Combined Diode Laser Research Articles

The chromatograph evaluation of white spot lesion treated with magnesium gel and diode laser: an in vitro study

Objective. White spot lesions are one of the most common concerns of orthodontic therapy. The present study was accomplished to evaluate the ability of Magnesium gel at different concentration and diode laser in combination compared with commercially available 1.23% APF in color restoring of WSL on permanent teeth. Methods. 42 extracted sound upper premolar teeth were recruited for this study. WSL was artificially induced, until it appears in wet and dry condition on buccal surface of each tooth. Different approaches have been utilized for treatment WSL. 6 experimental groups were involved: Group A: Control, Group B: 0.5%MgCl2 gel, Group C: 1%MgCl2 gel, Group D: 0.5%MgCl2 gel and Diode laser, Group E: 1%MgCl2 gel and Diode laser and Group F: 1.23%APF. The difference between the displayed color and the original color standard (ΔE) was assessed by colorimeter. The surface topography of teeth samples from each tested group was examined by a SEM. Collected data were investigated using one-way ANOVA followed by Duncan post hoc test at p ≤0.05. Result. A significant difference in (ΔE) was noticed among groups (p = 0.006). Group (B) showed the lowest ΔE value (9.4 ± 1.6), followed by group (D) (10.2 ± 1.1), group (F) (10.4±2.6), group (A) (11.6 ± 1.3), group (C) (12.9 ± 2.3) and group (E) (13.2 ± 1.3). Conclusion. In present study, topical application of 0.5% MgCl2 gel ensure color reinstating compared to other groups.

Effects of Magnesium Gel and Diode Laser in Combination on the Color Masking of Artificial White Spot Lesions: An in Vitro Study

Effects of Magnesium Gel and Diode Laser in Combination on the Color Masking of Artificial White Spot Lesions: An in Vitro Study

Submentonial fat reduction with 1470nm diode laser and Endolifting® technique: case report

Purpose: This study aims to present a clinical case of significant reduction in submental fat using the Endolifting®technique and the 1470nm diode laser, supported by an extensive literature review. Case report: The ongoing quest for innovative and minimally invasive aesthetic procedures has propelled research in the field of aesthetic dermatology. Submental fat reduction, commonly referred to as a double chin, is a prevalent aesthetic concern that impacts facial harmony and the self-esteem of many patients. In this clinical case report, we introduce the application of the 1470nm diode laser in combination with the Endolifting®technique as a non-surgical alternative for double chin reduction. A 45-year-old patient with a prominent double chin performed a single treatment session. Following the treatment, a noticeable reduction in submental fat was observed, resulting in a more balanced and rejuvenated facial profile. The patient reported an enhancement in self-esteem and satisfaction with the outcomes. Conclusion: This case report validates the effectiveness of the 1470nm diode laser and the Endolifting®technique in reducing double chin, showing it as an innovative, efficient, safe, and replicable approach for submental fat reduction.

The Effect of Er:YAG Laser and Diode Laser in Combination with MI Varnish on the Depth of Remineralization of Incipient Carious Lesions - An In vitro Study

Background Dental caries is a multifactorial disease that results from an imbalance between pathological and protective factors. The imbalance produced favors demineralization of enamel. If detected early non-cavitated lesions can be reverted with the help of remineralizing agents. The role of calcium-phosphate remineralization systems and the ErYAG and diode lasers in the treatment of these lesions has recently been taken into account.Aim The aim of the study was to evaluate the remineralization potential of Erbium-doped yttrium aluminium garnet laser ErYAG laser diode laser combined with MI varnish on the depth of remineralization of incipient carious lesions.Methods Forty eight human premolars were collected conditioned with demineralizing agents to create artificial carious lesions. Then the samples were coated with nail paint leaving a uncoated window of 4 mmtimes 4 mm facially. The samples were then randomly divided into four groups n12 Group I ndashControl Group II ndashMI Varnish Group III ndash MI Varnish ErYAG laser and Group IV ndashMI Varnish Diode laser. For a period of seven days specimens were conditioned with remineralizing agents followed by laser irradiation. Confocal laser scanning microscopy CLSM was used to assess the depth of demineralization and remineralization. Statistical Package SPSS 22.0 SPSS Inc. Chicago IL was used to analyze the data. KruskalndashWallis test was used to analyze the difference between the groups and post hoc MannndashWhitney test was used to compare the differences between the groups. The level of significance was set at p lt0.05.Results Samples in Group III showed greater remineralization depth 1488.235 compared to other groups with statistically significant p lt0.001.Conclusion Within the limitations of this in vitro study MI varnish alone is less effective compared to laser groups MI varnish ErYAG and MI varnish Diode laser which showed increased remineralization depths.

Efficacy of diode laser application versus silver diamine fluoride (SDF) as a modification of Hall technique in primary teeth

BackgroundThe Hall technique is a new technique aimed at depriving bacteria of any substrate, thereby limiting the progression of caries. Silver diamine fluoride (SDF) and diode laser are documented to have an antibacterial effect on carious enamel and dentin by eradicating bacteria such as Streptococcus mutans. AimThe current study aimed to increase the success rate of the Hall technique in carious primary molars by eradicating bacteria present in carious lesions using SDF or diode laser in combination with the Hall technique. Materials and methodsA total of 159 children aged 4–8 years were randomly divided into three equal groups: Group I, application of the Hall technique; Group II, SDF with Hall technique; Group III, diode laser with Hall technique. Children were recalled at regular intervals over a year. Results: At the end of the follow-up period, Group III showed the highest clinical success rate (94.3 %), followed by Group II (96.2 %), while Group I showed the lowest clinical and radiographic success rates (88.7 % and 86.8 %, respectively); however, these differences were statistically non-significant. ConclusionTreatment of carious lesions using SDF or Diode Laser increased the success rate of the Hall technique in primary teeth.

Comparative Evaluation of the Antibacterial Efficacy of Chlorhexidine and 810 nm Diode Laser in the Disinfection of Root Canals Contaminated With Enterococcus faecalis: An In Vitro Study.

Introduction: This study compared the antibacterial efficacy of three different root canal irrigants, sodium hypochlorite, chlorhexidine and 810 nm diode laser and diode laser in combination with chlorhexidine in root canals contaminated with Enterococcus faecalis.Methods: Fifty extracted mandibular first premolars were decoronated at the cementoenamel junction and cut at the apical end; biomechanical preparation was done, autoclaved and contaminated with Enterococcus faecalis. The specimens were divided into five groups containing 10 teeth each: group I: saline (negative control), group II: 2.5% sodium hypochlorite, group III: 2% chlorhexidine gluconate solution, group IV: diode laser, and group V: diode laser in combination with 2% chlorhexidine. Disinfection was carried out, after which dentinal shavings were collected from the specimens of each group. Antimicrobial efficacy was tested by counting the colony-forming units of viable Enterococcus faecalis on the agar plates. One-way ANOVA and Scheffe’s post hoc test were done to analyse the results.Results: Diode laser with chlorhexidine group showed minimum colony-forming units followed by the diode laser group. The post hoc test showed a statistically significant difference between saline, 2.5% sodium hypochlorite and 2% chlorhexidine groups (P = 0.001) and a non-significant difference between diode laser and diode laser with chlorhexidine group (P = 0.997).Conclusions: Diode laser can be used as a root canal disinfectant alone or in combination with chlorhexidine.

Watt-level beam combined diode laser systems in a chip-scale hybrid photonic platform.

Scaling up the power of on-chip diode lasers is of great importance for many emerging applications, such as integrated nonlinear optics, remote sensing, free space communication, infrared countermeasure, and light detection and ranging (LIDAR). In this manuscript, we introduce and demonstrate photonic integrated circuits (PIC) based beam combining methods to create power scalable, integrated direct diode laser systems. Traditional laser beam combining, including coherent beam combining (CBC) and wavelength beam combining (WBC), usually requires free space or fiber optical components, leading to bulky and complex systems. Instead, PIC based beam combining methods can greatly reduce the cost, size, weight, and power consumption (CSWaP) of next generation direct diode laser systems. We experimentally demonstrate four channel chip-scale CBC and WBC with watt-level on-chip power by using III/V-Si3N4 hybrid integration. Our results show that PIC based beam combining is very suitable for power scaling in a chip-scale platform.

A prospective multicenter randomized clinical trial comparing endovenous laser ablation, using a 1470 nm diode laser in combination with a Tulip-TipTM fiber versus radiofrequency (Closure FAST™ VNUS®), in the treatment of primary varicose veins.

The treatment of chronic venous disease, has largely shifted from high ligation and stripping to endovenous thermal ablation (EVTA) techniques, because of its comparable efficacy and lack of invasiveness. This clinical trial aimed to compare the efficacy of two thermal ablation techniques, endovenous laser ablation (EVLA) 1470-nm with Tulip-TipTM fiber and radiofrequency ablation (RFA) ClosureFastTM using a non-inferiority design for occlusion rate (primary outcome). A prospective multicenter randomized clinical trial randomized 280 patients for the treatment of great saphenous vein (GSV) reflux. Primary outcome was the GSV occlusion rate, secondary outcome factors were the possible side-effects of the treatment such as pain, ecchymosis, quality of Life (CIVIQ-20), revised Venous Clinical Severity Score (r-VCSS). One-year follow-up period. The total occlusion rates at one year follow-up were 96.4% and 94.5% in the EVLA and RFA groups respectively (P=0.15). Regarding secondary outcomes, such as postoperative CIVIQ-20, r-VCSS, analgesia, absenteeism, there was no significant difference between both treatment groups. RFA and EVLA, using a 1470 nm laser with Tulip-TipTM fiber, of the GSV results in equal occlusion rates at one year, with comparable postoperative pain and improved quality of life.

Comparative efficacy of diode laser, Iontophoresis and desensitizing agent in the treatment of dentinal hypersensitivity: A randomized clinical trial

Aim: The aim of this randomized clinical trial was to evaluate and compare the clinical efficacy of diode laser in combination with topical Potassium nitrate (KNO3) gel, Iontophoresis and KNO3 topical gel alone in the treatment of dentinal Hypersensitivity.Materials and Methods: 30 systemically healthy patients with Dentinal Hypersensitivity were enrolled in the randomized clinical trial. The patients with dentinal hypersensitivity were randomly allocated into 3groups: Group I was treated with diode laser and KNO3 gel; Group II with Iontophoresis using Sodium Fluoride (NaF) gel and Group III was treated with KNO3 topical gel alone. Sensitivity was recorded using the verbal rating scale before treatment, 10 min after treatment and 7, 15 and 21 days post therapy.Results: The mean difference among three groups showed a maximum reduction (-1.100) of dentinal hypersensitivity in group I as compared to group III and group II (-.300) after 15 days. On comparison of group II and group III, it showed reduction (-.800) of dentinal hypersensitivity after 15 days. A statistically significant difference was observed among all the three groups. All the groups showed significant reduction in Dentinal Hypersensitivity. However, the use of diode laser with KNO3 gel showed statistically significant reduction in sensitivity (P < 0.05) when compared to Iontophoresis and KNO3 topical gel alone

Comparison of the Effectiveness of Combined Diode Laser and GLUMA Bonding Therapy With Combined Diode Laser and 5% Sodium Fluoride Varnish in Patients With Dentin Hypersensitivity.

Introduction: Dentin hypersensitivity (DH) is one of the most common complaints of patients referred to a dental office, so this study aimed to compare the effectiveness of combined diode laser and GLUMA bonding therapy with combined diode laser and 5% sodium fluoride varnish in patients with DH. Methods: Sixty patients were divided into three groups (bonding, laser-bonding, laser-varnish), and before the intervention, the amount of DH was measured with the visual analogue scale (VAS) scale. In the bonding group, GLUMA Desensitizer solution was applied and then air-dried. In the bonding-laser group, first bonding was used, and then the affected tooth was irradiated with a diode laser. In the varnish-laser group, 5% sodium fluoride varnish was coated and then the laser was irradiated with the said method. DH was measured immediately after the treatment and then 2, 7 and 30 days after the treatment. Results: Laser-varnish treatment was not different from laser-bonding treatment at all measurement times (P=1). Laser-varnish and bonding treatment were not significantly different up to one week after the intervention, but on the 30th day after the intervention, the difference in pain was significant (P=0.01). There was no significant difference in laser-bonding treatment up to one week after the intervention, but on the 30th day after the intervention, the difference in pain was significant (P=0.003). Conclusion: The combined treatment with GLUMA bonding and the 660 nm diode laser is effective in reducing DH and this is more effective than GLUMA bonding alone in the long term. However, it does not have a significant advantage over the combined varnish-laser method, but it seems that due to its ease of use, it can be a suitable alternative to the varnish-laser method.

High-sensitivity biomedical sensor based on photoacoustic and cavity enhanced absorption spectroscopy with a new software platform for breath analysis.

An easy-to-use highly sensitive sensor is reported for trace gas analysis. A near-infrared fiber-coupled external cavity diode laser in combination with a photoacoustic spectroscopy cell and a cavity enhanced absorption spectroscopy cell is used for analysis of trace gases. A software platform for direct absorption and wavelength modulation spectroscopy is developed in order to identify and quantify the molecules and to achieve a higher signal-to-noise ratio. Considering all of these features, the main advantage of our system is to analyze two different samples simultaneously and quickly. Trace gas measurement is assessed, and a detection limit of 1.5 ppb at 6528.76cm-1 for ammonia is demonstrated. Furthermore, the sensor with our software platform can be easily used outside of the laboratory, for example, in hospitals.

Effect of Hydrogen Peroxide Photoactivated Decontamination Using 940 nm Diode Laser in Periodontal Treatment: A Pilot Study.

Objective: The aim of this study was to compare the antimicrobial effects of hydroxyl radical generation by photoactivation of hydrogen peroxide (H2O2) with diode laser (λ = 940 nm) in combination with conventional nonsurgical periodontal therapy. Materials and methods: Thirty-eight patients and 114 teeth were included in this study. The test teeth were randomly assigned to one of the three treatment groups: Group 1 (control group): scaling and root planning (SRP); and the following experimental groups: Group 2: SRP +940 nm diode laser; Group 3: SRP+photoactivation of H2O2 with 940 nm diode laser. Clinical examinations, such as periodontal probing depth (PPD), clinical attachment level (CAL), and bleeding on probing (BoP) were performed before and after the treatment. The microbiological evaluation included nine periodontal bacterial species investigated by means of real-time polymerase chain reaction assay before and after the treatment. The clinical and bacterial differences were assessed between the investigated groups. Results: The total bacteria load was reduced for all three studied groups and all periodontal indexes (PPD, CAL, and BoP) were improved after each treatment. Group 3 showed significant bacterial reduction of the major periodontal bacteria such as Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Prevotella intermedia, Peptostreptococcus micros, Fusobacterium nucleatum, Eubacterium nodatum (p < 0.001) in contrast to the other two groups (p > 0.001). Differences between tested groups showed significant results with regard to Group 3. Conclusions: The synergistic effect of SRP and photoactivation of H2O2 with 940 nm diode laser offers an efficient and reliable antimicrobial effect in the nonsurgical periodontal treatment approach.

NANO-ENGINEERED IRRIGATING SOLUTIONS AND LASERS – AN ANTIBACTERIAL STUDY AGAINST ENTEROCOCCUS FAECALIS

BACKGROUND:&#x0D; Enterococcus faecalis (E. faecalis) is the most commonly detected micro-organism in asymptomatic and persistent endodontic infections. Thorough disinfection of the root canal is more important than proper shaping for a successful endodontic treatment. This study is an attempt to implement nanoparticles which have proven anti-bacterial efficacy as irrigating solutions against E. faecalis.&#x0D; AIM:&#x0D; To compare and evaluate the anti-bacterial efficacy of 5% sodium hypochlorite (NaOCl), 0.2% chitosan nanoparticles solution (ChNP) and 0.01% silver nanoparticles solution (AgNP) against E.faecalis with and without diode laser activation.&#x0D; MATERIALS AND METHODS:&#x0D; 70 single rooted mandibular premolars were included in this study. Access opening, working length determination and biomechanical preparation were standardized. Samples were embedded in putty material inside an eppendorf tube to simulate periodontal ligament and autoclaved followed by inoculation of E.faecalis (MTCC 439) and incubated at 37℃ for 7 days. The samples were divided into 7 groups (10 samples in each group). Group 1- No treatment (Negative control), group 2 - 5% NaOCl without activation (Positive control), group 3 - 5% NaOCl with diode laser activation, group 4- 0.01% AgNP without activation, group 5- 0.01% AgNP with diode laser activation, group 6- 0.2% ChNP without activation and group 7- 0.2% ChNP with diode laser activation. A final rinse of the respective irrigants and activation were performed, followed by counting the colony forming units. Statistical analysis used were one-way analysis of variance (ANOVA) followed by Tukey’s post-hoc tests. Results showed that diode laser in combination with 5% NaOCl and 0.2% ChNP had significant effects in the reduction of microbial colony counts of E. faecalis in comparison to other experimental groups.&#x0D; Keywords: Nanoparticles, Irrigation, LASER, Enterococcus faecalis

Artificial Caries Resistance in Enamel after Topical Fluoride Treatment and 445 nm Laser Irradiation.

Objective This in vitro study is aimed at investigating the caries preventive effectiveness of 445 nm diode laser in combination with topical fluoridation. Materials and methods A total of 30 caries-free bovine teeth were used in this study. Eighteen teeth were covered with nail varnish except four windows on the labial surface. The windows were assigned to no treatment/control (C), laser (L) (0.3 W, 60 s, and 90 J/cm2), fluoride (F), and fluoride followed by laser (FL) treatment groups. Artificial caries lesions were created, and the teeth were sectioned and investigated under polarized light microscopy for quantitative measurement of the resulted lesion depth. Ten teeth were used for surface temperature measurement and two teeth for scanning electron microscopy (SEM). Extra twelve human molars were used for the intrapulpal temperature measurement. The absorbance of fluoride at 445 nm was measured. Results The means of lesion depth for the C, L, F, and FL groups were 123.48 (±21.93), 112.33 (±20.42), 99.58 (±30.68), and 89.03 (±30.38) μm, respectively. The pairwise differences of the L, F, and FL groups compared with the C group were significant (p < 0.05). The differences between groups were tested: FL versus L p=0.02, F versus L p=0.16, and FL versus F p=0.91, and the difference of the F versus FL was not significant (p=0.91). Temperature increment at the enamel surface and pulp roof were ∆T = 16.67 (±4.11) and 2.12 (±0.66)°C, respectively. The topical fluoride absorbance at 445 nm is five orders higher than that at 810 nm. SEM shows that after laser irradiation the enamel surface was intact and without thermal damage. Conclusions The 445 nm laser irradiation may be useful for caries prevention, and its effectiveness is lower than those previously achieved using the argon ion laser.

Antibacterial effect of chitosan nanoparticles in combination with diode laser on E.coli bacterial strain

Background /Aim: The antibacterial effect was assessed by dead/live technique by conjunction between chitosan nanoparticle and diode laser (970nm), were chitosan has an excellent biocompatibility with tissues; save to human with no side effect; excellent bioactivity effect; chelation ability, good absorptive capacity, and antimicrobial activity regarding gram-positive and gram-negative bacteria. The studies have showed chitosan mechanism action related to the films formed around the cell which prevents nutrients absorption. Other res,earch indicates that, using laser radiation in the treatment of dental hard tissue and helping in the root canal formation, the addition effects of diode laser is bacteriostatic effect on bacterial strains present in root canal. The laser radiation was transmitted through quartz optical fibers, which could introducing laser light inside root canal, around canal curvatures and irregularities more easily. Throughout this review the aim of our study is present and discuss the antimicrobial activity of chitosan nanoparticles in combination with diode laser against oral bacteria especially the E.coli and aimed for developing commercial products such as an irrigant solution for root canal. The aim of this study was to estimate the ability of 970-nm diode laser to disinfection in combination with chitosan nanoparticlesagainst negative charged E.coli bacterial strain Materials and methods: The root canals of 40 extracted single-rooted incisors teeth were prepared by rotary system. After crown removal, the roots were autoclaved. The teeth were inoculated with E. coli suspension for two weeks. The samples were divided into four groups (n=10). The samples of the first group G1 (n=10) were inoculated with bacteria only as control group, the second group G2 (n=10) were inoculated with bacteria & chitosan, the group will be divided in 2 subgroup according to the time of incubation (60 seconds, 90 seconds) (n=5). The third group G3 were inoculated with bacteria and treated with a 970-nm diode laser, the group will be divided in 2 subgroup according to the time of laser irradiation (60 seconds, and 90 seconds) (n=5). The fourth group G4 (n=10) were inoculated with bacteria &chitosan and treated with diode laser, the group will be divided in 2 subgroup according to the time of laser irradiation (60 seconds, and 90 seconds) (n=5). Bacterial samples were taken from the root canals and the cultivation. was carried out. The standard deviation of colony-forming units (CFU) for each specimen were measured to compare the reduction in CFU in each group. Results: low mean CFU/mL is recorded in Group2 (chitosan with laser) followed by Group3 (chitosan) and Group 4 (laser), respectively. The difference in CFU/mL between the three groups is statistical significant (P ≤ 0.05).Conclusion: The results of this research show that 970-nm diode laser in combination with chitosan nanoparticles could be used as a complementary disinfection device in root canal treatment and ability to increase the success rate in endodontic therapy.

Bronchoscopic Treatment of Benign Endoluminal Lung Tumors.

Background and Aim Endobronchial benign tumors are a rarely seen clinical entity but may cause significant symptoms. Endobronchial treatment has the potential for relieving symptoms while saving the patient from invasive surgical procedures. No trials have been published that present and compare the various endobronchial treatment modalities for endobronchial benign tumors. The aim of the present study is to define safety and efficacy of endobronchial treatment in patients with benign endobronchial tumors from the point of complications and success rate. Methods This study is a retrospective cohort study from a review of medical charts. Eligibility criteria included diagnosis of a benign endobronchial tumor. Our institution's bronchoscopy and pathology database was searched for specific benign tumors, and the results were further detailed based on the endobronchial location. Results Forty-four patients with pathologically confirmed benign endobronchial tumors were included. Tumor regression was achieved in all patients with diode laser and argon plasma coagulation in combination with or without cryotherapy and without any major complication. There were no significant differences between the use of either diode laser or of argon plasma coagulation as a modality with immediate effect from the occurrence of residual tissue that needed cryotherapy (P > 0.05). There were no major complications. Eight patients had minor complications including minor bleeding (6 patients) and hypertension (2 patients) that were controlled medically. Thirty-one patients (70%) had very good response, and 13 patients (30%) had good response as defined in literature before. Conclusion Diode laser and argon plasma coagulation in combination with or without cryotherapy are safe and effective methods for endobronchial treatment of benign endobronchial tumors.

Comparison of 980 nm Diode Laser and Q-Mix Solution Alone and in Combination on Removal of Smear Layer from Root Canal Surface; a Scanning Electron Microscope Study

Aim: The aim of this study was to compare the efficacy of 980 nm diode laser and QMix 2in1 solution (DENTSPLY Tulsa Dental Specialties) alone and in combination, for smear layer removal from the root canals. Background: Smear layer is an amorphous layer formed on root canal walls following instrumentation. This layer should be removed as it can harbor bacteria and bacterial products and prevents the penetration of intracanal medicaments into the dentinal tubules. Irrigation agitation techniques have been proposed recently to remove smear layer from root canals more efficiently. The diode laser has the potential for irrigant activation and studies are needed to establish their efficacy for smear layer removal especially from apical thirds of canals. Methods: Forty extracted single-rooted permanent human teeth were used. Root canals were prepared to full working length using manual K-files (MANI) till 40K. Prepared teeth were divided into four groups (n=10): Group 1, no irrigation; Group 2, QMix 2in1 solution; Group 3, diode laser; Group 4, QMix 2in1 in combination with a diode laser. The roots were split longitudinally and prepared for scanning electron microscopic (SEM) investigation. The split roots were examined for remaining smear layer at the coronal, middle, and apical portion of each canal under a scanning electron microscope (JSM5910, JEOL, Japan) at 1000x magnification. Results: Smear layer removal was scored according to Guttman rating system for remaining smear layer scores (Gutmann et al.). Diode laser in combination with QMix solution had the least smear layer scores. Conclusions: Diode laser irradiation in combination with QMix 2in1 solution effectively removes smear layer from apical thirds of root canals.

Clinical Investigation of 940 nm Diode Laser Power Bleaching: An In Vivo Study.

Introduction: The increased demand by patient to whiten their teeth in short time had made in-office bleaching procedure the common one. The accompanying tooth sensitivity remains an important factor affecting patients physically and psychologically. The aim of this in vivo study was to observe the effectiveness of 940 nm diode laser in combination with bleaching gel by analyzing tooth sensitivity and colour change. Methods: Fourteen patients treated by laser-assisted bleaching using diode laser at 940 nm and bleaching gel containing 38% hydrogen peroxide. Tooth sensitivity recorded during and after treatment at 6 hours and 1 day using visual analogue scale (VAS). Tooth shade had recorded before and after bleaching using Vita classical brightness scale. Results: Patients whom did not experienced pain during and after the treatment were 78.60% and 92.90%, respectively. Tooth brightness change after treatment was statistically different (P = 0.001). Conclusion: Diode laser of 940 nm is an effective adjunctive tool for reducing tooth sensitivity originated from high concentration H2 O2 bleaching gel.

Monitoring gas-phase CO2 in the headspace of champagne glasses through combined diode laser spectrometry and micro-gas chromatography analysis

During Champagne or sparkling wine tasting, gas-phase CO2 and volatile organic compounds invade the headspace above glasses, thus progressively modifying the chemical space perceived by the consumer. Gas-phase CO2 in excess can even cause a very unpleasant tingling sensation perturbing both ortho- and retronasal olfactory perception. Monitoring as accurately as possible the level of gas-phase CO2 above glasses is therefore a challenge of importance aimed at better understanding the close relationship between the release of CO2 and a collection of various tasting parameters. Here, the concentration of CO2 found in the headspace of champagne glasses served under multivariate conditions was accurately monitored, all along the 10 min following pouring, through a new combined approach by a CO2-Diode Laser Sensor and micro-gas chromatography. Our results show the strong impact of various tasting conditions (volume dispensed, intensity of effervescence, and glass shape) on the release of gas-phase CO2 above the champagne surface.

High-power direct diode laser output by spectral beam combining

We demonstrate a spectral beam combining scheme based on multiple mini-bar stacks, which have more diode laser combining elements, to increase the combined diode laser power and realize equal beam quality in both the fast and slow axes. A spectral beam combining diode laser output of 1130 W is achieved with an operating current of 75 A. When a 9.6X de-magnifying telescope is introduced between the output mirror and the diffraction grating, to restrain cross-talk among diode laser emitters, a 710 W spectral beam combining diode laser output is achieved at the operating current of 70 A, and the beam quality on the fast and slow axes of the combined beam is about 7.5 mm mrad and 7.3 mm mrad respectively. The power reduction is caused by the existence of a couple resonator between the rear facet of the diode laser and the fast axis collimation lens, and it should be eliminated by using diode laser chips with higher front facet transmission efficiency and a fast axis collimation lens with lower residual reflectivity.