Erbium(III) complexes with fluoroquinolones: Structure and biological properties

Four erbium(III) complexes with the fluoroquinolones enrofloxacin, levofloxacin, flumequine and sparfloxacin as ligands were synthesized and characterized by a wide range of physicochemical and spectroscopic techniques as well as single-crystal X-ray crystallography. The compounds were evaluated for their activity against the bacterial strains Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Xanthomonas campestris, which was higher than that of the corresponding free quinolones. The interaction mode of the complexes with calf-thymus DNA is via intercalation, as suggested by diverse studies such as UV-vis spectroscopy, DNA-viscosity measurements and competitive studies with ethidium bromide. Fluorescence emission spectroscopy revealed the high affinity of the complexes for bovine and human serum albumin and the determined binding constants suggested a tight and reversible binding of the compounds with both albumins.

Erbium: YAG laser treatment efficacy and association with histologic features for giant congenital melanocytic nevi management

BACKGROUND

Limited research exists on laser treatment of giant congenital melanocytic nevus (GCMN).

OBJECTIVE

We sought to elucidate the efficacy of the Erbium: YAG laser on GCMN and the histologic factors associated with a positive clinical response.

METHODS AND MATERIALS

Between 2019 and 2022, we enrolled 30 medium-to-giant CMN patients who underwent Er: YAG laser treatment. All patients received biopsies before and after laser treatments. Clinical efficacy outcomes were evaluated by the investigator's global assessment (IGA), 5-point scale of depigmentation, and Vancouver Scar Scale (VSS) scores at least 6 months after treatment.

RESULTS

Of the 30 cases, 18 (60.0%) showed improvement (IGA score ≥3). Eight (26.7%) patients showed repigmentation. Eight (26.7%) patients developed hypertrophic scars. The average IGA, depigmentation, and VSS scores were 2.93, 3.57, and 3.20. The IGA score was higher (3.24 ± 1.18 vs. 2.22 ± 0.97, p = 0.031) and a lower repigmentation rate (14.3% vs. 55.6%, p = 0.032) was observed in the cases with Grenz zone. The IGA score was higher (3.33 ± 1.24 vs. 2.13 ± 0.89, p = 0.023) and the repigmentation rate was lower (11.1% vs. 50.0%, p = 0.034) also in the cases with the melanocytes nests with aggregation of melanin. Lesions with superficial ablation resulted in less hypertrophic scar formation than those with deep ablation (5.9% vs. 53.8%, p < 0.05).

CONCLUSION

The Er: YAG laser demonstrated effective clinical results for GCMNs. The grenz zone and the melanocytes nests with aggregation of melanin are promising predictors of laser efficacy.

Vaginal erbium laser treatment for stress urinary incontinence: A multicenter randomized sham-controlled clinical trial

OBJECTIVE

To evaluate the efficacy and safety of non-ablative vaginal Er:YAG laser device in stress urinary incontinence (SUI) treatment.

METHODS

We conducted a multicenter blinded randomized sham-controlled trial in which women with urodynamic SUI were randomization to active arm using Er:YAG laser therapy, and sham arm using sham handpiece. Patients received two treatments 1 month apart. The primary outcomes measure was 1 h pad weight test measured at 6 months. Secondary outcomes were durability of treatment success at 12 months, and questionnaires for assessment of SUI severity (ICIQ-UI SF), sexual function (PISQ-12) and HRQoL (KHQ), and incidence and severity of device related adverse events and pain (VAS).

RESULTS

A total of 110 participants with SUI were recruited; 73 in the active arm and 37 in the sham arm. Two participants were excluded; one was assigned the wrong treatment and one withdrew their consent. Treatment success was observed in 36% of the sham arm and 59% of the active arm; in the latter, odds of achieving treatment success were more than three-fold higher (OR 3.63, 95% CI: 1.3-11.2, P = 0.02). HRQoL by KHQ showed significant improvement in the active versus the sham arm (OR 0.36, 95% CI: 0.15-0.87, P = 0.003). Similarly, subjective patient assessment of general and sexual function improvement with PISQ-12 and PGI-I showed superior effect over sham (OR 2.8, 95% CI: 1.2-7.0, P = 0.02 and OR 0.13, 95% CI: 0.05-0.36, P < 0.001, respectively).

CONCLUSION

Non-ablative vaginal Er:YAG laser therapy significantly improves SUI symptoms versus sham treatment. Er:YAG laser therapy should be considered as a non-surgical treatment option for SUI patients.

Full-face and neck resurfacing with a novel ablative fractional 2910 nm erbium-doped fluoride glass fiber laser for advanced photoaging

OBJECTIVES

Ablative fractional lasers have long been considered the gold standard for facial resurfacing for advanced photoaging. These lasers offer an improved safety profile compared to traditional ablative lasers but typically require more treatment sessions given their fractional approach. In this study, we evaluate a new novel 2910 nm erbium-doped fluoride glass fiber laser (2910 nm fiber laser) (UltraClear; Acclaro Medical) for full-face and neck resurfacing for the treatment of advanced photoaging.

METHODS

Twenty-two healthy subjects aged 44-80 years presenting for advanced facial photoaging and rhytides were enrolled in the study. All subjects received three full-face and neck, multipass treatments utilizing the 2910 nm fiber laser spaced 6-8 weeks apart. Subjects were asked to rate the average level of pain during the treatment. At 90 days following subjects' third treatment subjects evaluated their improvement using a Global Aesthetic Improvement Scale (GAIS) and rated their satisfaction with the treatment. Evaluation of pretreatment and posttreatment photos was completed by two blinded physician reviewers. Reviewers were asked to identify the pretreatment and posttreatment photographs and to rate the degree of improvement utilizing a GAIS.

RESULTS

Fifteen participants completed the study; six were exited from the study (withdrew or lost to follow-up). The average subject GAIS score for overall appearance was 3.8. The average subject satisfaction level at follow-up was 4.8. The average subject pain score was 4.9. One blinded physician reviewer correctly identified 100% of subjects' posttreatment photographs, while the second blinded reviewer correctly identified 93%. Blinded evaluation of digital photographs revealed an average GAIS score of 3.2. Posttreatment skin responses included pin-point hemorrhage, erythema, edema, and soft tissue crusting lasting 5-7 days. There were no instances of infection, scarring or hypopigmentation. There were two instances of temporary hyperpigmentation.

CONCLUSIONS

Treatment with the novel 2910 nm fiber laser is safe and effective in treating advanced photoaging and rhytides. Three treatments produced moderate to marked improvement with high patient satisfaction and treatment was associated with less discomfort and downtime compared to conventional fractional ablative lasers.

Er:YAG laser debonding of zirconia and lithium disilicate restorations

STATEMENT OF PROBLEM

Yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) restorations of different formulations are being used increasingly in monolithic form for a range of clinical applications. Using rotary instruments to remove such restorations for any purpose is challenging, but they can be removed conservatively with erbium lasers. However, studies on how a laser penetrates different zirconias to break the cement bond between the tooth surface and the zirconia are lacking.

PURPOSE

The purpose of this in vitro study was to evaluate and compare the time required for an erbium-doped yttrium-aluminum-garnet (Er:YAG) laser to remove different types of zirconia and lithium disilicate crowns.

MATERIAL AND METHODS

Forty extracted premolar teeth were prepared, scanned, designed, and milled to fabricate 40 computer-aided design and computer-aided manufacturing (CAD-CAM) crowns, which were assigned to 4 groups (n=10): 3 mol% Y-TZP, 4 mol% Y-TZP, 5 mol% Y-TZP, and lithium disilicate as a control. All crowns were bonded to the teeth with a self-adhesive resin cement (Panavia SA Cement Universal). Each specimen was irradiated with an Er:YAG laser with the following parameters: 300 mJ, 15 Hz, 5.0 W, and a 50-microsecond pulse duration (supershort pulse mode). The irradiation time required for crowns to be retrieved successfully was recorded for each specimen. Data were statistically analyzed using analysis of variance and the Tukey honestly significant difference post hoc test (α=.05). The intaglio surfaces of the restorations were analyzed using scanning electron microscopy (SEM).

RESULTS

The mean ±standard deviation times in minutes needed for crown debonding were 12.46 ±4.17 for the 3 mol% Y-TZP group, 10.30 ±3.33 for the 4 mol% Y-TZP group, 4.03 ±1.62 for the 5 mol% Y-TZP group, and 2.08 ±0.92 for the lithium disilicate group. A statistically significant difference (P<.05) in the debonding time was found for all investigated groups, expect between the 3 mol% and 4 mol% Y-TZP groups and between the 5 mol% Y-TZP and lithium disilicate groups. SEM analysis of the ceramic surfaces showed no visual damage associated with Er:YAG laser irradiation.

CONCLUSIONS

Zirconia crown retrieval time with the Er:YAG laser was influenced by the yttria content of the zirconia, with decreasing retrieval time with increasing yttria content. Er:YAG laser debonding of zirconia crowns is a noninvasive, efficient, and rapid approach to the removal of crowns and could be applied in clinical practice.

Efficacy and safety of lasers versus topical medications for acanthosis nigricans and pseudo-acanthosis nigricans treatment: a systematic review

Acanthosis nigricans (AN) is a cutaneous disorder identified by well-defined pigmented plaques mostly detected on skin folds. Timely diagnosis and treatment of AN is essential as it could be an early manifestation of an underlying condition. The treatment of choice for AN has not been determined yet. Our study aimed to compare the efficacy and safety of various lasers with topical medications, including cream and peel. PubMed, Scopus, and Web of Science databases, as well as the Google Scholar search engine, were thoroughly searched until May 1st, 2023. Study selection was restricted to clinical trials published in English language comparing lasers with topical treatments. This study followed the PRISMA guidelines for systematic reviews and meta-analyses. Out of 1748 studies, Six clinical trials met our inclusion criteria, with 133 patients. We examined laser therapies, including fractional CO2 laser, 1550-nm erbium fiber laser, and long-pulsed alexandrite laser, while the topical treatments comprised glycolic acid (GA) peel, retinoic acid peel, trichloroacetic acid (TCA) peel, and tretinoin cream. In two studies, GA peel demonstrated favorable results compared to fractional CO2 laser. Besides, fractional CO2 laser exhibited efficacy, surpassing TCA peel in AN management. Additionally, a fractional 1550-nm erbium fiber laser displayed superiority over tretinoin cream in reducing average roughness. Similarly, a long-pulsed alexandrite laser demonstrated its effectiveness in axillary AN treatment compared to the combination of tretinoin and ammonium lactate. Overall, the findings revealed that laser therapy was associated with superior results. Moreover, topical treatments are safe and efficacious in AN management.

Evaluation of the effectiveness and practicality of erbium lasers for ceramic restoration removal: A retrospective clinical analysis

BACKGROUND

The purpose of this study was to assess the effectiveness and practicality of erbium lasers in the removal of ceramic restorations and appliances from natural teeth and dental implant abutments in clinical practice.

METHODS

A retrospective analysis was conducted, involving 29 clinical cases with a total of 52 abutments requiring the removal of various ceramic restorations. The analysis evaluated the clinical procedures performed, including the type and material of the prosthetic, the type of cement used, laser setting parameters, retrieval time, and retrieval success.

RESULTS

Out of the 52 abutments, 50 were successfully retrieved without causing any damage (>95%) using either an Er,Cr:YSGG laser (N = 6) or an Er:YAG laser (N = 46). In one case, a crown was partially sectioned to prevent any negative impact of laser irradiation on the adhesive strength between the post and tooth, and in another case, a fracture occurred during debonding. The restorations consisted of 13 lithium disilicate and 39 zirconia units, including six veneers, 38 single crowns, and three fixed partial dentures (FPDs). The retrieval time varied depending on the restoration type, material thickness, cement type, retention form/fitting of the abutment and restoration, ranging from 2.25 ±0.61 minutes for veneers, 6.89 ±8.07 minutes for crowns, to 25 ±10 minutes per abutment for FPDs. Removal of a zirconia crown required more time, 7.12±8.91 minutes, compared to a lithium disilicate crown, 5.86 ±2.41 minutes. The debonding time was influenced by the laser settings as well as materials and types of prosthesis.

CONCLUSIONS

Erbium lasers present a safe and effective alternative to invasive methods for removing ceramic restorations, without causing harm to the abutment or prosthesis. Laser-assisted debonding allows for recementation of the restorations during the same appointment, making it a conservative and viable option for ceramic crown retrieval in clinical settings.

Use of fractionated laser therapy for the treatment of androgenetic alopecia: a systematic review and meta-analysis

Procedural management, including fractionated laser therapy, has been increasingly investigated for the management of androgenetic alopecia (AGA). However, no comprehensive resources exist detailing the efficacy of fractionated laser therapies used for the treatment of AGA. A systematic review investigating fractionated laser use for AGA was performed, separated into each distinct fractionated laser modality. A meta-analysis was performed to examine improvement in hair counts and hair shaft diameter. Fourteen studies were included for systematic review, which identified the use of erbium-glass, thulium, erbium-ytrrium:aluminum garnet (YAG), and carbon dioxide (CO2) fractionated laser for the treatment of AGA. In the meta-analysis, fractionated laser combination therapy showed significant improvement in hair shaft diameter (2.51, 95% CI 2.37-2.65, I2 = 90.54). Fractionated laser monotherapy alone significantly improved hair shaft diameter (2.28 95% CI 2.03-2.52, I2 = 91.20%). This effect was durable on subgroup analysis for both erbium-glass (2.36 95% CI 2.01-2.71, I2 = 92.05%) and thulium (1.61 95% CI 1.08-2.15, I2 = < 0.00%). There was no improvement in hair shaft count for any laser modality. Erbium-glass laser is an effective modality as either monotherapy or combination with topical/injectable therapies to improve hair shaft diameter in AGA.

Fractional erbium:yttrium aluminum garnet laser in the treatment of morphea mouse model

OBJECTIVE

To assess the efficiency and the mechanism of fractional erbium:yttrium aluminum garnet (Er:YAG) laser for the treatment of morphea in mouse model.

BACKGROUND

Morphea is a rare autoimmune disease characterized by excessive collagen deposition in skin. Fractional Er:YAG laser treatment is a promising treatment to improve morphea, despite limited studies about the therapeutic effect and underlying mechanism.

METHODS

The mouse model of morphea was established by subcutaneously injecting with bleomycin (BLM). A total of 24 mice received fractional Er:YAG laser treatment once a week for 4 weeks. Objective measurement employed was ultrasonic imaging to measure dermal thickness. Subjective measures included scoring according to the adjusted Localized morphea Cutaneous Assessment Tool (LoSCAT); hematoxylin and eosin (H&E) staining to evaluate the histological grade of fibrosis; and quantitative morphometric studies to determine the expression of transforming growth factor-β1 (TGF-β1) and matrix metalloproteinase-1 (MMP1) by immunohistochemistry.

RESULTS

In this self-controlled study, fractional Er:YAG laser treatment significantly ameliorate the severity of morphea, including lower clinical score (p < 0.01), decreased dermal thickness (p < 0.001), declined histological grade of fibrosis (p < 0.001), increased MMP1 (p < 0.001), and reduced TGF-β1 (p < 0.01) expression.

CONCLUSIONS

We found that fractional Er:YAG laser treatment of morphea has good clinical, ultrasonic, and histopathologic efficacy, which may be a promising treatment in the future.

Evaluation of the microleakage of class V composite restoration after cavity treatment with Erbium, CO2 lasers, Papain, and Bromelain enzymes

OBJECTVES

Different surface preparation and treatment methods may have dissimilar effects on the microleakage of composite resin. This study was conducted to determine the deproteinizing effect of 10% bromelain enzyme, 10% papain enzyme, CO2 , and erbium-YAG laser in regard to decrease in the microleakage of composite restorations.

MATERIALS AND METHODS

Thirty teeth were selected and 60 class V cavities were prepared on the lingual and buccal sides. They were divided into six groups (n = 10): Group 1, phosphoric acid gel; Group 2, bromelain enzyme 10%; Group 3, papain enzyme 10%; Group 4, mixed papain and bromelain enzymes 10%; Group 5, CO2 laser; and Group 6, erbium-YAG laser. They were stored in basic fuchsine and dye penetration was evaluated. Kruskal-Wallis and Mann-Whitney tests were used for statistical analysis, p < 0.05 RESULTS: In both occlusal and gingival margins, comparison of microleakage between groups 1, 2, 3, 4, and 5 showed no significant differences (p = 1) and group 6 had a significant difference with other groups (p ˂ 0.001).

CONCLUSIONS

Microleakage of composite resin in the dentin surface was not affected significantly using either bromelain or papain 10% enzymes or erbium laser. However, CO2 laser had a negative effect on the enamel and dentin margins and increased the microleakage. Erbium laser showed a better effect than enzymes on microleakage.

Spatially modulated erbium YAG laser as a treatment for diabetic ulcer

OBJECTIVE

Diabetic ulcers are a significant healthcare challenge, capable of diminishing quality of life, lengthening hospitalisation stay, and incurring substantial costs for patients and healthcare systems. Erbium-doped yttrium-aluminum-garnet (Er-YAG) laser has been evolving as a prospective intervention for addressing wounds of various aetiologies. Despite this, the literature remains limited in appraising the effectiveness of laser therapy specifically in diabetic wounds. This study investigates the impact of employing a spatially modulated Er-YAG laser as a therapeutic approach for treating diabetic ulcers.

METHOD

In a single-arm study conducted from November 2017 to April 2023, patients with hard-to-heal ulcers were treated in a two-step approach of wound debridement using Er-YAG laser for ablation and biostimulation through deep tissue resonance using RecoSMA (Multiline laser system, LINLINE MS, Latvia) laser technology. Ulcers received weekly laser treatment, together with routine care until healing occurred and were then followed up to observe any recurrence. The primary outcome measure was wound closure; the secondary outcome measures were time to closure, and the number of laser treatments required. Data related to sociodemographic details, size and number of diabetic ulcers, and number of sessions related to laser treatment were collected using a predesigned, pretested questionnaire before initiating the treatment.

RESULTS

A total of 59 patients attending the clinic during the study period with diabetic ulcers were included in the study. The mean wound surface area at baseline was 25.7cm2 (median: 12cm2). The average number of sessions of laser treatment required was 4.41, ranging from 1-11. The size of the ulcer reduced with each session of laser treatment. The diabetic ulcers healed completely at the end of the treatment, indicating the effectiveness of the Er-YAG/RecoSMA two-step approach.

CONCLUSION

Spatially modulated erbium YAG laser is effective as a therapeutic approach for treating diabetic ulcers.

Clinical evaluation of a new fractional ablative 2910 nm erbium laser on photodamaged skin: A pilot study

OBJECTIVE

To examine the efficacy and safety of a new fractional, ablative erbium:glass fiber (Er:glass) laser (2910 nm) at improving clinical signs of photodamaged skin.

MATERIALS AND METHODS

Thirty-seven healthy participants aged 38-75 years with photodamaged skin were enrolled into two treatment groups. Group A (n = 14) received up to four laser treatments with mild settings, and focal facial subunits were treated with deeper settings. Group B (n = 23) received a single treatment using deeper settings. Following treatment, pain scores and severity and duration of skin responses (erythema, edema, and pinpoint bleeding) were assessed. Primary outcome was the improvement in participant and investigator Global Aesthetic Improvement Scale (GAIS) at 3-month follow-up. Secondary outcomes were participant satisfaction with treatment and whether they would repeat treatment.

RESULTS

Thirty-five participants completed the study (n = 1 lost to follow up in each group). Both groups had similar mean participant and investigator GAIS scores of 3/5 corresponding to "Improvement." All but two patients (both from Group A) reported improvement, satisfaction with treatment, and would repeat treatment. Posttreatment skin responses were mild-to-moderate, lasting up to 5 days. There was no scarring or dyspigmentation.

CONCLUSION

The 2910 nm Er:glass laser provided improvement in photoaging with high patient satisfaction.

Er:YAG laser combined with botulinum toxin A for patients with local syringomas: A preliminary report

Syringoma is a common but refractory benign skin tumor. Conventional treatment, such as ultra-pulsed carbon dioxide (CO2 ) laser or cryotherapy, often requires multiple treatment and can easily cause prolonged erythema, scarring, or depression, which are frustrating, so there is an urgent need to seek a safer and more effective method. In this article, we tried to demonstrate the Er:YAG laser combined with botulinum toxin A (BTXA) as a safer and more efficacious method for treating syringomas.

MATERIALS AND METHODS

Twenty-one patients with local syringomas were treated with erbium laser ablation. Immediately after laser treatment, approximately 10 units of BTXA were sprayed on the wound for 10 min.

RESULT

In total, 21 patients underwent 1.62 ± 0.74 treatments; their Periorbital Syringoma Severity Index (PSSI) score declined from 4.19 (before treatment) to 1.10 (after treatment), and the number of treatments was significantly lower than those reported in previous literature using the erbium laser alone.

CONCLUSION

The Er:YAG laser combined with botulinum toxin A for the treatment of syringoma is a safer and more effective treatment than traditional treatment methods.

Number of vaginal lactobacilli in postmenopausal women with vaginal atrophy before and after treatment with erbium-YAG laser: a randomized sham-controlled trial

PRIMARY OBJECTIVE

To evaluate the effect of erbium-YAG laser on the number of vaginal lactobacilli in postmenopausal women.

SECONDARY OBJECTIVES

To evaluate the effect of erbium-YAG laser on vaginal atrophy symptoms and vaginal pH in postmenopausal women.

MATERIALS AND METHODS

A total of 44 postmenopausal women who met the inclusion criteria were randomized in the laser group (n = 22) and sham group (n = 22). Vaginal lactobacilli grading, vaginal pH, vaginal atrophy score, and vaginal atrophy symptoms were assessed before and after treatment with erbium-YAG laser for two consecutive times, with a four-week interval; the results were compared with the effects of the sham procedure. Any adverse events after the treatment were recorded.

RESULTS

A total of 44 women were included, and five were lost to follow-up. Compared with sham procedure, vaginal lactobacilli grading improved in the laser group (5/20 in the laser group and 1/19 in the sham group). However, the improvement did not reach statistical significance (adjusted odds ratio = 5.32, 95% CI = 0.5-56.21). Vaginal atrophy symptoms measured by the visual analog scale (VAS) and vaginal pH were improved in both groups without a statistically significant difference between the two groups. Vaginal "dryness" VAS and vaginal atrophy score after treatment were significantly lowered in the laser group compared with the sham group.

CONCLUSIONS

This study showed an improvement in vaginal lactobacilli grading after vaginal laser treatment. However, the difference in vaginal lactobacilli grading after treatment in both groups was not statistically significant.

Do erbium lasers promote changes in the tooth enamel during debonding of ceramic laminate veneers? A systematic review

The longevity of ceramic laminate veneers can be influenced by several factors, which can result in the need for a removal process. Laser removal has emerged as a good alternative to facilitate the procedure, and its repercussions on tooth enamel have been investigated. We aimed to evaluate the efficacy of erbium lasers for debonding ceramic laminate veneers without damaging the tooth enamel. This systematic review based on the PICOS model adhered to the PRISMA statement. The PubMed/MEDLINE, Web of Science, Embase, and Scopus databases were systematically searched until December 1, 2022, and 2902 studies were retrieved. After screening, four in vitro studies that analyzed the dental morphology using scanning electron microscopy, optical analysis, stereomicroscopy, or x-ray dispersion spectroscopy were included. The risk of bias was assessed using the Cochrane Collaboration tool. Our findings suggest that erbium lasers are useful for ceramic laminate veneer removal without damaging the tooth enamel. However, the removal is influenced by the type and thickness of ceramic and type of cement used. It could be concluded that the application of Erbium laser did not promote superficial changes in the dental enamel. This effect was observed in all analysis performed.

The application of lasers in vital pulp therapy: a review of histological effects

Vital pulp therapy (VPT) is primarily intended to preserve the vitality of pulp tissues, which have been exposed for any reason. Various materials and techniques have been proposed to improve treatment outcomes, including the use of lasers. This study aimed to review the histological results of different dental lasers including low-level lasers, carbon dioxide (CO2), erbium-doped yttrium aluminum garnet laser (Er:YAG), neodymium-doped yttrium aluminum garnet (Nd:YAG), erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) lasers, and diode lasers for VPT. This focused review included a comprehensive electronic search of Scopus, MEDLINE, Web of Science, and Google Scholar databases from 2000 to 2022 by two independent investigators. Different combinations of keywords were used, and reference mining of related papers was done. The review included studies related to histologic evaluation of laser-assisted vital pulp therapy that stated the laser parameters that were used. Articles with radiographic or clinical assessments or articles lacking necessary data were excluded. Non-English articles were excluded unless their abstract was in English and encompassed the necessary data. Most studies indicated the efficacy of lasers for reduction of inflammation, acceleration of healing, and increasing the thickness of dentinal bridge. According to the evidence, lasers used in combination with pulp capping agents are beneficial to enhance the success rate of VPT.

Erbium-ytterbium containing upconversion mesoporous bioactive glass microspheres for tissue engineering: luminescence monitoring of biomineralization and drug release

The development of functional biomaterials with real-time monitoring of mineralization processes, drug release and biodistribution has potential applications but remains an unsolved challenge. Herein, erbium- and ytterbium- containing mesoporous bioactive glass microspheres (MBGs:Er/Yb) with blue and red emission at an excitation wavelength of 980 nm were synthesized by a sol-gel combined with organic template method. As the concentration of Yb3+ ions gradually increases, the emission intensity of the MBGs:Er/Yb exhibits a clear concentration quenching effect. Combined with in vitro bioactivity tests, the optimal molar ratio of Er3+/Yb3+ was determined to be 4:3. Therefore, MBGs:4Er/3Yb was selected for in vitro biomineralization and drug release monitoring. The results of biomineralization monitoring show that the upconversion luminescence intensity is closely related to the degree of biomineralization. The upconversion luminescence intensity of MBGs:4Er/3Yb is quenched with the increase of the degree of biomineralization. The degree of luminescence quenching during biomineralization can be semiquantized. Drug release monitoring experiments showed that the anticancer drug doxorubicin hydrochloride (DOX) was successfully loaded into MBGs:4Er/3Yb and selectively quenched the green emission. When DOX was released, the green emission recovered stably, and It/I0 increased gradually. Moreover, there was a linear relationship between It/I0 and cumulative drug release, indicating that DOX-MBGs:4Er/3Yb is highly sensitive to DOX release, and monitoring the It/I0 values of DOX-MBGs:4Er/3Yb can achieve real-time tracking of the DOX release process to a certain extent. In conclusion, MBGs:4Er/3Yb has potential application as an upconversion luminescence biomonitoring material in the field of bone tissue engineering. STATEMENT OF SIGNIFICANCE: Mesoporous bioactive glasses have great potential for applications in bone tissue repair due to their excellent biological properties, but the effective information of the repair process cannot be grasped in a timely manner. Therefore, real-time monitoring of mineralization and drug release processes will be beneficial to obtain the degree of healing and optimize the amount and distribution of drugs to improve targeted therapeutic effects. For biomaterials, in vitro biological properties determine their biological properties in vivo, where the environment is more complex and diverse, and thus in vitro biomonitoring is particularly crucial. The organic combination of physical properties and biological properties will also provide a feasible idea for the development of biomaterials.

Efficacy and safety of intraurethral Erbium:YAG laser treatment in women with stress urinary incontinence following failed intravaginal laser therapy: a retrospective study

Urinary incontinence (UI) is a prevalent condition affecting 25-45% of women and is linked to factors such as menopause, parity, high body mass index, and radical pelvic surgery. Among the three types of UI, stress incontinence (SUI) is the most common, accounting for almost 50% of cases, followed by urgency and overflow incontinence. UI has been found to be associated with reduced quality of life and mental stress. Non-invasive laser treatment is the safest and most effective option for managing SUI, with intraurethral Erbium SMOOTHTM laser treatment holding promise for patients experiencing SUI even after undergoing previous failed intravaginal Erbium:YAG laser treatment. The study recruited 93 female patients with mild to moderate SUI who had received two courses of intravaginal Erbium:YAG laser between January 2015 and June 2018. Of these, 22 patients (23%) who continued to experience SUI after a four-week interval for a second intravaginal Erbium:YAG laser were selected for intraurethral laser treatment in January 2019. The efficacy of the treatment was evaluated by comparing the pre- and post-treatment ICIQ-UI SF score. The urethral length was measured before the procedure. The main procedure involved delivering non-ablative laser energy using Erbium SMOOTHTM technology 2940 nm via a 4-mm cannula with personalized length and fluence was 1.5 J/cm. The 22 female patients with persistent SUI received intraurethral Erbium:YAG laser treatment. Their average age was 47.5 years, with an average of 2 parities and a mean body mass index of 20.97. All patients completed the ICIQ-SF questionnaire before and 3 months after the procedure. Of the patients, 77% reported improvement in symptoms, with 6 reporting strong improvement and 11 reporting improvement. The treatment was well-tolerated, with mild and transient adverse effects such as urinary infection in 1 patient (4.5%) and mild pain in 7 patients (31.8%). Intraurethral laser treatment may be helpful for Taiwanese women with persistent SUI after vaginal laser treatment. However, patients with prior pelvic surgery or pelvic organ prolapse history may limit the efficacy of intraurethral laser. Additional research is necessary to comprehensively investigate the advantages of intraurethral laser therapy. However, using intraurethral Erbium SMOOTHTM laser treatments to rejuvenate tissues and enhance structural support could be a promising avenue for managing stress urinary incontinence in Taiwanese women.

Effect of Dentin and Zirconia Surface Treatments with Laser Irradiation Versus Sandblasting on the Bonding Ability of Zirconia

Objective: This study aimed to investigate the effects of laser irradiation applied to zirconia and tooth surfaces on shear bond strength (SBS) compared with acid etching and sandblasting. Background: The effect of laser irradiation on the bond strength between zirconia and adhesives is a controversial issue for dentin surface treatments. In addition, the effects of different combinations of surface treatments to increase adhesion on both the zirconia and dentin surfaces remain unclear. Materials and methods: A total of 90 tooth samples were assigned into groups according to various pretreatments: control group was left untreated, acid etching, and Erbium, Chromium:Yttrium Scandium Gallium Garnet (Er,Cr:YSGG) laser irradiation group (15 Hz, 2 W). In addition, the zirconia specimens were separated into three groups (n = 10) according to the different surface treatments performed: sandblasting (120 μm Al2O3), Er,Cr:YSGG laser (15 Hz, 2 W), and as untreated surface. The zirconia samples were cemented to the dentin surface using dual-cure resin cement and subjected to an SBS test at a speed of 0.5 mm/min under a universal testing machine until fractures occurred in the bonding surface. Results: The highest SBS values were observed in Group tooth acid (TA)-zirconia Er,Cr:YSGG laser (ZL), followed by Group tooth Er,Cr:YSGG laser (TL)-zirconia sandblasting (ZS) and Group TA-zirconia control (ZC). The lowest SBS values were found in Group TA-ZS. Significant intergroup difference was noted between Group TA-ZL, Group tooth control (TC)-ZC, Group TL-ZS, and Group TC-ZC. However, no significant difference was noted between Group TA-ZL, Group TL-ZS, and Group TA-ZC. Conclusions: Acid etching and laser treatments applied to the dentin and zirconia surfaces were found to be effective techniques for improving the zirconia-dentin bond, respectively. Clinical Trial Registration number: 33216249-604.01.02-E.24308.

Erbium:Yttrium Aluminum Garnet (Er:YAG) Laser: A Minimally Invasive Treatment Method in Selected Patients with Impaired Breathing During Sleep-The Assessment of Treatment Effectiveness After 4 Years

Objective: The aim of this study was to assess the long-term outcomes of nonablative Er:YAG laser treatment for snoring. Background data: Nonablative Er:YAG laser treatment has been shown to improve subjective quality of sleep without serious adverse effects, but long-term data are lacking. Materials and methods: Twenty-four patients with snoring problems due to soft palate hypertrophy were treated with three treatment procedures with Er:YAG laser performed at 2-week intervals. Subjective (questionnaires) and objective (polygraph) outcome measures were assessed at baseline, 3 months, and 4 years after the final laser treatment. Results: Twenty patients returned for the 4 years follow-up. The significant improvement in subjective sleep outcomes observed 3 months after Er:YAG laser treatment was still significant 4 years after treatment. No significant improvement or deterioration in objective polygraph outcome measures was observed during the 4 years of follow-up in our study. No side effects of laser treatment were observed. Conclusions: The Er:YAG laser treatment presents a safe and well-tolerated snoring treatment alternative for patients with airway obstruction in the oropharynx with improvement in subjective sleep outcomes lasting up to 4 years.

Comparison of micromorphological changes in enamel using SEM analysis after conventional and erbium, chromium:yttrium, scandium, gallium, and garnet hard-tissue laser fissurotomy: An in vitro study

Background

Well articulated by John Knowles - "Everything has to evolve or else it perishes." With the paradigm shift of emphasis toward the prevention of dental caries, it has been proven that laser irradiation protects against both caries initiation and caries progression.

Aim

The aim of the study was to evaluate and compare the micromorphology of caries-free extracted premolars using a Scanning electron microscope (SEM) after fissurotomy by conventional fissurotomy bur and erbium, chromium: yttrium, scandium, gallium, and garnet (ER, CR: YSGG) hard-tissue laser.

Methodology

Sixty caries-free premolars extracted atraumatically for orthodontic treatment were included in the study. The samples were divided into two groups randomly (Group 1: fissurotomy by bur, n = 30, and Group 2: fissurotomy by hard-tissue laser, n = 30). Each sample was further divided into halves from the occlusal surface wherein one-half of the occlusal surface received fissurotomy procedure and the other half was control. Samples were analyzed by scanning electron microscopy (SEM) for micromorphological changes.

Results

Profile image of control samples revealed the disorganization of enamel surface at the junction of fissures forming a heterogeneous tissue and agglomeration of enamel with deep pit and fissure. On the contrary, the image of experimented samples (with laser fissurotomy) showed smooth enamel surface and homogeneous enamel subsurface with wider pit and fissure owing to self-cleansing ability.

Conclusion

On the grounds of the present study results, it could be concluded that the intervention of ER, CR: YSGG hard-tissue laser possesses self-cleansable pit and fissures for caries prevention and has the potential to irradicate the smear layer entirely for superior attachment of remineralizing agents.

Erbium, chromium:Yttrium-scandium-gallium-garnet (Er, Cr:YSGG) laser versus diode laser in the treatment of pericoronitis

Background

There are limited number of studies about the lasers used for the treatment of pericoronitis infection.

Aim

To compare the Er, Cr:YSGG laser and diode laser applications clinically in the treatment of pericoronitis infection.

Patients and Methods

Sixty patients with pericoronitis infection were divided into three groups using block randomization: Er, Cr:YSGG + antibiotic group, n = 20 (mean age: 24.20 ± 6.13; 14 females, 6 males); diode group + antibiotic, n = 20 (mean age: 23.45 ± 2.96; 14 females, 6 males); and antibiotic, n = 20 (mean age: 22.45 ± 3.02; 11 females, 9 males). In addition, laser application was performed for patients in the Er, Cr:YSGG and diode laser groups on the 1st and 2nd days until the extraction day. Tooth extractions were performed on the 3rd day for all patients. Patients' pain (with visual analog scale [VAS]), lymphadenopathy, and local edema were clinically evaluated in the first 3 days and on the 7th day of treatment.

Results

Pain score on the 2nd day of treatment was determined to be significantly lower in the Er, Cr:YSGG + antibiotic laser group as compared with the other two groups (P = 0.019). Although regression of lymphadenopathy on the 3rd day was highest (P = 0.025) in the Er, Cr:YSGG group, there was no significant difference between the groups regarding local edema.

Conclusion

Er, Cr:YSGG laser improved the healing process in the treatment of pericoronitis and made an important contribution to the treatment.

[Prospective randomized controlled trial on 2 940 nm fractional erbium laser combined with fractional micro-plasma radiofrequency in the treatment of facial atrophic acne scars]

Objective: To compare the efficacy and safety of 2 940 nm fractional erbium laser combined with fractional micro-plasma radiofrequency (FMR) therapy and 2 940 nm fractional erbium laser in the treatment of atrophic acne scars. Methods: A prospective randomized controlled research was conducted. A total of 100 atrophic acne scar patients (38 males and 62 females, aged 18-37 years) who were treated in the Scar Laser Clinic of the Department of Plastic and Reconstructive Surgery of Shanghai Ninth People's Hospital of Shanghai Jiao Tong University School of Medicine from March 2018 to March 2021 and conformed to the inclusion criteria were recruited. The patients were randomly divided into erbium laser+FMR group and erbium laser alone group, with 50 cases in each group. The facial acne scars of patients in erbium laser alone group were treated with 2 940 nm fractional erbium laser, while the facial acne scars of patients in erbium laser+FMR group were treated with erbium laser as above, besides, the scars of U and M types were treated with FMR, once every 3 months for a total of 3 times. Before the first treatment and 3 months after each treatment, the Echelle D'Assessment Clinique des Cicatrices D'Acne (ECCA) was used to score the scar. The occurrence of adverse reaction during the treatment process was observed and recorded, and the incidence was calculated. Three months after the last treatment, the 5-level classification method was used to evaluate the satisfaction of patients with the treatment effect, and the satisfaction rate was calculated. Data were statistically analyzed with independent sample t test and chi-square test. Results: A total of 89 patients completed the study, including 46 patients in erbium laser+FMR group (19 males and 27 females, aged (26±5) years) and 43 patients in erbium laser alone group (15 males and 28 females, aged (27±6) years). The ECCA scores before the first treatment and 3 months after the first treatment of patients were similar between the two groups (P>0.05). The ECCA scores of patients in erbium laser+FMR group at 3 months after the second and third treatment were 72±23 and 61±18, respectively, which were significantly lower than 85±26 and 76±25 in erbium laser alone group (with t values of -2.45 and -3.26, respectively, P<0.05). During the treatment process, the incidence of adverse reaction of patients in erbium laser+FMR group and erbium laser alone group were 23.91% (11/46) and 16.28% (7/43), respectively, and there was no statistically significant difference between the two groups (P>0.05). The satisfaction rate of patients in erbium laser+FMR group was 78.26% (36/46) at 3 months after the last treatment, which was significantly higher than 53.49% (23/43) in erbium laser alone group (χ2=6.10, P<0.05). Conclusions: The 2 940 nm fractional erbium laser combined with FMR is superior to 2 940 nm fractional erbium laser alone in the treatment of facial atrophic acne scars, achieving significantly higher efficacy without significantly increasing the incidence of adverse reaction, and patients are more satisfied with the efficacy. It can be used as a recommended therapy in clinical practice.

Erbium(III) coordination compounds with substituted salicylaldehydes: Characterization and biological profile

Five erbium(III) complexes with salicylaldehyde (saloH for 1), and mono- (5-X-saloH; X = NO₂ and Me for 2 and 3, respectively) or di-substituted salicylaldehydes (3,5-diX-saloH; X = Cl and Br for 4 and 5, respectively) were synthesized and characterized by physicochemical and spectroscopic techniques and single-crystal X-ray crystallography. All five complexes have the general formula [Er(deprotonated salicylaldehyde)₃(MeOH)(H₂O)]. The structure of complexes [Er(3,5-diCl-salo)₃(MeOH)(H₂O)]·1.5MeOH (complex 4) and [Er(3,5-diBr-salo)₃(MeOH)(H₂O)]·1.75MeOH (complex 5) were verified by single-crystal X-ray crystallography. The evaluation of antioxidant activity of the complexes was focused on their ability to scavenge 1,1-diphenyl-picrylhydrazyl and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) free radicals and to reduce H₂O₂. The interaction of the complexes with calf-thymus DNA was investigated by UV-vis spectroscopy, viscosity measurements and via competitive studies with ethidium bromide in order to evaluate the possible DNA-binding mode and to determine the corresponding DNA-binding constants. The affinity of the complexes for bovine and human serum albumins was explored by fluorescence emission spectroscopy and the corresponding binding constants were determined.

A systematic review of the comparison between needling (RF-needling, meso-needling, and micro-needling) and ablative fractional lasers (CO2, erbium YAG) in the treatment of atrophic and hypertrophic scars

The aim of this study is to compare needling (RF-needling, meso-needling, micro-needling) and ablative fractional lasers (CO2, erbium-YAG) in the treatment of atrophic and hypertrophic scars in a systematic review. The database was searched, and 10 articles were selected that were relevant in terms of content, topic, and purpose and met the inclusion criteria. Of all the articles reviewed in this study, there were 2 randomized split-face trials (20%), 1 controlled nonrandomized trial (10%), 1 controlled randomized phase III clinical trial (10%), 1 prospective trial (10%), 1 prospective nonrandomized open-label trial (10%), and 1 randomized comparative trial (10%), with the type of study not reported in 3 articles. We used Endnote X8 to review the articles and extract data. After review, the studies were analyzed and categorized. No statistically significant difference was found between the two methods, laser and micro-needling, in the treatment of atrophic and hypertrophic scars in 60% of the articles studied, and both showed significant improvement (70% or more improvement to complete response). Significant improvement was noted in 20% of the studies reviewed for the laser and micro-needling treatment methods. The results of this study show that needling and ablative fractional lasers are tolerable and safe procedures with no significant difference in the treatment of skin scars in sixty percent of the studies.

Superficial dyspareunia treatment with hyperstacking of erbium:yttrium-aluminum-garnet SMOOTH laser: a short-term, pilot study in breast cancer survivors

OBJECTIVE

This prospective pilot study aimed to evaluate the effects of a modified vaginal erbium laser (VEL) protocol, using the hyperstack mode on the vaginal vestibulum and introitus to treat superficial dyspareunia in postmenopausal breast cancer survivors suffering from the genitourinary syndrome of menopause.

METHODS

In this pilot, prospective, randomized study, two groups of postmenopausal women suffering from superficial dyspareunia were included: 34 women (VEL group) were treated with erbium laser crystal yttrium-aluminum-garnet (XS Fotona SMOOTH; Fotona, Ljubljana, Slovenia) with a wavelength of 2,940 nm; for the other 34 (hyperstack group), a modified second step of the VEL protocol for the treatment of vestibulum and introitus was used, with hyperstacked (repeating a number of) subablative, long pulses with very low fluences. For each group, three laser applications at 30-day intervals were performed. Symptoms were assessed before, after each application, and after 1 and 3 months from the last laser application, using the visual analog scale score for superficial dyspareunia.

RESULTS

Superficial dyspareunia improved in both groups over time (P < 0.001), regardless of age and years since menopause status. The reduction in visual analog scale score after the third laser application was 58% in VEL versus 73.5% in hyperstack. The hyperstack group, since the first laser application, showed a greater (P < 0.001) and persistent improvement of superficial dyspareunia.

CONCLUSIONS

The hyperstack treatment of the introitus and vestibulum in breast cancer survivors leads to a more significant improvement in superficial dyspareunia than the VEL alone.

Effects of Er: YAG, Er,Cr: YSGG, and Nd: YAG laser irradiation and adhesive systems on the immediate and long-term bond strength of dentin: a systematic review and meta-analysis

At present, lasers are increasingly used in the oral clinical field, and research and applications in dental hard tissue treatment are also increasing. The effect of laser etching dentin on the bonding strength of composite resin reported in the literature is still inconclusive. The purpose of this review was to evaluate whether laser etching can improve the immediate and long-term bonding strength of dentin and investigate the effect of different types of adhesives on the bonding strength of dentin. Two reviewers performed a literature search up from January 2012 to November 2021 in four databases: MEDLINE (PubMed), Web of Science, EMBASE, and the Cochrane Library. A total of 25 studies were included in the meta-analysis. The Cochrane Collaboration Bias Risk Assessment tool was used to evaluate the quality of the included literature, and an analysis was carried out using Review Manager Software version 5.3. The aging bond strength of dentin after erbium (Er): yttrium aluminum garnet (YAG) laser treatment was significantly lower than that of dentin in the bur group (P < 0.00001). At the same time, the bond strength of dentin immediately and aging after (Er), chromium-doped (Cr): yttrium scandium gallium garnet (YSGG) laser treatment was lower than that of dentin in the bur group (P < 0.05). There was no significant difference in the immediate and aging bonding strength among samples in the Er: YAG laser, Er, Cr: YSGG laser, and blank control groups (no laser or bur). The aging bond strength of samples after neodymium-doped (Nd): YAG laser treatment was higher than that of samples in the blank control group (P < 0.05); in addition, the performance of self-etching adhesive was slightly better than that of acid etching adhesive. Regardless of the applied surface treatment and the adhesive employed, dentin after aging showed significant bond degradation (P < 0.05). There was high heterogeneity of bond strength between different groups, and the small number of studies and the contradictory results may be the main reasons for this outcome.

Ring Cavity Erbium-Doped Fiber for Refractive Index Measurements

In this study, an interrogation system based on an erbium-doped fiber ring cavity for refractive index measurements is presented and experimentally demonstrated. This cavity ring includes a 1 × 3 coupler wherein one of the fiber output ports is used to increase the optical power of the system by means of an FBG used as a reflector. The other two output ports are used as a refractive index sensing head and reference port, respectively. An experimental demonstration of this proposed sensor system for the measurement of a distinct refractive index is presented.

Effect of erbium family laser etching on shear bond strength of enamel surfaces: A meta-analysis-PRISMA

BACKGROUND

Recently, laser etching has appealed to people's attention. It is meaningful to compare the effect of erbium-doped yttrium-aluminum-garnet (Er:YAG) and erbium-chromium; yttrium-scandium-gallium-garnet (Er,Cr:YSSG) laser etching parameters with acid etching on bond strength of enamel surfaces. As far as we know, there still remains no related meta-analysis. To evaluate the efficacy of Er:YAG and Er,Cr:YSSG lasers etching on shear bond strength (SBS) of brackets bonded to enamel. The meta-analysis was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses, conducted with literature search.

METHODS

Twelve relevant randomized controlled trials (RCTs) were included.

RESULTS

The pooled analysis of SBS showed that there were no significant differences between erbium family lasers and acid etching. In the mass, we noticed they did not achieve statistical significance in the lasers etching and acid etching. However, pooled analysis of 5 studies showed the SBS bonding to enamel was lower in Er,Cr:YAG laser group compared with acid group. As a whole, there were statistical significance between erbium lasers groups and acid etching group in adhesive remnant index (ARI) aspects, which less adhesives remained can reduce damage to enamel. With regard to the rate of teeth with ARI score ≤2, the results in Er:YAG laser etching group were obviously higher than acid etching group.

CONCLUSION

Our data indicated that erbium lasers may be considered bonding of brackets to enamel instead of acid etching bonding to enamel.

Detection of Hydrogen Sulfide in Sewer Using an Erbium-Doped Fiber Amplified Diode Laser and a Gold-Plated Photoacoustic Cell

A photoacoustic detection module based on a gold-plated photoacoustic cell was reported in this manuscript to measure hydrogen sulfide (H₂S) gas in sewers. A 1582 nm distributed feedback (DFB) diode laser was employed as the excitation light source of the photoacoustic sensor. Operating pressure within the photoacoustic cell and laser modulation depth were optimized at room temperature, and the long-term stability of the photoacoustic sensor system was analyzed by an Allan-Werle deviation analysis. Experimental results showed that under atmospheric pressure and room temperature conditions, the photoacoustic detection module exhibits a sensitivity of 11.39 μV/ppm of H₂S and can reach a minimum detection limit (1σ) of 140 ppb of H₂S with an integration time of 1 s. The sensor was tested for in-field measurements by sampling gas in the sewer near the Shanxi University canteen: levels of H₂S of 81.5 ppm were measured, below the 100 ppm limit reported by the Chinese sewer bidding document.

Laser therapy for treating hypertrophic and keloid scars

BACKGROUND

Hypertrophic and keloid scars are common skin conditions resulting from abnormal wound healing. They can cause itching, pain and have a negative physical and psychological impact on patients' lives. Different approaches are used aiming to improve these scars, including intralesional corticosteroids, surgery and more recently, laser therapy. Since laser therapy is expensive and may have adverse effects, it is critical to evaluate the potential benefits and harms of this therapy for treating hypertrophic and keloid scars.

OBJECTIVES

To assess the effects of laser therapy for treating hypertrophic and keloid scars.

SEARCH METHODS

In March 2021 we searched the Cochrane Wounds Specialised Register, CENTRAL, MEDLINE, Embase, CINAHL EBSCO Plus and LILACS. To identify additional studies, we also searched clinical trials registries for ongoing and unpublished studies, and scanned reference lists of relevant included studies as well as reviews, meta-analyses, and health technology reports. There were no restrictions with respect to language, date of publication, or study setting.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) for treating hypertrophic or keloid scars (or both), comparing laser therapy with placebo, no intervention or another intervention.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies, extracted the data, assessed the risk of bias of included studies and carried out GRADE assessments to assess the certainty of evidence. A third review author arbitrated if there were disagreements.

MAIN RESULTS

We included 15 RCTs, involving 604 participants (children and adults) with study sample sizes ranging from 10 to 120 participants (mean 40.27). Where studies randomised different parts of the same scar, each scar segment was the unit of analysis (906 scar segments). The length of participant follow-up varied from 12 weeks to 12 months. All included trials had a high risk of bias for at least one domain: all studies were deemed at high risk of bias due to lack of blinding of participants and personnel. The variability of intervention types, controls, follow-up periods and limitations with report data meant we pooled data for one comparison (and only two outcomes within this). Several review secondary outcomes - cosmesis, tolerance, preference for different modes of treatment, adherence, and change in quality of life - were not reported in any of the included studies. Laser versus no treatment: We found low-certainty evidence suggesting there may be more hypertrophic and keloid scar improvement (that is scars are less severe) in 585-nm pulsed-dye laser (PDL) -treated scars compared with no treatment (risk ratio (RR) 1.96; 95% confidence interval (CI): 1.11 to 3.45; two studies, 60 scar segments). It is unclear whether non-ablative fractional laser (NAFL) impacts on hypertrophic scar severity when compared with no treatment (very low-certainty evidence). It is unclear whether fractional carbon dioxide (CO2) laser impacts on hypertrophic and keloid scar severity compared with no treatment (very low-certainty evidence). Eight studies reported treatment-related adverse effects but did not provide enough data for further analyses. Laser versus other treatments: We are uncertain whether treatment with 585-nm PDL impacts on hypertrophic and keloid scar severity compared with intralesional corticosteroid triamcinolone acetonide (TAC), intralesional Fluorouracil (5-FU) or combined use of TAC plus 5-FU (very low-certainty evidence). It is also uncertain whether erbium laser impacts on hypertrophic scar severity when compared with TAC (very low-certainty evidence). Other comparisons included 585-nm PDL versus silicone gel sheeting, fractional CO2 laser versus TAC and fractional CO2 laser versus verapamil. However, the authors did not report enough data regarding the severity of scars to compare the interventions. As only very low-certainty evidence is available on treatment-related adverse effects, including pain, charring (skin burning so that the surface becomes blackened), telangiectasia (a condition in which tiny blood vessels cause thread-like red lines on the skin), skin atrophy (skin thinning), purpuric discolorations, hypopigmentation (skin colour becomes lighter), and erosion (loss of part of the top layer of skin, leaving a denuded surface) secondary to blistering, we are not able to draw conclusions as to how these treatments compare. Laser plus other treatment versus other treatment: It is unclear whether 585-nm PDL plus TAC plus 5-FU leads to a higher percentage of good to excellent improvement in hypertrophic and keloid scar severity compared with TAC plus 5-FU, as the certainty of evidence has been assessed as very low. Due to very low-certainty evidence, it is also uncertain whether CO2 laser plus TAC impacts on keloid scar severity compared with cryosurgery plus TAC. The evidence is also very uncertain about the effect of neodymium-doped yttrium aluminium garnet (Nd:YAG) laser plus intralesional corticosteroid diprospan plus 5-FU on scar severity compared with diprospan plus 5-FU and about the effect of helium-neon (He-Ne) laser plus decamethyltetrasiloxane, polydimethylsiloxane and cyclopentasiloxane cream on scar severity compared with decamethyltetrasiloxane, polydimethylsiloxane and cyclopentasiloxane cream. Only very low-certainty evidence is available on treatment-related adverse effects, including pain, atrophy, erythema, telangiectasia, hypopigmentation, regrowth, hyperpigmentation (skin colour becomes darker), and depigmentation (loss of colour from the skin). Therefore, we are not able to draw conclusions as to how these treatments compare.  AUTHORS' CONCLUSIONS: There is insufficient evidence to support or refute the effectiveness of laser therapy for treating hypertrophic and keloid scars. The available information is also insufficient to perform a more accurate analysis on treatment-related adverse effects related to laser therapy. Due to the heterogeneity of the studies, conflicting results, study design issues and small sample sizes, further high-quality trials, with validated scales and core outcome sets should be developed. These trials should take into consideration the consumers' opinion and values, the need for long-term follow-up and the necessity of reporting the rate of recurrence of scars to determine whether lasers may achieve superior results when compared with other therapies for treating hypertrophic and keloid scars.

Achieving Photon Upconversion in Mononuclear Lanthanide Molecular Complexes at Room Temperature

Photon upconversion luminescence at the molecule scale is a rarely observed phenomenon despite possessing colossal potential for basic research and reality applications. Here we show that the eight-coordinate erbium molecular complex composed of Er³⁺ ion, dibenzoylmethane, and 2,2'-bipyridine exhibits upconversion emission. Under direct excitation at the absorption band of Er³⁺ ion at 980 nm, the complex shows upconverted green emissions of Er³⁺ ion at 525 and 545 nm at room temperature. Noticeably, upon the introduction of fluoride ions into this complex, an additional upconverted red emission at 667 nm appears as well, and the luminescence intensities of both the green and red emissions increase by a factor of 13 at most. This study not only provides a strategy to adjust the green and red emissions in mononuclear erbium complexes but also broadens the horizons of designing lanthanide-based molecular upconversion systems.

Ultrasound-Induced Mechanoluminescence and Optical Thermometry Toward Stimulus-Responsive Materials with Simultaneous Trigger Response and Read-Out Functions

Ultrasound-induced mechanoluminescence (USML) of Erbium-doped CaZnOS is reported. Using the fluorescence intensity ratio of the ² H_11/2 , ⁴ S_3/2 → ⁴ I_15/2 transitions of Er³⁺ allows for simultaneous temperature mapping at an absolute sensitivity of 0.003 K^-1 in the physiological regime. The combination of USML, local heating, and remote read-out enables a feedback and response loop for highly controlled stimulation. It is found that ML is a result of direct energy transfer from the host material to Er³⁺ , giving room for adapted spectral characteristics through bandgap modulation. ML saturation at high acoustic power enables independent control of local light emission and ultrasonic heating. Such USML materials may have profound implications for optogenetics, photodynamic therapy and other areas requiring local illumination, heating, and thermometry simultaneously.

Morphological and histological changes in the urethra after intraurethral nonablative erbium YAG laser therapy: an experimental study in beagle dogs

The purpose of this study was to investigate the morphological and histological changes in the urethra in beagle dogs after intraurethral Er:YAG laser irradiation in nonablative mode to confirm the safety of this therapy. Six 2-year-old healthy female virgin beagle dogs (13 ± 1.51 kg) were used in this study. The animals were divided into 2 groups: the sham group, which received sham treatment (n = 3) involving insertion of an intraurethral cannula and laser delivery handpiece into the urethra without laser irradiation, and the experimental group (n = 3), which received intraurethral Er:YAG laser irradiation. The laser irradiation parameters were set according to clinical criteria (4 mm spot size, 1.5 J/cm², 1.4 Hz, and 4 pulses) in nonablative mode. All animals received three sequential sessions at 4-week intervals. Urethrography and urethroscopy were performed in the 12th week and 13th week, respectively, after the first treatment. After urethroscopy, the animals were sacrificed, and urethral tissue was harvested for histological investigations. All procedures were performed under general anesthesia (40 mg/kg 3% sodium pentobarbital, i.v.). Transforming growth factor β1 (TGF-β1) and α-smooth muscle actin (α-SMA) expression levels were measured to evaluate the biochemical characteristics of the scar. Urethral stricture was not found by urethrography or urethroscopy in either group. Urethral epithelium thickness and collagen expression under the urethral mucosa were significantly increased in the experimental group compared with the sham group. However, there were no significant differences in TGF-β1 and α-SMA expression between the experimental group and sham group (p > 0.05). Urethral stricture is not found in beagle dogs after clinically relevant intraurethral nonablative mode Er:YAG laser irradiation. Proliferation of urethral collagen and the urethral mucosa may be one of the mechanisms by which urine leakage symptoms can be improved.

Comparison of fractional erbium:YAG laser-assisted tranexamic acid delivery alone and in combination with oral tranexamic acid in melasma

Tranexamic acid (TA) emerged as a promising agent for melasma. However, due to its hydrophilic structure, topical TA should be combined with a penetration-enhancing strategy to augment efficacy. To evaluate the efficacy of fractional erbium:YAG laser-assisted delivery (LAD) of topical TA 5% either with or without oral TA treatment in recalcitrant melasma patients. The authors retrospectively assessed the treatment outcomes of melasma patients treated by fractional erbium:YAG LAD of topical TA 5%. Patients receiving a standard protocol including four biweekly laser sessions were eligible. The study included two groups: group 1 patients received oral TA and LAD of topical TA 5%, and group 2 patients received only LAD of topical TA 5%. Two blinded dermatologists reported pre-treatment and post-treatment modified MASI (mMASI) scores. Mean mMASI scores in both group 1 (n = 15) and group 2 (n = 19) were significantly lower at the end of the treatment than baseline values (p = 0.001; p = 0.022, respectively). The decrease of mMASI scores were higher in group 1 (median = 2.1) (64.7%) than in group 2 (median = 1.2) (41.8%) (p = 0.027). Fractional erbium:YAG LAD of topical TA 5% is an efficient treatment regimen for melasma patients recalcitrant to conventional treatment approaches. The implementation of oral TA to this regimen improves the therapeutic outcomes.

Systematic review and meta-analysis of randomized clinical trials comparing efficacy, safety, and satisfaction between ablative and non-ablative lasers in facial and hand rejuvenation/resurfacing

Skin aging inevitably begins from the very early days of life. The lasers used in skin rejuvenation are mainly of two types: ablative and non-ablative. This meta-analysis aimed at comparing ablative with non-ablative lasers in terms of their efficacy and safety in skin rejuvenation. Articles published by March 15, 2020 in Embase, Medline (PubMed), Scopus, Cochrane, and clinicalTrials.gov were searched. The inclusion criteria included randomized controlled clinical trials (RCTs) in English using ablative and non-ablative lasers and comparing their safety and efficiency in wrinkle improvement and photoaging therapy. Out of 1353 extracted articles, 11 were selected for qualitative synthesis and of these, 4 were quantitatively analyzed. Different modes of various lasers were implemented; the ablative lasers included Erbium: yttrium-aluminium-garnet (Er:YAG) and CO₂, besides the non-ablative lasers, comprised Ytterbium/Erbium, Erbium: Glass, neodymium: yttrium-aluminum-garnet (Nd:YAG), and alexandrite. Pooled analyses on 124 participants showed insignificant differences between ablative and non-ablative lasers in the likelihood of excellent improvement with an odds ratio of 0.83 (95% CI: 0.24, 2.83). The analyses also showed good improvement with an odds ratio of 0.88 (95% CI: 0.44, 1.78), fair improvement with an odds ratio of 1.13 (95% CI: 0.56, 2.26) and side effects with an odds ratio of 0.82 (95% CI: 0.43, 1.56). The efficacy and safety of ablative laser were not higher than those of non-ablative laser in skin rejuvenation. Given the small samples of the included articles, it is recommended that further high-quality RCTs be conducted using larger samples to confirm this conclusion.

1,550 nm Erbium-Doped and 1,927 nm Thulium Nonablative Fractional Laser System: Best Practices and Treatment Setting Recommendations

BACKGROUND

The Fraxel Dual laser system (Solta Medical, Inc., Bothell, WA) contains a 1,550 and 1,927 nm wavelength single handpiece with different indications for each wavelength.

OBJECTIVE

To discuss treatment setting recommendations and best practices for select on-label and investigational applications of the 1,550 and 1,927 nm dual laser system.

MATERIALS AND METHODS

Eight board-certified dermatologists with 10 or more years of experience with the 1,550 and 1,927 nm laser system completed an online survey about their clinical experience with the system and then participated in a roundtable to share clinical perspectives and best practices for using the laser system.

RESULTS

For all Fitzpatrick skin types, treatment recommendations were described for selected approved indications for the 1,550 and 1,927 nm laser system, including both lasers in combination. Treatment recommendations were also reached for investigational applications with the 1,550 nm laser and 1,927 nm laser. Best practices for using the lasers during the treatment session to achieve optimal outcomes and decrease the post-treatment recovery time were compiled.

CONCLUSION

The 1,550 and 1,927 nm dual laser system is effective for a wide range of aesthetic and therapeutic applications, on and off the face and across all Fitzpatrick skin types.

Enhanced visible-light-driven photocatalytic degradation of tetracycline by 16% Er3+-Bi2WO6 photocatalyst

The widespread use of antibiotics in drug therapy and agriculture has seriously polluted the aquatic environment. Bismuth tungstate (Bi₂WO₆) is a new and efficient visible-light catalyst that is simple to prepare, non-toxic, stable, and corrosion resistant. Nonetheless, its efficiency has remained limited, and erbium (Er) mixing has been tested to address this. Here, a new Er³⁺-mixed Bi₂WO₆ photocatalyst was successfully prepared through the one-step hydrothermal method; pigments were characterized via XRD, SEM, BET, XPS, Uv-vis, PL and EIS. The results showed that the 16% Er³⁺-Bi₂WO₆ photocatalyst is a 250 nm flower-like nanosheet with a specific surface area of 67.1 m²/g and bandgap (Eg) of 2.35 eV, which provides the basis for superior performance. When the concentration of the catalyst was 0.4 g/L, 94.58% of the tetracycline (TC) solution (initial concentration of 10 mg/L) degraded within 60 min under visible light irradiation (λ ≥ 420 nm). ESR and LC-MS were used to identify the free radicals and intermediates for the degradation of TC pollutants; a photocatalytic degradation system and pathway were proposed. This solar-driven system will ultimately reduce resource consumption, providing a sustainable and energy-saving environmental decontamination strategy.

Association of Rare Earth Elements with Passive Smoking among Housewives in Shanxi Province, China

Background: Rare earth elements (REEs) are emerging contaminants. Previous studies reported the association between REEs and active smoking, but little is known about the effects of passive smoking on this condition. In China, female passive smoking is widespread, particularly in rural areas. Objective: This study aimed to estimate the relationship between REEs accumulation and passive smoking among rural housewives. Methods: We recruited 385 subjects in Shanxi Province of northern China, of whom 117 housewives were exposed to passive smoking, and 268 were not. We analyzed 15 REEs in the hair of housewives with ICP–MS, including lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, and yttrium. Results: The results indicated higher levels of 14 REEs except for Sm in both the univariate and adjusted models among the housewives exposed to passive smoking. The increasing linear trend of adjusted odds ratios of 15 REEs supported their association. The Bayesian kernel machine regression (BKMR) models showed that 15 REEs had a significant overall effect, and Eu had a single-exposure effect with passive smoking. Conclusion: We concluded that passive smoking might be associated with increased exposure to REEs among rural housewives.

The Beneficial Effects of Erbium:Yttrium-Aluminum-Garnet Laser in an Ulcer Caused by Lower Leg Arteriopathy

Ablative fractional laser is suggested to promote wound healing in diabetic and venous leg ulcers. In this article, we report the treatment outcome of a recalcitrant foot ulceration related to lower leg arteriopathy. A 43-year-old man with typical digital substraction angiographic findings of arteriopathy was admitted to our department after 30 sessions of hyperbaric oxygen therapy. There was heterotopic tissue within the ulcer consistent with osseous metaplasia and mature bone tissue. This tissue was removed with full-field erbium:yttrium-aluminum-garnet laser, and the remaining parts received fractional erbium:yttrium-aluminum-garnet laser for the induction of wound healing. A decrease in ulcer dimensions was achieved by the second month of laser interventions without recurrence in the first-year control.

Efficacy of an Er:YAG laser in the decontamination of dental implant surfaces: An in vitro study

BACKGROUND

Emergence of peri-implant diseases led to the development of various methods for implant surface decontamination. This study was designed to compare the efficacy of biofilm removal from implant-like titanium surfaces by an erbium-doped yttrium-aluminum-garnet (Er:YAG) laser, titanium brush, and carbon fiber curet.

METHODS

Eight study subjects were recruited. A custom mouth appliance that held eight sandblasted and acid-etched titanium discs was fabricated for each subject. Subjects were asked to wear this appliance for 72 hours to allow for biofilm development. After retrieval, discs were removed and randomized to one of four treatment groups. The discs were stained with a two-component nucleic acid dye kit, and the residual biofilm was visualized under fluorescence microscopy. Quantification of residual biofilm was performed using an image analysis software and expressed as the percentage surface area.

RESULTS

Fifty-nine titanium discs were randomized to the four treatment groups. The percentage of titanium disc area covered by residual biofilm was 74.0% ± 21.6%, 32.8% ± 24.0%, 11.8% ± 10.3%, and 20.1% ± 19.2% in the control, Er:YAG, titanium brush and carbon fiber curet groups, respectively (mean ± SD). The biofilm-covered area significantly decreased in each of the three treatment groups compared with control (P < 0.008). Comparisons between treatment groups did not reveal statistical significance.

CONCLUSIONS

Er:YAG laser treatment is an effective method for reducing the bacterial biofilm on titanium discs. However, on a threadless titanium surface, Er:YAG laser does not exhibit a significantly greater efficacy in biofilm removal than commonly used titanium brushes or carbon fiber curets.

A hybrid erbium(III)-bacteriochlorin near-infrared probe for multiplexed biomedical imaging

Spectrally distinct fluorophores are desired for multiplexed bioimaging. In particular, monitoring biological processes in living mammals needs fluorophores that operate in the 'tissue-transparent' near-infrared (NIR) window, that is, between 700 and 1,700 nm. Here we report a fluorophore system based on molecular erbium(III)-bacteriochlorin complexes with large Stokes shift (>750 nm) and narrowband NIR-to-NIR downconversion spectra (full-width at half-maximum ≤ 32 nm). We have found that the fast (2 × 109 s-¹) and near-unity energy transfer from bacteriochlorin triplets to the erbium(III) 4I13/2 level overcomes the notorious vibrational overtones quenching, resulting in bright and long-lived (1.73 μs) 1,530 nm luminescence in water. We demonstrate the excitation/emission-multiplexed capability of the complexes in the visualization of dynamic circulatory and metabolic processes in living mice, and through skull tracking of cancer cell metastases in mouse brain. This hybrid probe system facilitates robust multiplexed NIR imaging with high contrast and spatial resolution for applications ranging from fluorescence-guided surgery, diagnostics and intravital microscopy.

Erbium, chromium-doped: yttrium, scandium, gallium, garnet and diode lasers in the treatment of peri-implantitis: clinical and biochemical outcomes in a randomized-controlled clinical trial

This study aims to evaluate the effects of 940 nm diode laser and 2780 nm erbium, chromium-doped: yttrium, scandium, gallium, garnet (Er,Cr:YSGG) laser used in addition to mechanical therapy in the non-surgical treatment of peri-implantitis on clinical parameters and matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinase-1 (TIMP-1) levels in the peri-implant crevicular fluid. A total of 50 patients with peri-implantitis were randomized into three groups to receive peri-implant treatment. The control group (n = 17) only received conventional non-surgical mechanical therapy. The trial groups [(diode group (n = 16) and Er,Cr:YSGG group (n = 17)] received dental laser in addition to mechanical therapy. Gingival index (GI), plaque index (PI), bleeding on probing, probing depth (PD), MMP-9, and TIMP-1 levels were assessed at baseline (T0) and at 6 months after treatment (T1). The GI, PI, and PD significantly decreased in all groups at T1, compared to T0 (p < 0.05). The decrease in the PD was similar between the control and diode groups with Er,Cr:YSGG providing more reduction (1.16 ± 0.64 mm) than either method (p = 0.032). A significant intra-group decrease in MMP-9 level was only observed in the Er,Cr:YSGG group (p = 0.009). The decrease in TIMP-1 level from T0 to T1 was similar between the control and the diode groups (p > 0.05) and it was significantly lower than the decrease in the Er,Cr:YSGG group (p < 0.05). Addition of diode laser to non-surgical mechanical therapy does not provide any additional benefit for treatment outcomes. The Er,Cr:YSGG laser seems to be more efficient both at clinical and molecular levels. ClinicalTrials, ID: NCT04730687. Registered 13 April 2021. Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT04730687.

Effective Scarless Wound Healing Mediated by Erbium Borate Nanoparticles

The developments of nanoparticle-based treatments that benefit from novel discoveries have an essential place in the regeneration of acute and chronic wounds. Furthermore, research about the treatment methods which attempt to swiftly and scarless wound recovery has increased over time. In recent years, it has been shown that metallic-based nanoparticles, especially silver and gold derived, have an accelerating effect on chronic and contaminated wound healing. The crucial factors of inducing and completion of regeneration of wound are enhanced epithelialization rate and neovascularization in the tissue. In our study, the main purpose is the investigation of the boosting effects of erbium borate nanoparticles on the wound healing process, especially scarless ones. Newly syntesized erbium borate nanoparticles (ErB-Nps) were characterized by their concentration and particle size using nanoparticle tracking analysis (NTA). In order to examine the effect of ErB-Np on wound closure, scratch assay for dermal epithelial cells and tube formation assay for endothelial cells were performed. In addition, in order to examine the effect of the ErB-Np at a molecular level, the levels of genes related to both wound healing, inflammation, and scarless wound closure were determined with the RT-PCR experiment. Consequently, it has been shown that erbium borate nanoparticles have increased the melioration speed of scar tissue and have given clues about scarless healing potential. The investigation of the regeneration potential of erbium borate nanoparticles was done via MTS assay, quantitative PCR analysis, reactive oxygen species assay, and scratch assay. Our results show that ErB-Np is a proper agent that can be used for scarless wound healing.

Effect of different types of adhesive systems on the bond strength and marginal integrity of composite restorations in cavities prepared with the erbium laser-a systematic review

There are inconclusive results regarding etching and bonding protocol to achieve optimal bond strength and marginal integrity of adhesive composite resin restorations in erbium laser prepared cavities. This systematic review aimed to consider which adhesive system protocol may be optimal in achieving the bond strength and marginal integrity in erbium laser-prepared cavities, comparable to that obtained with conventional method of cavity preparation. This review was developed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement with literature search based on all publications during the period January1, 2000-October 10, 2020, in three databases: MEDLINE, Google Scholar and ScienceDirect. The necessary information was extracted by two independent authors. The search resulted in 139 articles from all databases, and a total of thirty-one articles met the inclusion criteria. The results indicated that the selection of adhesives depending on their pH and composition and the laser pulse duration and pulse energy used plays an important role in predicting the adhesion and marginal integrity. The 10-MDP containing moderate self-etch adhesives has demonstrated predictable outcomes. Longer pulse durations used for cavity preparations may indicate the use of etch-and-rinse (EnR) or moderate self-etch adhesives (SEA) to allow better resin infiltration in deep craters formed due to laser irradiation. However, further studies with more standardizations in relation to adhesives and laser parameters are needed.

Efficacy of Erbium:YAG Laser for Regenerative Surgical Treatment of Peri-implantitis: Clinical, Microbiological, and Biomarker Analyses

This paper reports on a study undertaken to ascertain the efficacy of the erbium:YAG laser (EYL) for peri-implantitis treatment. A total of 12 patients with bone loss resulting from peri-implantitis were involved in this study. The treatment protocol consisted of using the EYL for implant surface debridement and deproteinized bovine bone mineral (DBBM) for bone grafting. The following parameters were analyzed: probing pocket depth (PPD), clinical attachment level (CAL), bleeding on probing (BOP), bone levels (BLs), and the lipopolysaccharide levels before and after debridement with the EYL. This study found a statistically significant improvement in PPD, CAL, BOP, and BL at 3 and 12 months postoperative. Furthermore, a statistically significant decrease in implant-surface LPS levels was observed following debridement with the EYL. These findings show that using the EYL for debridement in peri-implantitis cases is effective in decreasing LPS levels. Moreover, after partial reconstruction with DBBM grafting, BLs were restored for at least 12 months. It was shown in one case that BLs had remained stable over 6 years, which also attests to the efficacy of this treatment. The combined use of EYL and DBBM could be effective for regenerative surgical peri-implantitis treatment.

Assessment of Effectiveness of Erbium:Yttrium-Aluminum-Garnet Laser, GentleWave Irradiation, Photodynamic Therapy, and Sodium Hypochlorite in Smear Layer Removal

AIM AND OBJECTIVE

To compare the effectiveness of erbium:yttrium-aluminum-garnet laser, GentleWave irradiation, photodynamic therapy (PDT), and sodium hypochlorite in smear layer removal and dentin permeability with a scanning electron microscope (SEM).

MATERIALS AND METHODS

Seventy-five recently extracted single-rooted teeth (maxillary second premolars) were randomly divided into 5 groups of 15 each. Group I teeth was the control group in which conventional root canal preparation (RCP) [17% ethylenediaminetetraacetic acid (EDTA)] was done without laser irradiation, group II teeth underwent RCP and GentleWave™ treatment, group III teeth were subjected to Er:YAG laser irradiation, group IV uses low-level 660 nm (PDT), and group V samples were irrigated with 5.25% NaOCl. All samples were viewed under the SEM. Images at the coronal, middle, and apical part of the root canal were obtained at ×1000. A scoring system for smear layer removal and debris removal scoring was used for analysis.

RESULTS

Smear layer removal was significantly higher at different points (coronal, middle, and apical area) in group I, followed by V, IV, II, and group III in declining order (p < 0.05). Intercomparison between the groups at different points indicates a significant difference in smear layer removal score between group I and group V at coronal, middle, and apical third. The result was not significant at coronal third and middle third, between group I and V, II and III, II and IV. The result was not significant at apical third between I and V, II and III, and II and IV (p < 0.05). Ethylenediaminetetraacetic acid and sodium hypochlorite are effective in smear layer removal followed by the Er-YAG laser technique.

CONCLUSION

Ethylenediaminetetraacetic acid and NaOCl are effective in smear layer removal. Er:YAG laser-activated RCP was comparatively efficient in cleaning the smear layer and opening dentinal tubules.

CLINICAL SIGNIFICANCE

Er:YAG laser-activated RCP was comparatively efficient in cleaning the smear layer and it can be used for effective removal of smear layer for clinical usage.