Design and Application of Near Infrared LED and Solenoid Magnetic Field Instrument to Inactivate Pathogenic Bacteria.

PURPOSE: This study aims to evaluate the efficiency of infrared LEDs with a magnetic solenoid field in lowering the quantity of gram-positive Staphylococcus aureus and gram-negative Escherichia coli bacteria, as well as the best exposure period and energy dose for inactivating these bacteria. METHOD: Research has been performed on a photodynamic therapy technique called photodynamic inactivation (PDI), which combines infrared LED light with a wavelength range of 951-952 nm and a solenoid magnetic field with a strength of 0-6 mT. The two, taken together, can potentially harm the target structure biologically. Infrared LED light and an AC-generated solenoid magnetic field are both applied to bacteria to measure the reduction in viability. Three different treatments infrared LED, solenoid magnetic field, and an amalgam of infrared LED and solenoid magnetic field, were used in this study. A factorial statistical ANOVA analysis was utilized in this investigation. RESULTS: The maximum bacterial production was produced by irradiating a surface for 60 min at a dosage of 0.593 J/cm2, according to the data. The combined use of infrared LEDs and a magnetic field solenoid resulted in the highest percentage of fatalities for Staphylococcus aureus, which was 94.43 s. The highest percentage of inactivation for Escherichia coli occurred in the combination treatment of infrared LEDs and a magnetic field solenoid, namely, 72.47 ± 5.06%. In contrast, S. aureus occurred in the combined treatment of infrared LEDs and a magnetic field solenoid, 94.43 ± 6.63 percent. CONCLUSION: Staphylococcus aureus and Escherichia coli germs are inactivated using infrared illumination and the best solenoid magnetic fields. This is evidenced by the rise in the proportion of bacteria that died in treatment group III, which used a magnetic solenoid field and infrared LEDs to deliver a dosage of 0.593 J/cm2 over 60 min. According to the research findings, the magnetic field of the solenoid and the infrared LED field significantly impact the gram-positive bacteria S. aureus and the gram-negative bacteria E. coli.

An in-vivo study of photobiomodulation using 403 nm and 649 nm diode lasers for molar tooth extraction wound healing in wistar rats.

PURPOSE: This study aims to examine the effects of red 649 nm 4 J/cm2 and blue 403 nm 8 J/cm2 diode laser treatment for post-extraction wounded healing in rats through histopathological and immunohistochemical analysis. METHODS: Samples of 54 Wistar rats were divided into six groups: C- control group without treatment; C + wounded group without treatment; TB wound group with Povidone-iodine treatment; TD wounded group with doxycycline treatment; TLB wounded group with 403 nm diode laser treatment; and TLR wounded group with 649 nm diode laser treatment. Mandibular samples were observed for the number of lymphocytes and fibroblasts cells, new blood vessels formation, Interleukin 1ß, and Collagen 1α expression level. RESULTS: Based on the histopathological test results, red laser diode treatment significantly increased the number of lymphocyte, fibroblast cells and the formation of new blood vessels. Meanwhile, immunohistochemical tests showed an increase in the expression of the Colagen-1α protein which plays a role in the formation of collagen for new tissues formation after damage, as well as a decrease in Interleukin-1ß expression level. Blue laser is also able to show a positive effect on wound healing even though its penetration level into the tissue is lower compared to red laser. CONCLUSION: The red diode laser 649 nm has been shown to accelerate the process of proliferation in wound healing post molar extraction based on histopathological and immunohistochemical test results.

Combination effect of laser diode for photodynamic therapy with doxycycline on a wistar rat model of periodontitis.

BACKGROUND: Periodontitis is a chronic inflammatory disease characterized by progressive damage on the structure of tooth-supporting tissues. The aim of the study is determining the combination photodynamic effect of diode laser 405 nm treatments and the administration of doxycycline 0.1% within 1, 3, 5, and 7 days on a Wistar rat model of periodontitis. METHODS: Samples were induced with Porphyromonas gingivalis ATCC33277 to allow periodontitis development and were treated with combination of doxycycline and laser diode, then statistical analysis was carried out (One-Way ANOVA test and the post-hoc Duncan test; Kruskal-Wallis test and Mann-Whitney follow-up test for non-parametric data). Samples were divided into five groups, laser exposure used was 405-nm diode laser with energy density of 8 J/cm2. The expression level of histomorphometric was calculated by measuring the number of macrophages, lymphocytes, fibroblasts and the distance between the CEJ-AV. RESULTS: The results showed that the combination treatment of doxycycline and laser exposure yielded immunomodulatory effects. The expression level of fibroblast and the distance between CEJ-AV bone showed that the combination of doxycycline and laser therapy exerted healing effect in rat models of periodontitis on day 5 and 7. CONCLUSION: The combination of doxycycline 0.1% and diode laser therapy provides a healing effect in rats models of periodontitis.

The efficacy of photodynamic inactivation with laser diode on Staphylococcus aureus biofilm with various ages of biofilm.

Biofilms are able to cause microorganisms to be 80% more resistant to antibiotics. The extracelullar polymeric substance (EPS) in biofilm functions to protect bacteria, making it difficult for antibiotics to penetrate the biofilm layer. This study aims to determine the effectiveness of photodynamic inactivation with blue diode laser to reduce Staphylococcus aureus biofilm at various ages of biofilms. The light source is a 403 nm blue diode laser with an energy power of about 27.65±0.01 mW. The study was designed with two groups: Group C was the untreated control group with variations in age of biofilms (0; 6; 11; 17; 24; 32; 40 and 48) hours; Group T was a laser treatment group with variations in age of biofilm and energy density (4.23; 8.46; 12.70; 16.93 and 21.16) J/cm2. Biofilm reduction measurement method using ELISA test was performed to calculate OD595 value. The statistical analysis results of variance showed that there was an influence of biofilm age and irradiation energy density of laser on biofilm reduction. Optical density analysis showed the most optimum biofilm reduction happened when biofilm age is perfectly constructed (about 17 hours) and with 91% reduction. The longer biofilm age lived among those biofilms, the greater the reduction. The results of the Scanning Microscope Electron and fluorescent microscope measurement showed destruction site of the EPS biofilm and bacterial cell death. So, the activated photodynamic with 403 nm laser diode is effective to reduce the Staphylococcus aureus biofilm in the maturation phase.