Lasers in Medical Science最新文献

Acne vulgaris, commonly known as acne, is the most prevalent skin disorder affecting mainly adolescents and young adults, though it can affect people of all ages, making it the most common complaint by patients presenting to a dermatologist. The overactivity of sebaceous glands primarily drives this skin condition due to androgen influence and the presence of Cutibacterium acnes bacteria. Although typically not directly harmful to patient health, acne can be a highly debilitating disease for patients, affecting their self-image and psychosocial well-being. Standard treatments include topical retinoids, benzoyl peroxide, topical antibiotics, and, for more severe cases, systemic antibiotics or isotretinoin, which require prolonged periods of compliance. All these pharmacologic treatments have a risk of side effects ranging from mild ones, like skin irritation and dryness, to severe ones, like depression. Thus, there is a demand for exploring other treatment modalities in treating acne, and laser and light-based therapies have garnered significant interest. This review article will comprehensively assess emerging laser and other light-based therapies that have shown efficacy in treating acne, including the recently FDA-approved 1,726 nm laser.

To evaluate and compare the shear bond strength of composite resin restorations in primary teeth, following cavity preparation with both traditional dental burs and laser irradiation. One hundred primary molars extracted from the children visiting our department were collected and randomly divided into five groups (A-E) with 20 teeth in each group. In groups A, B, C, D, and E the teeth samples were etched with phosphoric acid, Er; YAG laser followed by acid etching, Er, Cr: YSGG laser followed by acid etching, Er; YAG laser etching only and Er, Cr: YSGG laser etching only, respectively. Following, all the samples were restored with composite resin and subjected to 500 cycles of thermocycling. The shear bond strength of the resin composite was analyzed. The type of fractures was also noted. Data obtained were subjected to statistical analysis. The mean value of shear bond strength of Group A, B, C, D, and E was 17.562 ± 0.810, 15.928 ± 0.415, 14.964 ± 0.566, 11.833 ± 0.533 and 11.187 ± 0.517, respectively. Adhesive failure was most commonly seen in all the groups. The phosphoric acid etching remains a highly effective technique for pre-treating dentin in composite resin restorations. The shear strength of composite resin to the dentin of laser-prepared cavity in primary teeth can be improved by the addition of acid etching.

Ulnar neuropathy at the elbow (UNE) is the second most common entrapment neuropathy and presents with symptoms such as pain, paresthesia, and weakness in the elbow. Provocative tests and electrophysiological examinations are helpful in the diagnosis of UNE. Low-level laser therapy is one of the conservative treatments of UNE however, limited results were reported on the effectiveness of low-level laser therapy (LLLT) in the treatment of UNE. In our study, we aimed to the efficacy of LLLT in reducing symptoms and providing clinical and electrophysiological improvement in patients with UNE. This study with a randomized-sham controlled, and double-blind design included 68 patients aged 18-60 years who were diagnosed with UNE. LLLT was applied to the first group, and sham laser was applied to the second group. The VAS pain, paresthesia, and weakness scores, grip strength, and provocative test positivity were evaluated in clinical examination. The QuickDASH questionnaire was administered to assess functional status. Electrophysiologically, motor distal latency (MDL) differences, sensory distal latency (SDL), motor and sensory nerve conduction velocity (NCV) were examined. Evaluations were performed before treatment and on the 15th day and at the third month after treatment. The LLLT group showed improvement in symptoms, clinical findings, motor NCV, and MDL at both post-treatment evaluations and sensory NCV on the post-treatment 15th day (p < 0.05). The comparison of post-treatment changes between the two groups revealed that the LLLT group had greater improvement in VAS day and night pain scores at both post-treatment evaluation times, QuickDASH scores at the third month, and sensory NCV on the 15th day (p < 0.05) compared to the SL group. There were no significant differences between the groups in terms of the post-treatment changes in VAS weakness scores, grip strength and electrophysiological findings (p > 0.05). It was observed that splinting alone was effective in UNE, but the addition of LLLT, one of the conservative treatment methods, enhanced treatment outcomes.

Infraorbital dark circles are a common manifestation of periorbital melanosis, which is aesthetically defective and bring a negative impact on life quality. However, there is no acknowledged treatment for infraorbital dark circles. The 1064-nm Q-switched Nd: YAG laser (QSNYL) is commonly utilized to treat hyperpigmentation disorders. Radiofrequency (RF) therapy can improve the transdermal absorption rate of drugs. A prospective clinical trial was conducted to investigate the clinical efficacy and safety of 1064-nm QSNYL combined with RF-imported vitamin C for the treatment of infraorbital dark circles. A questionnaire was used to explore the relevant factors affecting the severity of infraorbital dark circles. A total of 30 patients with pigmented infraorbital dark circles were enrolled in this clinical trial. Each participant received 4 treatments and was followed up for at least 12 months after the last treatment.We focused on the overall change in the appearance of the included participants before and after treatment, by using satisfaction evaluation.In order to reduce evaluation bias, the vivo reflectance confocal microscopy images were taken on days 1 and 120 to detect pigmentation. The questionnaire survey before treatment showed that high-frequency makeup was positively and statistically significant with the severity of infraorbital dark circles (p < 0.01). Both participants and independent evaluators found that the hyperpigmentation in the infraorbital region was significantly reduced after combined treatment with high treatment satisfaction. The density of melanin particles in the infraorbital dark circles region showed a decreased trend. No significant side effects were observed. The 1064-nm QSNYL combined with RF-imported vitamin C is a safe and effective treatment for pigmented infraorbital dark circles by reducing melanin particles.

This study compared the efficacy of pharmaceutical (ibuprofen) and non-pharmaceutical (photobiomodulation and chewing gum) interventions for pain reduction after elastomeric separator placement in orthodontic patients. This 3-arm, parallel-group randomized clinical trial was conducted on 90 orthodontic patients. The level of anxiety and pain threshold of patients were measured at baseline using the Pain Catastrophizing Scale (PCS) and an algometer, respectively. The patients were randomly assigned to three groups (n = 30; equal number of males and females). In the laser group, 940 nm diode laser (Epic X, Biolase, USA, 12.35 J/cm2 energy density and 300 mW power in continuous-wave mode., The cross-sectional area of the laser handpiece tip was 1.7 cm2.) was irradiated to the buccal and lingual surfaces for 35 s each, prior to placement of separators. In the gum group, the patients were asked to chew a piece of sugar-free gum immediately after the placement of separators and repeat every 8 h for 5 min for one week in case of pain. In the ibuprofen group, patients received 400 mg ibuprofen (Hakim Pharmaceuticals, Tehran, Iran) after the placement of separators and were asked to take one tablet every 8 h for one week in case of pain. The pain score was recorded using the Modified McGill Pain Questionnaire (MPQ). The normality of data distribution was analyzed by the Kolmogorov-Smirnov test. ANOVA was applied to compare age, and the Chi-square and Monte Carlo Chi-square tests were used to compare gender and patient responses to the questions among the groups. Repeated measures ANOVA was used to compare the pain score at different time points and among the three groups. All statistical analyses were conducted using SPSS version 19 (SPSS Inc., Chicago, IL, USA) at 0.05 level of significance. Data analysis in this study had an intention to treat approach. Although the pain score was slightly lower in ibuprofen and gum groups, the difference among the three groups was not statistically significant (P > 0.05). 'Repeated measures ANOVA showed no significant effect of method of pain reduction on pain score (F = 1.520, P = 0.225). Time had a significant effect on pain score (F = 20.310, P < 0.001). The interaction effect of time and pain reduction method on pain score was not significant (F = 0.737, P = 0.651). patients experienced a lower level of pain in the ibuprofen and chewing gum groups, the difference in pain score was not significant among the three groups (P = 0.225). patients experienced a higher level of pain at 12 and 24 hours after the placement of separators in all groups. Considering the comparably equal analgesic efficacy of this modalities, non-pharmaceutical interventions can be used for pain reduction of elastomeric separator. The study protocol was registered in the Iranian Registry of Clinical Trials (IRCT20210927052611N1). Date of registration 2022/03/14.

Laryngeal cancer is the second most common cancer in the upper aerodigestive tract, with its incidence increasing across all ages. The conventional treatments for laryngeal cancer include surgical procedure, radiation, and chemotherapy; however, these treatments can lead to various complications. Photothermal therapy (PTT) using laser light has been employed form cancer effective treatment because of its minimal invasion and short operation time. The current study aims to investigate the feasibility of 532 nm PTT on laryngeal cancer in an invivo tumor model. Ex vivo dosimetry evaluation was conducted to determine the laser irradiation conditions, and HEP-2 tumor bearing mice were used to demonstrate in vivo photothermal effects. In addition, histology and western blot analysis were conducted to verify tumor necrosis and any changes in cancer-associated factors in the tumor tissues. The current in vivo results showed that PTT at 5 W for 40 s and 20 W for 10 s had comparable effects in terms of temperature increase and tumor removal. The 532 nm PTT significantly decreased the remaining tumor and downregulated the expression levels of MMP- 9 and ERK. The current study demonstrated that the 532 nm PTT could be a feasible option for treatment of laryngeal tumor with high power delivery for a short exposure time. Further investigations will confirm the endoscopic application of the 532 nm PTT for the treatment of intralaryngeal tissue prior to clinical translation.

This systematic review and meta-analysis aims to identify, critically appraise, and summarize the effects of high-intensity laser therapy on subacromial impingement syndrome. Three databases, PubMed, Embase, and Scopus were searched from inception to March 1, 2024. Clinical trials comparing the effects of high-intensity laser therapy to conventional therapy are eligible for inclusion. Two independent reviewers conducted study selection, data extraction, and quality assessment. Methodological quality was assessed using the Physiotherapy Evidence Database scale. Meta-analyses were performed to determine the effects of high-intensity laser therapy. Five randomized controlled trials and one controlled clinical trial were included, with a total of 284 patients with subacromial impingement syndrome. All included studies were evaluated as good or above for quality assessment. Compared to conventional therapy, high-intensity laser therapy demonstrated significantly better outcomes for pain at both post-intervention (SMD = -1.01, 95%CI = -1.85 to -0.17) and three-month post-intervention (SMD = -0.51, 95%CI = -0.90 to -0.13); shoulder and arm function at both post-intervention (SMD = 0.40, 95%CI = 0.14 to 0.66) and three-month post-intervention (SMD = 0.45, 95%CI = 0.06 to 0.84); shoulder abduction active range of motion (SMD = 3.26, 95%CI = 0.49 to 6.03). No significant difference was found for shoulder flexion and external rotation range of motion. This review highlights the promising effects of high-intensity laser therapy for the rehabilitation of subacromial impingement syndrome. Rehabilitation professionals and policymakers should increase their awareness of high-intensity laser therapy as an emerging technology that may facilitate greater outcomes than current widespread standards.

Breast cancer remains a significant global health challenge, spurring ongoing investigations into innovative treatment approaches. Low-level laser therapy (LLLT) has emerged as a promising non-invasive therapeutic avenue of interest. This research delves into the impact of LLLT on the cytotoxicity of the MCF-7 breast cancer cell line, employing lasers emitting various wavelengths. The objective is to assess whether diverse LLLT wavelengths elicit disparate cytotoxic responses, shedding light on LLLT's potential as a targeted breast cancer treatment. MCF-7 cell cultures were subjected to lasers of varying wavelengths, including blue (473 nm), red (660 nm), and near-infrared (780 nm). Each wavelength was delivered at four different power levels: 10, 25, 45, and 65 mW, with exposure durations of 60, 300, 600, and 900 s. Cellular responses, encompassing factors such as cell viability, and cytotoxicity were assessed using WST-1 assays technique. Statistical analysis was performed to discern the wavelength-specific impacts of low-level laser therapy (LLLT) on MCF-7 cells. The study revealed that the blue laser had the least noticeable adverse impact on MCF-7 breast cancer cell lines, leading to the highest cell survival rate of 107.62% after 24 h. The most severe toxicity occurred when the laser was used at 45 mW for 900 s, resulting in cell viability ranging from 81.85% to 107.62%. As for cell viability after exposure to the red laser, the mildest harmful effect was observed at 45 mW power for 60 s, resulting in a cell survival rate of 147.62%. Conversely, the most significant toxic response occurred at 10 mW power for 60 s, resulting in a cell viability of 91.56%. In contrast, when employing infrared laser irradiation, the least substantial cytotoxic effect on MCF-7 cells was observed at 10 mW power for 600 s, resulting in the highest cell viability of 109.37% after 24 h. The most pronounced cytotoxic effect was observed by infrared laser (780 nm) at 25 mW power for 900 s, leading to the lowest viability of 32.53%.

This clinical study assessed photobiomodulation (PBM) induced analgesic effects of diode lasers and an LED light source on the dental pulp. Baseline responses to electric pulp testing (EPT) were recorded in 93 healthy unrestored premolar teeth in 26 adults (age range 22–63 years) attending a private dental practice. The teeth were irradiated on buccal and lingual aspects of the crown, by placing the tips on the middle third of the crown of the teeth, on separate days for each of 4 different light sources (660, 808, or 904 nm diode lasers, or a novel multi-wavelength LED light source (700–1100 nm)) using comparable parameters (100 mW, 30 s, 6 J). EPT scores were measured after a further 1-, 2-, 5- and 20-min. Discomfort caused by PBM therapy was recorded using the Wong-Baker scale. EPT changes were tracked over time using repeated measures analysis of variance. Baseline EPT scores were very consistent between different days (linear regression r² 0.9422–0.9648). All PBM devices caused a significant elevation in EPT at 5 min, with an earlier onset at 2 mins for 904 nm and LED. The LED was the only light source that elevated scores at 20 min. Across 2–20 min, when ranked by effectiveness, the greatest EPT elevations were seen for LED, followed by 904 nm, then 660 nm and finally 808 nm. Discomfort during PBM was most common with 904 nm, followed by 808 nm. No discomfort occurred from the LED. Among the light sources utilized, the LED multi-wavelength system demonstrated the largest increase in EPT readings, suggesting its potential as a non-pharmacological alternative for achieving dental analgesia compared to diode lasers.