Neodymium-doped yttrium aluminum garnet (Nd: YAG) laser treatment in ophthalmology: a review of the most common procedures Capsulotomy and Iridotomy.

Nowadays, lasers are used in various medical fields. Ophthalmology was the first medical specialty to utilize lasers in patient treatment and still remains the leading medical field that uses laser energy for both therapeutic and diagnostic purposes. The neodymium: yttrium-aluminum-garnet (Nd: YAG) laser is one of the most common lasers used in ophthalmology. It is a solid-state laser with a wavelength of 1064 nm that works on the principle of photodisruption. Since its introduction in ophthalmology over 40 years ago, it has found various applications, mainly for procedures where cutting or disruption of ocular tissue is required. Compared to surgical alternatives, the use of Nd: YAG lasers on ocular tissue is minimally invasive. In this review, we focus on the two most common ophthalmic applications of Nd: YAG laser - laser peripheral iridotomy and posterior capsulotomy. The history of the techniques, current trends, potential complications, and the prognosis for future use is discussed.

Safety of using laser for hair removal in patients with skin diseases: a retrospective study.

Laser hair removal is a commonly used method in dermatology which is based on selective thermolysis and utilizes the appropriate wavelength, pulse width, and energy density to damage hair follicles. Given the prevalence of skin diseases such as psoriasis, dermatitis, and vitiligo, and the increasing popularity of laser hair removal, the aim of this study was to investigate the safety of laser hair removal in individuals with skin diseases. This retrospective study was conducted at the laser department of Razi Hospital on 99 patients who underwent laser hair removal. The exacerbation of disease after laser therapy was significantly associated with active skin disease (p = .021) and laser treatment at the site of the disease (p < .001). The incidence of Koebner phenomenon was significantly associated with age (p = .017) and the number of sessions with the ND-YAG device (p = .034). It is crucial to exercise caution when performing laser treatment on individuals with active skin disease and to avoid treating the affected area were possible. If necessary, it is recommended to delay laser treatment until the disease is under control for patients with active skin disease or those who wish to receive laser treatment at the site of the disease.

Advanced Optical Analysis of Divergence Between the Foci of the Neodymium-Doped Yttrium Aluminum Garnet (Nd:YAG) and Aiming Beam Lasers.

Purpose: To evaluate the divergence between the neodymium-doped yttrium aluminum garnet (Nd:YAG) surgical laser and the aiming diode laser beams foci. Design: Optical analysis and measurements were performed using a Volk Goldmann 3-mirror lens with a Nidek YC-1800 Nd:YAG laser apparatus. Subjects: None. Methods: We used the Zemax OpticStudio program for the model of Nd:YAG treatment in a human eye. Additionally, theoretical calculations were performed. Main Outcome Measures: The divergence between the Nd:YAG laser focus and the intersection of the 2 aiming beams inside the eye. Results: Focal points of the 2 laser beams converge 8 mm behind the cornea. Posterior to this point, the intersection of the diode laser aiming beams lies in front of the focal point of the Nd:YAG treatment laser, with distance between the 2 foci progressively increasing up to 305 microns at 24 mm behind the cornea. Conclusions: We report the degree of divergence between the 2 lasers' focal points due to the difference in refraction between the corresponding wavelengths. These results have high practical relevance, as they provide a starting point for increasing the accuracy of Nd:YAG laser treatment, particularly when applied to the posterior segment, thereby minimizing the risk of complications. Current Nd:YAG laser devices have the built-in ability to modify the focal point of the aiming beam along the z-axis, thus providing possibility for an immediate application of our findings in clinical practice. Financial Disclosures: The authors have no proprietary or commercial interest in any materials discussed in this article.

The investigation and comparison of the efficacy and safety of stromal vascular fraction (SVF), platelet rich plasma (PRP), and 1064-nm Q-switched Nd:YAG laser in reducing nanofat treated infraorbital dark circles and wrinkles: A controlled blinded randomized clinical trial.

BACKGROUND: To evaluate the efficacy and safety of stromal vascular fraction (SVF), platelet rich plasma (PRP), and 1064-nm Q-switched Nd:YAG laser in reducing nanofat treated dark circles and wrinkles under the eyes. METHOD: This study was a single-blinded randomized clinical trial conducted on patients with suborbital darkening under the eyes that randomly divided into control and case groups. In the control group, 15 patients were treated with one session of nanofat injection only, and five patients of each intervention groups received one session of nanofat+SVF injection, nanofat+PRP injection, and nanofat injection+Nd:YAG laser, respectively. Assessments methods were (1) evaluation of the degree of darkness and repair under the eyes by a blinded dermatologist based on clinical photographs, (2) investigating patient satisfaction, (3) using biometric variables for color, thickness, and density of the skin (only 3 months after the treatment), and (4) recording the possible adverse effects. CONCLUSION: In terms of the extent of reduction in the intensity of darkness under the eyes, the combined treatment of nanofat injection together with SVF, PRP, and Nd:YAG laser had a much greater therapeutic effect than nanofat injection alone. In all three groups of combined treatments, patients were 100% satisfied. In terms of biometric variables, amount of changes in colorimeter, complete and dermal thickness, complete and dermal density, between the different groups was statistically significant. The use of combined treatments including nanofat with SVF injection, PRP, and 1064 Q-switched Nd:YAG laser may be more effective than nanofat alone, in reducing infraorbital dark circles and wrinkles.

Intraoral Applications of Lasers in the Prosthetic Rehabilitation with Fixed Partial Dentures-A Narrative Review.

Laser, an acronym for Light Amplification by Stimulated Emission of Radiation, is a powerful tool with diverse applications in modern dentistry. It emits monochromatic, coherent light resulting from photon-induced chain reactions. Available dental lasers include diode, argon, Er,Cr:YSGG, Er:YAG, Nd:YAG, and CO2. The unique property of these lasers, allowing them to be effectively used on both soft and hard tissues based on the operational parameters, positions them as particularly suited for a wide range of dental procedures. Compared to traditional methods, lasers offer advantages such as improved hemostasis and quicker wound healing. Such benefits stress the shift towards laser technology in dental treatment. In the realm of dental prosthodontics, which focuses on esthetics, functionality, and the physiological aspects of dental prostheses, lasers provide promising outcomes. Among the prosthetic options, fixed partial dentures stand out for their ability to mimic natural teeth, offering both esthetic and functional features, leading to satisfactory long-term outcomes if managed properly. This review paper delves into the specific application of laser technology in the context of prosthetic rehabilitation involving fixed partial dentures. By investigating intraoral laser procedures, it contributes to understanding laser's role in improving patients' satisfaction and clinical efficiency in this field.

Optical Effects of Focused Fractional Nanosecond 1064-nm Nd:YAG Laser: Techniques of Application on Human Skin.

BACKGROUND AND OBJECTIVES: Considering the pulse widths of picosecond and nanosecond lasers used in cutaneous laser surgery differ by approximately one order of magnitude, can nanosecond lasers produce the optical effect in human skin similar to laser-induced optical breakdown (LIOB) caused by picosecond lasers? METHODS: Cutaneous changes induced by a focused fractional nanosecond 1064-nm Nd:YAG laser were evaluated by VISIA-CR imaging, histological examination, and harmonic generation microscopy (HGM). RESULTS: A focused fractional nanosecond 1064-nm Nd:YAG laser can generate epidermal vacuoles or dermal cavities similar to the phenomenon of LIOB produced by picosecond lasers. The location and extent of photodisruption can be controlled by the laser fluence and focus depth. Moreover, laser-induced shock wave propagation and thermal degeneration of papillary collagen can be observed by HGM imaging. CONCLUSION: Focused fractional nanosecond lasers can produce an optical effect on human skin similar to LIOB caused by picosecond lasers. With techniques of application, the treatment can induce epidermal and dermal repair mechanisms in a tunable fashion to improve skin texture, wrinkles, scars, and dyspigmentation, without disrupting the epidermal surface.

Lasers for the treatment of nail psoriasis: a systematic review.

This systematic review assesses the evidence concerning laser treatments for nail psoriasis (NP), a prevalent condition among individuals with cutaneous psoriasis that notably affects their quality of life. Traditional treatments have limitations in terms of drug delivery and poor patient adherence, leading to interest in laser therapies for their targeted approach, extended treatment intervals, and the potential to enhance topical medication effectiveness. The MEDLINE, Embase, Web of Science, and Cochrane Library databases were searched. English-language randomized and non-randomized controlled trials with full-text availability were included. Data on the laser type, treatment protocol, Nail Psoriasis Severity Index (NAPSI) outcomes, and adverse events were extracted, and nail bed and matrix features and patient satisfaction were assessed. The primary effect measure was a percentage reduction in NAPSI scores from baseline. Nineteen studies involving the pulse dye laser (PDL), long-pulsed neodymium:yttrium aluminum garnet (Nd:YAG) laser and fractional carbon dioxide laser (FCL) were identified. Lasers, particularly those used in conjunction with topical agents, have shown favorable results. PDL effectively lowered NAPSI scores, and the Nd:YAG laser had comparable effectiveness but more discomfort. FCL also shows promise, particularly for topical drug delivery. PDL and Nd:YAG laser treatment were more effective at reducing nail bed features, whereas FCL was effective at reducing both nail bed and matrix features. Overall, lasers are promising treatment alternatives for NP, with similar NAPSI outcomes to topical therapies and intralesional injections.

Long-pulsed nd: YAG laser treatment of nail psoriasis: clinical and ultrasonographic assessment.

Nail psoriasis is a chronic, inflammatory condition which is difficult to treat, linked with greater psoriasis severity, and may be associated with anxiety and significant functional impairment of the quality of life. The 1064 nm Nd: YAG laser was reported to yield satisfactory results in the treatment of nail psoriasis.The aim of the study was to assess the clinical and ultrasonographic efficacy of long-pulsed 1064 nm Nd: YAG laser in the treatment of fingernail psoriasis and compare its effect to control fingernails.This intra-patient randomized controlled trial analyzed 86 fingernails collected from 13 patients suffering from cutaneous and nail psoriasis. The nails were randomized into two groups. Group A was treated with Nd: YAG laser once monthly for three sessions while group B served as control. Assessment took place at baseline, 1 and 3 months after the last treatment session. For scoring, the 32-points target NAPSI scoring systems was used. Additionally, two blinded dermatologists' score of improvement, patients' pain assessment by visual analogue score and ultrasonographic assessment were all performed.At the end of follow up, the medians of tNAPSI score, plate definition, matrix thickness, bed thickness and bed vascularity decreased significantly in the Nd: YAG laser treated group in comparison to baseline (p = 0.001, 0.006, 0.039, < 0.001 and 0.010, respectively). While, there was a non-significant reduction in median tNAPSI score in the control group at last follow up, however, ultrasonography recorded a significant reduction in the medians of plate definition, bed thickness and vascularity (p = 0.002, 0.011 and 0.033, respectively) from the baseline. Comparison of the Nd: YAG laser and the control groups showed no significant difference from baseline regarding the medians of tNAPSI, tNAPSI percentile improvement, pits count, blinded evaluation of photographs and ultrasonographic assessments.In conclusion, Nd: YAG laser showed clinical and ultrasonographic improvement in fingernail psoriasis. Ultrasonography is a useful noninvasive tool in diagnosing and monitoring the clinical and even the subclinical changes in nail psoriasis. Nail psoriasis although difficult to treat, may show spontaneous improvement.

A prospective comparative study of efficacy and safety of 15% trichloroacetic acid peel, 35% glycolic acid peel and Q-switched Nd-YAG laser in patients of macular amyloidosis.

Background: The unappealing appearance of skin in macular amyloidosis (MA) interferes with the patient's quality of life, and treating the condition has been challenging. Aims and Objectives: To compare the efficacy and safety of 15% trichloroacetic acid (TCA) peel, 35% glycolic acid (GA) peel, and Q-switched Nd-YAG Laser in MA. Materials and Methods: Open, prospective study was conducted over 2 years, where after fulfilling the criteria, randomization was done into three groups. Group A: 15% TCA peel; Group B: 35% GA peel; Group C: Q-switched Nd-YAG Laser. Procedures were repeated at monthly intervals for six sittings. On each visit, patients were scored on the following parameters: color score, visual analog score (VAS), physician global assessment (PGA) scale, subjective improvement, and adverse effects. Results: A total of 75 patients (25 patients in each group) completed the treatment. The mean age of study-population was 35.68 ± 9.8 years, with female to male ratio of 11.5:1. The mean change in color score (1.68) was more by Group A, followed by Group C (1.4), followed by Group B (1.16). Similar results were noted by subjective improvement, VAS, and PGA. Adverse events were more in Group A, followed by Group C, followed by Group B. No patient showed permanent adverse events. Conclusion: TCA-peel showed superior results over Nd-YAG laser and glycolic-acid peel. TCA-peel being cost-effective with excellent acceptability should be considered a treatment modality.

Canal disinfection using Nd: YAG Laser, synchronized microbubble-photodynamic activation, and carbon quantum dots on microhardness, smear layer removal, and extrusion bond strength of zirconia post to canal dentin. An invitro scanning electron microscopic analysis.

Evaluation of the impact of the latest root canal disinfectant, that is carbon quantum dots (CQDs), synchronized microbubble-photodynamic activation (SYMPA), and Nd: YAG laser along with ethylenediaminetetraacetic acid (EDTA) as a final irrigant on the Marten hardness (MH), smear layer (SL) removal, and extrusion bond strength (EBS) of zirconia post to the canal dentin. Eighty intact single-rooted premolars were obtained and disinfected using 0.5% chloramine-T solution. Root canal preparation was performed using ProTaper files followed by obturation. The post space was prepared for prefabricated zirconia post and all the teeth were randomly divided into four groups based on the disinfection used (n = 20 each) Group 1: 5.25% NaOCl + 17% EDTA (Control), Group 2: Nd: YAG laser + 17% EDTA, Group 3: SYMPA + 17% EDTA, and Group 4: CQDs + 17% EDTA. MH, SL removal, and EBS of zirconia post-bonded to root dentin were performed using a microhardness tester, scanning electron microscope (SEM), and universal testing machine, respectively. Both intragroup and intergroup comparisons were performed using one-way analysis of variance (ANOVA) and posthoc-Tukey test for significant difference (p < .05). Group 2 samples (Nd: YAG laser + 17% EDTA) (0.24 ± 0.06 GPa) exhibited highest values of MH. Samples in group 3 (SYMPA + 17% EDTA) treated teeth unveiled the lowest MH scores (0.13 ± 0.02 GPa). Moreover, the coronal third of Group 3 specimens (SYMPA and 17% EDTA) (1.54 ± 0.31) eliminated SL from the canal with the greatest efficacy as well as presented the highest EBS (10.13 ± 0.69 MPa). However, the apical third of Group 1 samples (5.25% NaOCl + 17% EDTA) (2.95 ± 0.33) exhibited the least efficient elimination of SL from the radicular dentin as well as the lowest bond strength (5.11 ± 0.19 MPa) of zirconia post to the dentin. The SYMPA technique with 17% EDTA proved highly effective in removing the SL from canal dentin and enhancing the EBS of zirconia posts. The least preferable method for SL removal and MH improvement was found to be 5.25% NaOCl + 17% EDTA. CQDs and Nd: YAG laser demonstrated satisfactory smear layer removal properties from the canal, along with achieving appropriate bond strength of zirconia posts. RESEARCH HIGHLIGHTS: Nd: YAG laser and 17% EDTA as canal disinfectant exhibited the highest values of MH. Specimens irrigated with SYMPA and 17% EDTA eliminated SL from the canal with the greatest efficacy. The coronal third of Group 3 (SYMPA + 17% EDTA) samples unveiled the highest zirconia post-bond integrity score to the canal dentin. Cohesive failure was a dominant failure type among different experimental groups.

Vitrectomy for a traumatic macular hole caused by cosmetic laser in a beauty salon: A case report.

Background: The Nd:YAG laser is widely used in various aspects of work and life. Currently, it has become a popular cosmetic technique in beauty salons. The laser can be dangerous when it flashes into people's eyes. Case presentation: A 34-year-old female sustained a 1064-nm Q-switched Nd:YAG laser injury to her left eye. One month after the injury, she presented to our clinic with best-corrected visual acuity (BCVA) of 20/250 and a full-thickness macular hole on the optical coherence tomography (OCT). The patient received pars plana vitrectomy, internal limiting membrane peeling and sterile air injection 3 months after the injury. OCT showed closure of the hole 9 days postoperatively. After a 3-month follow-up, her BCVA improved to 20/100. Conclusions: This case report comprehensively introduces the whole progression of a cosmetic laser-induced macular hole from formation to recovery. Due to the potential threats of the laser and its irreversible damage to the retina and choroid, sufficient education should be given before performing any laser devices, especially those without professional knowledge.

No side effects on rabbit retina or vitreous microenvironment by nd:YAG laser vitreolysis.

BACKGROUND: To explore the safety of Neodymium:Yttrium-aluminum-garnet (Nd:YAG) laser vitreolysis based on the histological examination of the retina and the alteration of vitreous cytokines in the rabbits. METHODS: Nine male New Zealand rabbits underwent Nd:YAG laser vitreolysis of 10 mJ x 500 pulses in the left eyes, while the right eyes were used as controls. Intraocular pressure, color fundus photography, and ultrasound B scan were measured before, as well as 1 day, 4 weeks, and 12 weeks after Nd:YAG laser vitreolysis. Three rabbits were euthanized 1 day, 4 weeks, and 12 weeks after treatment, respectively. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining and hematoxylin-eosin (H&E) staining were used to look for pathological changes in the retina. An enzyme-linked immunosorbent assay (ELISA) was utilized to detect the expression of vascular endothelial growth factor (VEGF) and some inflammatory cytokines, including interferon inducible protein 10 (IP-10), monocyte chemoattractant protein 1 (MCP-1) and interlenkin 6 (IL-6) in the vitreous humor. The ascorbic acid (AsA) and total reactive antioxidant potential (TRAP) in the vitreous humor were also measured. RESULTS: Following Nd:YAG laser vitreolysis, the levels of VEGF, IP-10, MCP-1, IL6, AsA, and TRAP in the vitreous humor did not change substantially (P > 0.05). There were no detectable pathological changes in the retinal tissues, and no apoptotic signal was found. CONCLUSIONS: Rabbits tolerate Nd:YAG laser vitreolysis without observable impact on retinal tissue or the microenvironment of the vitreous.

An energy efficiency assessment of Yttrium-aluminum-garnet laser in vitro.

To study the effect range of the Nd:YAG laser through various levels of cloudy medium for targets with varying grayscale values in vitro. The coated paper cards with grayscale values of 0, 50, 100, and 150 were used as the laser's targets, which were struck straightly with varying energies using three burst modes (single pulse, double pulse, and triple pulse). Six filters (transmittances of 40, 50, 60, 70, 80, and 90) were applied to simulate various levels of cloudy refractive medium. Image J software was used to measure the diameters and regions of the laser spots. The ranges of the Nd:YAG laser spots increased with energy in the same burst mode (P < 0.05). Under the same amount of energy, the ranges of the Nd:YAG laser spot increased with the grayscale value of the targets (P < 0.05). The greater the transmittance of the filters employed, the larger the range of the Nd: YAG laser spots produced. Assuming that the total pulse energy is identical, the effect ranges of multi-pulse burst modes were significantly larger than those of single-pulse burst mode (P < 0.05). The effect range of a Nd:YAG laser grows with increasing energy and the target's grayscale value. A cloudy refractive medium has a negative impact on the effect range of the Nd: YAG laser. The single pulse mode has the narrowest and safest efficiency range.

1444-nm Nd:YAG for Laser-Assisted Lipolysis: A Minimally Invasive Technique for the Treatment of Pseudogynecomastia.

Background: The options for treating pseudogynecomastia are limited, and there is a growing demand for noninvasive breast fat reduction. We evaluated the efficacy and safety of a laser-assisted lipolysis (LAL) device emitting 1444 nm for the treatment of pseudogynecomastia. Methods: A total of 9 male patients diagnosed with pseudogynecomastia underwent laser procedure with a Nd:YAG laser emitting at 1444 nm. The goal was to generate adequate heat propagation and thermal action in the dermis as homogeneous as possible to induce fat cell lipolysis. The results were clinically evaluated by comparing pictures at baseline and 4 months later. Results: An independent comparison of baseline and post-treatment pictures by a physician evaluator 4 months after treatment revealed significant improvement in all patients. Three subjects (33%) showed grade 4 improvement; 4 (44%) showed grade 3 improvement, and 2 (22%) showed grade 2 improvement. Breast sizes decreased in all patients 4 months after 1444-nm LAL. All patients experienced an incident-free postoperative period. Conclusions: The LAL procedure performed in this study using 1444-nm Nd:YAG laser appears to be a very effective/comfortable outpatient solution to the problem for patients. It has proven a safe procedure, and all subjects in the study experienced a significant clinical improvement regarding their pseudogynecomastia, with a decrease in breast volume and visible skin contraction.

Multiphotonic Ablation and Electro-Capacitive Effects Exhibited by Candida albicans Biofilms.

This work reports the modification in the homogeneity of ablation effects with the assistance of nonlinear optical phenomena exhibited by C. albicans ATCC 10231, forming a biofilm. Equivalent optical energies with different levels of intensity were irradiated in comparative samples, and significant changes were observed. Nanosecond pulses provided by an Nd:YAG laser system at a 532 nm wavelength in a single-beam experiment were employed to explore the photodamage and the nonlinear optical transmittance. A nonlinear optical absorption coefficient -2 × 10-6 cm/W was measured in the samples studied. It is reported that multiphotonic interactions can promote more symmetric optical damage derived by faster changes in the evolution of fractional photoenergy transference. The electrochemical response of the sample was studied to further investigate the electronic dynamics dependent on electrical frequency, and an electro-capacitive behavior in the sample was identified. Fractional differential calculations were proposed to describe the thermal transport induced by nanosecond pulses in the fungi media. These results highlight the nonlinear optical effects to be considered as a base for developing photothermally activated phototechnology and high-precision photodamage in biological systems.

Pilot Study to Demonstrate Improvement in Skin Tone and Texture by Treatment with a 1064 nm Q-Switched Neodymium-Doped Yttrium Aluminum Garnet Laser.

BACKGROUND: The 1064 nm Q-switched neodymium-doped yttrium aluminum garnet (QS Nd:YAG) laser was developed to treat unwanted pigmentation in the skin such as lentigines caused by photoaging, and tattoos from dye/ink insertion. This laser has also been used for non-ablative epidermal rejuvenation (skin toning). OBJECTIVE: To evaluate changes in skin tone, skin texture and overall improvement after a series of treatments with the QS Nd:YAG laser. METHODS: Participants received seven full-face treatments with M22 or Stellar M22, a 1064 nm QS Nd:YAG laser, at 2-week intervals. The investigators and participants evaluated the improvement in skin tone and texture at 1, 3 and 6 months after the last treatment. Patient satisfaction, patient discomfort, downtime and adverse events were recorded. Histological changes in the treated area were also evaluated. RESULTS: Thirteen women with a median age of 45 years (range, 34-61 years) were included in the study. The majority of the participants (53.9%) had skin type VI. One month after the last treatment session, 38% of participants reported good to very good improvement. This value increased to 100% participant improvement at both the 3-month and 6-month follow-up visits. The reduction in melanin index and the histological analysis demonstrated that the laser procedure contributed to a reduction in epidermal melanin content. Treatments were not associated with high levels of pain or discomfort. The most common immediate post-treatment response was erythema and edema. Most participants were satisfied with the resulting treatment outcome. CONCLUSION: Skin treatment with the 1064 nm QS Nd:YAG laser module on the M22 and Stellar M22 devices, using a large spot size, low fluence, moderately high repetition rate, improves skin tone and texture in patients with skin types II-VI.

Angiolymphoid hyperplasia with eosinophilia and Kimura disease: A case report and literature review.

Angiolymphoid hyperplasia with eosinophilia (ALHE) is a benign vascular proliferative condition, typically presenting as subcutaneous nodules in the head and neck region of middle-aged women. Kimura disease (KD) is a benign condition that presents with subcutaneous nodules in a similar distribution with lymphadenopathy and eosinophilia, typically in Asian adult males. These diseases are often discussed together, including whether they exist on a spectrum or if they represent separate disease entities. Both are very rare in the pediatric population; in this report we highlight the case of a 10-year-old Caucasian male presenting with ALHE and KD.

Effects of Nd:YAG laser irradiation at different energy densities on dentin bond durability under simulated pulpal pressure.

OBJECTIVES: To evaluate the effects of Nd:YAG laser irradiation on the microstructures of dentin surfaces and the long-term bond strength of dentin under simulated pulpal pressure. MATERIALS AND METHODS: Under simulated pulp pressure, 30 freshly extracted caries-free third molars were cut into 2-mm-thick dentin samples and then divided into five groups: the control and laser groups (93.3 J/cm2; 124.4 J/cm2; 155.5 J/cm2; 186.6 J/cm2). Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), and Vickers hardness were used to analyze the surface morphology, composition, and mechanical properties of the dentin before and after laser irradiation. Another 80 caries-free third molars were removed and treated as described above, and the resin was bonded to the dentin surface with Single Bond Universal (SBU) adhesive in self-etch mode to make stick specimens. Microtensile bond strength (µTBS), confocal laser scanning microscopy (CLSM), and interfacial silver nanoleakage tests before and after 10,000 times thermocycling were then performed to analyze the bonding properties and interfacial durability of each group. RESULTS: SEM observations revealed that the surfaces of all laser group specimens were rough with open dentin tubules. Laser irradiation altered the surface composition of dentin while removing some collagen fibers but did not affect its surface hardness or crystallographic characteristics. Furthermore, laser irradiation with an energy density of 124.4 J/cm2 significantly promoted the immediate and aging bond strengths and reduced nanoleakage compared to those of the control group. CONCLUSIONS: Under simulated pulp pressure, Nd:YAG laser pretreatment altered the chemical composition of dentin and improved the immediate and long-term bond strength. CLINICAL RELEVANCE: This study investigated the optimal parameters for Nd:YAG laser pretreatment of dentin, which has potential as a clinical method to strengthen bonding.

Combined Effects of Glutaraldehyde-based Desensitizer and Nd: YAG Laser on Dentinal Tubules Occlusion.

AIM: The aim of this study was to assess the impact of Nd:YAG laser, glutaraldehyde-based desensitizer (GD), or their combination on occluding dentinal tubules. MATERIALS AND METHODS: Fifty dentin samples were obtained from non-carious human third molars and randomly divided into five groups (n = 10): (1) Control group treated with 37% phosphoric acid, (2) GD group, (3) Nd:YAG laser group (1064 nm, 100 µs, 10 Hz, 300 µm fiber, 1 W power, 100 mJ energy, and 85 J/cm2 energy density), (4) GD followed by Nd:YAG laser group, and (5) Nd:YAG laser followed by GD group. Scanning electron microscopy (SEM) was used to capture five images from each sample for analysis of dentinal tubules using Image J software. SEM/EDX elemental analysis was performed to determine the main mineral contents. Data analyzed using one-way ANOVA and Tukey's post hoc test for statistical comparisons. RESULTS: Laser and combination groups showed a significant decrease in dentinal tubule counts compared with the control and GD groups (p < 0.0001). There were no significant differences in open dentinal tubule counts between the control and GD groups, as well as between the laser and combination groups. However, significant differences were observed in the total area, average size of the tubules, and percentage area between the control group and the treatment groups (GD, laser, GD + laser, laser + GD). No significant difference was found in the Ca/P ratio between the tested groups. CONCLUSION: The use of Nd:YAG laser alone or in combination with GD was more effective in occluding dentinal tubules compared to GD alone. CLINICAL SIGNIFICANCE: This study has shown that Nd:YAG laser alone and in combination with GD has superior dentinal tubule occlusion in vitro. Its clinical use in the treatment of dentinal hypersensitivity may overcome the drawback of conventional treatment approaches for dentin hypersensitivity needing repeated applications to achieve continuous relief from pain since acidic diet and toothbrushing result in the continuing elimination of precipitates and surface coatings. How to cite this article: Alzarooni AH, El-Damanhoury HM, Aravind SS, et al. Combined Effects of Glutaraldehyde-based Desensitizer and Nd: YAG Laser on Dentinal Tubules Occlusion. J Contemp Dent Pract 2024;25(1):52-57.

Effects of pulsed Nd:YAG laser kernel irradiation on maize (Zea mays L.): Insights into germination, gas exchange, photosynthetic pigments, and morphological modifications.

Energy has always been the most concerned topic worldwide due to its large consumption. Among various types of energies, light has amazing characteristics and have interesting effects on living organisms. Interest is increasing in the use of laser kernel treatment as an environment friendly physical technique for better results in agronomic crops, but the work is still in progress. The present study was conducted with the aim to examine the application of range of Neodymium-doped Yttrium Aluminum Garnet (Nd:YAG) pulsed laser exposures (200, 400, 600, 800, 1000, 1200, 1400 J/cm2) as pre-sowing kernel treatment on seedling survival rate, leaf photosynthetic activity in relation with photosynthetic pigments and visual morphological effects at seedling to maturity stage. Results showed that the low laser exposure (200, 400 and 600 J/cm2) improved the photosynthetic activity in parallel with improvement in chlorophyll a, chlorophyll b, total chlorophyll, carotenoids as well as morphological traits. Kernel treatments with higher laser fluences (800, 1000, 1200 and 1400 J/cm2) showed irregular responses in studied attributes examined at the individual plant level. At 800 and 1000 J/cm2 improvements were found in some plants but at higher doses clear negative impacts were recorded on studied attributes. In conclusion, the lower doses of Nd:YAG pulsed laser fluences are found beneficial for induction of improvement in maize plants for better growth but higher doses were found toxic ones. In future further studies are needed to check the impacts of low laser doses on yield related attributes under field conditions and the high doses might also be used to create variants with beneficial characteristics if possible.