Laser Group Research Articles

Effects of Er:YAG laser debonding on changes in the properties of dental zirconia.

To investigate changes in the optical and mechanical properties of novel zirconia ceramics applied in dentistry after Er:YAG laser debonding and to evaluate the feasibility and value of reusing zirconia restorations debonded by an Er:YAG laser. Four types of zirconia ceramics were investigated: self-glazed zirconia (SGZ), 3Y-TZP, 4Y-PSZ and 5Y-PSZ. Forty rectangular (25 mm*8 mm*1.5 mm) specimens were fabricated for each zirconia type, and a total of 160 specimens were manufactured. The zirconia specimens were divided into four subgroups according to the applied Er:YAG laser debonding process: the control group, 4 W laser group, 5 W laser group, and 6 W laser group. For each subgroup, 10 specimens were subjected to color tests (color difference (△E) and transparency parameter (TP) tests) and subsequent mechanical tests (flexural strength (FS), elastic modulus (EM), Vickers hardness (VH) and surface roughness (Ra) tests). The △E, TP, FS, EM, VH and Ra values were measured and calculated. One random sample from each subgroup was observed by SEM. Statistical analyses were performed by one-way ANOVA followed by post hoc comparisons (α = 0.05). The △E and TP values after Er:YAG laser debonding were not significantly different among the subgroups (P > 0.05). However, the 6 W laser group had the highest △E and lowest TP. The ranges of changes in △E and TP were below the clinically detectable threshold (△E = 1.2, △TP = 1.33). In terms of the mechanical properties, there were no significant differences in the FS, EM, VH or Ra among the subgroups. No obvious microcracks were detected on the surfaces of the zirconia specimens during SEM. Er:YAG laser debonding does not obviously affect the optical or mechanical properties of novel zirconia ceramics in dentistry. Moreover, it is potentially feasible and valuable to reuse zirconia restorations after Er:YAG laser debonding.

Combined fractional CO2 laser with topical tioconazole versus Q-switched Nd-YAG laser in the treatment of onychomycosis; a randomized comparative trial.

Treatment of onychomycosis includes topical and systemic agents. However, prolonged use of oral treatment could cause adverse effects and topical antifungal agents have limited penetration. To compare the clinical efficacy and the safety of fractional CO2 laser combined with topical tioconazole nail solution versus Q-switched 1064 Nd: YAG laser in the treatment of fingernail onychomycosis. This randomized comparative clinical trial was conducted on 13 patients (47 nails) with fingernail onychomycosis. Patients were randomized to receive either fractional CO2 laser combined with topical tioconazole or Q-Switched Nd: YAG 1064nm laser every 2 weeks for 3 months followed by a 1-month follow up assessment. Onychomycosis severity index (OSI) score, Dermatology life Quality Index (DLQI) score, patient satisfaction score, dermoscopic evaluation and KOH examination were used for assessment of improvement. OSI showed improvement after treatment in both arms (from 16.17 to 10.92 in fractional CO2 arm (p = 0.026) and 23.13 to 22.43 (p = 0.92)). When comparing both groups OSI score significantly reduced in the fractional CO2 laser combined with tioconazole more than the Q-switched laser group (p = 0.002). The mean DLQI score significantly improved in both groups but no statistically significant difference between the two groups. Significant improvement in patient satisfaction score was noted in both groups. Mycological cure using KOH examination was detected in both groups (44.4% in the CO2 group and 56.5% in the Q-switched group) with no significant difference (P value < 0.05). Ruin pattern keratosis found to be the most dermoscopic pattern to be associated with poor OSI score improvement. Fractional CO2 laser combined with topical tioconazole is more efficient in treatment of onychomycosis than Q-Switched Nd: YAG 1064nm laser group as regards clinical improvement but both have comparable effect on mycological cure. Their use as adjuvant treatment rather than alone is recommended to ensure mycological cure in onychomycosis.

Laser hemorrhoidoplasty versus hemorrhoidectomy in the treatment of surgically indicated hemorrhoids in inflammatory bowel patients: a randomized comparative clinical study.

This study aims to assess and compare the outcomes of traditional surgery and laser surgery for anal hemorrhoids in patients with inflammatory bowel disease. This is a single-center prospective randomized comparative clinical trial performed at Zagazig University Hospitals from September 2023 to September 2024. The study comprised 48 patients who were admitted during this period and had inflammatory bowel disease along with hemorrhoids. The patients were randomly allocated into two groups: Group I consisted of 24 patients who underwent laser hemorrhoidoplasty, selected based on odd numbers, while Group II consisted of 24 patients who underwent traditional surgery, selected based on even numbers. Group I, which underwent laser treatment for hemorrhoids in inflammatory bowel patients, demonstrated significantly better outcomes than traditional surgery (p < 0.001) regarding operation time, pain score and duration, postoperative anal discharge, return to work time, and patient satisfaction. Moreover, laser treatment was found to be more effective than traditional surgery for treating hemorrhoids in inflammatory bowel patients in terms of postoperative bleeding and anal stenosis. Additionally, there was a higher frequency of residual hemorrhoids in laser group. Laser treatment is mostly superior to traditional surgery for hemorrhoids in inflammatory bowel patients. Clinical Trial.gov (NCT06216223), registered on December 27, 2023, last updated in May 12, 2024. PROTOCOL REGISTRATION ID: #101080-5-9-2023.

Cord occlusion in twin reversed arterial perfusion sequence: a retrospective study of laser photocoagulation vs radiofrequency ablation.

Twin reversed arterial perfusion (TRAP) sequence is a rare condition complicating monozygotic multiple gestations. Prenatal management via umbilical cord occlusion (UCO) of the anomalous twin has been shown to improve pump twin survival. We compared outcomes of gestations with high-risk TRAP sequence treated with mid-trimester UCO using laser photocoagulation vs radiofrequency ablation (RFA). This is a retrospective, single-center, cohort study of all patients with high-risk TRAP sequence who underwent UCO from 2006-2023. High-risk criteria were defined as follows: larger abdominal circumference of the anomalous twin, polyhydramnios, critically abnormal Doppler waveforms in the pump twin, hydrops in the pump twin, and/or monoamniotic twins. The primary outcome was 30-day survival of the pump twin. The 74 patients were divided equally between the laser and RFA groups. For the 2 groups, mean gestational age (GA) at UCO (20.5 ± 2.3 vs 20.7 ± 3.1 weeks, P=.987) and mean GA at delivery (35.2 ± 4.6 vs 34.5 ± 5.7 weeks, P=.812) were similar. The 30-day neonatal survival rate did not differ (91.9% [34/37] vs 89.2% [33/37], OR: 1.37 [0.29-6.61], P=.692). No difference in 30-day neonatal survival was identified in patients with high-risk TRAP sequence who underwent mid-trimester UCO by laser vs RFA.

Photobiomodulation Therapy in the Prevention of Chemotherapy Induced Oral Mucositis in Children with Acute Myeloid Leukemia: A Randomized, Double-blind, Clinical trial.

Many preventive modalities have been advocated to reduce the incidence and severity of chemotherapy-induced Oral Mucositis (OM). Photobiomodulation, also known as Low-Level laser. Therapy, has shown promising results. This clinical trial was performed to evaluate the effectiveness of Photobiomodulation (PBM) for the prevention of chemotherapy-induced oral mucositis (OM) in children with Acute Myeloid Leukemia (AML). A double-blinded randomized clinical trial was performed, including forty-two children diagnosed with Acute Myeloid Leukemia (AML) admitted to receiving chemotherapy (CT) at Children's Cancer Hospital 57357, Cairo, Egypt. Patients were randomly assigned to either the control or test group. Both groups followed the standard preventive protocol for oral mucositis. In the control group I sham therapy, while in the Laser group I had Photobiomodulation sessions for five consecutive days once a day performed by Diode laser (Sirrolaser Blue ™, USA) 660nm, 15watt, 10 s. Laser sessions began on day 1 of chemotherapy and were repeated on days 2,3, 4, and 5. The response to both groups was evaluated according to the development of oral mucositis; graded using the classification criteria of the World Health Organization (WHO) and the National Cancer Institute scale (NCI - Common Terminology Criteria for Adverse Events, version 4.0). Incidence of oral mucositis was evaluated from baseline to 5, 12, 19, and 30 days after treatment. A clinical significant difference between the laser and control group was observed. The laser group showed a higher prevalence of no oral mucositis with decreased incidence of OM, while on day 12, the control group showed a higher prevalence of grades I and II (P-value <0.001, effect size = 0.796). However, the laser group showed higher prevalence of mucosa free of OM; on day 19, the control group showed higher rates of grades II and III, (P-value <0.001, effect size = 0.670). while on day 30 there was higher rates of grades I and II (P-value <0.001, effect size = 0.576) with higher rates of healthy oral mucosa in the laser group. Photobiomodulation effectively reduces the incidence and severity of chemotherapy-induced oral mucositis in pediatric patients diagnosed with AML.

Effects of various laser applications on surface roughness and bond strength to veneering composites of polyether ether ketone (PEEK) and polyether ketone ketone (PEKK) materials.

The aim of this study was to investigate the bond strength between PEEK/PEKK and composite resins after various laser treatments and to compare the effectiveness of lasers on these polymers. 130 disc-shaped PEEK and PEKK blocks were obtained (10mm diameter-4mm height). One sample from each group (10 in total) was selected for scanning electron microscopy (SEM) analysis. The samples were randomly divided into 5 different surface treatment groups for each material (PEEK and PEKK): Er: YAG laser, Nd: YAG laser, diode laser, femtosecond laser and control (no surface treatment) (n = 12). Baseline and post-treatment surface roughness measurements were performed using a profilometer. The composite resin was bonded and SBS was measured. Comparisons among the groups were conducted via Kruskal-Wallis, one-way ANOVA; Tukey and Dunn tests were used as a post hoc test (p ≤ 0.05). All lasers significantly increased the roughness values of the PEEK and PEKK samples. In terms of shear bond strength; the Er: YAG and femtosecond laser groups had the highest values and the Nd: YAG, diode and control groups had the lowest values of the PEEK samples (p ≤ 0.05). The control group had the highest bond strength values and the femtosecond group had the lowest values for PEKK samples (p ≤ 0.05). All laser treatments increased the surface roughness of the PEEK and PEKK. Lasers increased the bond strength of PEEK to the veneering composite resin and decreased the bond strength values of PEKK. This shows that lasers behave differently in PEEK and PEKK materials.

Vaginal LASER and estrogen comparison in Genitourinary Syndrome of Menopause

Aim:This study aims to compare the efficacy of CO2 fractionated laser therapy and topical estrogen treatment in managing Genitourinary Syndrome of Menopause (GSM). Materials and Methods:A total of 88 patients diagnosed with GSM were included in this retrospective study. Of these, 39 received CO2 fractionated laser treatment, while 49 were treated with topical estrogen. Patients whose treatment was completed 1 to 1.5 months prior and had pre-treatment Vaginal Health Index (VHI) and International Consultation on Incontinence Questionnaire-Short Form (ICIQ-SF) scored recorded were included in the study. These patients were invited for a follow-up visit, during which post-treatment VHI and ICIQ-SF scores were assessed by a physician. Results:Both the laser and estrogen groups showed significant improvements in VHI and ICIQ-SF scores after treatment (p < 0.00001 for both groups). No statistically significant difference was found between the post-treatment VHI and ICIQ-SF scores of the two groups (p < 0.923 and p < 0.579, respectively). Conclusion:Although there was no significant difference in the treatment efficacy between estrogen and CO2 fractionated laser therapy, there was a considerable difference in cost, with CO2 fractionated, with laser treatment being 23–24 times more expensive. Therefore, CO2 fractionated laser therapy, which shows similar short-term efficacy to topical estrogen, may be more suitable for patients where hormone therapy is contraindicated.

Comparison of two treatment modalities in the management of gingival enlargement during orthodontic treatment: a randomized clinical trial.

This clinical trial aimed to evaluate and compare the effectiveness of diode laser gingivectomy, conventional gingivectomy, and nonsurgical periodontal treatment (NSPT) in the management of gingival enlargement (GE) during orthodontic treatment. forty-five healthy, orthodontic patients with labial gingival enlargement on the 6 anterior teeth were selected and randomly assigned to one of the groups (Conventional, Laser, and NSPT). Clinical parameters including clinical crown length (CCL) , periodontal pocket depth (PPD), and vertical gingival overgrowth index (vGOi) were recorded at baseline, 1 month, 3 months, and 6 months. Postoperative pain was evaluated at 1,3, and 7 days. Esthetic satisfaction and acceptance of the procedure were recorded on day 10 and repeated after 6 months. Statistically significant results were obtained for mean reduction in PPD for conventional, laser, and NSPT groups (-1.43, -.1.75, and -0.9 mm, respectively; P < 0.001), CCL gain (1.45, 1.7, and 0.38 mm, respectively; P<0.001) and mean vGOi score (-1.14, -1.29 and -0.76, respectively; P<0.001) over 6 months. Both test groups showed greater statistically significant changes in clinical parameters over 6 months compared to NSPT (P<0.001). There was a gradual decrease in postoperative pain for all three groups over 7 days, with conventional group showing statistical difference in mean pain score on days 1 and 3 compared to other groups. Both conventional and laser gingivectomies were more effective in controlling enlargement over non-surgical periodontal treatment alone at 1, 3, and 6 months. laser and conventional gingivectomies as adjunctive treatments achieved superior results when compared to NSPT alone in the treatment of GE and gingival inflammation during orthodontic treatment, with no significant clinical differences between the two treatments.

The comparative study of temperature rise, time consuming and cut quality among piezosurgery, conventional rotary instruments and Er: YAG laser in apicectomy

ObjectivesThis study aimed to compare the temperature rise, time consuming and cut quality of apicectomy using three different methods.Materials and methodsTwenty-four single-rooted teeth were collected and divided into four groups operating apicectomy with a NINJA tip of a piezoelectric device (G1), a diamond bur with 300,000 rpm (G2), and Er: YAG laser at 200 mJ/ 30 Hz (G3) as well as 250 mJ/ 30 Hz (G4). The temperature elevation and time were recorded and the cut quality was evaluated via stereomicroscope and scanning electronic microscopy (SEM).ResultsThe temperature increases for G1 was significantly higher than for G2. However, there was no significant difference between G1 and G2 with laser groups respectively. The median time for apicectomy was: 100.14s for G1, 22.65s for G2, 33.58s for G3, and 21.80s for G4. G1 is the most time-consuming group and there was no statistically significance in the comparisons with G2, G3 and G4. Cut quality was assessed by crack occurrence, smear layer formation and dentinal tubules exposed. The percentage of cracked teeth in G1 and G2 was 33.33% and for laser groups the percentage was 16.67% each. SEM showed that no smear layer formed and almost all dentinal tubules were exposed on resected surfaces for G3&G4, surfaces from G2 were partly covered by smear layer, and surfaces from G1 were fully covered by smear layer and with no dentinal tubules exposed.ConclusionsEr: YAG laser and conventional rotary instruments were safe and efficient for apicectomy and with a better cut quality when compared with piezoelectric equipment. Er: YAG laser could be a promising technique for apicectomy and further studies are necessary, especially larger sample in vivo investigations, to verify the feasibility of Er: YAG laser in endodontic surgery.

Study on the Mechanism of Nd:YAG Laser-Assisted Therapy on the Changes of Subgingival Flora in Periodontitis.

This study evaluated the therapeutic efficacy of combining Neodymium-doped Yttrium Aluminum Garnet (Nd:YAG) laser with subgingival curettage and root planing (SRP) in generalised stage III/grade C periodontitis patients and its effects on cytokine dynamics and microbial community. Fifteen patients diagnosed with stage III/grade C periodontitis were included in the cohort. The right and left sides of the mouth were randomly assigned either the conventional SRP (control) group or the SRP supplemented with Nd:YAG laser group (experimental group, 160 mJ, 4 W) in a split-mouth design. Clinical periodontal indices were recorded at baseline and at the 6-week follow-up post-treatment. ELISA was utilised to measure IL-1β and TNF-α levels in gingival crevicular fluid. The subgingival microbiota's composition and variations were characterised using 16S rDNA amplicon sequencing, while quantitative real-time polymerase chain reaction (qRT-PCR) was employed to analyse the changes in the red-complex bacteria in subgingival plaque. The SRP&#43;Nd group exhibited a statistically significant reduction in record probing depth (PD) and bleeding on probing (BOP) compared to the SRP group after treatment (p0.05). The SRP&#43;Nd group showed a markedly lower IL-1β level than the SRP group (p0.05). Furthermore, there was no statistically significant difference in the dominant subgingival microbiota composition and level of the red-complex bacteria between the two groups (p>0.05). The adjunctive use of Nd:YAG laser with SRP demonstrates promising short-term therapeutic benefits for patients with extensive stage III/grade C periodontitis. Both SRP as a standalone treatment and its combination with Nd:YAG laser effectively facilitate a transition in the dominant bacterial community from periodontitis-associated to periodontal health-associated microbiota.

The Biofilm Removal and Bactericidal Effect of an 810-nm High-Power Laser on an Orthodontic Bracket Surface: An In Vitro Study.

Objective: The present study aimed to analyze the biofilm removal and bactericidal effect of laser treatment alone and laser combined with ultrasonic scaling on orthodontic brackets. It also assessed whether the use of a laser can improve the efficiency of biofilm removal and bactericidal effect compared with traditional ultrasonic instrumentation. Background Data: Streptococcus mutans (S. mutans) can lead to white spots and dental caries. Orthodontic brackets make teeth cleaning more difficult, and biofilms or bacteria on the surface of brackets worsen the oral environment, which may cause some oral diseases. Laser can be used for biofilm removal and killing bacteria on the surface of an object through thermal, photochemical, and pressure effects, which is widely used in the treatment of oral diseases. Methods: A total of 600 mandibular incisor brackets were collected for this study. Among these, 320 unused brackets were used for the S. mutans crystal violet assay (n = 160) and for S. mutans live/dead bacterial staining (n = 160). Another 280 brackets, obtained from patients who had undergone therapy for over two years, were used for the mature multispecies biofilms removal assay (n = 120) and multispecies bacterial live/dead bacterial staining (n = 160). Ultrasonic scaling, laser, and laser combined with ultrasonic scaling were applied to the labial surface of brackets covered by S. mutans biofilm or mature multispecies biofilms. Specifically, we used the following three methods: ultrasonic scaling for 10 sec without laser; 810-nm laser (Doctor Smile, Italy, LA5D0 001.1) with 0.3-mm spot size at total 21.2 kJ/cm2 for 10 sec; and 810-nm laser at total 10.6 kJ/cm2 for 5 sec, followed by ultrasonic scaling for 5 sec. The 810-nm diode laser removed biofilms with a power of 1.5 W and a power density of 2.12 kW/cm2. The S. mutans biofilm was examined using crystal violet assay, and scanning electron microscopy (SEM) was used for mature multispecies biofilms to evaluate the effect of the three methods on biofilm removal. Live/dead bacterial staining was used to examine the bactericidal effect on remaining biofilms by confocal laser scanning microscopy (CLSM). Results: For S. mutans biofilm, the optical density (OD) value and live/dead bacterial ratio in the laser and the laser combined with ultrasonic scaling groups were significantly lower than those in the ultrasonic scaling group (p < 0.05); moreover, the OD value and the live/dead bacterial ratio in laser treatment combined with ultrasonic scaling and laser treatment alone showed no significant difference (p > 0.05). For mature multispecies biofilms, the percentage of biofilm coverage after treatment was higher in the laser group than in the ultrasonic scaling group (p < 0.05) and lower in the laser combined with ultrasonic scaling group than in the ultrasonic scaling group (p < 0.05), and live/dead bacterial staining showed that laser treatment alone killed the most bacteria, followed by laser treatment combined with ultrasonic scaling, while ultrasonic scaling alone seldom killed bacteria. Conclusions: Laser treatment alone has a better bactericidal effect and can also remove more S. mutans biofilm than ultrasonic scaling alone, but it fails to remove more mature multispecies biofilms. Laser treatment combined with ultrasonic scaling can remove more S. mutans biofilm and mature multispecies biofilms than ultrasonic scaling alone and also has a better bactericidal effect than ultrasonic scaling alone on a bracket surface.

The proliferation and viability of human periodontal ligament stem cells cultured on polymeric scaffolds can be improved by low-level laser irradiation.

This study assessed the impact of low-level laser irradiation on the viability and proliferation of human periodontal ligament stem cells (hPDLSCs) cultivated on polylactic acid (PLA) scaffolds. hPDLSCs were obtained, characterized, and grown on the surface of PLA films produced via the solvent casting technique. The study involved two groups: the control group, which was not exposed to radiation, and the laser group, which was irradiated with a diode laser (InGaAIP) with a power of 30 mW, a wavelength of 660 nm, and a single dose of 1 J/cm² emitted continuously. Cell viability was assessed 24 and 48 hours after irradiation using the Alamar blue and Live/Dead assays. Flow cytometry was used to assess cell cycle events, and scanning electron microscopy (SEM) was used to evaluate the interaction between cells and the biomaterial. The results revealed a statistically significant increase in cell metabolic activity in the laser group compared with the control group at 24 hours (p <0.05) and 48 hours (p <0.001), as indicated by the Alamar blue assay. The Live/Dead assay also revealed a greater density of viable cells in the laser group. The cell cycle analysis revealed a significant increase in the number of cells in the proliferative phase (G2/M) in the laser group compared with the control group (p <0.001). The SEM images demonstrated that the irradiated group had a greater concentration of cells while still maintaining their cell shape and projections. This study demonstrated that photobiomodulation can increase the viability and proliferation of periodontal stem cells cultured on PLA scaffolds, suggesting the potential of this protocol for future studies on periodontal tissue engineering.

Soft tissue response to titanium healing abutments treated by Er: YAG laser or plasma spray: A randomized controlled feasibility clinical study with SEM and histological analysis.

Soft tissue seal around implants ensures stable osseointegration and a long-term survival of dental implants. Different surface modification and decontamination for implant abutments were endorsed in order to improve peri-implant soft tissue healing, such as laser, plasma spray, acid etching, and steaming. The aim of this study was to evaluate the response of peri-implant soft tissue to titanium abutments treated with Erbium-doped: Yttrium-Aluminum-Garnet (Er:YAG) laser versus plasma spray. Twenty-four patients who required implant placement in the maxillary arch participated in this study. Patients were divided into three groups, abutments treated with Er:YAG laser versus cold plasma spray and untreated abutments. Fourteen days following the implant abutment insertion, soft tissue peri-implant biopsies were taken for histological, histochemical, and immunohistochemical evaluation. Scanning electron microscopy was done for the abutments; plaque index (PI) and gingival index (GI) were assessed 14 days and 3 months following final restoration. Regarding the histological results, the least mean inflammatory cell count was in the plasma group (174.09 ± 40.67), followed by the laser group (654.27 ± 85.95) and the control group (852.00 ± 117.98), with statistically significant differences between them. The mean area fraction of collagen fibers showed the highest value in the plasma group (9.73 ± 1.91), followed by the laser group (3.25 ± 0.49), while the lowest value was found in the control group (1.17 ± 0.51). The immunohistochemical expression of E-cadherin was significantly higher and uniformly distributed in the plasma group (42.4 ± 11.2%) followed by the laser group (15.4 ± 4.07%) and the control group (6.8 ± 1.7%). SEM analysis of healing abutments showed fibroblast-like cells, which were more developed with dense fibers in the plasma group; laser group fibers showed fewer and more delicate fibers than the plasma group, while no fibers were detected in the control group. Within the limitations of this feasibility study, the present data concluded that plasma spray and Erbium: YAG laser can be used for abutment surface treatment to achieve better peri-implant soft tissue healing. Clinically and histologically, plasma spray showed a better effect on the peri-implant soft tissues by reducing the inflammatory reaction, promoting collagen fiber formation, higher fibroblast-like cell attachment, and upregulating E-cadherin expression than Erbium: YAG laser and control groups.

Enhanced wound closure in rabbit oral vestibule: a comparative analysis of suturing and laser tissue soldering

This study investigates the comparative effectiveness of laser soldering technique and conventional suturing methods for wound closure in rabbits. Over a 60-day post-operative period, scar formation and healing were monitored, with a particular focus on scar characteristics such as width, height, and overall appearance. Results indicate that the laser group exhibited improved scar characteristics, especially in the early stages (first and third days) of healing. By the seventh day, both groups demonstrated similar scar conditions, though the laser group showed a slightly faster recovery trajectory, with marginally lower scar height observed on the 21st and 60th days. While the laser technique showed some advantages in minimizing short-term complications, the long-term outcomes between the two methods were largely comparable. These findings suggest that the laser soldering method may offer some benefits over traditional suturing, particularly in the early stages of healing, but further research is needed to fully assess its clinical potential.

Combination of Losartan and Platinum Nanoparticles with Photothermal Therapy Induces Immunogenic Cell Death Effective Against Neuroblastoma.

Photothermal therapy (PTT) is a promising therapeutic procedure with minimal side effects, which can not only kill tumor directly but also cause immunogenic cell death (ICD). However, most solid tumors, including neuroblastoma, are abundant in fibroblasts, which limit the penetration and delivery of nanoparticles. Losartan is an antihypertensive drug approved by the FDA, and it has been proved to have the effect of breaking down excessive ECM network. In this study, we investigated the application and potential mechanism of the combination of mesoporous platinum nanoparticles (MPNs) and losartan in the PTT of neuroblastoma by establishing neuroblastoma models in vitro and in vivo. Compared to the MPNs group without 808 nm laser irradiation, Neuro-2a cells pretreated with PTT and losartan showed lower survival rates, increased surface calreticulin, and higher release of HMGB1 and ATP. The group also exhibited the highest anti-tumor efficacy in vivo, with a tumor suppression ratio of approximately 80%. Meanwhile, we found that CD3+ T cells, CD4+ T cells and CD8+ T cells from the peripheral blood of experimental group mice were significantly higher than control groups, and CD8+PD-1+ cells were significantly lower than those in MPNs + Los group and Los + laser group. And the expression of PD-1 and α-SMA in Neuro-2a tumors tissue was reduced. Furthermore, losartan could reduce damage of liver function caused by MPNs and laser treatment. This study demonstrated that losartan-induced fibroblasts ablation increased the penetration of MPNs into tumors. Enhanced penetration allowed PTT to kill more tumor cells and synergistically activate immune cells, leading to ICD, indicating the great promise of the strategy for treating neuroblastoma in vivo.

Effects of Laser Acupuncture on Metabolic Functions of Sedentary People: A Double-Blind Randomized Clinical Trial.

Background: Laser acupuncture regulates energy flow and restores body fluid metabolism. Objective: To evaluate the effects of the laser acupuncture protocol (LAP) on hepatic and renal metabolism in sedentary people. Methods: Longitudinal, double-blind, and randomized clinical trial with 29 participants, adults, both sexes, sedentary, without pre-existing metabolic diseases, subdivided into control and laser groups. Based on the STandards for Reporting Interventions in Clinical Trials of Acupuncture 2010 guidelines, 10 laser applications (660 nm ±10 nm wavelength, 100 mW power. The irradiation tip has a diameter of 5 mm, which corresponds to an area of 0.19 cm2, totaling a power density of 0.52 W/cm2 and considering the irradiation time of 90 s, the energy density applied was 47.3 J/cm2) were performed on the acupoints of metabolic functions (LR3, SP6, ST36, and LI4) and blood samples were collected for fasting glycemia, lipid profile (HDL, LDL, total cholesterol, and triglycerides), liver function (AST/GOT and ALT/GPT), and renal function (serum creatinine and urea). A repeated measures analysis of variance (ANOVA) with Bonferroni corrected post hoc comparisons was applied to compare statistical differences between groups and times, adopting p < 0.05 as the null hypothesis. Results: The laser stimulated changes in serum lipid profile values and renal and hepatic functions. There was a significant (p = 0.014) reduction in LDL ("bad" cholesterol) from 105.75 ± 32.83 pre- to 84.32 ± 18.38 mg/dL postintervention, associated with cardioprotective function. Positive significant (p = 0.035) impacts were also observed in the reduction of creatinine (0.86 ± 0.12 mg/dL to 0.75 ± 0.12 mg/dL) and the enzyme AST/GOT (33.73 ± 12.95 U/L to 20.80 ± 4.99 U/L, p = 0.002). Conclusion: LAP applied to basal metabolism acupoints promoted positive metabolic changes in the lipid profile (LDL), and in main markers of the liver (AST/GOT) and kidney (creatinine) functions, contributing to risk control of cardiovascular diseases.

Clinical Efficiency of Diode Lasers (810+980nm) in Exposure of Maxillary Impacted Canines

Objective: An impacted canine has no eruption following the completion of the normal growth pattern. To expose an impacted canine, a laser can be used as an additional tool in addition to a scalpel and electrocautery. To compare the effectiveness of a dual diode laser with a traditional scalpel procedure for exposing impacted canines, with the parameters of bleeding and pain as main outcomes. Methods: Thirty patients were chosen for this investigation. Each of them needed an operation for canine impaction, and they were divided into two groups at random: the study group, which were treated with a dual diode laser (980+810nm), and included fifteen patients, and the control group, which were treated with a scalpel. Data obtained prior to, during, and following surgery were compared. There were follow-ups after two hours, on the second, and third days after surgery. The Student's t and the one-way ANOVA tests were used for all comparisons. Results: Thirteen males and seventeen females were examined in this study, and their mean age was 23 years. Intraoperative bleeding score showed a significantly decrease in laser group versus the surgical blade group (0.4666 vs. 0.29333, P=0.001). The postoperative pain score was significantly decreased in the laser group compared to the surgical blade group, at two hours (4.6 vs 8.233, P = 0.001), two days (2.067 vs 4.833, P=0.001), and three days (1.066 vs 2.01, P=0.001). There were significant differences in the pain and bleeding scores (P≤ 0.05). Conclusion: When using a dual diode laser (810+910nm) as opposed to a scalpel, hemostasis can be achieved with minimal pain.

Comparative efficacy of pharmaceutical (Ibuprofen) and non-pharmaceutical (photobiomodulation, and chewing gum) interventions for pain reduction after elastomeric separator placement in orthodontic patients: a randomized clinical trial.

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, 940nm diode laser (Epic X, Biolase, USA, 12.35J/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 35s 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 8h for 5min for one week in case of pain. In the ibuprofen group, patients received 400mg ibuprofen (Hakim Pharmaceuticals, Tehran, Iran) after the placement of separators and were asked to take one tablet every 8h 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.

The Evaluation of 660, 810, and 940nm Laser Wavelengths on Nystatin-Resistant Candida albicans: An In-Vitro Study

Background: Candida albicans is the primary pathogen responsible for oral candidiasis. The emerging resistance of fungi to antifungal agents has led to the development of new fungicidal treatments. Objectives: This study aimed to analyze the effects of 660, 810, and 940 nm laser wavelengths on nystatin-resistant C. albicans. Methods: In this in vitro study, a standard strain of C. albicans and eight nystatin-resistant isolates were irradiated with 660, 810, and 940 nm diode lasers for 40 and 80 seconds (s) and compared with nystatin. Colony numbers and nystatin susceptibility were evaluated using the minimum inhibitory concentration (MIC). Results: All laser wavelengths significantly decreased the colony count of the standard strain of C. albicans, with 40s of 810 nm laser irradiation causing the maximum reduction in colony count (P810 nm &lt; 0.001). Similarly, all laser wavelengths significantly reduced the colony count of nystatin-resistant isolates, and they were more effective than nystatin (unlike with the standard strain) (P &lt; 0.05). The 810 nm laser irradiation for 40s demonstrated the greatest effect on MIC among the laser groups. Conclusions: The 810 nm laser for 40s was the most effective in reducing the colony count of nystatin-resistant C. albicans, and it eliminated resistance in all clinical isolates.

Gambogic acid and IR780 self-assembled nanoparticles for combined chemo-phototherapy

Combined chemo-phototherapy has shown considerable advantages and potential in cancer treatment. For this purpose, self-assembled nanoparticles by gambogic acid (GA) and IR780 (referred to as GA-IR780 NPs) were prepared. Herein, GA, an active compound derived from Garcinia hanburyi Hook.f, was selected as a chemo-agent. IR780 was used as a photothermal agent as well as a photosensitizer, which could kill tumor cells via photothermal effect and photodynamic effect. The obtained GA-IR780 NPs were uniform spheres with particle size of ca. 50 nm. The drug loading efficiency of GA and IR780 was 38.42 % and 56.64 %, respectively. The GA-IR780 NPs exhibited excellent photothermal properties as well as photodynamic effect when irradiated by near infrared (NIR) light (808 nm, 2.0 W/cm2). Moreover, the GA-IR780 NPs showed enhanced cytotoxicity with NIR light activation. Results of animal experiments showed that GA-IR780 NPs had the most significant tumor inhibition when irradiated by laser, and the results of H&E, Ki-67 and TUNEL staining confirmed that the GA-IR780 NPs+Laser group caused the most severe tumor tissue damage. The above results indicated that GA-mediated chemotherapy combining with IR780-based phototherapy could significantly improve the anti-tumor efficacy.