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Effectiveness of Different Laser-Assisted In-Office Bleaching Techniques: 1-Year Follow-Up
摘要： Objective: The aim of this study was to evaluate color longevity after different bleaching techniques. Background: Laser-activated bleaching methods are gaining popularity due to decreased chair time and increased patient compliance. However, the longevity of such methods has not been stated clearly. Methods: Sixty patients were divided into the following three groups (n = 20); group 1: chemical bleaching with 35% hydrogen peroxide (HP) gel, group 2: bleaching with 35% HP gel with diode laser activation, and group 3: bleaching with 35% HP gel with Er,Cr:YSGG laser activation. Color changes (DE*) were calculated by using two different formulas: (i) CIELAB (DEab) and (ii) CIEDE2000 (DE00) with a spectrophotometer before treatment, 24 h after treatment 3, 6, and 12 months after treatment. Evaluation of postoperative sensitivity was performed before and immediately after treatment, followed by re-evaluation 24 h and 1 week after treatment. Results: For DEab calculation, no significant difference was observed during both intra- and inter-group evaluations ( p > 0.05). For DE00 calculation, no significant intergroup difference was observed ( p > 0.05), whereas significant intragroup differences between the values of after treatment, 6–12 months. In the chemical bleaching group, increased postoperative sensitivity was observed after 24 h ( p < 0.001). In the diode-laser-activated group, postoperative hypersensitivity was detected at 24 h and 1 week. No significant hypersensitivity was observed in the Er,Cr:YSGG-laser-activated group ( p > 0.05). Conclusions: All three techniques provided efficient bleaching. Chemical and diode-activated bleaching methods resulted in slight sensitivity after application, whereas Er,Cr:YSGG-laser-activated bleaching did not cause sensitivity.
关键词： diode laser,laser-assisted bleaching,Er,Cr:YSGG laser,hydrogen peroxide
更新于2025-09-23 15:19:57
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Er,Cr:YSGG Laser Performance Improves Biological Response on Titanium Surfaces
摘要： Porphyromonas gingivalis infection is one of the causes of implant failures, which can lead to peri-implantitis. Implant surface roughness is reportedly related strongly to P. gingivalis adhesion, which can lead to peri-implantitis and, later, cell adhesion. Our aim was to evaluate the effects of Er,Cr:YSGG laser on titanium (Ti) disc surfaces and its interaction with bacterial adhesion and fibroblast viability. Ti discs underwent two treatments: autoclaving (control) and erbium, chromium-doped yttrium scandium gallium garnet (Er,Cr:YSGG) laser treatment (test). Ti disc surfaces were examined with scanning electronic microscope (SEM), Energy-dispersive spectrometry (EDX), X-ray photoelectron spectroscopy (XPS). The surface roughness same as wettability were also investigated. Fibroblast viability was assessed with the water-soluble tetrazolium 1 (WST-1) test, and osteoblast differentiation was assessed with the alkaline phosphatase (ALP) assay. Bacterial structure and colony formation were detected with scanning electron microscopy and Gram stain. In comparison to control discs, the test discs showed smoother surfaces, with 0.25-μm decrease in surface roughness (p < 0.05); lower P. gingivalis adhesion (p < 0.01); less P. gingivalis colonization (p < 0.05); and increased fibroblast viability and osteoblast differentiation (p < 0.05). Er,Cr:YSGG laser treatment improved disc surfaces by making them slightly smoother, which reduced P. gingivalis adhesion and increased fibroblast viability and osteoblast differentiation. Er,Cr:YSGG laser treatment can be considered a good option for managing peri-implantitis. Further investigations of laser-assisted therapy are necessary for better guidelines in the treatment of peri-implantitis.
关键词： laser treatment,Er,Cr:YSGG laser,dental implant,Ti discs
更新于2025-09-19 17:13:59
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Lip Repositioning Surgery Using an Er,Cr:YSGG Laser: A Case Series
摘要： Excessive gingival display (EGD) is a common esthetic concern. Lip repositioning surgery (LRS) was introduced as one of the treatment options to manage EGD. LRS can be used for skeletally and/or muscularly induced EGD. The present case series applied LRS using an Er,Cr:YSGG laser to treat 24 patients with minor vertical maxillary overgrowth or a hypermobile lip. At 6 months, the gingival display had decreased by 3.79 ± 1.59 mm (mean ± standard deviation), and the visible lip body when smiling had increased by 1.23 ± 0.74 mm. A questionnaire revealed that the level of satisfaction with the smile increased among the patients and that they had a positive attitude toward Er,Cr:YSGG laser–assisted LRS.
关键词： Er,excessive gingival display,Lip repositioning surgery,Cr:YSGG laser,smile esthetics
更新于2025-09-19 17:13:59
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Combined effect of Er,Cr:YSGG laser and casein phosphopeptide amorphous calcium phosphate on the prevention of enamel demineralization: <i>An in-vitro study</i>
摘要： Objectives: To compare the effect of use of laser, casein phosphopeptide–amorphous calcium phosphate (CPP–ACP), and their combination on prevention of enamel demineralization using polarized light microscopy to assess lesion depth. Materials and Methods: Eighty premolars were randomly allocated to four equal groups (n ? 20): Group I: Control group, no preventive measures. Group II: CPP–ACP. Group III: Er,Cr:YSGG laser. Group IV: Er,Cr:YSGG laser followed by CPP–ACP. Specimens were subjected to thermocycling and brushing protocols equivalent to 1 year intraorally. Then, all teeth were subjected to acid challenge. Teeth were then sectioned longitudinally and examined under a polarized light microscope and lesion depth was measured. Results: Group IV resulted in the least lesion depth with a significant difference between it and all other groups. CPP–ACP alone and laser alone also showed a significant difference in white spot lesion (WSL) depth compared to the control group; however, no significant difference was found between them. Conclusions: The combined use of laser and CPP–ACP showed the best prevention against WSL development. The use of CPP–ACP or laser alone also resulted in a significant reduction in lesion depth but was significantly less than their combined use, with no significant difference between them.
关键词： Prevention,Er,Cr:YSGG Laser,WSL,CPP-ACP
更新于2025-09-16 10:30:52
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Effect of acid etching, Er, Cr: YSGG laser conditioning and combining on shear bond strength of orthodontic metal bracket
摘要： Aim The present study aims to evaluate the shear bond strength and the adhesive remnants index (ARI) of metal brackets. For this purpose, enamel etched with acid, Er; Cr: YSGG (2780 nm) laser, and a combination of them. Methods In this study, 60 human premolars were divided into three groups (acid, Er, Cr: YSGG (2780 nm) laser, and combined etching). Each group contains 20 teeth. For testing of shear bond strength (SBS), the force applied by a universal testing machine. All the samples were examined under a light stereomicroscope to determine the bond failure mode. Results The results revealed that the laser-acid group had the maximum mean shear bond strength while the acid group had the minimum shear bond strength. The values of mean shear bond strength obtained of 25.90, 16.94, and16.60 MPa for laser-acid, laser, and acid, respectively. Laser and acid groups were negligibly different from each other, while they were significantly different from the lasers–acid group (p < 0.05). Regardless of the preparation of the enamel, bond failure occurred predominantly in the enamel-adhesive site. Conclusions Er, Cr: YSGG (2780 nm) laser conditioning in combination with acid led to high shear bond strength, but the hazardous effect on tooth should be considered. The bond failure mode was almost similar among all three groups, where there was no adhesive left on the surface of the tooth.
关键词： Er,Shear bond strength,Orthodontic bracket,Cr: YSGG laser,Acid etching
更新于2025-09-12 10:27:22
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Influence of Er,Cr:YSGG Laser Irradiation on the Push-Out Bond Strength of Zirconia and Glass Fiber Posts with Radicular Dentin
摘要： Objective. This in vitro study was designed to evaluate the influence of an Er,Cr:YSGG laser on the bond strength of zirconia and glass fiber posts with root dentin. Materials and methods. Ninety extracted single-rooted human teeth were randomized into 6 groups (n = 15/group) on the basis of different posts (zirconia/glass fiber) and Er,Cr:YSGG laser tips (axial and radial). Specimens were prepared for push-out testing with the help of a cutting machine; six slices (2 on each cervical, middle, and apical) of approximately 1 mm thickness were sectioned for all roots on a plane perpendicular to the long axis of the post. All specimens were placed into a universal testing machine with a defined 0.5 mm/min crosshead speed until the maximum failure load was obtained. Results. The highest mean push-out bond strength of the glass fiber and zirconia groups was achieved with laser treatment. The highest push-out bond strength was achieved with the axial fiber tip (7.63 ± 1.22 MPa), and the lowest was achieved with a radial fiber tip of the glass fiber group (6.98 ± 0.96 MPa). ANOVA showed a statistically significant difference between the groups (p ? 0.041). The mean push-out bond strength was found to be higher with an axial fiber tip for both cervical and apical segments in the glass fiber and zirconia groups (p < 0.05). The independent t-test resulted in the overall highest mean push-out bond strength in the apical segments (p ? 0.026). Conclusion. Within the limits of the present in vitro research study, an enhancement in the push-out bond strength of resin cement, mainly in the cervical region of the root canal, was achieved after irradiation with an Er,Cr:YSGG laser using an axial fiber tip.
关键词： root dentin,push-out bond strength,Er,Cr:YSGG laser,glass fiber posts,zirconia posts
更新于2025-09-12 10:27:22
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The Effect of Diode and Er,Cr:YSGG Lasers on the Bond Strength of Fiber Posts
摘要： Background: Laser irradiation modi?es the topography and composition of dentin surface aiming to increase the retention of bonded posts. Objective: To assess the effect of dentin irradiation with Er,Cr:YSGG or diode lasers on the bond strength of ?ber posts using self-adhesive resin cement. Materials and methods: Sixty bovine root canals were root-canal treated, post spaces were prepared, and subsequently ?ber posts were cemented. The samples were distributed according to the surface treatment: distilled water (control), Er,Cr:YSGG (1.5 W, 20 sec), or diode (1.5 W, 20 sec) lasers. Bond strengths were assessed by pull-out (n = 10) or push-out testing (n = 10). Pearson’s correlation was calculated. Failure mode after testing and the depth of tags in the dentinal tubules were analyzed by confocal laser microscopy. Data were submitted to analysis of variance and Tukey’s test. A p < 0.05 was considered signi?cant. Results: In the push-out test, Er,Cr:YSGG laser had signi?cantly different higher values (5.43 – 0.10 MPa) compared to the control (4.79 – 0.05 MPa). Diode laser values were not signi?cantly different from the other groups (5.12 – 0.27 MPa). In the pull-out test, there were no signi?cant differences between Er,Cr:YSGG (6.86 – 2.16 MPa) and diode (8.43 – 1.77 MPa) lasers, and both had signi?cant differences compared to the control (4.18 – 1.29 MPa). No correlation was found. Adhesive failures were predominant in all groups, and no signi?cant differences in tag penetration among the groups were found. Conclusions: The Er,Cr:YSGG laser increases the bond strength of resin cement and ?ber post to dentin in both tests, compared to control group without laser treatment. Diode laser only enhanced bonding for pull-out test.
关键词： dentistry,bond strength,Er,Cr:YSGG laser,?ber post,Diode laser
更新于2025-09-11 14:15:04
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Influence of gamma radiation on microshear bond strength and nanoleakage of nanofilled restoratives in Er, Cr:YSGG laser-prepared cavities
摘要： Objective: To evaluate the effect of gamma radiation on microshear bond strength and nanoleakage of nanofilled restoratives in laser-prepared cavities. Materials and Methods: Twenty?eight flat buccal dentin surfaces were prepared for microshear bond strength test. Er, Cr:YSGG laser was used to prepare another 28 Class V cavities on the buccal surfaces of the molars. All teeth were divided into four groups; 1st group: Application of Filtek Z350 nanocomposite material, 2nd group: As the 1st group and then exposure to gamma radiation, 3rd group: Application of Ketac N100 nanoglass ionomer, and the 4th group: As the 3rd group and then gamma irradiated. The bond strength test was performed after storage in artificial saliva for 24 h. For the nanoleakage test, teeth were submerged in a solution of ammoniacal silver nitrate, sectioned, and then examined under a scanning electron microscope. The collected data were statistically analyzed. Results: Nanocomposite showed higher bond strength values than nanoglass ionomer. Despite the fact that gamma radiation did not decrease nanocomposite bond strength, it decreased nanoglass ionomer bond strength. Nanoglass ionomer-restored cavities showed higher silver ion penetration than nanocomposite in both control and gamma-irradiated groups. Conclusion: Gamma radiation has no effect on bond strength and nanoleakage of nanocomposite so that it can be placed before radiotherapy. On the other hand, the bond strength of nanoglass ionomer was adversely affected by gamma radiation.
关键词： nanoleakage,gamma radiation,Bond strength,Er, Cr:YSGG laser,nanocomposite,nanoglass ionomer
更新于2025-09-11 14:15:04