Effect Of Laser Irradiation Research Articles

Nanosecond laser-induced contact reactive brazing of Si3N4 ceramic to Al

In this study, a nanosecond laser was conducted to modify the Si3N4 surface to realize the bonding of Si3N4 to Al. The effects of nanosecond laser irradiation on the surface morphology and chemical compositions of Si3N4 ceramic together with the bonding of Si3N4 ceramic to Al were investigated. The laser irradiation induced the thermal decomposition of Si3N4 ceramic, resulting in the formation of a recast silicon layer upon the ceramic surface. Then bonding of Si3N4 ceramic and Al was achieved by the eutectic reaction between the recast silicon layer and Al at a bonding temperature of 600 °C under a uniaxial pressure of 10 MPa for 60 min. The nanosecond laser irradiation method proposed in this study provided a new idea to realize the direct bonding of ceramic to metal.

The effect of femtosecond laser irradiation on the growth kinetics of Staphylococcus aureus: An in vitro study.

We investigated the effect of femtosecond laser irradiation on the growth kinetics of Staphylococcus aureus. In order to improve laser-based antimicrobial therapy and develop a clinically viable modality, various laser parameters such as laser light wavelength, laser power, exposure time, and energy density were studied. The INSPIRE HF100 laser system (Spectra Physics) provided the femtosecond laser light, which was pumped by a mode-locked femtosecond Ti: sapphire laser MAI TAI HP (Spectra Physics). The survival of the bacterial cells was monitored after irradiation by determination of growth rate using optical density, which is a rapid, simple, and reliable method. The growth rate of laser-exposed cultures was compared to control cultures. Fifteen minutes of exposure to femtosecond laser radiation with a wavelength of 390nm and 400nm at an average power of 50mW was enough to significantly reduce bacterial viability, with a lag in the growth phase of 5h longer than the control culture (P<0.0001 by ANOVA and Tukey test).

Effect of Low-Level Laser Irradiation on Accommodation and Visual Fatigue.

PurposeThis study used low-level laser irradiation on auricular points for the eyes of junior college teenagers with myopia to observe the changes in refractive errors and eye accommodation. According to the Sterner’s study, we used the relationship between the amplitude and subjective symptoms to assess the degree of improvement in visual fatigue caused by changes in accommodation.MethodsParticipants were 49 healthy junior college teenagers, with an average age of 16.04±0.80 years old, and the refractive errors of both eyes were between −1.50 D and −5.00 D. All participants underwent refractive error tests before and after class and after a 30-min break. In a 30-min break, all participants underwent two tests of with (experimental group) and without (control group) low-level laser irradiation on the auricular points. Then, refractive error tests were conducted to evaluate the participants’ eye accommodation.ResultsThe results revealed that with treatment of the auricular points with and without low-level laser irradiation, the refractive error of the participants’ binocular left and right eyes decreased by −0.12 D (−0.18 D) in the experimental grou and by −0.05 D (−0.02D) in the control group. For the amplitudes of accommodation (AA) examination, the AA of the participants’ binocular in the experimental group became 7.98 ± 1.35 D (7.65 ± 1.37 D). The AA of participants’ binocular can recover to the level before the class.ConclusionThe results indicated that low-level laser irradiation at auricular points restored the eye accommodation faster than did natural closing of the eyes.

The enhanced light diffuse reflection of laser marking Al substrate for the back reflector purpose

This study set out with the aim of assessing the possibilities of incorporating the laser marking strategies for the purpose of diffuse back reflector fabrication. The correlation between the laser process parameters of fabricated samples’ microstructure and their optical properties has been determined. The laser texturizing was conducted on the aluminum substrate throughout the Nd:YAG (1064 nm) laser varying the laser process parameters, i.e. scanning speed (v) and pulse repetition rate (f). The effect of laser irradiation on surface nanostructure was investigated by means of confocal optical microscopy (COM) and scanning electron microscopy (SEM). In order to evaluate the phase composition and optical properties of fabricated nanotextures, the X-ray diffraction (XRD) and spectrophotometric measurements were performed. The obtained reflectance spectra of samples were used to perform the colorimetry analysis and calculate the luminous reflectance. The morphological evaluation of patterned surfaces gives evidence of periodic crater-shaped structures formation influenced by chaotic radial-ligaments patterns resulting from splashing liquid metal solidification. Laser-textured Al reflectors show almost similar total reflectance as the untreated substrate whereas the significant enhancement of diffuse reflectance of patterned sample series can be observed. The different hues of white colour appear on all laser-patterned Al surfaces. The calculated luminous reflectance of proceeded samples ranging from 65% to 75%. The overall results show the effectiveness of the laser marking process in order to obtain highly diffusive scattering layers on Al substrate without employing any additional coating.

Rehardening of Eroded Enamel with CPP-ACFP Paste and CO2 Laser Treatment.

Background Diet and lifestyle can destroy tooth structure due to the dissolution of enamel by acidic beverages. The present study evaluated the effect of CO2 laser irradiation and CPP-ACFP (casein phosphopeptide and amorphous calcium phosphate with fluoride) paste on the remineralization of enamel eroded by carbonated soft drinks. Methods In the present in vitro study, 46 human sound premolar teeth were sectioned mesiodistally to achieve 84 samples. Fourteen samples were assigned to the positive control group (G1), and the remaining samples were immersed in 500 mL of cola drink for 2 minutes, followed by rinsing with distilled water for 10 seconds. This procedure was carried out three times to create erosive lesions. Then, the 60 eroded samples were randomly assigned to five groups of G2 to G6 in terms of the treatment as follows: negative control (G2), CO2 laser irradiation (G3), CPP-ACFP paste (G4), CO2 laser irradiation followed by CPP-ACFP paste application (G5), and CPP-ACFP paste application followed by CO2 laser irradiation (G6). The mean surface microhardness of the enamel surface was evaluated and determined at three points for each sample. Data were analyzed with one-way ANOVA and Tukey HSD tests (α = 0.05). Results The highest and the lowest hardness values were recorded in the G1 (314 ± 12 kg/mm2) and G2 (213.7 ± 12 kg/mm2) groups, respectively. ANOVA revealed significant differences between the study groups (P < 0.001). Two-by-two comparisons showed significant differences between the G2 group and the other groups, indicating the efficacy of all the treatment modalities in tooth remineralization and rehardening procedures (P < 0.05). Only in group G6, the enamel microhardness was not significantly different from the G1 positive control group (P > 0.05). Conclusion Considering the parameters used in the present study, CO2 laser irradiation or CPP-ACFP paste application alone increased eroded enamel's surface hardness; however, their sequential application was more effective in rehardening the eroded enamel's surface to near-normal levels.

Study on application of laser in maskless localized electrodeposition and surface quality enhancement

To obtain electrodeposited layers with different patterns, the additional auxiliary measures such as mask prepared by photoresist are usually required for traditional electrodeposition (ECD) technology, which may reduce the flexibility and convenience of this method. Meanwhile, the ultrashort pulsed laser can be introduced into ECD process and increase current density in the selected area on cathode, and has potential in helping achieve maskless localized ECD. In this paper, the picosecond (ps) laser-assisted ECD (LECD) method is studied, in which a cyclic laser scanning scheme is used to produce different electrodeposited layers on the cathode substrate. In addition, the realizing mechanism of localized ECD is discussed, and the surface quality of Ni-P coating prepared by LECD is evaluated. The results show that the electrodeposited layers with different sizes (1 × 1 mm, 2 × 2 mm and 3 × 3 mm) can be obtained by laser selective irradiation on the copper substrate (10 × 10 mm), demonstrating that the critical current can be increased to reach the reaction conditions in the irradiated zone by the laser-caused thermal effects. Analysis also shows that the theoretical diameter of zigzag edge can be calculated, which is consistent with that of actual electrodeposited layer, indicating that the precision and localization of electrodeposited layer is controllable by adjusting laser processing parameters. Furthermore, measurement shows that a surface roughness of 0.012 μm and better surface flatness can be obtained by LECD under a pulse energy of 16 μJ, and the amorphous degree Ni-P can be increased by the thermal and photoelectric effects of ps laser irradiation. Besides, the corrosion potential and current density are −0.19 V and 3.83 × 10−6 A/cm2, respectively, and the AC impedance spectrum also indicates a higher electron transfer resistance, illustrating better corrosion resistance can be achieved by LECD (16 μJ).

Influences of CO2 laser modification on the surface morphology and optical absorption of graphene thin films

Abnormal optical absorption phenomena were observed in as-modified few-layer graphene thin films by 10.6-μm CO2 laser under ambient conditions. Saturable absorption (SA) responses were measured using z-scan technology. The graphene samples showed SA before laser modification, whereas they exhibited reverse SA behavior after laser modification due to the effects of thinning and damage to samples. The shift of 2D peak and appearance of D peak from Raman scattering spectra further confirm the effects of laser irradiation on graphene.

The effect of excimer laser irradiation on mid-IR spectra of mineral mixtures for remote sensing

We examined the influence of micrometeorite bombardment simulated with an excimer laser, which irradiated mixtures of minerals with an energy density between 1.9 J/cm2 and 3.3 J/cm2. As starting material for the mixtures, we selected a natural olivine (Fo91) and a natural pyroxene (En87). Olivine and pyroxene are important rock-forming minerals of Earth's upper mantle and also occur on other terrestrial planetary bodies. The minerals were used to prepare a compositional range of mixtures that were pressed into pellets and examined especially by diffuse reflectance mid-infrared spectroscopy to identify changes caused by micrometeorite impacts as one tracer of space weathering on airless bodies such as Mercury or Moon. Spectral mid-IR measurements were carried out on untreated and treated samples in high vacuum. For comparison, the untreated samples are investigated in low vacuum under various phase angles. Especially the spectral variation between 7 μm–14 μm is of interest as the most important mid-IR features of rock-forming minerals as the Christiansen feature, Reststrahlen bands, and Transparency feature are located in this spectral region.As a result, we found that the mid-IR spectra of the powder pellets show signs of agglutination after irradiation. Here, olivine demonstrates a larger effect on irradiation than pyroxene, whereby pyroxene in mixtures can mask the presence of olivine in the mid-IR spectra after micrometeorite bombardment. We also observed a shift of the CF to longer wavelengths (shorter wavenumbers) after irradiation, and from high to low vacuum, a modification more prominent in olivine than in pyroxene. Therefore, this study shows that the identification and quantification of minerals in mixtures solely on the base of the CF location of the respective material can lead to an overestimation of modal abundances, which is important for the interpretation of data coming back from space missions, e.g., from the MERTIS experiment onboard BepiColombo.

The current state of Atlantic salmon reproduction in the Keret River, White Sea basin, and how it can be increased

The Keret River is one of large salmon rivers in the White Sea basin. The estimated abundance of Atlantic salmon in the river began to decrease in 1991, reaching a maximum in 1997 due to the abruptly increased illegal fishing level and the invasion of juvenile Atlantic salmon by the monogeny of Gyrodactylus salaris. The studies conducted have shown that the salmon population in the Keret River is depressed and that the average distribution density of juveniles aged 1+ and older is 1.6 fish / 100 m2. Atlantic salmon reproduction on fish hatcheries is important for maintaining the population abundance (farm individuals make up over 50% of the population). Artificial Atlantic salmon reproduction in the Republic of Karelia’s rivers is carried out by the Karelian Branch of Glavrybvod FGBU at the Kem and Vyg fish hatcheries. The fish hatcheries could achieve better results by updating the juvenile breeding technology. An example of a new high-intensity biotechnology is the use of physical factors controlling the vital activity of fish in the various periods of ontogenesis. The study of the effect of low-intensity laser radiation in the early stages of ontogenesis has shown that red light over a certain dose range enhances the adaptability of fish by decreasing mortality and accelerating growth, thus decreasing the loss of fish products in fish hatcheries.

Determining the stressed-strained state of concrete in the zone of exposure to local laser radiation

This paper reports the results of the physical and numerical experiments on determining the stressed-strained state of concrete in protective structures in the region of the effect of local point laser radiation. The software package LIRA10.8 (release 3.4) was used to build a computer model in the statement of a stationary thermal conductivity problem. To this end, the findings from the experimental studies were applied – the resulting temperature distribution and changes in the structure of concrete on the surface and deep into concrete cubes for more than 120 samples of concrete with three levels of moisture content: dried, natural humidity, and water-saturated. This paper gives the parameters of the simulation, the results of a numerical experiment, their analysis, and comparison with the results of a physical experiment. The temperature fields when establishing the dynamic temperature equilibrium, the level of stresses in concrete, derived from the physical experiments, correlate well with the results of the numerical experiment. The maximum temperature determined by the optical method at the surface of concrete was 1,350+50 °С. Deviations at control points do not exceed 12–70 °С in the temperature effect zone and 18–176 °С (1–11 %). At the rated radiation power of 30 W, the second stage of interaction was achieved; at 100 W – the fourth stage for concrete with a moisture content of 0–2.5 %; and, for water-saturated concrete, the fifth stage of interaction with the laser beam. A significant decrease in the thresholds between the stages of interaction between laser radiation and concrete was revealed, especially water-saturated concrete, compared to the thresholds for metals (the thresholds between the third and fifth stages were reduced by 103–104 times). The destruction of the walls of water-saturated pores in concrete occurred under the pressure of water vapor. The tangent stresses, in this case, were 1.7 MPa, and the values for the coefficient Kр, determined by the method of acoustic emission, were in the range of 4‒6. Such results explain the absence of normal microcracks due to the hoop effect. It was established that in the contact zone between a laser beam and concrete, about 90 % of the radiation energy dissipates, and in the adjacent heating zone ‒ up to 77 %. The optimal speed of beam movement when cleaning the concrete surface from organic, paint, and other types of contamination of 0.5–2 mm/s (surface temperature, 100–300 °С) has been proposed

Effect of a Low-Level Laser on Liposomal Doxorubicin Efficacy in a Melanoma Cell Line.

Introduction: The cytotoxicity of chemotherapy drugs is a significant challenge in the way of surmounting cancer. Liposomal drug delivery has proven to be efficacious in increasing the function of the drugs. Its potential to accumulate drugs in the target site and enhance the efficiency of anti-cancer agents with lower doses hinders their cytotoxicity on normal healthy cells. Since the release of drugs from liposomes is not generally on a controlled basis, several studies have suggested that external stimuli including lasers could be used to induce controlled release and boost the efficiency of liposomal drug delivery systems (LDDSs). Methods: The A375 cancer cell line was used and exposed to the liposomes containing doxorubicin in the presence of a low-level laser beam to investigate its effect on the liposomal stimuli-responsiveness release and its toxicity on cancer cells. So as to achieve that goal, Annexin V/PI was employed to analyze the number of cells that underwent apoptosis and necrosis. Results: Here, we report the effect of laser irradiation on LDDSs. According to the results obtained from the annexin V/PI assay, the pattern of viability status has shifted, so that the number of pre-apoptotic cells treated with liposomal doxorubicin and a laser beam was more than that of cells treated with only liposomal doxorubicin. Conclusion: The use of stimuli-responsive LDDSs, in this case, laser-responsive, has led to favorable circumstances in the treatment of cancer, offering enhanced cancer cell cytotoxicity.

EFFECTS OF LOW-LEVEL LASER IRRADIATION ON THE GROWTH OF THE RAT MANDIBULAR CONDYLE IN ORGAN CULTURE

<h3>Objective</h3> The present study was carried out to histologically, immunohistochemically, and histometrically investigate the effect of low-level laser irradiation by a diode laser on the growth of the rat mandibular condyle in organ culture. <h3>Methods</h3> The mandibular condyles were removed from rats' embryos on the 21st day and then cultured for 8 days. The 20 cultured condyles were divided into 4 groups: F−L− group (serumless BGJb); F+L− group (serumless BGJb with bFGF 100 ng/mL); F−L+ group (serumless BGJb and laser irradiation); and F+L+ group (serumless BGJb with bFGF 100 ng/mL and laser irradiation). The laser irradiation (output 1.3 W/cm² and wavelength 633 nm) was performed on the cultured condyle for 30 seconds every 24 hours for 5 days. Immunohistochemically, PCNA was used to analyze cell proliferation. <h3>Results</h3> The mesenchymal cells in the layer of differentiation and hypertrophy in the F+L+ group showed a marked increase in cell number and the size of the condyle. The positive cell number of PCNA in F+L− and F+L+ group was significantly higher compared with the control group. <h3>Conclusions</h3> Our data showed that low-level laser irradiation promotes cell proliferation in the cultured condyle same as in bFGF addition. It is suggested that low-level laser irradiation by a diode laser (wavelength 633 nm) stimulated the proliferation of mesenchymal cells, which resulted in an increase in the number of chondrocytes in the layers of differentiation and hypertrophy by leading to the enlargement of the condylar size.

Dependence of morphology evolution of fused silica on irradiation parameters of CO2 laser

The influence of CO2 laser parameters on the irradiation effect of the fused silica was studied. The morphological characteristics of fused silica treated by a CO2 laser with varying power and frequency were studied experimentally. The properties of the irradiated area were studied by acid etching and hydrophilicity methods in order to verify the effect of CO2 laser irradiation on the SiO2 network. The temperature characteristics of the irradiated region were also calculated using numerical simulations based on experimental parameters. It indicated that the frequency of the CO2 laser plays a key role in the morphology of the irradiated region, and more attention should be focused on the size of the affected zone after laser irradiation in order to fully understand the irradiation process. The good agreement found between numerical simulations and experimental results provides a reference for further research on the application of CO2 laser heating of fused silica.

Effects of phosphate anodization and laser irradiation on adhesive property of AZ91D magnesium alloy

Effects of phosphate anodization and laser irradiation on adhesive property of AZ91D magnesium alloy

Sub-100 nm high spatial frequency periodic structures driven by femtosecond laser induced desorption in GaAs

This paper presents a previously unreported mechanism for the formation of High Spatial Frequency Laser Induced Periodic Surface Structures (HSFL) in GaAs upon irradiation by femtosecond laser pulses (repetition rate = 1 kHz, τ = 150 fs, λ = 390 nm) that is driven by point defect diffusion, desorption of surface atoms, and roughening of the surface. The HSFL have trenches that are 100 nm deep, an average spatial period of 65 nm, and are completely below the original surface. Sub-100 nm periodicity with high depth to period aspect ratio has not been previously observed in GaAs. In the proposed mechanism, laser irradiation generates point defects that diffuse to the surface. Interstitials that reach the surface can be easily desorbed and the remaining vacancies coalesce into vacancy islands. This results in a rough surface, which can excite surface plasmon polaritons. Despite our observations of periodicity corresponding to SPPs, calculations done using the excited dielectric function indicate that SPPs should not be supported. This points to the need to incorporate the cumulative effects of laser irradiation in existing models. This paper also presents evidence that desorption can also occur during HSFL formation in GaAs when irradiated with 780 nm in vacuum. The HSFL have the similar spatial period as GaAs irradiated in air with 780 nm, but completely below the original surface.

Laser Therapy in the Treatment of Peri-Implantitis: State-of-the-Art, Literature Review and Meta-Analysis

(1) Background: The treatment of the peri-implantitis is still challenging, and no consensus was found in the literature on which is the best treatment protocol. In recent years, numerous authors have proposed the use of the dental laser as an alternative and effective method for decontaminating the surface of infected implants. Therefore, the aim of this work was to examine the state-of-the-art on the use of lasers in the treatment of peri-implantitis through the literature. (2) Methods: An electronic search was conducted through the PubMed database; we selected and reviewed articles that evaluated the effects of laser irradiation in the treatment of peri-implantitis. (3) Results: The use of lasers seems to provide similar results if compared with conventional mechanical therapy. The included studies were divided into three groups based on the active medium of the laser used for the treatments being tested (Erbium: Yttrium Aluminum Garnet, CO2 and diode laser). (4) Conclusions: The lasers showed positive results, on average, after 6 months of follow-up. Comparative clinical trials conducted with the aim to test the efficiency of laser irradiation, in addition to conventional therapy, indicate that this technique can induce similar results if compared to conventional therapy alone.

Protective effect of low-level laser irradiation on lipopolysaccharide-mediated inflammatory injury of human periodontal ligament fibroblasts.

To study the effect and mechanism of low-level laser irradiation (LLLI) on lipopolysaccharide (LPS)-induced inflammatory injury of human periodontal ligament fibroblasts (hPDLFs). hPDLFs were inoculated into well plates and randomly divided into the normal group, LPS group, and LPS+LLLI group. The cells in the normal group were cultured in conventional medium. The hPDLFs in the LPS and LPS+LLLI groups were cultured in RPMI1640 medium containing 1 mg·L-1 LPS. The three subgroups of the LPS+LLLI group were exposed to different LLLI. After 4 days, the cell apoptosis, viability, and intracellular free Ca2+ concentration of each group were measured. The contents of tumor necrosis factor-α (TNF-α), interleukin (IL)-8, IL-1β, and IL-6 were measured by enzyme linked immunosorbent assay (ELISA). Reverse transcription-polymerase chain reaction (RT-PCR) and Western blot were used to detect the expression of matrix metalloproteinase (MMP)-2, MMP-3, and MMP-9 genes and proteins of hPDLFs in each group. Compared with the normal group, the LPS group showed increased apoptosis rate of hPDLFs and intracellular free Ca2+concentration and decreased cell viability (P<0.05). The TNF-α, IL-8, IL-1β, and IL-6 levels were higher in the cell supernatant (P<0.05), and the expression of MMP-2, MMP-3, and MMP-9 genes and proteins of hPDLFs was significantly increased (P<0.05). Compared with the LPS group, the LPS+LLLI group showed significantly decreased apoptosis rate and intracellular free Ca2+ concentration and significantly increased cell viability (P<0.05). The TNF-α, IL-8, IL-1β, and IL-6 levels in the supernatant of cells and the expression of MMP-2, MMP-3, and MMP-9 genes and proteins of hPDLFs were significantly decreased (P<0.05). LLLI has a protective effect on the inflammatory injury of hPDLFs induced by LPS, and the effect is most obvious when the irradiation intensity is 4 J·cm-2.

Effect of uniform laser irradiation on thermal response of temperature sensitive structures

The analysis of the temperature distribution, thermal deformation, and stress of thin plate structures attributed to laser irradiation is of great significance because the thermal effects substantially affect a suite of properties. In this paper, based on the theory of thin plate thermal bending, the analytical expressions of deflection and thermal stress in the local uniform temperature field are derived and compared with the numerical simulation results. The influence of the boundary constraint and irradiation factor on the thermal response is analyzed. Considering the temperature sensitivity of material parameters, the effect of heat flux density on the structural response is analyzed by the finite element method. The results show that the analytical solutions of the circular plate deflections are consistent with the numerical results. The maximum values of both deflection and compressive stresses occur at the center. The maximum tensile stress occurs near the boundary of the spot. In the heat affected zone (HAZ), the deflection of a point shows a trend of the Gaussian decrease with the increase in the distance to the center, while the thermal stress almost does not change with the distance. Outside the HAZ, both deflection and thermal stress are related to the boundary conditions and irradiation factors. Considering that the material parameters change with temperature, the HAZ area, deflection, and von Mises stress are positively correlated with the heat flux density, but the change patterns are different.

The effect of laser irradiation on reducing the noise of solid-state nanopore

The performance of solid-state nanopore is affected by the noise level. This study aimed to investigate the effect of laser irradiation on the noise performance of solid-state nanopore in situ. Laser irradiation is applied to fresh and contaminated nanopores. The measurement results show that the noise of fresh and contaminated nanopores decreases with the laser power and there is a threshold of laser power in reducing the noise of contaminated nanopores. The possible reasons for reducing noise in the laser irradiation process are discussed. The laser treatment is proven to provide a convenient method for reducing the noise of solid-state nanopore.

The effect of Erbium-doped Yttrium Aluminum Garnet laser irradiation on push-out bond strength of endodontic sealers with root canal dentin: An in vitro evaluation of push-out bond strength and failure modes

Objectives: The aim of this study was to evaluate and compare the push-out bond strength of bioceramic sealer and resin-based sealer on Erbium-doped Yttrium Aluminum Garnet (Er:YAG) treated root canals. Material and Methods: Sixty single-rooted teeth were collected, decoronated apical to the cementoenamel junction, maintaining the minimum root length of 14 mm. Samples were instrumented with WaveOne Gold primary file and divided into two experimental groups (n = 30), based on laser irradiation: Group I: No laser and Group II: Er:YAG laser irradiated. Groups I and II were again divided into two subgroups “a” (AH Plus) and “b” (mineral trioxide aggregate [MTA] Fillapex) with 15 samples in each group. As per the grouping, sealers were coated onto the canal walls and obturated. After 24 h of storage in 100% humidity at 37°C, all the samples were sectioned transversely and push-out test was performed using universal testing machine. Stereomicroscope was used to determine the mode of failure. A one-way analysis of variance was employed to compare the mean POBS. Kolmogorov–Smirnov and Shapiro–Wilk parametric tests were done to check the normality. The Games-Howell multiple post hoc test was used for pairwise comparison of the groups at a 95% confidence level. Results: Both AH Plus and MTA Fillapex exhibited higher bond strength in the laser-treated canals. AH plus exhibited superior bond strength compared to MTA Fillapex in both laser and non-laser-treated groups (P &lt; 0.05). AH Plus groups have predominantly presented cohesive failure whereas MTA Fillapex presented mixed failures. Conclusion: Irradiation with Er:YAG laser in the root canal before obturation improves the bond strength significantly. The adhesive properties of MTA Fillapex are comparable to that of AH Plus.