Journal of lasers in medical sciences最新文献

Introduction: Recently, the positive effects of photobiomodulation (PBM) and nano-bone on bone regeneration have garnered significant attention. The purpose of the research was to assess the impact of PBM and nano-bone on the process of mandibular bone repair in mice. Methods: A 4-mm diameter bone defect was created in the left mandibular angle of 24 mice separated into 4 equal groups: group I: control; group II: PBM by irradiation at 100 mW of a 980 nm diode laser for one minute (three sessions per week; day on and day off); group III: nano-bone; group IV: PBM with nano-bone. Every group was sectioned into 3 equal subgroups corresponding to the evaluation method period: (A) one week, (B) two weeks, and (C) four weeks. Histological examination was done with hematoxylin, eosin, and Masson's Trichrome after one, two and four weeks for inflammation, bone defect coverage, vascularization within the newly formed bone, and new bone formation. Statistical analysis of the data was done and presented as percentage values using chi-square. The significance level was set at P value≤0.05 within all tests. Results: In general, by histological examination of the mandibular bone defect of the rats, the intensity of inflammation was the least in group IV when compared with groups II and III and the control group at all evaluation periods (P<0.001). Also, group IV showed a high significant rise in the percentage of new bone formation following four weeks when compared with the control (P≤ 0.001) and groups II and III (P<0.001). Conclusion: The present research results confirmed that the combination of PBM and nano-bone can aid in the repair of mandibular bone abnormalities. This animal study suggests that the use of PBM and nano-bone should be investigated further in clinical studies.

Introduction: One of the common problems among dental patients is tooth hypersensitivity. There are various treatments for hypersensitivity, such as gels, solutions, toothpaste, and laser treatments. This report examined the effect of three treatments, namely 810 nm wavelength diode laser, Gluma gel, and Sensodyne Repair and Protect toothpaste, on tooth hypersensitivity. Methods: This experimental survey selected 40 premolars free of caries, fractures, restorations, root canal therapy, or wear. The enamel of the midline in the cervical part of the buccal surface was removed by a bur (the area was 2*2 mm and the depth was 2 mm), and the samples were then prepared and divided into four groups. Sensodyne Repair and Protect toothpaste, Gluma gel, and an 810 nm diode laser with 0.5 W power were applied to three groups of teeth. The samples were analyzed by using a field emission scanning electron microscope (FE-SEM). The data from the occluded dentinal tubules, partially occluded tubules, and open tubules were analyzed by using the Tamhane test. Results: The amount of occluded dentinal tubules was 83.2±9% in the laser group, 74.4±11.62% in the Gluma group, 67.1±18% in the Sensodyne group, and 15.03±3.39% in the control group. The difference between the treatment groups and the control group was meaningful (P<0.05). However, the difference between the Gluma group, the Sensodyne group, and the 810 nm laser group was not significant (P>0.05). Conclusion: The three treatments (810 nm diode laser, Gluma, and Sensodyne) were all effective in occluding dentinal tubules compared to the control group. However, there was no significant difference between these three treatment methods (P>0.05).

Introduction: Heat stress is one of the environmental causes of damage to the testis, whose effects are less known before puberty. The aim of the present study was to investigate the impact of photobiomodulation (PBM) on the testis of prepubertal mice subjected to hyperthermia. Methods: Twenty-four three-week-old prepubertal male mice were allocated to the following groups: I) control, II) scrotal hyperthermia (Hyp), and III) Hyp+PBM (n=8/each group). In order to induce hyperthermia, the scrotum was placed in water at 43 °C for 20 minutes every other day for a total duration of 10 days. In the Hyp+PBM group, after hyperthermia induction, the testis of the mice was subjected to laser irradiation at a wavelength of 890 nm (0.03 J/cm² for 30 seconds) for 35 days. After the mice were sacrificed, the testis and epididymis were removed for testing. Results: Compared with those of the Hyp group, the sperm parameters of the laser irradiation group improved notably. In addition, histological examinations revealed that the final number of testis cells and the volume of tissue in the Hyp+PBM group were dramatically greater than those in the Hyp group. The analysis of molecular data revealed an increase in the expression of mitotic genes and testosterone levels and a decrease in the formation of reactive oxygen species (ROS) and the expression of the apoptotic gene in the testis subjected to PBM. Conclusion: Based on the present findings, laser therapy can reduce complications caused by scrotal hyperthermia during prepuberty and ameliorate spermatogenesis during puberty.

Introduction: The retina is a light-sensitive tissue, and intensive light exposure leads to light-induced retinal damage. It is pointed out that photoreceptor damage is responsible for the decrease in retina function. The aim of this study was to detect the main genes and biological terms which are involved in retinal response to intensive light exposure. Methods: The effect of intensive light on the mouse retina function was searched in the Gene Expression Omnibus (GEO) database. The data of GSE22818 were assessed by the GEO2R program. The significant differentially expressed genes (DEGs) were determined and evaluated via directed protein-protein interaction (PPI) network analysis. The critical significant DEGs were enriched via gene ontology analysis to find the related biological processes, molecular function, and biochemical pathways. Results: Data analysis indicates that the high intensity of light induces gene expression alteration in the retina. 105 significant DEGs were identified as the main responsive genes to light damage in the retina. STAT3, JUN, IL6ST, SOCS3, ATF3, JUNB, FOSL1, CCL2, ICAM1, FGF2, AGT, MYC, LIF, CISH, and EGR1 were introduced as the critical affected genes. STAT3, JUN, IL6ST, SOCS3, and ATF3 and "Positive regulation of the receptor signaling pathway via JAK-STAT" were highlighted as the key elements of molecular events. Conclusion: It can be concluded that regulation of the key DEGs and the dependent biological terms can effectively provide tools to prevent the development of light-induced retinal damage.

Introduction: Laser therapy employs a concentrated and slender light beam to eliminate or eradicate cancerous cells and pre-cancerous abnormalities. The specific wavelength of 808 nm light is preferentially absorbed by tumor cells compared to healthy cells. This study aimed to assess the combined therapeutic impact of laser and gold, given that gold exhibits photothermal properties when exposed to laser radiation. Methods: In this in vitro study, two cell lines, namely healthy HuGu cells (human gingival fibroblast cells) and head and neck cancer cells (HN-5), were obtained from the Pasteur Institute. The effect of the laser diode with a density of 3 J/cm² and wavelength of 808 nm on the proliferation and the survival rate of oral squamous cell carcinoma (HN-5) and human gingival fibroblast (HUGU) was assessed in 60seconds. MTT assay, DAPI test, and trypan blue staining were used to determine the growth and proliferation of HN-5 and HUGU cell lines. Results: Findings showed that the laser diode along with gold decreased the rate of proliferation and survival cells in HN-5 compared to healthy cells. The changes in the cell population treated with gold and laser diode 808 were insignificant. Conclusion: Findings reveal that using a low-power laser can effectively inhibit the growth of oral cancer cells. It seems that photothermal therapy is a novel approach to oral cancer therapy.

Introduction: The elderly population wants to improve skin function and maintain a youthful appearance without wrinkles. Laser is one of the highly developed and widely used therapeutic modalities of skin aging by stimulating dermal collagen formation. Picosecond laser therapy is performed on skin with wrinkles to determine the mechanism of wrinkle improvement with a picosecond laser through an increasing in tissue inhibitor of metalloproteinases 1 (TIMP-1), and a decrease in matrix metalloproteinase-1 (MMP-1), which was confirmed by collagen density. Methods: The study was started from March 2021 to July 2021 at URJ Dr. Soetomo Hospital Surabaya and Surabaya Skin Centre. Twenty patients meeting the inclusion criteria of being 36-55 years of age and having a wrinkle in the forearm were enrolled by random sampling. Each sample data was recorded, the average TIMP-1, MMP-1, collagen density, and clinical wrinkles were calculated, and the laser was performed by using a picosecond 755 nm laser. Results: All patients showed a moderate pre-test wrinkle scale. The figure for TIMP-1 and MMP-1 after therapy was higher. The MMP-1/TIMP-1 ratio in wrinkles treated by using a picosecond laser was lower but insignificant than before. The picture of collagen density indicates that collagen density after laser therapy was higher than before. Conclusion: The result of clinical examination, histopathology, and immunohistochemistry in this research explained that a picosecond 755 nm laser with DLA is an effective therapy for wrinkles in Indonesian patients without any adverse effects.

Introduction: Photobiomodulation with low-level laser treatment can enhance bone formation by stimulating the cell division of osteoblasts and increasing the amount of protein deposition, thus encouraging the formation of new bone. The aim of this study was to evaluate the effects of photobiomodulation with a low-level laser on proliferation and gene expression related to calcium signaling in human osteoblasts. Methods: Osteoblastic cell lines of the hFOB1.19 lineage, human osteoblasts, were grown and assigned into two groups, control (C; n=78 cultured wells) and photobiomodulation (L; n=78 cultured wells) with n=6 per day of the experimental period. Cells were cultured (immature at 34 ºC), and after maturation at 37 ºC, group L cells were exposed to laser irradiation with a low-level laser device (gallium and aluminum arsenide), at a wavelength of 808 nm, a power output of 200 mW, and a power density of 200 mW/cm². The energy delivered to the cells was 37 J/cm², with a beam area of 0.02 mm² and an exposure time of 5 seconds. This treatment was applied daily for a period of 13 days. Following this, the number of cells was counted, and RNA was isolated, measured, and then converted into cDNA for further quantification using a comparative Ct method with real-time polymerase chain reaction. The results were then subjected to statistical analysis through a Mann-Whitney test, with a significance level of P<0.05. Results: The cell count in the L group (37.25x10±4±22.02) was statistically higher compared to the control group (22.75x10±4±7.660) with a P value of 0.0259. The values of 2^-ΔΔCt for S100A6, plasma membrane calcium ATPase (PMCA), and calmodulin genes indicated hyper-expression on the thirteenth day, while the osteocalcin gene showed hypo-expression. Conclusion: The study suggests that the photobiomodulation mechanism with a low-level laser may regulate gene expression in human osteoblasts in a dose-dependent and cumulative manner.

Introduction: Unhealthy lifestyle choices such as alcohol, chemicals, and heat stress can worsen male infertility. Heat stress can cause damage to the essential structure known as the blood-testis barrier (BTB). Photobiomodulation therapy (PBMT) has been employed in various studies to enhance sperm quality in individuals with genital inflammatory conditions in recent times. The current research sought to study how laser therapy affects spermatogenesis and the structure of the BTB in a mouse model of scrotal heat exposure. Methods: Thirty adult male NMRI mice, 8 weeks old, were divided into three groups: Control, Hyperthermia, and Hyperthermia+Laser 0.03 J/cm². The animals in the hyperthermia group had their testicles exposed to water at 43 °C for 20 minutes five times every other day. Then, the testicles were exposed to laser radiation every other day for 35 days, lasting 3 minutes each time, with an energy density of 0.03 J/cm². Animals were sacrificed, and sperm parameters, reactive oxygen species (ROS) and glutathione (GSH) levels, stereological parameters, and gene expression were assessed in the end. Results: The study showed that PBMT can significantly enhance sperm quality, quantity of spermatogenic cells, testicular volume, levels of ROS and GSH, and gene expression related to the blood-testis barrier. Conclusion: Currently, PBMT is a novel approach for addressing male infertility by preserving the integrity of the BTB in Sertoli cells, which in turn supports the growth and specialization of germ cells.

Introduction: This study aimed to assess the effect of repeated irradiations of 660 nm photobiomodulation therapy (PBMT) after photodynamic therapy (PDT) with curcumin on the viability of human gingival fibroblasts (HGFs). Methods: In this in vitro, experimental study, HGFs were cultured and assigned to five groups: One control group with no intervention and four experimental groups of PDT with curcumin, PBMT (660 nm laser irradiation) immediately after PDT, PBMT immediately and 24 hours after PDT and PBMT immediately and 24 hours and 48 hours after PDT. Cell viability was assessed after 1, 4, and 7 days using the methyl thiazolyl tetrazolium (MTT) assay. Data were analyzed by one-way ANOVA. Results: On day 1, the control group had no significant difference with one-time (P=1.00), two-time (P=1.00), and three-time (P=0.88) laser irradiation groups. On day 4, the difference between the control and one-time (P<0.001), two-time (P<0.001) and three-time (P=0.02) laser irradiation groups was statistically significant, suggesting more cell viability in test groups. On day 7, the three-time laser irradiation group showed significant cell viability compared to the other two test groups but not with the control group (P=0.98). Conclusion: PBMT with 660 nm laser irradiation after PDT with curcumin would increase the viability of HGFs by increasing the frequency of irradiation.

Introduction: Dentin hypersensitivity (DH) is a prevalent unpleasant condition which might affect quality of life. Laser therapy is one of the non-invasive treatments for dentin hypersensitivity. The aim of this umbrella review was to assess the effect of lasers on the treatment of dentin hypersensitivity by analyzing the previously published systematic reviews and meta-analyses. Methods: Electronic databases (PubMed, Embase, Scopus, Cochrane, and ISI) were searched to identify relevant systematic reviews and meta-analyses based on the keyword search strategy. Two independent reviewers carried out the selection of studies, extraction of data, and assessment of methodological quality. The actual overlap of primary studies was measured through the visual tool known as the citation matrix and three indices of % overlaps, covered area (CA), and corrected covered area (CCA). The reviews were appraised for methodological quality through A Measurement Tool to Assess Systematic Reviews (AMSTAR)-2, and the risk of bias was evaluated using the Risk of Bias in Systematic Reviews (ROBIS) tool. Results: Following eliminating duplicates, a total of 2,768 articles were found, and of them, 9 systematic reviews met the inclusion criteria. Six of them included a meta-analysis as well. The actual overlap of primary studies was low. The AMSTAR 2 tool classified one systematic review as high quality, three as moderate quality, three as low quality, and the remaining two as critically low quality. The results of the included reviews generally showed that all types of lasers reduced dentin hypersensitivity compared to placebo/no treatment. Conclusion: Lasers are effective in treating dentin hypersensitivity.