YAG Laser Group Research Articles

Comparison of the efficacy and adverse effects of long pulsed 1064 nm Nd: YAG laser and sclerotherapy in the treatment of pyogenic granuloma in children: a retrospective study

Pyogenic granuloma (PG) is benign vascular lesions of the skin and mucous membranes that often involve the skin and mucous membranes, which often trouble patients due to its frequent bleeding. The traditional treatment is surgical removal, but its bleeding, pain, and trauma have led doctors to look for more minimally invasive methods. Between June 1, 2022 to March 1, 2024, we retrospectively analyzed 72 children with PG who were seen and treated in our department for long pulsed 1064 nm Nd: YAG laser (Gentle Nd: YAG laser) and sclerotherapy, respectively. The efficacy of the two treatments, pain scores, duration of surgery, and adverse events were assessed. The results showed no significant difference between the two groups in the efficacy of first treatment and the efficacy of secondary treatment. Although the procedure time was shorter in Gentle Nd: YAG laser group than in sclerotherapy group, the pain was more pronounced and the incidence of scarring was higher. No significant recurrence was detected in either group during the 6-month follow-up period. Gentle Nd: YAG laser and sclerotherapy for PG are sensitive, less invasive, and safe treatments. Sclerotherapy may be more acceptable to patients than Gentle Nd: YAG laser therapy because it is less painful and scarring is rare.

The Efficacy of Er:YAG Laser in the Extraction of Impacted Third Molars: A Randomized Clinical Trial.

(1) Background: Impacted third molar extraction with a scalpel and rotary instruments is one of the most traumatic surgeries in dentistry. Therefore, it is necessary to discover less traumatic methods and instruments to reduce the risk of postoperative complications. (2) Methods: This study is reported in accordance with the CONSORT guidelines. The study aim is to assess the effectiveness of an Er:YAG laser with a wavelength of 2.94 μm, cutting and rotating instruments in the extraction of lower third molars in comparison with the traditional instruments using clinical and radiology parameters. In the control group, the impacted third molars were extracted with the traditional instruments, like scalpel and rotary instruments; in the test group, the impacted third molars were extracted with an Er:YAG laser. As per the inclusion and exclusion criteria, we enrolled 60 patients who were randomly assigned into two groups (Er:YAG laser group and control group). The efficacy of the Er:YAG laser was assessed by postoperative pain, collateral swelling, mouth opening, and radiology parameters such as radiographic infrabony defects and radiographic bone height after tooth extraction. (3) Results: The results showed that the clinical postoperative parameters like pain, collateral swelling, and mouth opening were less pronounced in the Er:YAG laser group than those in the control group (p < 0.001). According to the data of the radiology parameters (RBH and RID), the regeneration of the socket after extraction was better in the laser group than in the control group (p < 0.001). (4) Conclusions: Based on the obtained results of clinical and radiology parameters assessment, it was shown that third molar extraction using an Er:YAG laser is a less traumatic method than extraction using a scalpel and rotary instruments.

Clinical efficacy and safety of the superpulse thulium fiber laser and holmium laser for ureteroscopic lithotripsy in the treatment of upper urinary tract calculi: a randomized, positive control, blinded, single-center clinical study {1}

BackgroundKidney stone disease is a common problem. The holmium: yttrium–aluminum–garnet (HO:YAG) laser is currently the gold standard laser for ureterorenoscopic (URS) lithotripsy. Recently, the superpulse thulium fiber laser (SP TFL) has shown potential as a substitute for the HO:YAG laser. We aim to compare and evaluate the clinical efficacy and safety of the HO:YAG laser and SP TFL in the treatment of upper urinary calculi in this trial.MethodsIn this randomized, positive control, blinded management, single-center clinical study, patients with upper urinary calculi will be randomized (1:1) to the experimental group (SP TFL group) or the control group (HO:YAG laser group). Patients in both groups will undergo URS lithotripsy under general anesthesia, and according to the results of randomization, the patients will be treated with an SP TFL (trial group) or a holmium laser (control group). The primary outcome is the stone-free rate at 30 ± 7 days after surgery. The secondary outcomes include the duration of surgery, the duration of laser use, the length of postoperative hospital stay, postoperative clinical indicators, total hospitalization costs, the second-stage stone clearance rate, perioperative complications, the average hemoglobin change, and the mean white blood cell count change.DiscussionThis study aims to evaluate and compare the clinical efficacy and safety of the SP TFL and HO:YAG for URS lithotripsy in the treatment of upper urinary calculi.Trial registration {2a and 2b}chictr.org.cn ChiCTR2300076893. Registered on October 24, 2023, with ChiCTR (https://www.chictr.org.cn/bin/project/edit?pid=206827).Protocol version {3}August 15, 2023 (V.20230815).

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.

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.

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.

The effect of laser therapy for the treatment of dentin hypersensitivity on surface roughness and bacterial adhesion

The aim of the study was to measure the degree of dentine surface roughness caused by five distinct lasers used to treat dentine hypersensitivity, as well as to evaluate the subsequent bacterial colonization on these irradiated surfaces. Sixty human maxillary premolar teeth without caries or restoration which were extracted for periodontal reasons were used in this study. Five different types of lasers were applied to the root dentin surface. Tested samples were divided into six groups of 10 samples each; control, diode (810 nm), diode (980 nm), Nd: YAG, Er: YAG, and Er, Cr: YSGG laser groups. The arithmetic mean of the surface roughness values (Ra) and the average roughness over a measurement area (Sa) were measured pre- and post-application using any of the laser types. Swab samples were then collected from the dentin surface. Following a 24-hour incubation period at 37 °C, the colony forming units were counted using a stereoscope. The results demonstrated a statistically significant difference in the surface roughness values pre- and post-application (Ra and Sa, respectively) in the Er, Cr: YSGG laser group (p = 0.037,p = 0.007). No significant difference was observed in the other groups (p > 0.05). There was no statistically significant difference in the number of bacterial colonies observed between the test and control groups. Diode and Nd: YAG lasers showed either a decrease or no change in surface roughness; however, the hard tissue lasers (Er: YAG, Er, Cr: YSGG) showed an increase. The Er: YAG and Nd: YAG laser groups exhibited decreased bacterial adhesion compared to the other groups.

The effect of surface treatment and thermal aging on the bonding of clear aligner attachments to provisional resin-based material: shear bond strength analysis.

The aim of this study is to evaluate the effect of different surface treatments on the shear bond strength (SBS) of clear aligner attachments bonded to Bis-acryl provisional crowns. 120 cylindrical bisacrylic composite material (ProTemp type) specimens were prepared and divided into six groups (n = 20) based on surface treatment, control: (no treatment); super coarse grit diamond bur, carbide bur, alumina-blasting, non-thermal plasma treatment, and Er:YAG laser treatment. The features of treated surfaces were examined using scanning electron microscopy (SEM). A flowable composite resin (Transbond XT; 3M Unitek) was bonded to the specimens forming the attachment. Half of specimens were subjected to thermal cycling (5,000 cycles). SBS was measured before and after thermal cycling. Each specimen was loaded at the attachment/resin interface at a speed of 0.5 mm/min until failure. The nature of the failure was analyzed using the composite remnants index (CRI). Two-way ANOVA and Tukey HSD were used for data analysis α = 0.5. For CRI scores analysis, Kruskal-Wallis test and Dunn's multiple comparison were used as post-hoc test. SEM analysis showed that all surface treatments altered surface properties and increase surface bonding area. The specimens treated with plasma, Er:YAG laser, and alumina-blasting had higher SBS values before and after thermal cycling. In comparison to control plasma, Er:YAG laser, and alumina-blasting showed a significant increase in SBS (P < 0.001) while carbide and diamond bur groups showed no significant differences (P > 0.05). Thermal cycling significantly decreased the SBS of control, carbide bur, diamond bur, and Er:YAG laser while no significant effect of alumina-blasting and plasma group. Er:YAG laser and plasma groups significantly exhibited more dominance for scores 2 and score 3 and the absence of score 0. Alumina-blasting, Er:YAG laser, or non-thermal plasma surface treatments increased the shear bond strength between clear aligner attachments and resin-based restorations.

Effects of Lasers and Fluoride Varnish on Microhardness and Calcium and Phosphorus Content of Demineralized Enamel.

Objectives: This study assessed the effects of blue and Er:YAG lasers, fluoride varnish, and their combination on microhardness, and calcium and phosphorus content of demineralized enamel. Materials and Methods: The primary Vickers microhardness of 28 third molars was measured and their enamel calcium and phosphorous content was quantified by energy-dispersive X-ray spectroscopy. They were then randomly assigned to five groups of 5% sodium fluoride (NaF) varnish, 445nm blue laser, Er:YAG laser, 5% NaF + 445nm blue laser, and 5% NaF + Er:YAG laser. The teeth then underwent pH-cycling to induce caries-like lesions. The surface microhardness of the teeth and the calcium and phosphorous content of demineralized enamel were measured again. Data were analyzed by one-way ANOVA and Tukey's test (alpha=0.05). Results: NaF, NaF-diode laser, and NaF-Er:YAG laser groups experienced a significant increase in microhardness of demineralized enamel close to the baseline value (P<0.05). The efficacy of NaF-blue laser and NaF-Er:YAG laser was higher than NaF . In blue and Er:YAG laser groups, the mean final microhardness was significantly lower than the baseline microhardness. The percentage of phosphorus in all groups was similar to that of sound enamel. The percentage of calcium in NaF group was significantly lower than that of sound enamel and all other groups. The calcium content in other groups was similar to that of sound enamel. Conclusion: Fluoride varnish had a synergistic effect with Er:YAG and blue lasers to increase the demineralized enamel microhardness; blue and Er:YAG lasers alone were less effective.

Evaluation of Surface Roughness of Translucent Zirconia After Applying Nd:YAG and CO2 Lasers: An In Vitro Study.

Surface roughness is one of the most important factors that play an important role in increasing the connection between the surface of the tooth and the applied restoration. Due to the increased interest in zirconia and the improvement of its mechanical and aesthetic properties, studies have increased that work to improve and increase its surface roughness so that it can be used as a veneer in the future. This study aims to compare the effect of two types of lasers on the surface of highly transparent zirconia to evaluate the surface roughness resulting from the two techniques. The study sample consisted of 20 ceramic cubes made of translucent zirconia (DD cubeX2, Dental Direct, Germany). It was made using a CAD-CAM Zircodenta device (Imes-Icore, Germany) and a zirconia sintering furnace (Imes-Icore, Germany). The study sample was divided into two groups; the first group consisted of 10 cubes exposed to Nd:YAG laser and the second group consisted of 10 discs exposed to continuous wave CO2 laser. The surface roughness test was conducted for the study samplesin each of the groups using a surface roughness tester. Data were collected and analyzed using SPSS v25 software. The surface roughness was measured and its mean was 1.208±0.22in the Nd:YAG laser group and 0.809±0.21in the CO2laser group. There was a significant difference between the study groups according to the independent sample T-test. This study concluded that the Nd:YAG laser surface roughensof zirconia isgreaterthan the continuous wave CO2 laser, with a substantially significant difference.

The safety and efficacy of five surgical treatments in prostate enucleation: a network meta-analysis

PurposeThe aim of our study was to investigate the comparative outcomes of five different energy types on surgical efficacy and postoperative recovery in patients with benign prostate hyperplasia.MethodsThe literature was systematically reviewed on December 1st, 2023, encompassing studies retrieved from PubMed, Embase, Web of Science, and The Cochrane Library databases that incorporated clinical studies of holmium laser enucleation of the prostate (HoLEP), Thulium:YAG laser enucleation of the prostate (ThuLEP), transurethral plasmakinetic enucleation of prostate (PKEP), diode laser enucleation of the prostate (DiLEP) and thulium fiber laser enucleation of the prostate (ThuFLEP) in the treatment of prostatic hyperplasia. Two independent reviewers extracted study data and conducted quality assessments using the Cochrane Collaboration's Risk of Bias tool and Newcastle–Ottawa Scale (NOS). Network meta-analysis (NMA) was employed to indirectly analyze the outcomes of endoscopic enucleation of the prostate (EEP) techniques.ResultsThe study included a total of 38 studies, comprising 21 non-randomized controlled trials (nRCTs) and 17 randomized controlled trials (RCTs), incorporating five distinct techniques: holmium laser, Thulium:YAG laser, bipolar plasma, diode laser and thulium fiber laser. In comparing treatment durations, ThuLEP and HoLEP had shorter overall hospital stays than PKEP, while the enucleation time of ThuLEP and HoLEP was shorter than that of ThuFLEP. Moreover, the enucleation tissue weight of both thulium fiber laser and holmium laser was heavier than bipolar plasma. However, the analysis did not reveal any statistically significant variation in complications among the various types of enucleation. In postoperative follow-up, the IPSS at 3 months post-operation was superior in the Thulium:YAG laser group compared to the holmium laser group. The thulium fiber laser technique demonstrated significant advantages over other enucleation methods in terms of QoL and PVR at 12 months after surgery.ConclusionTheoretical properties may vary among different energy sources; however, there are no discernible clinical differences in operation-related parameters, postoperative complications, and postoperative follow-up. Therefore, the choice of laser does not significantly impact the outcome. However, due to the limited number of included studies, future research should focus on larger sample sizes and multicenter investigations to further validate the findings of this study.

Effect of laser and coating surface treatment on the bond strength of zirconia ceramics.

This study aims to investigate bond strength between zirconia and resin cement through surface treatments with Er: YAG laser, Nd: YAG laser, and Si-Zr coating. Seventy-five round pre-sintered zirconia discs with a diameter of 18 mm and a thickness of 1.5 mm were prepared by a powder compactor. Fifty discs were randomly divided into five groups of 10 discs each and were subjected to five surface treatments: no treatment (control group), sandblasting with alumina particles (sandblasting group), Er: YAG laser treatment (Er: YAG laser group), Nd:YAG laser treatment (Nd: YAG laser group), and Si-Zr coating treatment (Si-Zr coating group). The discs were then bonded to composite resin columns with resin cement. The shear bond strength of each group was tested with a universal tester. Roughness tester, scanning electron microscope (SEM), and energy dispersive spectroscopy were used to analyze surface performance. The bond strength of the Si-Zr coating group was higher than that of the remaining groups (P<0.05). The difference in bond strength between the sandblasting group and the Er: YAG laser group was not statistically significant (P>0.05), but both of them had higher bond strength than the Nd: YAG laser group (P<0.05). The Si-Zr coating group had the highest surface roughness (P<0.05). The surface roughness of the sandblasting, Er: YAG laser, and Nd: YAG laser groups was higher than that of the control group (P<0.05), but the difference among the three groups was not statistically significant (P>0.05). SEM observations showed irregular scratches on the surface of the sandblasting group and large pits with holes on the surface of the Er: YAG and Nd: YAG laser groups. In the Er: YAG laser group, the crystal structure was replaced by a smooth surface with a large amount of microcracks due to partial melting. Complex porous structures that comprised "island-like" structures and mass pores among the grains were observed on the surface of the Si-Zr coating. Only Zr, O, and Y were detected on the surfaces of the control, Er: YAG laser, and Nd: YAG laser groups. Al was found on the surface of the sandblasted group, and a higher proportion of Si was detected on the surface of the Si-Zr coating group. Er: YAG laser and Nd: YAG laser treatment on the zirconia ceramic surface could increase roughness and improve the bond strength to resin cement. Si-Zr coating treatment is an effective alternative for increasing the roughness and bond strength of zirconia surface and is superior to sandblasting and laser treatments.

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

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. 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. 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. The use of Nd:YAG laser alone or in combination with GD was more effective in occluding dentinal tubules compared to GD alone. 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.

The effect of various surface treatments on the repair bond strength of denture bases produced by digital and conventional methods.

There is limited information on the repairability of prostheses produced with digital technology. This study aims to evaluate various surface treatments on flexural bond strength of repaired dentured base resins produced by digital and conventional methods. A total of 360 samples were prepared from one heat-polymerized, one CAD/CAM milled and one 3D printed denture base materials. All of the test samples were subjected to thermocycling (5-55°C, 5000 cycles) before and after repair with auto-polymerizing acrylic resin. The test samples were divided into five subgroups according to the surface treatment: grinding with silicon carbide (SC), sandblasting with Al2O3 (SB), Er:YAG laser (L), plasma (P) and negative control (NC) group (no treatment). In addition, the positive control (PC) group consisted of intact samples for the flexural strength test. Surface roughness measurements were performed with a profilometer. After repairing the test samples, a universal test device determined the flexural strength values. Both the surface topography and the fractured surfaces of samples were examined by SEM analysis. The elemental composition of the tested samples was analyzed by EDS. Kruskal-Wallis and Mann-Whitney U tests were performed for statistical analysis of data. SB and L surface treatments statistically significantly increased the surface roughness values of all three materials compared to NC subgroups (p < 0.001). The flexural strength values of the PC groups in all three test materials were significantly higher than those of the other groups (p < 0.001). The repair flexural strength values were statistically different between the SC-SB, L-SB, and NC-SB subgroups for the CAD/CAM groups, and the L-SC and L-NC subgroups for the 3D groups (p < 0.001). The surface treatments applied to the CAD/CAM and heat-polymerized groups did not result in a statistically significant difference in the repair flexural strength values compared to the NC groups (p > 0.05). Laser surface treatment has been the most powerful repair method for 3D printing technique. Surface treatments led to similar repair flexural strengths to untreated groups for CAD/CAM milled and heat-polymerized test samples.

The Effect of 10% Sodium Ascorbate and Er: YAG Laser on the Microtensile Bond Strength of Composite Resin to Bleached Enamel

Background: There are various methods proposed to prevent the reduction of substrate micro tensile bond strength to bleached enamel. Therefore, this study aims to evaluate and compare the effectiveness of two common methods, namely 10% sodium ascorbate and Er:YAG laser irradiation, in increasing the microtensile bond strength of composite resins to bleached enamel. Methods: In this in vitro study, 72 maxillary premolar teeth were divided into four equal groups: bleached control group, unbleached control group, treated with 10% sodium ascorbate, and Er:YAG laser-treated group (60 mJ, frequency = 10 Hz, and power of 0.6 W with a 400-µm diameter tip). The samples were cut by a CNC cutting machine for a microtensile bond strength test. Results: The Er:YAG laser group showed the highest mean bond strength (27.3 MPa), while the bleached control group had the lowest (15.06 Mpa). There was a significant difference between the bleached and unbleached control groups (P&lt;0.001). Samples prepared with 10% sodium ascorbate and the Er:YAG group had higher tensile bond strength than the bleached control group (P&lt;0.0001). Tensile bond strengths were not significantly different between the 10% sodium ascorbate and the Er:YAG laser preparation groups (P=0.361). Conclusion: The findings of this study indicate that the microtensile bond strength of composite resins to bleached enamel can be increased by 10% sodium ascorbate and Er:YAG laser irradiation.

The Effect of Different Surface Treatments on the Color Stabilities of Lithium Disilicate Material

Background: The aim of this study is to investigate the clinical acceptability of the color change that may occur in time about full ceramic materials used for aesthetic restorations, which are bonded after different surface conditioning processes, by measuring with spectrophotometer.&#x0D; Methods: The lithium disilicate CAD material we used in our work was prepared with isomet in the form of 1-millimeter-thick specimens. Three random groups of 21 specimens were selected from the specimens. One of these groups was conditioned with phosphoric acid, which is recommended by the manufacturer. Er:YAG laser was applied to the second group. The third group was conditioned by Nd:YAG laser. Surface changes in the groups were evaluated by scanning electron microscope (SEM) and atomic force microscope (AFM). The specimens were bonded with the adhesive resin cement to the background material for color change measurement. The first color measurement of the bonded specimens was done by spectrophotometer. The specimens were aged at 10,000 cycles in the thermal cycle device. The second color measurement after aging was done with the same spectrophotometer. &#x0D; Results: After aging with thermal cycle, there was a clinically acceptable color change in all groups. The Nd:YAG laser group presented better color stability (p

Effect of Er: YAG laser and plasma treatment on the bond strength of Y-TZP

ObjectivesThis study aimed to evaluate the effects of Er:YAG laser and plasma treatment on the bond strength between Y-TZP and resin cement. Materials and methodsSixty yttrium-stabilized tetragonal zirconia polycrystal (Y-TZP) specimens were fabricated and randomly assigned to six groups (n = 10): control group (group A); Sandblasting treatment (group B); Er:YAG laser group (group C); Ar plasma group (group D); Sandblasting + Ar plasma group (group E); and Er:YAG laser + Ar plasma group (group F). The surface of each zirconia specimen was tested using a contact angle meter, profilometer, and scanning electron microscope, and the shear bonding strength (SBS) was calculated. Statistical analysis was performed with One-way analysis of variance (ANOVA) combined with a least significant difference (LSD) test. ResultsThe surface morphology showed no difference between group A and group D, with smooth surfaces and shallow scratches after polishing. The surface roughness value of group C was 2.58 ± 0.14μm and was not significantly different from that of group F (P > 0.05), was higher than that of group A (P < 0.05). The SBS of group B was not significantly different from that of group D (P > 0.05). The hydrophilicity, carbon and oxygen contents, and SBS of group E were similar to those of group F (P > 0.05) and significantly higher than those of groups A, B, C, and D (P < 0.05). SignificanceThe Er:YAG laser and Ar plasma treatment can improve the bonding strength between zirconia and resin cement, and mechanical treatment followed by Ar plasma surface modification is more effective.

Effect of Self-Cured and Self-Etch Adhesive Systems on Shear Bond Strength After Photodynamic Therapy and Disinfection with Different Types of Lasers

Effect of Self-Cured and Self-Etch Adhesive System on Shear Bond Strength After Photodynamic Therapy and Disinfection with Different Types of Lasers&#x0D; &#x0D; Ayşe Çeşme1-a*, Ihsan Hubbezoğlu1-b&#x0D; 1 Sivas Cumhuriyet University, Faculty of Dentistry, Department of Restorative Dentistry Sivas, Türkiye.&#x0D; &#x0D; ABSTRACT &#x0D; Objectives: The aim of this study was to investigate the strength of shear bonding of self-cured and self-etch adhesive systems to dentin after surface disinfection with Photodynamic Therapy (PDT), Er:YAG, Nd:YAG, and KTP laser.&#x0D; Materials and Methods: In the study, 6 main-groups were formed as Control, Er:YAG Laser, Nd: YAG Laser, KTP Laser, KTP Laser activated PDT and Diode Laser activated PDT. Each group was divided into two subgroups; Self-cured (Tokuyama Universal) and self-etch (Scotchbond Universal) adhesive system(n=10). 120 molar teeth were prepared to expose dentin surfaces. After disinfection and adhesive application, nanohybrid composite resin with a diameter of 3 mm and a height of 2 mm was applied to the dentin surface with the help of transparent molds. All samples were thermally cycled 5.000 times at 5°C and 55°C. Shear bond strength (SBS) test was applied to the samples in a universal test device.&#x0D; Results: The differences between the Er:YAG laser group and the control, KTP and Nd:YAG laser groups of the self-cured adhesive samples were statistically significant. While the differences between the Nd:YAG laser group and the PDT groups were statistically significant (p

Skin barrier function and changes of serum inflammatory factor level in hyperpigmentation disorders treated with Nd:YAG laser.

It was to compare the differences in efficacy and safety for the treatment of hyperpigmentation disorders by Q-switched alexandrite (Q-SA) laser and Neodymium-doped Yttrium Aluminium Garnet (Nd:YAG) laser. The clinical data of 86 patients with hyperpigmentation disorders were collected and grouped: in the Q-SA laser and Nd:YAG laser groups according to the treatment methods, with 43 cases in each group. The clinical efficacy, skin barrier function (transdermal water loss (TEWL), stratum corneum water content, pH value, proteoglycan content), degree of pigmentation, serum inflammatory factors (high-sensitivity C-reactive protein (hs-CRP), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6)), and adverse reaction rate were compared after treatment. Compared with the Q-SA laser group, Nd:YAG laser group had decreased scab formation, healing, and scab shedding time, TEWL, pH value, and proteoglycan content, the increased water content of stratum corneum, decreased pigmentation score and area, and decreased serum levels of hs-CRP, TNF-α, and IL-6 (P<0.05). The total effective rates were 76.74% and 95.35%, and the adverse reaction rates were 30.23% and 6.98%, respectively in the Q-SA laser and Nd:YAG laser groups. Compared with the Q-SA laser group, Nd:YAG laser group had a higher total effective rate and lower incidence rate of adverse reactions (P<0.05). Nd:YAG laser plus rhEGF gel in the treatment of hyperpigmentation disorders can effectively protect the skin barrier function, reduce skin pigmentation, reduce the inflammatory response, and improve the therapeutic effect, with high safety.

Temperature limits during irradiation in laser-assisted treatment of peri-implantitis - labo-ratory research

Peri-implantitis is a relatively new and difficult disease that is becoming more common. Of the different therapeutic options to manage this condition, lasers show certain advantages over other therapeutic alternatives because of their antibacterial potential. The aim of the present study was to investigate the temperature rise of implant surfaces, soft tissues, and bone during irradiation with diode, CO2, and Er:YAG lasers. Ten implants inserted in biological models were irradiated with three laser systems with different parameters: a diode laser (980nm) with power levels of 0.75W and 1.6W; a CO2 laser (10600nm) with power levels of 252W and 241W; and an Er:YAG laser (2940nm) with power levels of 1.5 W, 6.8 W, and 7.5 W. The temperature rise was measured using a specially designed thermal probe (type K thermocouple) with accuracy of ±0.1°C over the range from 20°C to 80°C. The temperature was measured at 5 points - in the implant body, in the mucosa, in the middle part of the implant, in the implant apex, and in the bone around the implant apex. Measurements were obtained at 1 minute working interval. Diode and CO2 lasers with both parameters used increased significantly the temperature of more than 46°C, whereas the temperature in the Er:YAG laser group was less than 30°C. There was a statistically significant difference between diode, CO2, and Er:YAG lasers in favor of the erbium laser. The Er:YAG laser demonstrates the best thermal properties during irradiation of the implant surface. The three working modes tested - 1.5W, 6.8W, and 7.5W - provide safe intervention on both the soft and bone tissues of the implant interface and on the implant itself.