Lasers in Medical Science最新文献

While fractional CO₂ laser and concentrated growth factor (CGF) have been individually applied in scar management, their combined therapeutic potential remains underexplored. This study aimed to evaluate the synergistic efficacy and underlying mechanisms of fractional CO₂ laser combined with CGF in a rabbit ear hypertrophic scar model, with a focus on inflammatory modulation and collagen remodeling. Hypertrophic scars were induced on both ears of six rabbits. The scars were divided into three groups: combined CO₂ laser + CGF, CO₂ laser + saline, and untreated control. Scar tissues were assessed via macroscopic observation, H&E staining, Masson trichrome staining, and immunohistochemistry for CD34, IL-6, and TGF-β1. The combined treatment group exhibited significantly improved scar appearance, collagen organization, and reduced microvessel density compared to both the laser-only and control groups. Immunohistochemical analysis revealed a marked downregulation of IL-6 and TGF-β1 in the combined group, indicating enhanced anti-fibrotic and anti-inflammatory effects. The combination of fractional CO₂ laser and CGF synergistically promotes scar regression through dual mechanisms of physical ablation and biological regulation. This approach represents a promising strategy for enhancing scar treatment outcomes, with potential for clinical translation.

Dentin hypersensitivity (DH) is characterized by intense, short-lasting pain, triggered by dentin exposure to different stimuli. It is often associated with hypomineralized teeth due to increased enamel porosity and exposed dentinal tubules. The high-power Er: YAG laser has emerged as a promising therapeutic strategy for the treatment of this condition. The aim of this in vitro study was to test different protocols for managing dentin hypersensitivity in hypomineralized teeth using a high-power Er: YAG laser. Six protocols were evaluated, varying in power, frequency, application mode, and the use of cooling. Qualitative analysis of morphological changes were evaluated by scanning electron microscopy (SEM). Further, the most promising protocol - 20 mJ, 10 Hz, 0.20 watts, applied in focused mode, without cooling - was selected for assessing intrapulpal temperature variation using thermocouples connected to a monitoring system. The SEM images showed that this protocol promoted homogeneous surface melting of dentin, effectively sealing the dentinal tubules without inducing a thermal increase greater than 2 °C. These findings support the feasibility of using the Er: YAG laser with conservative parameters and no cooling as a safe and effective alternative for the management of DH in hypomineralized teeth. However, clinical trials are recommended to validate its applicability in pediatric dentistry.

This study is aimed to explore the direct effects of low-level laser therapy (LLLT) at different wavelengths on lymphatic motility int healthy individuals. The goal was to identify the most effective protocol and assess the potential application of LLLT in managing lymphedema. The study included 32 healthy participants (12 males, and 20 females), divided into two groups. Each participant underwent a single session of unilateral upper extremity manual lymphatic drainage (UE MLD), followed by two types of LLLT applied to the ipsilateral axilla region to promote lymphatic drainage. Indocyanine green (ICG) lymphography was used during each treatment session to evaluate the immediate effect of LLLT on lymphatic motility. Additionally, extracellular fluid (ECF) and local tissue water level were assessed before and after the intervention using multiple frequency bioelectrical impedance analysis (MFBIA) and tissue dielectric constant (TDC). The overall reduction in body water content post-intervention was observed across multiple areas in both groups but without consistent statistical significance between groups. After UE MLD, the number of lymph packets significantly increased in both groups (Group A: from 3.20 ± 0.76 to 6.00 ± 1.38; Group B: from 2.80 ± 0.95 to 5.38 ± 1.44). However, during LLLT, the lymph packet count decreased significantly (Group A: to 1.73 ± 0.51; Group B: to 1.96 ± 0.67). Linear mixed model analysis showed that LLLT was associated with a reduction in lymph packet velocity (Estimate = - 1.22, 95% CI: - 2.08 to - 0.36, p = 0.006) and count (Estimate = - 1.11, 95% CI: - 1.57 to - 0.66, p < 0.001), while UE MLD significantly increased packet count (Estimate = 2.73, 95% CI: 2.28 to 3.19, p < 0.001). No significant intergroup differences were observed in lymphatic motility. This study quantitatively assessed lymphatic motility and tissue water content following different types of LLLT in healthy individuals. The findings suggest the need for further clinical studies to evaluate the effect of various LLLT parameters in lymphedema patients.Clinical trial number Not applicable.

To evaluate and compare the clinical effectiveness of photobiomodulation (PBM) in managing temporomandibular disorders (TMDs) of muscular versus articular origin, drawing from randomized controlled trials (RCTs) assessing pain reduction and improvement in mandibular function. This systematic review and meta-analysis adhered to PRISMA 2020 guidelines and was registered with PROSPERO (CRD420251029633). Comprehensive searches were conducted in PubMed, MEDLINE, LILACS, and the Cochrane Library for articles published up to March 31, 2025. Eligible studies were RCTs examining PBM in patients with muscular or articular TMDs, reporting outcomes on pain (Visual Analogue Scale [VAS]) and/or mandibular function (Maximum Mouth Opening [MMO]). Risk of bias was assessed via the Cochrane RoB 2.0 tool, and meta-analyses employed random-effects models with subgroup analyses based on TMD subtype. Eighteen randomized controlled trials (n = 1038 participants) were included: 11 focused on muscular TMD, 4 on articular TMD, and 3 on mixed types. PBM demonstrated significant improvements in pain and mandibular function across all subtypes. Meta-analysis revealed consistent benefits for pain (SMD = - 0.84; 95% CI: -1.18 to - 0.51) and function (SMD = 0.72; 95% CI: 0.38 to 1.05). Trials involving articular TMD showed the most robust and homogeneous effects, suggesting greater PBM efficacy in intra-articular conditions. Photobiomodulation is an effective modality for the management of both muscular and articular TMDs. The data indicate superior and more consistent outcomes in articular presentations, potentially due to PBM's anti-inflammatory properties. These findings support the implementation of subtype-specific PBM protocols in clinical practice.

Combined nevi are defined as the presence of 2 or more melanocytic cell groups within one lesion. They now refer to all cases of combinations of benign melanocytic nevus, including nevus cell nevi, Spitz nevi, and other melanocytic tumors, as well as blue nevi. In previous reports, treatment options for combined nevus primarily include surgical excision, laser therapy, cryotherapy, and combination therapy. However, there are no established guidelines for selecting the most appropriate treatment. A treatment for a combined nevus should be selected based on the histopathological structure of the combined nevus. On the other hand, laser therapy for combined nevi affects only blue nevus with melanocytosis and nevus spilus. Considering this background, we devise a treatment flowchart for a combined nevus against a blue nevus background. And we adapted this flowchart to two cases of combined nevus and underwent a combination therapy of excision and laser treatment, and neither case appeared to have any complications(e.g., postoperative hyperpigmentation, ectropion) and didn't recur. The combination therapy of surgical excision and laser treatment is one of the best treatments for combined nevus, considering the cosmetic aspect. We propose a treatment selection flowchart for combined nevus against a blue nevus background.

Dental mesenchymal stem cells (DMSCs) are increasingly recognized for their regenerative properties, particularly in the context of pulp regeneration. Among the various treatment's diode laser irradiation, has gained more attention for its potential to promote stem cell differentiation, particularly osteogenic differentiation. To evaluate the effect of diode laser irradiation on the proliferation and osteogenic differentiation of dental tissue-derived mesenchymal stem cells. A comprehensive search was performed between January 2025 to June 2025 across five databases including PubMed, Cochrane Library, LILACA, Google scholar and ScienceDirect. Only in vitro studies that assessed cellular or osteogenic differentiation of DMSCS were included. The risk of bias for was assessed using the QUIN tool. A total of 21 studies were included in the review, encompassing various DMSC types, The studies explored a range of diode laser wavelengths (420-980 nm) and energy densities. Findings indicate that diode laser irradiation, particularly at wavelengths of 660 nm, 810 nm, and 980 nm, promotes osteogenic differentiation by enhancing the expression of osteogenic markers such as RUNX2, ALP, and OCN. The effect of diode laser irradiation on stem cell proliferation and osteogenic differentiation was found to be dose-dependent, with lower energy densities promoting proliferation and higher energy densities favoring differentiation. Diode laser irradiation at wavelengths of 660 nm, 810 nm, and 980 nm demonstrates potential for enhancing osteogenic differentiation of DMSCs. However, variability in laser parameters led to inconsistencies in the results, and no consensus could be reached regarding the optimal laser settings for maximum differentiation efficiency.

Purpose This in vitro study evaluated the microleakage of four self-adhering flowable composites (SAFCs) and one flowable composite with a self-etch adhesive (S3MF, included as a comparative control group) in Class V cavities prepared by bur or Er, Cr: YSGG laser on human premolars. Materials and methods Fifty premolars were divided into five groups (n = 10). Buccal cavities were prepared with a diamond bur and palatinal cavities with an Er, Cr: YSGG laser. Restorations were placed according to manufacturers' instructions. After 2000 thermocycles, specimens were immersed in AgNO₃, and microleakage was evaluated using a 0-3 ordinal scale under a stereomicroscope and SEM. Data were analyzed with non-parametric tests (α = 0.05). Effect sizes (Cohen's d, η²) together with their 95% confidence intervals (CI) were calculated to indicate clinical relevance. Results Although all groups showed clinically acceptable microleakage scores (≤ 1), VF exhibited the lowest (0.1), while S3MF showed the highest (0.65). Differences were significant between S3MF and VF (p = 0.011), FLD (p = 0.017), and NCS (p = 0.017). Bur-prepared cavities demonstrated less microleakage than laser-prepared cavities (p < 0.001), and microleakage at occlusal margins showed lower scores than gingival margins (p < 0.001). Conclusions Within the limitations of this study, the sealing ability of SAFCs were better in bur-prepared restorations, presumably due to the presence of the smear layer. However, at enamel margins of laser-prepared cavities, microleakage scores were comparable with bur preparations. It can be concluded that both the preparation method and the surrounding tooth tissue should be carefully considered when deciding to use SAFCs to ensure optimal bonding. Further studies are needed to confirm these findings.

Percutaneous Laser Disc Decompression (PLDD) is a minimally invasive treatment for lumbar disc herniation (LDH), but its effectiveness can be influenced by factors like laser power and treatment time, which vary with the degree of disc degeneration. Reduced water content in degenerated discs may affect treatment outcomes. This study examines how low-energy laser treatment impacts intervertebral discs with different water content, focusing on photothermal and carbonization effects. Fresh intervertebral discs from adult pig spines (L2-L5) were used. Discs with poor and rich water content were prepared by vacuum freeze-drying and saline soaking, respectively, with untreated discs serving as controls. Three groups-poor, normal, and rich water content-were exposed to laser irradiation at 1 W, 2 W, and 3 W. Images of the discs were captured, and the irradiated and carbonized areas were measured to evaluate photothermal effects. After 5 min of irradiation, the poor water content group showed the largest irradiated area at low power (112,894 ± 18,664 pixels), compared to the normal (75,644 ± 11,298 pixels) and rich (51,641 ± 7,348 pixels) groups. As power increased, the poor water content group continued to show a larger irradiated area. For carbonization, the poor water content group exhibited the largest carbonized area (64,759 ± 9,876 pixels) at low power, and this trend continued at higher powers. The water content of intervertebral discs significantly affects laser irradiation and carbonization. Discs with poor water content show larger irradiated areas and earlier, more extensive carbonization. Careful control of treatment time is necessary when treating severely degenerated discs to avoid excessive carbonization and potential negative effects.

Low-energy semiconductor percutaneous laser disc decompression (LS-PLDD) is a minimally invasive technique that employs laser energy to treat lumbar disc herniation (LDH). To date, no clinical studies have evaluated its efficacy in adolescent patients. This study aimed to assess the safety and effectiveness of LS-PLDD compared with percutaneous endoscopic lumbar discectomy (PELD) in the management of adolescent LDH. Collected data on 30 adolescent LDH patients who underwent LS-PLDD, and 60 adolescent LDH patients who underwent PELD, matched for age and sex. Lumbar ODI scores and back pain VAS scores were recorded preoperatively and at 1 week, 1 month, 3 months, and 6 months postoperatively to evaluate clinical outcomes in the two groups. In addition, lumbar MRI scans obtained preoperatively and at 3 months postoperatively were compared to assess disc changes. The preoperative back VAS scores were (7.0 ± 0.91) and (7 ± 0.8) in the LS-PLDD group and PELD group respectively, with no significant statistical difference (P = 0.779). The VAS scores of both groups had improvement after surgery. At the last follow-up, the VAS scores of both groups were (2.0 ± 1.3) and (1.0 ± 0.8) respectively ( P < 0.01). The VAS scores of patients in PELD group improved most significantly in the first week after surgery and then gradually stabilized, while that in LS-PLDD group improved more gradually during 6 months after surgery. The preoperative ODI scores of the LS-PLDD group and PELD group were (71.1 ± 7.9)% and (68.0 ± 7.3)% (P = 0.061), at the last follow-up, the ODI scores were (28.0 ± 13.1)% and (19.0 ± 8.4)% (P < 0.01). The preoperative canal cross-sectional areas in the LS-PLDD group and PELD group were (1373.0 ± 376.6) and (1457 ± 415.9) respectively, with no significant difference between the two groups (P = 0.157), at the last follow-up, the canal cross-sectional area of the surgical segments were (1373 ± 476.6) and (1457 ± 579.1) (P = 0.227)respectively. This study shows that low energy semiconductor laser LS-PLDD is a safe and effective treatment method for adolescent LDH. It can achieve sustained retraction of the herniated disc and retain the intact structure of the disc.

Chronic stress can induce both depression and low sexual desire (LSD); however, selective serotonin reuptake inhibitors (SSRIs) may exacerbate LSD while being used to treat depression. It's known that sunlight could improve sexual desire, therefore we want to explore whether near-infrared laser transcranial photo-biomodulation (NIR-tPBM) could improves LSD caused by chronic stress. Forty-eight male eight-week-old Balb/c mice were divided into six groups; including chronic restraint stress (CRS) groups that received different levels of NIR-tPBM, the forced swim test and tail suspension test were used to evaluate depression in these mice. Ovariectomized and sex hormone induced sexual experienced female mice were used to evaluate the mating motivation of the male mice. The fraction of time spent sniffing a female (FTSSF) during the first five minutes of the pre-mounting period was used to evaluate the sexual desire, the function statues of the anteroventral and preoptic periventricular (AVPV/PVpo) dopaminergic neurons in the hypothalamus of the male mice were checked, the serum testosterone and cortisol were also measured. In mice undergoing CRS, NIR-tPBM improved both LSD and depression, with the ultimate effect related to radiant exposure level. The elevated c-Fos expression in AVPV/PVpo dopaminergic neurons induced by NIR-tPBM could be the reason for the improvement in LSD. While chronic stress led to LSD in male mice, we herein speculated that NIR-tPBM improved the LSD by activating AVPV/PVpo dopaminergic neurons in the hypothalamus.