Erbium-doped Yttrium Aluminum Garnet Laser Research Articles

Laser applications in smear layer removal from posterior root canals: A comparative study.

Aim:The aim of the study is to evaluate erbium laser efficiency in removing smear layer from mesial roots of mandibular first molars at different laser settings.Subjects and Methods:One hundred (100) mandibular first molars were selected. Ninety six (96) mesial roots were assigned to two experimental groups according to the laser wavelength applied: I. Er, Cr: YSGG and II. erbium-doped yttrium aluminum garnet laser system. Four samples were used as control group. Samples of each group were distributed into two subgroups (A and B), following specific irrigation protocol. Each subgroup was divided into four subcategories according to the applied power laser. Each subcategory consisted of six samples. Teeth were observed under scanning electron microscope.Statistical Analysis:Results were statistically analyzed with Kruskal–Wallis and Mann–Whitney test (SPSS statistics software).Results:No statistically significant difference was observed between experimental groups I and ΙΙ. However, statistically significant difference was found among subgroups IA and ΙB and ΙIA and ΙΙΒ. In every root third, groups IIA and ΙΙB had better outcomes but it was not statistically significant. There was no statistically significant difference among subcategories of Group I (ΙΑ1-4 and ΙΒ1-4) and Group ΙΙ (ΙΙΑ1-4 and ΙΙΒ1-4).Conclusion:Erbium laser with tested parameters did not completely remove the smear layer from the root canals. Chelating factors can contribute in the laser mechanism of smear layer removal from apical part of narrow and curved root canals.

Bone Ablation Depth Estimation From Er:YAG Laser-Generated Acoustic Waves

Using a laser for cutting bones instead of the traditional saws has been shown to improve a patient’s healing process. Additionally, the laser has the potential to reduce the collateral damage to the surrounding tissue if appropriately applied. This can be achieved by building additional sensing elements besides the laser itself into an endoscope. To this end, we use a microsecond pulsed Erbium-doped Yttrium Aluminium Garnet (Er:YAG) laser to cut bones. During ablation, each pulse emits an acoustic shock wave that is captured by an air-coupled transducer. In our research, we use the data from these acoustic waves to predict the depth of the cut during the ablation process.We use a Neural Network (NN) to approximate the depth, where we use one or multiple consecutive measurements of acoustic waves. The NN outperforms the base-line method that assumes a constant ablation rate with each pulse to predict the depth. The results are evaluated and compared against the ground-truth depth measurements from Optical Coherence Tomography (OCT) images that measure the depth in real-time during the ablation process.

An In Vitro study to Compare Dental Laser with other Treatment Modalities on Biofilm Ablation from Implant and Tooth Surfaces.

Background:Periodontal and peri-implant disorders are etiologically linked to bacterial biofilms. The researchers wanted to see how well the erbium-doped yttrium aluminum garnet (Er:YAG) laser removed bacterial biofilms along with attached epithelial cells (EC), gingival fibroblasts (GF), in addition to osteoblast-like cells (OC) dentin along with titanium surfaces compared to previous therapy methods.Methodology:3.5 days were spent growing bacterial biofilms on standardized dentin and also titanium samplings using a sand-blasted along with the acid-etched surface. Following that, the specimens were positioned into pockets that had been formed artificially. The following approaches were used to remove biofilm: (1) Er:YAG, (2) photodynamic therapy (PDT), and (3) curette (CUR) along with supplementary PDT (CUR/PDT). The remaining biofilms' colony forming units (CFUs) were determined, as well as the attachment of EC, GF, in addition to OC. Analysis of variance with a posthoc least significant difference was utilized in the statistical analysis.Results:When compared to untreated dentin and titanium surfaces, all therapy strategies reduced total CFUs in statistically significant biofilms (p = 0.001). On the dentin, Er:YAG was as effective as CUR and PDT, but not as effective as CUR/PDT (p = 0.005). The application of Er:YAG on titanium surfaces leads to statistically significantly improved biofilm eradication equated to the supplementary three therapies (all p = 0.001). On untouched infested dentin and titanium surfaces, the counts of attached EC, GF, and OC were the lowermost. Atop the dentin, increased EC counts were detected after CUR/PDT (p = 0.006). On titanium, all cleaning procedures increased the counts of attached EC by a statistically significant amount (p = 0.001), with no variations between groups. After Er:YAG decontamination, there were statistically substantially elevated amounts of GF (p = 0.024) and OC (p = 0.001) than on untreated surfaces.Conclusion:The usage of Er:YAG laser to ablate subgingival biofilms and, specifically, to decontaminate titanium implant surfaces appears to be a promising strategy that needs further research.

In vitro evaluation of laser vs. handpiece for tooth preparation

Background:The erbium-doped yttrium aluminium garnet (Er:YAG) laser has been revealed to effectively ablate dental hard tissues, and its utilisation to caries eradication and cavity preparation is envisaged. Nevertheless, only a limited research has been performed on the Er:YAG laser's capacity to treat caries.Aim and Objectives:The efficiency of caries elimination with an Er:YAG laser in vitro was equated to that of traditional mechanical therapy in this study.Methodology:The investigation made use of teeth that had suffered from root caries. The Er:YAG laser was used to treat half of each tooth, while the other half was either removed with a conventional bur or left untouched as a control. Each therapy was evaluated in terms of how long it took to remove cavities, histological examinations of decalcified serial sections, scanning electron microscopy (SEM) analyses and the density of the dentin.Result:A longer treatment time was required for the Er:YAG laser to completely eradicate carious dentin because of its precise irradiation strategy. However, the Er:YAG laser was effective in removing diseased and softening carious dentin with little heat injury to neighbouring intact dentin, much as the bur treatment. It was also shown that the Er:YAG laser treatment had a lower amount of vibration than other methods. The SEM study of the lased dentin surface revealed characteristic micro-irregularities.Conclusion:The Er:YAG laser system appears to be a potential novel technical option for caries therapy, based on our findings.

Hydroxyapatite Film Coating by Er:YAG Pulsed Laser Deposition Method for the Repair of Enamel Defects.

There are treatments available for enamel demineralization or acid erosion, but they have limitations. We aimed to manufacture a device that could directly form a hydroxyapatite (HAp) film coating on the enamel with a chairside erbium-doped yttrium aluminum garnet (Er:YAG) laser using the pulsed laser deposition (PLD) method for repairing enamel defects. We used decalcified bovine enamel specimens and compacted α-tricalcium phosphate (α-TCP) as targets of Er:YAG-PLD. With irradiation, an α-TCP coating layer was immediately deposited on the specimen surface. The morphological, mechanical, and chemical characteristics of the coatings were evaluated using scanning electron microscopy (SEM), scanning probe microscopy (SPM), X-ray diffractometry (XRD), and a micro-Vickers hardness tester. Wear resistance, cell attachment of the HAp coatings, and temperature changes during the Er:YAG-PLD procedure were also observed. SEM demonstrated that the α-TCP powder turned into microparticles by irradiation. XRD peaks revealed that the coatings were almost hydrolyzed into HAp within 2 days. Micro-Vickers hardness indicated that the hardness lost by decalcification was almost recovered by the coatings. The results suggest that the Er:YAG-PLD technique is useful for repairing enamel defects and has great potential for future clinical applications.

A Comparative Evaluation of Root Surface Biomodification with Erbium-Doped Yttrium Aluminum Garnet Laser, Ethylenediaminetetraacetic Acid Gel, and Titanium Nitride Curette: In Vitro Scanning Electron Microscope and Profilometry Analyses.

Objective: This study aims to evaluate the in vitro effects of different biomodification treatment methods on extracted tooth/root surfaces in terms of biologically acceptable changes favoring better periodontal healing. Background data: The use of various agents for root surface biomodification (RSB), during periodontal procedures is of critical importance to increase the success of the treatments through healing. Ethylenediaminetetraacetic acid (EDTA) is the most frequently used chemical RSB agent in periodontal clinical practice. Erbium-doped yttrium aluminum garnet (Er:YAG) lasers have well-known advantages on blood cell adhesion and fibrin network formation on root surfaces. Recently, novel titanium nitride (TIN) curettes are of great interest due to smoother surface changes obtained after their application. Materials and methods: Forty-four dentine specimens from extracted single-rooted teeth were randomly divided into four groups: Group 1: No treatment; Group 2: Er:YAG laser irradiation; Group 3: EDTA gel application; Group 4: TIN curette instrumentation. All specimen surfaces were wet polished before treatments. Before and after root surface roughness parameters of all specimens were assessed with a profilometer. Further, all scanning electron microscopy micrographs were analyzed and scored for root surface and smear layer morphology characteristics by two different blinded researchers. Results: There were no statistical differences between the initial roughness of all groups (p = 0.687). After treatments, EDTA gel group revealed an intact intertubular area, some smear debris on dentine surfaces, and partially occluded dentine tubules. Er:YAG laser created the highest roughness (p < 0.05) among all treatment groups with no smear layer and exhibited fully exposed dentine tubules and collagen fibrils. Surfaces instrumented with TIN curette were the smoothest (p < 0.05) and covered with a compact and thick smear layer. Conclusions: Within the limits of this study, Er:YAG laser-irradiated surfaces exhibited exposed collagen fibrils, and Er:YAG laser irradiation was found as the only method yielding the desired surface characteristics for better periodontal healing, where the fibrils are exposed in the absence of smear layer.

Scanning Electron Microscope Image Analysis of Bonding Surfaces following Removal of Composite Resin Restoration Using Er: YAG Laser: In Vitro Study.

It is impossible to remove tooth-colored restorations by mechanical means without unnecessary damage to the adjacent sound tooth structure. This study is aimed at investigating erbium-doped yttrium aluminum garnet (Er: YAG) laser (Hoya ConBio, VersaWave, CA, USA) in removing composite resin restorations and assessing the change in morphology of bonding surfaces using a scanning electron microscope (EDX, CAMSCANNER, 3200LV, UK). The investigators collected thirty extracted sound human premolar teeth for this investigation, and the conventional design class V cavity was prepared on the buccal surface of each specimen. The specimens were allocated randomly into three groups, according to the procedure used for the ablation of the composite restoration: group A (high-speed diamond fissure bur), group B, and group C (Er: YAG laser) using a different pulse repetition rate of 20 Hz (group B) and 25 Hz (group C). The AutoCAD software program (Autodesk, Inc., 2016) was used to calculate the surface area and the resulting dimensional change of the cavities after restoration removal. The cavities were filled with composite resin and randomly assigned into two groups conforming to the methods applied to eliminate the restoration; diamond turbine fissure bur and laser. In each group, two specimens were selected randomly for scanning electron microscope analysis of bonding surfaces. The least meantime for the composite resin removal was observed in the high-speed diamond bur, significantly less than both Er-YAG laser groups (p < 0.001). However, at a higher pulse repetition rate, time-consuming decreased. The results showed that laser is more conservative in removing composite resin restoration as the change was most remarkable in group A (0.800 mm), then group C (0.466 mm), and the slightest change is in group B (0.372 mm) (p = 0.014). The dentin surface of group A showed a smooth surface with no opened dentinal tubule and intact smear layer. In groups B and C, dentin surfaces were irregular, scaly, or flaky, and dentinal tubules were opened without a smear layer. Therefore, Er: YAG laser is effective for composite resin removal considering the parameters chosen in this study with fewer changes in cavity surface area and better microretentive features.

Combination of Full-Field and Fractional Erbium: YAG Laser for Nonhealing Wounds.

To evaluate the outcomes of a heterogeneous group of patients with chronic ulcer receiving a combination regimen of full-field and fractional erbium-doped yttrium aluminum garnet (erbium: YAG) laser applications. Enrolled in this study were patients with chronic ulcer who had received at least 2 erbium: YAG laser sessions. Fractional applications followed the initial full-field application for debridement. The therapeutic outcomes were evaluated by serial photographs. The primary outcome measure was the proportion of patients achieving complete re-epithelialization at the first year. Forty-three treatment regions from 23 patients between 40 and 90 years (F: M = 11:12; age: 60.3 ± 15.5 years, mean ± SD) were eligible. The ulcers' median duration was 24 months (min-max: 2-240 months). The median number of laser sessions was 5 (min-max: 2-12). Of arterial (n = 13), immunologic (n = 9), venous (n = 8), diabetic (n = 8), and mechanical ulcers (n = 5), the primary outcome measure was achieved in 69%, 77.7%, 75%, 88.8%, and 100% of the groups, respectively. Full-field erbium: YAG laser applications preserve the vascular architecture and enable delicate debridement. Ongoing maintenance fractional laser sessions promote wound healing. Similar to the previous reports of erbium: YAG laser in venous and diabetic ulcers, arterial ulcers, and ulcers of immunologic origin demonstrated an objective treatment response along with different adjuvant approaches.

Physicochemical Changes of Contaminated Titanium Discs Treated With Erbium-Doped Yttrium Aluminum Garnet (Er:YAG) Laser Irradiation or Air-Flow Abrasion: An In Vitro Study.

Introduction: Peri-implantitis is a common complication of dental implant treatment. A cause-and-effect relationship has been previously documented between microbial plaque and peri-implantitis and implant failure. A difference has been reported in the disinfection efficacy of erbium laser irradiation and air-flow abrasion for contaminated titanium surfaces. Also, the surface changes caused by lasers and air-flow abrasion have not been well studied. Thus, the purpose of this study was to compare the surface changes of contaminated titanium discs following decontamination by erbium-doped yttrium aluminum garnet (Er:YAG) laser irradiation and air-flow abrasion. Methods: Twenty-eight intact, sandblasted, and acid-etched (SLA) titanium discs were used. Twenty-four titanium discs were contaminated with Escherichia coli. Then, they were decontaminated by using Er:YAG laser irradiation and air-flow abrasion. Four discs remained intact. The mean and standard deviation of the contact angle and the weight percentage of aluminum, titanium, oxygen, carbon, phosphorus, and calcium were measured. Qualitative changes in surface topography of titanium discs were assessed by scanning electron microscopy (SEM). Results: The mean weight percentage of carbon in the air-flow abrasion group (4.98%) experienced a significant reduction compared with the contaminated (positive control) group (P=0.035). The contact angles were 46.54° and 38.67° in the laser and air-flow abrasion groups respectively, which were significantly lower than the value in the positive control group (75.15°) (P ≤0.001). SEM micrographs showed no significant change in the surface area in either technique. Conclusion: Air-flow abrasion was more successful in improving the surface characteristics of titanium discs with no alteration in surface topography or elements, compared with Er:YAG laser irradiation. Further studies regarding the safety of the Er:YAG laser for the decontamination of titanium surfaces are recommended.

Residual Adhesive Removal Methods for Rebonding of Debonded Orthodontic Metal Brackets: Systematic Review and Meta-Analysis.

Debonding of orthodontic brackets is a common occurrence during orthodontic treatment. Therefore, the best option for treating debonded brackets should be indicated. This study aimed to evaluate the bond strength of rebonded brackets after different residual adhesive removal methods. This systematic review and meta-analysis was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. PubMed, Web of Science, The Cochrane Library, SciELO, Scopus, LILACS, IBECS, and BVS databases were screened up to December 2020. Bond strength comparisons were made considering the method used for removing the residual adhesive on the bracket base. A total of 12 studies were included for the meta-analysis. Four different adhesive removal methods were identified: sandblasting, laser, mechanical grinding, and direct flame. When compared with new orthodontic metallic brackets, bond strength of debonded brackets after air abrasion (p = 0.006), mechanical grinding (p = 0.007), and direct flame (p < 0.001) was significantly lower. The use of an erbium-doped yttrium aluminum garnet (Er:YAG) laser showed similar shear bond strength (SBS) values when compared with those of new orthodontic brackets (p = 0.71). The Er:YAG laser could be considered an optimal method for promoting the bond of debonded orthodontic brackets. Direct flame, mechanical grinding, or sandblasting are also suitable, obtaining clinically acceptable bond strength values.

Effect of Er:YAG Laser Irradiation and Acidulated Phosphate Fluoride Therapy on Re-Mineralization of White Spot Lesions.

Statement of the Problem: Studies on the efficacy of erbium laser for enhancement of enamel resistance to acid attacks and its effects on fluoride uptake by the enamel are limited.Purpose: This study sought to assess and compare the effects of erbium-doped yttrium aluminum garnet (Er:YAG) laser irradiation and application of acidulated phosphate fluoride (APF) gel (alone and in combination) on remineralization of artificial white spot lesions (WSLs).Materials and Method: This in vitro, experimental study evaluated 90 buccal and lingual slabs of extracted human premolars. The specimens underwent pH cycling to induce WSLs. They were then randomly divided into 6 groups of caries-free positive control (c+), negative control with WSLs (ws), 1.23% APF gel applied on the enamel (F), Er:YAG laser irradiation (80 mJ, 10 Hz, and 8 J/cm2) of enamel (L), APF gel application followed by laser irradiation (FL), and laser irradiation followed by fluoride gel application (LF). The fluoride ion content of specimens was measured before and after the intervention using a potentiometer. Data were analyzed by ANOVA (p< 0.05).Results: APF gel application before/after laser irradiation maximally increased the fluoride uptake by the enamel (p= 0.000). Application of APF gel in group F and laser irradiation in group L increased fluoride uptake by the enamel, compared with groups 1 and 2 (p= 0.000). Laser- treated (L) and APF-treated (F) groups had no significant difference in this respect (p= 0.945). Maximum fluoride concentration was noted in combined laser and fluoride groups (FL=332.07ppm and LF=341.27ppm) with no significant difference between the two (p= 1.000).Conclusion: Er:YAG laser irradiation changes the chemical composition of enamel and probably promote its remineralization, especially when combined with APF gel application, which highlights its cariostatic potential.

The clinical efficacy of Er:YAG lasers in the treatment of peri-implantitis: a systematic review and meta-analysis.

Erbium-doped yttrium aluminum garnet (ER:YAG) lasers have been used to treat peri-implant, but there are some disputes. To dispel these negative views, our study aims to compare the efficacy and safety of Er:YAG lasers versus conventional mechanical debridement in the treatment of peri-implantitis. Seven databases were used to search for relevant studies and full-text articles which evaluate the comparisons of Er:YAG lasers and mechanical debridement for patients with peri-implantitis. Review Manager 5.4 was employed to assess the effects of the results among the selected studies. Forest plots, subgroup analyses, and on the included articles were also completed. Cochrane risk of bias assessment tool was used to assess the risk of bias. Our study focused on 10 previously conducted studies which included 294 patients with peri-implantitis and a total of 461 implants. No significant differences in clinical attachment level (CAL) (MD =0.17, P=0.25, at 6 months; MD =0.23, P=0.15, at 12 months), reduction in bleeding on probing (BOP) (MD =9.54%, P=0.18, at 6 months; MD =11.28%, P=0.24, at 12 months), or plaque index (PI) (MD =-0.02, P=0.75, at 6 months; MD =-0.07, P=0.66, at 12 months) were observed between the Er:YAG laser group and the mechanical debridement group. However, in reducing probing depth (PD) (MD =0.28, P=0.03, at 6 months; MD =0.35, P=0.002, at 12 months) and gingival recession (GR) changes (MD =-0.12, P=0.04, at 6 months; MD =-0.16, P=0.03, at 12 months), the Er:YAG laser group showed some advantages at 6-month and 12-month intervals following treatment. No significant publication bias existed in our meta-analysis by using funnel plot and Egger's test (PD: P=0.65; CAL: P=0.73). Our research supported the premise that Er:YAG lasers offer health benefits to patients with peri-implantitis and can effectively reduce PD and GR. Due to the limitations of the included studies, further studies should be carried out to validate our findings.

Low-Level Erbium-Doped Yttrium Aluminum Garnet Laser Irradiation Induced Alteration of Gene Expression in Osteogenic Cells from Rat Calvariae.

Objective: The aim of this study was to investigate the effect of low-level erbium-doped yttrium aluminum garnet (Er:YAG) laser irradiation on gene expression in osteogenic cells from rat calvariae. Background: Previous studies showed beneficial effects of laser irradiation on bone-related cells. However, few studies have examined the gene expression alteration by laser irradiation on osteogenic cells in a calcified condition. Materials and methods: Osteogenic cells were prepared by culturing rat calvarial osteoblast-like cells in osteoinductive medium for 21 days. The cells at the bottom of the culture dish were irradiated with Er:YAG laser (wavelength: 2.94 μm, energy density: 3.1 and 8.2 J/cm2) positioned at distance of 25 cm. Lactate dehydrogenase (LDH) assay of the irradiated cells was performed. After screening for genes related to bone formation, mechanotransduction, and thermal effect by quantitative polymerase chain reaction (qPCR), gene expression at 3 h after 3.1 J/cm2 irradiation was comprehensively analyzed using microarray. Results: No dramatical increase in surface temperature and LDH activities after laser irradiation were observed. Sost expression was significantly reduced at 3 h after 3.1 J/cm2 irradiation. Bcar1 and Hspa1a expression was significantly increased following 8.2 J/cm2 irradiation. Microarray analysis identified 116 differentially expressed genes. Gene set enrichment analysis showed enrichment of histone H3-K9 methylation and modification gene sets. Conclusions: Er:YAG laser irradiation, especially at 3.1 J/cm2, showed positive effect on the expression of genes related to bone formation in osteogenic cells, without inducing significant cell damage. These findings may represent critical mechanisms of early bone formation after Er:YAG laser irradiation.

Residual periodontal pocket treatment with Er:YAG laser-assisted comprehensive periodontal pocket therapy: a retrospective study

Recently, the application of erbium-doped yttrium aluminum garnet (Er:YAG) laser has been increasing in periodontal therapy. In this retrospective study, we evaluated the safety and effectiveness of a novel pocket therapy using Er:YAG laser in combination with conventional mechanical scaling and root planing treatment (Er:YAG laser-assisted comprehensive periodontal pocket therapy). Forty sites in 29 elderly patients having residual periodontal pockets of ≥ 5mm depth were treated by curette and Er:YAG laser from 2006 to 2009. After root debridement by curette, laser irradiation was performed on the root surfaces. Then, inflamed connective tissue on the inner gingival surface and on the bone surface/within extant bone defects was thoroughly debrided by curette and laser. Furthermore, in most cases, removal of the outer epithelium and coagulation of the blood clot in the pocket entrance were additionally performed with laser. Clinical parameters were evaluated before and 3, 6, and 12months after treatment. With Er:YAG laser-assisted pocket therapy, debridement of pockets was thoroughly and safely performed, and favorable clinical improvements were observed in most cases, without any adverse side effects and complications. After 1year, probing pocket depth significantly decreased from 6.4 ± 1.4 to 3.5 ± 1.3mm (p < 0.001, 3.0mm reduction), and clinical attachment level significantly decreased from 7.5 ± 1.6 to 5.2 ± 1.9mm (p < 0.001, 2.3mm gain). The results of this study indicate that Er:YAG laser-assisted therapy is useful for the treatment of residual pockets as a minimally invasive flapless surgery. Er:YAG laser-assisted comprehensive pocket therapy reduces the necessity of more conventional surgical therapies.

Efficacy of combined treatment with intense pulsed light and fractional erbium:YAG Laser in scar prevention: A randomized split wound trial.

Various methods have been used for scar prevention; however, the optimal method remains unclear. We investigated the efficacy of combinational intense pulsed light (IPL)/fractional erbium-doped yttrium aluminum garnet (Er:YAG) laser treatment in early wound healing. This was a prospective, randomized, controlled split wound trial. Scars were divided into three sites: the combined IPL/fractional Er:YAG treatment, fractional Er:YAG laser treatment, and untreated control sites. Treatment was conducted in three sessions: at removal of stitches and after 4 and 8 weeks. Treatment efficacy was evaluated using the Patient Observer Scar Assessment Scale (POSAS) and Vancouver Scar Scale (VSS) scores. The erythema index (EI) and melanin index (MI) were measured. In the total POSAS score, the IPL/fractional Er:YAG site showed steady and significant improvement, in contrast to the other sites. At week 8, the combined treatment sites had better POSAS scores than the fractional Er:YAG laser alone sites (p=0.001) and the control sites (p=0.000). The effect of combinational treatment was maintained until the follow-up period by comparing the Er:YAG (p=0.015) and control sites (p=0.007). In terms of VSS scores, the IPL/fractional Er:YAG combined treatment sites had consistent improvement at week 8 (p=0.005) and week 20 (p=0.02) compared to that at week 4, while the other sites showed no such improvement. In conclusion, the combination of IPL and Er:YAG showed more favorable effects on scar prevention than Er:YAG or no treatment. IPL/Er:YAG therapy could be an effective and safe strategy in the early wound healing process for reducing scar formation.

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.

The Effect of Erbium-Doped Yttrium Aluminum Garnet Laser in Debonding of Orthodontic Brackets: A Systematic Review of the Literature.

Objective: The purpose of this review is to systematically assess the existing literature and summarize the evidence regarding the effect of erbium-doped yttrium aluminum garnet (Er:YAG) laser on enamel surface roughness and pulp health compared with the conventional orthodontic debonding techniques. Materials and methods: Following the preferred reporting items for systematic reviews (Preferred Reporting Items for Systematic Reviews and Meta-analyses) statement, the electronic database, PubMed, Scopus, Web of Science, Google scholar, and Saudi Digital Library were searched for relevant published records. Data were collected following specific keywords: "debonding" "Er:YAG laser" etc. In vitro studies, and clinical randomized- and nonrandomized-controlled studies limited to the English language and published in peer-reviewed journals were included. Results: A total of 564 articles were identified as relevant to the topic. Duplicates were excluded resulting in 382 articles, out of which 374 articles were discarded upon screening titles and abstracts. The remaining eight articles were read to their entirety and included in the current qualitative review after fulfilling the eligibility criteria. In all the included studies, a total of 480 sound posterior teeth were used to evaluate the effect of Er:YAG laser on debonding of orthodontic brackets from the enamel surface. Conclusions: Er:YAG laser debonding has demonstrated a reduced risk of enamel damage (fracture or cracks) but resulted in increased enamel surface roughness and was time-consuming for adhesive removal procedures compared with the conventional debonding methods. Further, within the applied laser settings, Er:YAG lasers have found to exhibit low thermal exhaustion in relation to the pulp. The laser source with a wavelength of 2940 nm has been used with different setting ranges (power of 2.5-5 W, energy 125-600 mJ, frequency 4-30 Hz, and pulse duration 50-350 μsec) for debonding of orthodontic brackets.

Comparison of Shear Bond Strength, Adhesive Remnant Index and Enamel Cracks in Bonding and Rebonding of Stainless Steel Brackets to Enamel Surface Conditioned with Er:YAG Laser Versus Conventional Acid Etching

Objectives : The aim of the present study was to compare shear bond strength (SBS), adhesive remnant index and enamel cracks in bonding and rebonding of brackets to enamel, conditioned with erbium-doped yttrium aluminium garnet (Er:YAG) laser and conventional acid-etching. Material s and Methods: Fifty-two bovine lower incisors were randomly divided into four groups consisting of group 1 (acid-conditioning in both bondings), group 2 (acid-conditioning in first and laser-conditioning in second bonding), group 3 (laser-conditioning in first- and acid-conditioning in second bonding), and group 4 (laser-conditioning in both bondings). After bracket placement, the samples were thermocycled and tested for SBS in both bonding procedures. Adhesive remnant index scores and enamel cracks were also determined. Tukey's test and one-way analysis of variance was used for statistical analysis (P<0.05). Results: Mean SBS in the first bonding was 23.59MPa in groups 1 and 2, and 6.9MPa in groups 3 and 4. (P<0.001). The acid-etched teeth had a significantly lower SBS in rebonding, regardless of the reconditioning method (P<0.001). The SBS of the teeth conditioned with Er:YAG laser in the first bonding did not show significant changes in rebonding, although mean SBS was higher compared to the first bonding (P=0.675). Bonding most often failed at the enamel-adhesive interface and enamel cracks were observed in a few teeth. Conclusion: The method of primary enamel preparation can affect SBS in rebonding. Based on our results, the mean SBS of Er:YAG-conditioned groups was clinically acceptable in bonding and rebonding, although it was lower compared to the acid-etched samples.

Post-Space Treatment Influences the Bond Strength In Endodontically Treated Teeth: A Systematic Review and Meta-Analysis of In Vitro Studies.

This systematic review of in vitro studies investigated the influence of the post-space treatment used to remove the smear layer on the bond strength of the post to root canal dentin. In vitro studies included in this study were identified from PubMed/MEDLINE, Lilacs, and Scopus databases up until March 2019, without limits on publication year or language. Two reviewers independently selected the studies based on the inclusion and exclusion criteria, extracted the data, and evaluated the risk of bias of all studies. A random effects model was used for pairwise meta-analyses (control vs. post-space preparation groups) at a significance level of p<0.05. Of the 2,832 potentially eligible studies, 453 studies were selected for full-text analysis, and 75 were included in this systematic review. Only one study was considered to have a low risk of bias. Overall, post-space treatment significantly improves the bond strength to root canal dentin (p<0.00001). Post-space treatment has a positive influence on the bond strength of the post to root canal dentin. In this review, the post-space treatments that improve the adhesive resistance of the post were ethanol, sodium hypochlorite, and ethylene diamine tetra-acetic acid (NaOCl + EDTA), NaOCl + EDTA + ultrasound, erbium-doped yttrium aluminium garnet laser (Er:YAG laser), neodymium-doped yttrium aluminium garnet laser (Nd:YAG laser), and diode laser.

Short-term results of the combined application of neodymium-doped yttrium aluminum garnet (Nd:YAG) laser and erbium-doped yttrium aluminum garnet (Er:YAG) laser in the treatment of periodontal disease: a randomized controlled trial

ObjectivesNd:YAG and Er:YAG lasers have been previously used as an adjunct in periodontal therapy. The aim of this single-blinded randomized controlled clinical trial was to evaluate the efficacy of a combined application of Nd:YAG and Er:YAG laser irradiation in periodontal treatment.Materials and methodsTwenty-two patients with at least one site of ≥ 6 mm periodontal probing depth (PPD) after mechanical debridement with curettes and sonic instruments at periodontal reevaluation were included in the study. Patients were randomly allocated at a 1:1 ratio to either a combined Nd:YAG/Er:YAG laser therapy (test group) or a “turned off” laser therapy (control group). The Nd:YAG laser was used for periodontal pocket deepithelialization and to stabilize the resulting blood clot. The Er:YAG laser was primarily used for root surface modification. PPD (mm), clinical attachment level (CAL, mm), and bleeding on probing (BOP, +/−) at the site of laser treatment were evaluated at baseline and 2 months after treatment.ResultsThe mean improvements from baseline to 2-month follow-up for PPD were significantly better in the laser group (2.05 ± 0.82 mm) compared to the control group (0.64 ± 0.90 mm; p = 0.001). Likewise, the gain in CAL was significantly better in the laser group (1.50 ± 1.10 mm) than in the control group (0.55 ± 1.01mm; p = 0.046).ConclusionsThe combined application of Nd:YAG and Er:YAG laser irradiation as an adjunct to conventional non-surgical therapy showed a significant beneficial effect on periodontal treatment results.Clinical relevanceCombined Nd:YAG and Er:YAG laser irradiation could be a useful procedure additionally to conventional non-surgical periodontal therapy to improve periodontal treatment results.Clinical trial registrationISRCTN registry #ISRCTN32132076