980-nm Diode Laser Research Articles

Down conversion and efficient NIR to visible up-conversion emission analysis in Ho3+/Yb3+ co-doped tellurite glasses

A series of glasses with chemical composition (50−x−y) TeO2–30ZnO–10YF3–10NaF–xHo2O3–yYb2O3 (x=0.5 and y=0.5, 1.0, 3.0, 5.0mol%) were prepared by melt-quenching procedure. The absorption spectra, excitation, down conversion emission spectra, up-conversion (UC) emission spectra and decay time measurements were analyzed. In down conversion, the visible emission transition intensity associated with 5F4→5I8 (547nm), 5F5→5I8 (657nm), and 5F4→5I7 (755nm) of Ho3+ ions decreased with Yb3+ concentration due to the energy transfer (ET) process from Ho3+ to Yb3+ ions. In up-conversion, on exciting with 980nm diode laser beam, we observed a strong green (543nm) and red (657nm) UC emissions, that refers to the energy level transitions; 5F4 (5S2)→5I8 and 5F5→5I8 of Ho3+. The influence of excitation power on UC intensities studies revealed that the population at 5F4 (5S2) and 5F5 levels of Ho3+ ion occurs due to two-photon absorption process associated energy transfer from Yb3+ to Ho3+. The influence of Yb3+ doped concentration on UC was studied, and it is observed that both the green and red UC intensities improved significantly on increasing Yb3+ ions concentration.

Challenges and Prospects of Laser Haemorrhoidoplasty in a Low Resource Setting: The LUTH Experience.

Haemorrhoids are the most common condition of the anal canal causing significant disability. Traditional excisional haemorrhoidectomy and its various modifications, while effective, may be attended by severe postoperative pain and other complications. Laser haemorrhoidoplasty is reported to be effective with fewer complications and shorter hospital stay. The aim of this study was to report the outcome of intrahaemorrhoidal coagulation with 1470-nm diode laser at the Lagos University Teaching Hospital. The procedures were performed with a radially emitting laser fibre from Biolitec AG-CeramOptec (Bonn, Germany). The duration of symptoms, grade of the haemorrhoids, duration of the procedures, and postoperative complications were evaluated. Eleven patients had laser haemorrhoidoplasty. There were seven males and four females. The age range was 23-71 years, with a median age of 47 years and an interquartile range (IQR) of 28-57 years. Duration of surgery ranged from 20 to 90 min, with a median of 33 min and IQR of 25-53 min. Postoperative pain was mild in eight patients and moderate in three. Ten patients were discharged as day cases and one 3 days later due to spinal anaesthesia-related headache and acute urinary retention. One patient later had an anal ulcer probably due to too much energy delivered during the procedure, this was managed conservatively. There was no postoperative wound infection, anal incontinence, anal stenosis, subcutaneous abscess, and fistula or recurrence. The advantages of laser haemorrhoidoplasty make it a readily acceptable form of treatment for haemorrhoids in our setting.

ATYPICAL PLASMA CELL GINGIVOSTOMATITIS: A RARE CASE REPORT

ATYPICAL PLASMA CELL GINGIVOSTOMATITIS: A RARE CASE REPORT

Evaluation of the effectiveness of diode laser therapy in conjunction with nonsurgical treatment of peri-implantitis.

Peri-implantitis (PI) is an inflammatory condition associated with the destruction of bone tissue around a dental implant, and diode lasers can be used to treat this disease. In this study, we aimed to evaluate the effectiveness of a 940-nm diode laser for the nonsurgical treatment of PI. Twenty patients (8 women and 12 men) were enrolled in a split-mouth randomized controlled study. In the control group (CG), mechanical debridement with titanium curettes accompanied by airflow was performed around the implants. The test group (TG) was treated similarly, but with the use of a diode laser. Clinical measurements (plaque index, gingival index [GI], probing pocket depth [PPD], bleeding on probing [BOP], clinical attachment level, and interleukin-1β [IL-1β] in the peri-implant crevicular fluid) were evaluated and recorded at baseline and 3 months. IL-1β levels were determined using the enzyme-linked immunosorbent assay method. The symptoms were alleviated in both groups at 3 months as assessed through clinical measurements. GI, BOP, and PPD were significantly lower in the TG than in the CG (P<0.05). The IL-1β level increased post-treatment in both groups, but this increase was only statistically significant (P<0.05) in the CG. The diode laser enabled improvements in clinical parameters in the peri-implant tissue. However, it did not reduce IL-1β levels after treatment. Further studies about the use of diode lasers in the treatment of PI will be necessary to evaluate the effects of diode lasers in PI treatment.

Photodynamic Periodontal Therapy vs. Diode laser as an Adjunctive to Conventional periodontal treatment in Management of Chronic Periodontitis

Purpose: This study was made to evaluate and compare the efficacy of photodynamic periodontal therapy and diode laser as an adjunctive approach to conventional periodontal therapy in management of chronic periodontitis. Subjects and methods: 30 patients with chronic periodontitis and age range from 30-40 years old were divided randomly into three groups. Group I (control group) 10 patients received conventional periodontal therapy alone. Group II (laser group): patients received SRP + additional application of a 940-nm diode laser. Group III (photodynamic group): patients received SRP + antimicrobial photodynamic therapy by using low level 670 nm diode laser application in addition to application of 1% toluidine blue as photosensitizer. Results: there were a significant difference of PD, CAL, IL-1β, IL6, NO, NO2 between three groups with superior result found in photodynamic group, but there were no significant differences between three groups in the term of NO3. Conclusion: Diode laser and photodynamic therapies add a beneficial effect in clinical and biochemical parameters when used as adjunctive to scaling and root planning but there was no significant difference between them.

Endolift® the “lunch-time” laser lifting for the lower eyelids

Lasers and others energy-based devices have reached very high levels of results. Although the area of the lower eyelids is one of the most difficult to treat without surgery, Endolift® represents one of the safest and effective techniques that we can offer. Endolift® procedure was performed with a 200 microns second-generation bare fiber connected to an Italian 1470nm semiconductor laser to treat the lower eyelids of a 43-year-old patient with wrinkles and skin laxity. No anesthesia was required. The fiber was easily inserted through the skin, without any incisions, directly between the orbicularis oculi muscle and the septum. The total laser energy delivered was 80 J for each side. Post-procedure the patient immediately resumed her daily activities. Snap Back test was performed before (T0) and 6 months (T1) after the procedure; Fitzpatrick “wrinkle score” and “degree of elastosis” were assessed at T0 and T1; investigator Global Aesthetic Improvement scale (iGAIS), external investigator Global Aesthetic Improvement scale (eiGAIS) and participant Global Aesthetic Improvement scale (pGAIS) were also recorded at T1. The treatment has been completed with a session of a vascular 532nm diode laser for treating the fine telangiectasias, immediately before the Endolift® procedure. The lower eyelids have benefited from the possibility that the Endolift® has to remodel and retract the tissues, activate the collagen production, and stimulate the neo-angiogenesis. Results are evaluated at T1, when the skin laxity is reduced and superficial wrinkles are smoothed, resulting in an overall compacting of the skin which is visible and continues to progress over the following months. The only adverse events recorded were redness for 3 hours and a light swelling for 2 days. Snap Back test at T0 was severe and negative at T1; at T0 wrinkle score” was II and Fitzpatrick “degree of elastosis” was 7-9 but at T1 Fitzpatrick “wrinkle score” was I and Fitzpatrick “degree of elastosis” was 1-3; iGAIS, eiGAIS and pGAIS at T1 were all +3. Endolift® can currently be considered one of the leading non-surgical treatments for the laxity of lower eyelids.

Vibration amplitude mapping by stroboscopic structured light projection

In this work a method to evaluate the distribution of vibration amplitudes of objects was demonstrated, combining for the first time oblique structured light projection, stroboscopic illumination and fringe evaluation. The light pattern was formed by straight and parallel fringes produced by a slightly misaligned Twyman–Green interferometer illuminated by a 40-mW, 650-nm diode laser. Stroboscopic illumination was achieved by driving the laser with a PWM signal with the same frequency than that of the vibrating object. By evaluating the fringes with phase stepping and phase unwrapping procedures, the amplitude mapping of a formica bar and circular rubber membranes was performed. By averaging the fringe position over the light pulse duration a correction ratio between the actual phase and the measured phase was obtained as a function of the pulse duty cycle, and the dependence of the fringe visibility on the duty cycle was studied. The experiments showed that relatively large amplitudes in a range from tens of millimeters up to few millimeters can be measured.

The effect of different irrigation and disinfection methods on post-operative pain in mandibular molars: a randomised clinical trial

BackgroundTo examine post-operative pain (PP) after conventional irrigation and sonic activation methods, with and without laser disinfection in mandibular molars.MethodsEighty patients with symptomatic apical periodontitis were included in this randomized clinical study. There were four study groups. In group 1, conventional irrigation only was applied. In group 2, a sonic irrigation activation system (EDDY (VDW, Munich, Germany)), was applied. In groups 3 and 4, irradiation with a 980-nm diode laser was performed, following irrigation with the conventional method and sonic irrigation activation system, respectively. The patients were instructed to record their PP and analgesic intake using a numerical rating scale 8, 24, 48 h and 7 days post-procedure. A chi-square test, Fisher’s exact chi-square test and Fisher–Freeman–Halton exact test were used to assess qualitative data. Inter-group and intra-group parameters were assessed using the Kruskal–Wallis test and Wilcoxon’s test at a significance level of p < 0.05.ResultsThere was no statistically significant difference among the groups in terms of age, sex, pre-operative pain, PP and analgesic intake (p > 0.05).ConclusionsThe use of sonic irrigation activation system in the final irrigation protocol and irradiation with the 980-nm diode laser did not significantly reduce PP levels and analgesic intake.

The Effect of Low-Level Laser Therapy on the Viability of Human Dental Pulp Stem Cells.

Introduction: This study assessed the effect of low-level laser (LLL) irradiation on the viability of dental pulp stem cells (DPSCs). Methods: In this in vitro experimental study, human DPSCs were purchased from the cell bank of Iranian Genetic Resources and cultured in flasks containing Dulbecco's modified Eagle's medium supplemented with 20% fetal bovine serum (FBS) at 37°C, 5% CO2, and 95% humidity. The cells were stored in semi-confluent form, and the culture medium was refreshed every two days. The cells in the control group were not laser-irradiated, but the cells in the experimental groups were irradiated with 660-nm and 808-nm diode lasers with 4.1 J/cm2 energy density. Cell viability was assessed at baseline and after 24, 48, and 72 hours using the methyl thiazolyl tetrazolium (MTT) assay. The effects of laser irradiation, laser wavelength, and time on the percentage of cell viability were analyzed by two-way ANOVA and Tukey's test. Results: The effects of laser irradiation and its wavelength (P=0.04), time of assessment (P<0.001), and the interaction effect of group and time (P=0.02) on cell viability were significant. Cell viability in 660-nm and 808-nm laser groups at 48 and 72 hours was higher than that of the control group; however, only the difference in cell viability between the 660-nm laser group and the control group at 72 hours was statistically significant (P=0.03). Conclusion: Considering the optimal effect of diode laser irradiation (particularly 660 nm) on the viability of DPSCs, we conclude that it may be suitable for relevant clinical applications.

Enhanced 3.1µm mid-infrared emission from Er3+/Yb3+ co-doped tellurite glass pumped by 980nm laser diode

Yb3+ ions co-doping was attempted for the first time for sensitizing Er3+ ions and increasing the 3.1 µm fluorescence, originating from the transition from Er3+: 4S3/2 → 4F9/2. Under a 980 nm LD excitation, strong 3.1 µm fluorescence in the mid-infrared (MIR) region and the related energy level change process were investigated. An enhanced 3.1 µm emission was attained from the Er3+/Yb3+ co-doped tellurite glass with the increment in Yb2O3 content, which demonstrated that the Yb3+ ions may act as the sensitizer to the Er3+ ions, thereby providing an effective energy transport channel from the 2F5/2 state of Yb3+ ions to the 4S3/2 state of Er3+ions. Moreover, the measured emission band full width at half maximum reaches about 164 nm along with the maximum emission cross-section (2.88 × 10−21 cm2). The outcome of our work suggests that upon co-doping with Er3+/Yb3+, the tellurite glass may function as a prospective material for fabricating the matrix of 3.1 µm MIR lasers.

Comparative effectiveness of ice packs versus topical lidocaine-prilocaine mixture for pain control in laser hair removal of the axilla: A rater-blinded randomized controlled trial

Laser hair removal is associated with moderate acute pain. To compare effectiveness of ice pack to topical lidocaine-prilocaine for pain reduction during axillary laser hair removal. Participants were randomly assigned to receive topical anesthetic to one axilla and ice packs to the other before each of three, monthly 810-nm diode laser sessions. The primary endpoint was participant-reported pain on the visual analog scale (VAS) immediately following and 5 minutes after laser. Post-treatment erythema, overall edema, and perifollicular edema were assessed by two blinded photoraters. Skin temperatures, patient preferences, and adverse events were recorded. Eighty-eight of 90 (98%) planned laser treatments were delivered, and randomized. Participants reported higher VAS scores immediately after laser with lidocaine-prilocaine compared to ice (p=0.03). Five minutes after, participants reported higher VAS scores with ice (p=0.03). After 53 of the 88 treatments (60.2%), participants reported preferring ice (p=0.055). No serious adverse events were reported. All participants were Caucasian or Asian with Fitzpatrick skin type I-III and coarse dark axillary hair, which may limit generalizability. While pain control with ice and topical anesthesia is associated with time after treatment, the two modalities do not differ in terms of degree of pain reduction associated with axillary laser hair removal.

Safety and Effectiveness of Diode Laser Used in Stapes Surgery.

Objective: We comprehensively assessed the safety and effectiveness of a 980-nm diode laser with fiberoptic delivery in stapes surgery by laser energy use, complications, and audiometric outcomes. Materials and methods: We retrospectively reviewed 116 primary stapes surgery cases. A high-power (30-40 W), short-pulse (60 msec), 980-nm diode laser was used for superstructure removal and footplate fenestration in the diode laser group (DLG) and, the hook and drill method in the conventional technique group (CTG). Data on complications and surgical diode laser use were collected; audiometric results within 6 months postoperatively were included in the analysis. Results: In DLG, the median fenestration and superstructure resection energy were 4.80 and 18.23 J, respectively. Footplate floating occurred in two ears (2/128, 1.56%) with manual fenestration, although none in the DLG (p = 0.07). Six CTG patients (6/26, 23.08%) underwent inevitable stapedectomy owing to footplate dislocation, which was higher than that in the DLG (2.11%, p < 0.01). No patients in the DLG experienced sensorineural hearing loss, and bone conduction (BC) improved at 1 (preoperative and postoperative means: 23.69 and 20.93 dB, respectively; p = 0.003) and 2 kHz (preoperative and postoperative means: 35.28 and 31.40 dB, respectively; p < 0.001), whereas changes in BC at 0.5 and 3 kHz were stable (p > 0.05). Four DLG patients (4/107, 3.74%) experienced transient facial nerve palsy postoperatively. Laser energy analysis showed shorter superstructure vaporization intervals in patients with transient facial nerve palsy (mean, 11.65 sec; median of control, 24.57 sec; p = 0.037). Conclusions: High-power, short-pulse, 980-nm diode laser is safe and effective in stapes surgery.

Laser diode-pumped compact hybrid lithium niobate microring laser.

We demonstrate a compact hybrid lithium niobate microring laser by butt coupling a commercial 980-nm pump laser diode chip with a high-quality Er3+-doped lithium niobate microring chip. Single-mode lasing emission at 1531-nm wavelength from the Er3+-doped lithium niobate microring can be observed with the integrated 980-nm laser pumping. The compact hybrid lithium niobate microring laser occupies the chip size of 3 mm × 4 mm × 0.5 mm. The threshold pumping laser power is 6 mW and the threshold current is 0.5 A (operating voltage 1.64 V) at atmospheric temperature. The spectrum featuring single-mode lasing with small linewidth of 0.05 nm is observed. This work explores a robust hybrid lithium niobate microring laser source which has potential applications in coherent optical communication and precision metrology.

Effect of Irradiation with 980-nm Diode Laser on the Microhardness of Young and Old Root Canal Dentin after Treatment with Chemical Solutions

Effect of Irradiation with 980-nm Diode Laser on the Microhardness of Young and Old Root Canal Dentin after Treatment with Chemical Solutions

Evaluation of the efficacy of diode laser (810 nm) as an adjunct to non-surgical treatment in chronic periodontitis at Can Tho University of Medical and Pharmacy Hospital in 2020 - 2022

Background: Diode laser 810nm as an adjunct to non-surgical treatment in chronic periodontitis is a modern and safe method with several advantages such as no need for flaps or sutures, reducing pain, controlling bleeding, etc. Objectives: To evaluate the clinical effects of diode laser used as adjunctive therapy to scaling and root planing (SRP) to that of scaling and root planing alone for the treatment of chronic periodontitis. Materials and methods: Case series report study over 20 chronic generalized periodontitis patients with ³ 4mm probing pocket deep. They were treated with scaling and root planing (SRP) and divided into 2 groups with laser and SRP alone at Can Tho University of Medicine and Pharmacy Hospital. Results: Probing pocket depth (PPD) and Clinical attachment loss (CAL) were reduced at 1 and 3 months in both groups. In the laser group, PPD and CAL were reduced 1.27±0.79mm and 1.32±0.85mm after 1 month, 1.92±0.8mm and 2.09±0,7mm after 3 months. The reduction has statistically significant compared to the no-laser group at both times (P &lt; 0.001). Conclusion: Diode laser 810nm as an adjunct to non-surgical for chronic periodontitis: good effect, suitable concept, minimal invasion, quick healing, etc.

In vitro Effect of Photodynamic Therapy with Curcumin and Methylene Blue Photosensitizers on Staphylococcus Aureus.

Staphylococcus aureus (S.A) can colonize in the skin, nasal cavity, and oral cavity. In the oral cavity, it can cause dental caries and periodontal disease. Mouthwashes can be used as an adjunct to mechanical plaque control methods to decrease the load of oral microorganisms. Chlorhexidine (CHX) is a commonly used antimicrobial mouthwash with side effects such as changing the sense of taste, tooth discoloration, oral mucosal burning, allergy, and xerostomia. It also has adverse systemic effects, if swallowed. This study aimed to assess the effect of photodynamic therapy (PDT) with curcumin and methylene blue (MB) photosensitizers and different laser parameters on S.A colony count. In this in vitro experimental study, 99 samples of standard-strain S.A were subjected to PDT with curcumin and MB photosensitizers with/without irradiation of 660 and 445 nm laser with different exposure parameters, and CHX in 9 groups (n=11). The samples were cultured in microplates containing Mueller-Hinton agar, and the number of colony forming units (CFUs) was counted after 24 h of incubation at 37°C. Data were analyzed by the Kruskal-Wallis and Dunn tests. The minimum colony count was noted in CHX group (CFUs=0) followed by MB and 660nm diode laser group irradiated for 100 s (CFUs=147.2727±169.35707). The difference in this respect was significant between MB+660nm diode laser for 100 s and other groups (p< 0.05) except for the MB + 660 nm diode laser for 60 s group. CHX is superior to laser for elimination of S.A. However, PDT with 660 nm diode laser + MB has considerable antimicrobial efficacy against S.A; increasing the duration of laser irradiation enhances the antimicrobial effect.

Laser-induced porous graphene from PEDOT:PSS films for dye-sensitized solar cells

• 3D porous graphene was firstly fabricated from PEDOT:PSS by a laser-scribing method. • Sheet resistance and morphology of LIG can be easily tuned by changing laser power. • LIG shows enhanced photovoltaic performance as a counter electrode for DSSCs. For the emerging laser-induced graphene (LIG) technologies, the exploration of laser irradiation interactions with various polymers and their new applications remains challenging. Herein, we report a novel strategy for the fabrication of 3D porous graphene electrodes from the aqueous PEDOT:PSS dispersion by a 445-nm diode laser in ambient air. By adjusting the laser power, LIG films exhibit a sheet resistance as low as 50 Ω/sq and their morphologies can change from a carbonized surface to a hierarchical porous structure. The dye-sensitized solar cell with a LIG70 counter electrode achieved a power conversion efficiency of 3.66%, which is over four times that of the pristine PEDOT:PSS electrode (0.80%). This work demonstrates the great potential for the application of PEDOT:PSS-based LIG films in photovoltaic devices.

Effect of conventional and power office bleaching with diode laser and led light on enamel microhardness

Aim: The present study aimed to asses enamel microhardness after office bleaching with diode laser and LED light compared to the conventional bleaching procedure. Methods: Thirty-nine human premolar teeth were collected and randomly divided into three groups regarding of the bleaching technique. Group 1: Snow O bleaching gel with LED light-curing unit; Group 2: Snow L bleaching gel with diode laser irradiation; and Group 3: Opalescence Boost bleaching gel with no light source in group 3. Enamel surface changes were evaluated in one tooth in each study group and one intact tooth as a reference under a scanning electron microscope (SEM). In the remaining samples (n=12), enamel microhardness was determined by Vickers microhardness test before and after bleaching. Data were analyzed with repeated-measures ANOVA to compare microhardness changes, followed by post hoc Tukey tests at the 0.05 significance level. Results: Enamel microhardness decreased in all the groups after bleaching, with the maximum decrease in microhardness in the Snow O bleaching group with LED light, which was significantly higher than the other groups (P=0.002). The two other groups did not exhibit any significant difference in microhardness decrease (P&gt;0.05). Conclusion: Based on the limitations of this study, it can be concluded power bleaching with 980nm diode laser was less time-consuming compare to conventional bleaching procedure and yielded better outcomes in terms of enamel surface microhardness compared to the use of an LED light-curing unit.

Surgical excision of lobular capillary hemangioma with laser under N2O/O2 conscious inhalational sedation in an uncooperative pediatric patient, Frankl class 2: a case report

&lt;p&gt;Here, we report a case of lobular capillary hemangioma (LCH) associated deleterious oral habit on lateral border of the tongue in an anxious child excised under nitrous oxide (N&lt;sub&gt;2&lt;/sub&gt;O) sedation using soft tissue diode laser. LCH are rapidly growing vascular lesions and are common occurrence over tongue, but to be associated with deleterious oral habit is an uncommon occurrence. A 9-year-old female child was brought to the dept by her parent due growth on the tongue. The child was quite anxious and displayed negativity towards examination and treatment. The child was classified as Frankl 2 on the behaviour rating scale. A pre-anaesthetic check-up was carried out on the child as it was envisaged to carry out the treatment under inhalational sedation. The anaesthesiologist along with crash cart were present throughout the procedure to cater to any adverse events. The excision was done with 980-nm soft tissue diode LASER to reduce intraoperative haemorrhage, enhance patient comfort and improve postoperative healing. A novel combination of inhalational sedation with soft tissue diode LASER with all necessary precautionary protocols as used in management of this child may be an useful approach for successful and uneventful management. To highlight the importance of proper use of pharmacologic methods in behaviour management as well as surgical techniques for better management of these vascular lesions in children.&lt;/p&gt;&lt;p&gt;&lt;strong&gt; &lt;/strong&gt;&lt;/p&gt;

The The Effectiveness of a 980-nm Diode Laser to Treat Face Haemangioma: A Randomised within-Patient Trial

Haemangiomas are benign noncancerous vascular malformations of capillaries and are commonly present on the face. All types of lasers are suitable for the management of such vascular lesions. Here, we aimed to determine the effectiveness of a 980-nm diode laser for the treatment of Iraqi patients with facial haemangioma. This randomised trial was conducted at Laser Medicine Research Clinics, Iraq, from 15 October 2018 to 15 August 2019. The improvement of the condition at 6 months was the first endpoint. The patient's quality of life, diminished lesions, and safe administration of diode laser were the second endpoints. At follow-up, the lesions were less elevated, smoother in texture, and the colour had changed from red to pink. Based on these results, this laser is an effective and safe tool for the treatment of haemangiomas of the face.