violet spectrum associated or not with hydrogen peroxide (HP) has been suggested as a promising technique for dental bleaching. Violet led has a wavelength of 405-410 nm, which is very close to that of ultraviolet (UV) radiation, and this has raised biological safety concerns., Aim: To investigate the effectiveness of the violet led dental bleaching technique by evaluating color parameters, enamel surface microhardness, and biological safety analysis., Methods: One hundred bovine dental blocks were divided into groups according to the bleaching technique (G1 - only HP; G2 - HP associated with blue led; G3 - only blue led; G4 - HP associated with a violet led; and G5 - only violet led). The color analysis (ΔE, ΔL, and WID) and enamel surface microhardness were assessed before and after bleaching (immediately, 5, 14, and 30 days). The biological safety of the violet led irradiation was assessed by measuring the number of micronuclei formed in human cells in culture in response to irradiation. Data analysis included Kruskal-Wallis test, Friedman test, and Mann-Whitney test., Results: In groups G4 and G5 there was the formation of precipitates on the enamel surface. At the time of 14 days, it was observed that the G2 group had lower values of microhardness than G5. ΔL and ΔE showed differences between groups in experimental times. Mean percentages of micronuclei occurrence were similar in the control group and the violet led group., Conclusion: The violet led irradiation can be applied for dental bleaching because this approach produces significant color changes preserving tooth enamel integrity and causes no genotoxic effects on vital cells., (Copyright © 2022. Published by Elsevier B.V.)

Aim: To conduct a systematic review of the literature on biosafety with the use of lasers., Methods: The systematic review of literature was performed using MEDLINE (PubMed), Science Direct and Web of Science databases. The electronic search strategy included terms in the Medical Subject Heading (MeSH) related to biosafety in dentistry and laser, forms of contamination with aerosols, as well as their synonyms. The selected keywords were "aerosol virus transmission dentistry," "laser-generated air contaminants," "biosafety dentistry laser" combined with the terms AND/OR., Results: A total of 1334 abstracts were reviewed, resulting in inclusion of 23 reviews. The dental surgeons are professionals with a high risk of contamination; high-power lasers form aerosols that need to be controlled and low-power lasers must be protected to minimize the risks of cross-infection., Conclusion: The biosafety of using lasers is important for professionals can be more oriented as to the correct use of this equipment. This study has the relevance of showing biosafety measures for the professional, staff and patients, as well as suggesting that more studies that are clinical should be conducted in this area., (© 2021 Special Care Dentistry Association and Wiley Periodicals LLC.)

Antimicrobial Photodynamic Therapy (aPDT) with photobiomodulation therapy (PBT) can be used in herpes simplex and may have a role in improving modulation of inflammatory process, pain relief and acceleration of tissue repair. This article reports through a case series, a proposal for an efficient resolution in clinical manifestations of herpes simplex labialis using aPDT associated with PBT., (Copyright © 2020. Published by Elsevier B.V.)

Antimicrobial photodynamic therapy (aPDT) has emerged as a promising antimicrobial treatment to control microorganisms including those involved in oral diseases, especially dental caries. Hence, the aim of this study was to evaluate the influence of aPDT - pre-irradiation time (PIT), at different periods, on antimicrobial rate of Streptococcus mutans (S. mutans). A standard suspension of S. mutans UA159 was prepared and submitted at sensitization of 0.005 % methylene blue (MB) for 0, 1, 3 and 5 min (G1 - G4 groups, respectively) and irradiated with a red laser (660 nm; 321 J/cm 2 ; 9 J; 90 s) afterward. A control group using PBS instead of MB was performed as well (G5). The number of colony-forming units (CFU)/mL was recorded, transformed into log 10 and analyzed by ANOVA and Tukey's test at a cutoff value at 0.05. Overall, the aPDT groups tested achieved a bacterial reduction > 1-log 10 when compared to G5 (p < 0.05) with no statistical difference among the different PIT tested. The need of PIT before aPDT application deserves attention, since its time reduction implies on shorter clinical approaches without compromising the photodynamic antibacterial efficacy in the in vitro parameters employed., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Objective: We developed an experimental ex-vivo model to define factors that may influence continence of catheterizable channels by urinary and colonic stomas based on the principle of imbrication of the outlet tube., Materials and Methods: From 20 pigs, colon specimens with 25 cm length were obtained and a transverse flap with 3.0 cm length x 1.5 cm width in the average point of the intestine was tubulated to create an efferent tube. With the tube configured, it was embedded by 3 seromuscular stitches far 0.5 cm each other. A pressure study of both intra-luminal surface and channel was then conducted during the filling of the submerse piece with environmental air in a water container, to define the efferent channel continence. The study was repeated after the progressive release of suture stitches until only one stitch remains., Results: Channel continence analyzed in each segment in three different valve length situations, making a total of 20 segments, revealed that with 3 stitches (1.5 cm valve) the maximum average pressure prior to overflow was 54 cm H2O; 53.65 cm H2O with 2 stitches (1.0 cm of valve), and 55.45 cm H2O with only one stitch (0.5 cm of valve), which are the same values. The record at the segment explosion pressure was 67.87 cm H20., Conclusion: The study showed that angulation of channel with colon, maintained by only one stitch (0.5 cm imbrication) was more important than a larger extension of the valve, represented by 3 suture stitches (1.5 cm imbrication) in order to allow continence to the efferent channel.