Journal of lasers in medical sciences最新文献

Introduction: The purpose of this study is to achieve a significant increase in the proliferative activity of mesenchymal stem cells (MSCs) of the bone marrow (BM) at early passages after laser exposure to a suspension of these cells and to estimate the effect of light and heat components of laser radiation on the proliferation of BM MSCs. Methods: The studies were performed on rats BM MSCs. MSC suspension was placed into the wells and heated by using laser radiation (980 nm wavelength) or a water bath at 70 °C providing similar temperature dynamics. The studies were carried out in 3 comparison groups: (1) control suspension of MSCs, which was not subjected to heating in a water bath or laser exposure; (2) MSC suspension, which was heated for in a water bath; and (3) suspension of MSCs, which was subjected to laser exposure. The exposure times for the 2nd and 3rd experimental groups were 10- 50 seconds. Results: Under optimal parameters of laser action on the suspension of BM MSCs, a six-fold increase in the number of BM MSCs colonies was registered compared to the control. The role of the light and heat components of laser exposure to MSCs was determined by comparable heating of a suspension of BM MSCs in a water bath, at which only a twofold increase in the number of colonies was maximally obtained. Conclusion: The increase in the MSC proliferation activity occurs due to their Thermo-Photobiomodulation. The result obtained is important for practical use in cell transplantation in the treatment of traumatic injuries of bone, cartilage, and tendon tissues when a rapid and multiple increase in the initial number of autologous BM MSCs is required.

Introduction: One of the clinical problems following orthodontic treatment is white spot lesions around orthodontic brackets due to enamel demineralization. Confronting enamel demineralization during fixed treatments has long been a challenge for orthodontists. The aim of this in vitro study was to evaluate the effect of CO₂ laser and Titanium Tetra-fluoride (TiF4) application on the prevention of enamel demineralization around orthodontic brackets. Methods: Eighty permanent premolars were selected and bonded with brackets. They were randomly divided into four groups (n=20): topical titanium tetra-fluoride gel 4% (TiF4), CO₂ laser (10.6 μm wavelength for 10 seconds, peak power=291 W), fluoride+laser (F+L) and control (C). All specimens were demineralized for 10 days in a 0.2 M acetate buffer solution. The mean lesion depths were determined by using polarized light microscopy. Results: The mean depth of lesion was the highest in the C group and then decreased in the TiF4, CO₂ laser, and F+L groups, respectively. The difference between all groups was significant (P<0.05), except for the CO₂ laser and F+L groups. Conclusion: The lowest amount of demineralization around the orthodontic brackets was observed in the L+F group, followed by the CO₂ laser, TiF4, and control groups, respectively.

Introduction: Endodontic treatment of teeth with periapical lesions presents more clinical difficulty. Various lasers in several methods are used in endodontics, and most of them are utilized as an adjunctive protocol in order to reduce the bacterial load of the root canal system. Improved disinfection plays a crucial role in enhanced and accelerated healing of periapical lesions. This review aims to summarize studies assessing the effect of lasers on periapical lesion healing. Methods: PubMed/MEDLINE, Scopus, Embase, and Web of Science (ISI) online databases were searched, with no publication year or status restriction, for relevant articles on April 2023. Clinical studies evaluating the effect of laser application on the periapical lesion of patients using radiographic assessment were considered eligible for inclusion. Results: Eight studies were included after carefully screening the obtained articles, first by their title and abstract and then by their full texts. Diode (4), Er, Cr: YSGG (3), and Nd: YAG (1) lasers were used with output powers that varied from 0.75 to 2 watts. Photodynamic therapy was employed in two studies, and in other studies, the root canal system was directly irradiated. Irradiation of the root canal system was adjunctive to standard preparation in all studies. The healing of the teeth treated with lasers was not inferior to those conventionally treated. In all of the included studies, laser application outperformed the standard cleaning and shaping protocol; however, this improved or faster healing was not statistically significant in most studies. Conclusion: Lasers might expedite and improve the healing process of periapical lesions. Since lasers enhance the quality of cleaning of the root canal system, it is hard to point out the exact mechanism of it. Further investigations are needed to realize the effectiveness of this treatment modality and to discover the underlying biological concepts.

Introduction: In men, several factors cause infertility, among which we can mention damage to sperm due to high temperature. So far, various treatments have been proposed for it, but they have not been highly effective. The current study aimed to evaluate the effect of exosome therapy (EXO) and photobiomodulation therapy (PBMT) on spermatogenesis arrest in male mice after scrotum hyperthermia. Methods: In this experimental study, the animals were divided into four groups: control, scrotal hyperthermia, scrotal hyperthermia+EXO (100 μL/d) (mice were treated for 30 days), scrotal hyperthermia+PBMT (laser of 0.03 J/cm2 for 30 seconds/for 30 days). Hyperthermia was induced by exposure to the temperature of 43 °C for 20 minute every day for 5 times. After 6 weeks, the animals were sacrificed. Results: The treated groups showed a significant increase in sperm parameters, as compared to the hyperthermic groups. Moreover, these favorable effects were observed in relation to the volume of testicular tissue, the number of germ cells, Leydig cells and Sertoli cells, and the level of testosterone. Research on antioxidants showed a significant reduction in oxidized glutathione (GSSG) and reactive oxygen species (ROS) in the treatment groups in comparison to the hyperthermia group (P<0.001). Also, there has been a significant increase in the amount of hydrogen peroxide enzyme observed in the hyperthermia group as opposed to the treatment group (P<0.001). Conclusion: These findings show that EXO and PBMT can improve spermatogenesis caused by hyperthermia, reduce ROS and GSSG, and increase glutathione (GSH) and sperm quality.

Introduction: The preference for endovascular techniques in treating varicose veins, particularly in the great saphenous vein (GSV), has increased due to their minimally invasive nature and reduced complications. Post-operative care, especially involving compression therapy, remains crucial to improve outcomes, prevent varicose vein recurrence, and enhance overall recovery. This study aimed to evaluate the efficacy of eccentric compression therapy compared to alternative post-operative care methods following endovenous laser treatment (EVLT) for GSV insufficiency. Methods: This prospective randomized clinical trial encompassed 88 EVLT procedures for GSV insufficiency. The participants were divided into two groups, each receiving different postoperative compression methods, and were evaluated over a specified period. The primary outcome was the pain scale after EVLT; meanwhile, the secondary outcome measured in the present study was the rate of GSV occlusion after EVLT. Results: Both groups underwent all EVLT procedures successfully without any complications. At the one-month duplex ultrasound (DUS) follow-up, the sapheno-femoral junction occlusion rates were 97% (43 out of 44) for group A (eccentric compression plus gradual compression stocking) and 95% (42 out of 44) for group B (only gradual compression stocking). Ecchymosis was observed in only 12 patients across both groups, accounting for an overall occurrence of 13.6%. Group A patients reported significantly lower analgesic usage (10%) compared to group B (18%), although this difference did not reach statistical significance. Analysis of postoperative pain data utilizing the visual analog scale (VAS) showed a median value of 5.5 in group B patients, which decreased to 3.1 with the application of eccentric compression. Moreover, there was less ecchymosis in group A observed by one week. Conclusion: This study contributes to the ongoing discourse on the efficacy of postoperative compression in varicose vein treatment. It underscores the necessity for more comprehensive, well-designed studies to yield clearer conclusions and provide better guidance for post-procedure care.

Introduction: Hyperhidrosis (HH) refers to uncontrollable excessive sweating that has a significant negative impact on the quality of life. The aim of this study was to compare the efficacy and safety of the long-pulsed, 1064-nm Nd:YAG laser and aluminum chloride (ALCL₃ ) 20% solution in axillary HH treatment. Methods: In this single-center, within-patient comparison clinical trial, 12 patients with axillary HH were treated monthly for 3 to 4 consecutive sessions with the long-pulsed, 1064-nm Nd:YAG laser system on one axilla, while the contralateral axilla was treated with ALCL₃ 20 % by the patient. Treatment response was evaluated by comparing the area of sweating at the end of each session and 6 months after treatment termination using the iodine starch test. Results: Both treatments led to the reduction of HH from baseline with the mean area of sweating reduced from 109.3±36.6 to 38.3±19.8 and from 92.5±31.6 to 35.6±17.1 in laser- and ALCL₃-treated axilla respectively (Both P<0.001). In the 6-month follow-up, the area of sweating was 60.6±29.2 in the laser-treated armpit and 78.3±23.6 in the ALCL₃-treated side, which were 45% and 14.4% lower compared to the baseline respectively. Adverse events were temporary, and none caused each of the treatments to be discontinued. Conclusion: The long-pulsed, 1064-nm Nd:YAG laser with hair reduction setting can stand as a potential therapeutic option for axillary HH since it is as effective as ALCL₃. The therapeutic effect is superior in the long term for the laser; nevertheless, the beneficial effect of both treatments may lessen the following treatment cessation.

Introduction: The current study aimed to assess the effect of non-thermal plasma (NTP) on the pushout bond strength (PBS) of epoxy resin and tricalcium silicate-based endodontic sealers. Methods: Forty single-canal extracted teeth were decoronated at the coronal region, underwent root canal preparation, and were assigned to four groups (n=10) for the application of AH26 sealer, NTP+AH26 (P-AH26), Endoseal TCS sealer, and NTP+Endoseal TCS sealer (P-TCS). The root canals were sectioned into 1 mm slices, and the PBS value was measured in a universal testing machine. Data were analyzed by the Friedman, Kruskal-Wallis, and Dunn tests (P<0.05). Results: The PBS of TCS and P-TCS groups was not significantly different (P>0.05). The PBS of the P-AH26 group was significantly lower than that of the AH26 group in the middle third (P<0.05). The PBS of the AH26 group was higher than the other groups in all sections. The PBS in the apical third was lower than other sections in all groups (P<0.05). Conclusion: NTP had no significant effect on the PBS of Endoseal TCS. NTP significantly decreased the PBS of AH26 sealer in the middle third but had no significant effect on its bond strength in other sections.

Introduction: Living organisms, particularly humans, frequently encounter microorganisms like bacteria, fungi, and viruses in their surroundings. Silver nanoparticles are widely used in biomedical devices due to their antibacterial, antifungal, and antiviral properties. The study evaluates the efficacy of blue laser and silver nanoparticles from grape seed extract (AgNPs-GSE) in reducing gram-negative Escherichia coli and gram-positive Staphylococcus aureus bacteria causing infections. Methods: The sample consisted of four groups: a control without laser irradiation (T0), E. coli samples (A1 and A2) irradiated with a 405 nm diode laser at different times and concentrations of silver nanoparticles, and S. aureus samples (A3 and A4) irradiated with a 405 nm diode laser at different times and concentrations. Bacteria in groups A2 and A4 were treated with a photosensitizer (PS) made from grape seed extracts, incubated for 10 minutes, and then irradiated for 90, 120, 150, and 180 seconds. The samples were cultured on Tryptic Soy Agar (TSA) media, incubated at 37 °C, counted by using a Quebec colony counter, and analyzed using ANOVA and Tukey tests with a significance level of P<0.05. Results: The study found that 10 µl of AgNPs-GSE, when combined with exposure to a blue laser at 405 nm and a dose of 3.44 J/cm², can effectively photoinactivate E. coli and S. aureus bacteria. The addition of AgNPs-GSE to E. coli bacteria led to a significant reduction in their viability, with a reduction of 73.93%, 80.96%, and 83.80%, respectively. Similarly, when S. aureus bacteria were irradiated for 180 seconds by adding 1 mM, 1.5 mM, and 2 mM AgNPs-GSE, bacterial viability was reduced by 70.87%, 78.04%, and 87.01%, respectively. Conclusion: The findings from the present study indicate that at an energy density of 3.44 J/cm², it was possible to inactivate E. coli by 83.80% and S. aureus by 87.01%.

Introduction: Surgical procedures involving the temporomandibular joint (TMJ) are frequently associated with nerve injuries and subsequent dysfunctions. Considering that traumatic peripheral nerve injuries may resolve slowly and their prognosis is generally unpredictable, the current study aimed to report a clinical case in which both motor (affecting the temporal and zygomatic branches of the facial nerve) and sensory dysfunctions (affecting the auriculotemporal nerve of the trigeminal nerve) following TMJ surgery were effectively treated by using photobiomodulation therapy (PBMT). Case Report: PBMT sessions, involving a total of 30 facial points, were administered twice a week for 10 weeks. The following parameters were utilized: wavelength of 808 nm, energy density of 75 J/cm², power output of 100 mW, total energy of 3 J, and duration of 30 seconds per point. A considerable improvement in both facial asymmetry and muscle function was achieved within 5 weeks, along with a total restoration of cutaneous sensitivity. By the 10th week of PBMT, the facial movement dysfunction was completely resolved. Conclusion: According to the current case, PMBT seems to be an effective intervention to manage motor and sensory nerve dysfunctions following TMJ surgery.

Introduction: Dental hard and soft tissues have been successfully removed by using the Er,Cr:YSGG laser, but there is a controversy about using lasers over conventional tooth surface preparation for bonding aesthetic restoration. Surface roughness and wettability in response to Er,Cr:YSGG laser irradiation are essential properties for restoration longevity. Methods: Fifty-one intact human premolars removed in orthodontic treatment were included in this study and divided into three groups (n=17). The first group (G1) was the control without surface treatment, (G2) was treated with 37% phosphoric acid for 15 seconds, and (G3) was treated with the Er,Cr:YSGG laser using the following parameters: 2 W or 3 W at 20 Hz, 10% air and water ratio using the MZ6 laser tip. The standardization of laser irradiation was accomplished by a computerized numerical control unit. The surface of the samples was evaluated by using a light microscope, profilometer, atomic force microscopy (AFM), SEM, and wettability tests. Results: The SEM examination revealed that the lased enamel surface was clean, irregular, and devoid of a smear layer, while the acid etch surface was relatively smooth and covered with a smear layer. The surface roughness of the lased enamel surface was significantly higher than that of other groups, according to the results of the profilometer as well as the AFM tests. The wettability test showed that the lased enamel surface recorded a significant reduction in the contact angle in comparison to the other groups. Conclusion: It can be concluded that the Er,Cr:YSGG laser can be used as an alternative and safe method to the acid-etching technique for surface treatment.