Utilizing Laser-Induced Fluorescence to Evaluate the Efficiency of Carbon Dioxide and Diode Lasers in Dentin Sealing after Tooth Preparation: An in-vitro Study.

Adhesive dentistry has made it feasible to design restorations with high aesthetic qualities and little invasiveness. However, the freshly cut dentin after the tooth preparation needs to be sealed to prevent its contaminations, bacterial leakage, and hypersensitivity. Consequently, the immediate dentin sealing (IDS) method has been advised. This study examines different dentinal tubule sealing methods via CO2 laser, diode laser (980-nm) and a two-step self-etch adhesive system applied directly to the fresh cut dentin preceding the placement of the provisional phase. The sealing efficiency of each laser and bond system was evaluated based on the laser-induced fluorescence (LIF) properties and image analysis by scanning electron microscopy. Moreover, the obtained LIF spectra were evaluated using partial least square progression. A two-step adhesive containing a high concentration of S-PRG fillers produced a thick layer that was not perfectly uniform at all sites due to uneven filler distribution in the bond with totally and partially closed dentinal tubules. However, the peaks of the LIF spectra dropped after applying laser because of its sealing effectiveness. Accordingly, CO2 and diode lasers have strong evidence in dentinal tubule sealing and a definitive treatment modality for dentinal hypersensitivity. Moreover, IDS with an adhesive system is superior in occluding dentinal tubules in a biomimetic manner based on its filler content and bioactive properties.

Laser Therapy Versus Traditional Scaling and Root Planing: A Comparative Review.

Scaling and root planing (SRP) removes bacterial plaque, calculus, and associated microorganisms from the surface of the tooth and the surrounding soft tissue. While complete eradication of pathogenic microbes is impossible, gross removal can lower the microbial load, which in turn reduces inflammation and contributes to positive clinical outcomes. Instrumentation in limited-access anatomic areas like furcation, grooves, deep pockets, concavities, and distal molar areas is technically demanding with traditional mechanical debridement. However, emerging advanced systems such as lasers with bactericidal and detoxification effects offer the benefit of reaching limited-access areas that traditional SRP cannot reach. A digitized search was done on PubMed, Embase, Medline, and Google Scholar using the keywords "lasers", "periodontal therapy", "scaling", and "root planing". Upon screening and reviewing, the shortlisted articles comprised narrative reviews, systematic reviews, randomized controlled trials, comparative studies, split-mouth studies, case series, and reports of non-surgical laser therapy and lasers as an adjunct to SRP. This review presents a comprehensive comparative evaluation of different laser modalities utilized in non-surgical periodontal treatment in contrast to standard SRP, rather than an exhaustive article review. It delves into the history and development of lasers, highlighting key advancements made in the realm of periodontics and dental care. This review includes an elucidation of the theory behind laser operation, along with an exploration of its intrinsic characteristics and breakdown of the various types of lasers that are currently available, and an examination of existing literature in both present and historical contexts regarding the comparison of various types of lasers with traditional periodontal treatment.

Symptom-Free Intervals Following Laser Wedge Excision for Recurrent Idiopathic Subglottic Stenosis.

OBJECTIVE: Analyze the duration of symptom-free intervals following laser wedge excision (LWE) for recurrent idiopathic subglottic stenosis (iSGS). Secondary aim includes evaluating the influence of patient-related or disease factors. STUDY DESIGN: Retrospective review. SETTING: Tertiary center. METHODS: Review of iSGS patients who underwent LWE between 2002 and 2021. LWE patients without prior airway surgery were labeled LWE primary (LWEP) and those with prior history of dilation were labeled LWE secondary (LWES). A conditional frailty repeated events model was used to analyze the median time to recurrence (MTR) for each nth recurrence. Secondary analysis included stratification by use of medical therapy and initial preoperative characteristics of scar (Myer-Cotton grade, distance between the glottis and superior-most aspect of scar, DGS; length of scar, DL). RESULTS: Two hundred and ten iSGS patients underwent LWE (131 LWEP, 79 LWES). The proportion of patients experiencing at least 1, 3, 6, and 12 recurrences, respectively, was 68.0% (n = 143), 40.7% (n = 85), 20.0% (n = 42), and 5.2% (n = 11). There was exponential time-shortening from the 1st to 12th recurrence (P < .0001). While MTR was 4.1 years after the first LWE, this fell to 2.8, 1.7, 1.0, and 0.7 years for the 2nd, 3rd, 6th, and 12th recurrences. Furthermore, LWEP patients experienced longer MTR than LWES counterparts within the first 6 recurrences (P < .01). There was no significant relationship between intersurgical interval and medication adherence, DL, DGS, or grade for recurrences beyond the first (P = .207, P = .20, P = .43, P = .16). CONCLUSION: Symptom-free intervals in iSGS shorten with each subsequent recurrence and LWE. The difference in MTR between LWEP and LWES groups was significant within the first 6 recurrences with LWEP having longer MTR.

CO2 LASER versus Blade Scalpel Surgery in the Management of Nasopharyngeal Masses in Dogs.

We aimed to compare surgical time, bleeding level, patient pain level, healing period, scar tissue, relapse of the initial process and complications in patients with nasopharyngeal oncological masses undergoing surgery using a scalpel blade versus a CO2 surgical laser. This is a clinical prospective study comprising surgical work in the nasopharynx area. A sample of 12 inpatients dogs (N = 12) of both genders underwent a surgical excision of nasopharyngeal masses with a scalpel blade (GS n = 6) and CO2 surgical laser (GL n = 6). An Aesculigth CO2 surgical laser-Vetscalpel® model with a superpulse mode, 12 W of power, and a multi-focus pen was used. Statistically significant differences were registered for a p-value of < 0.05. Variations were noted between both groups (GS and GL) concerning surgery time (p = 0.038), first meal time (p = 0.013), pain level (p = 0.003), and healing time (p = 0.014), with the GL group presenting lower values. GL exhibited only one relapse case, with the elapsed time being more than double that of the GS group. Surgical and healing times were shorter in the GL group, and pain levels were lower, with the GL group also demonstrating less scar tissue than the GS group, along with a lower relapse rate. Nasopharynx surgical exposure with precision via the soft palate using the CO2 laser has facilitated successful treatment of regional masses without discomfort and complications, compared to conventional blade scalpel procedures.

Laser-induced 2D/0D graphene-nanoceria freestanding paper-based films for on-site hydrogen peroxide monitoring in no-touch disinfection treatments.

A one-shot CO2 laser-based strategy to generate conductive reduced graphene oxide (rGO) decorated with nanoceria (nCe) is proposed. The 2D/0D rGO-nCe films, integrated as catalytic sensing layers in paper-based sensors, were employed for on-site monitoring of indoor fogging treatments against Listeria monocytogenes (Lm), a ubiquitous pathogenic bacterium. The rGO-nCe laser-assisted synthesis was optimized to preserve the rGO film morphological and electron-transfer features and simultaneously integrate catalytic nCe. The films were characterized by microscopical (SEM), spectroscopical (EDX, Raman, and FTIR), and electrochemical techniques. The most performing film was integrated into a nitrocellulose substrate, and the complete sensor was assembled via a combination of xurography and stencil printing. The rGO-nCe sensor's catalytic activity was proved toward the detection of H2O2, obtaining sensitive determination (LOD = 0.3 µM) and an extended linear range (0.5-1500 µM). Eventually, the rGO-nCe sensor was challenged for the real-time continuous monitoring of hydrogen peroxide aerosol during no-touch fogging treatment conducted following the EU's recommendation for biocidal product use. Treatment effectiveness was proved toward three Lm strains characterized by different origins, i.e., type strain ATCC 7644, clinical strain 338, and food strain 641/6II. The sensor allows for discrimination and quantification treatments at different environmental biocidal amounts and fogging times, and correlates with the microbiological inhibition, promoting the proposed sensor as a useful tool to modulate and monitor no-touch treatments.

Correlation Between the Effects of CO2 Laser and Histopathological Analysis in Vocal Cord Lesions: An Observational Study.

Lasers are based on the principle of light amplification by empowering atoms to store and emit light in a coherent form. Through their effect on tissues, lasers reduce hemorrhage allowing the surgeon to work in a clear field with precise removal of the tissues. Irradiation of the soft tissues by lasers produces thermal effects on the surrounding healthy tissues which can make histopathological examination difficult. Hence this study was done to find a correlation between adjustable parameters of CO2 laser and the extent of collateral thermal damage in the excised vocal cord lesions on histopathological examination and diagnosis. In this study, we enrolled 80 patients who were divided into 4 groups with different combinations of laser power and mode, used during transoral laser micro laryngeal surgery for the excision of vocal cord lesions and subsequent histopathological analysis to objectively measure the extent of thermal damage zone and subjectively assess histo-morphological effects of thermal damage in terms of grade of carbonization. The extent of the thermal damage zone is directly related to the power of the laser, but the mode of the laser had no relation with the thermal damage zone in our study. On subjective histo-morphological examination of excised lesions showed that both power and mode of laser have significant effects on tissue morphology. Continuous mode causes a significantly higher grade of carbonization as compared to the superpulsed mode of the laser. However, in our study it was seen that charring in no way affected the diagnosis in any of the biopsies examined whatever the power or mode of the laser used. The depth and width of the tissue thermal damage zone are mainly dependent upon the laser parameters (power and mode). Although considering the limitations of this study carried out in terms of sample size, it would be pertinent to mention here that further studies with larger cohorts need to be done to authenticate these results.

Comparison of the fractionated Nd: YAG 1064-nm picosecond laser with holographic optics and the fractional CO2 laser in atrophic acne scar treatment: a prospective, randomized, split-face study.

KEY POINT: The 1064-nm picosecond laser with holographic optics demonstrated significant efficacy in treating atrophic acne scars. BACKGROUND: Picosecond lasers with fractionated optics have enabled the development of a breakthrough skin rejuvenation method. The authors compared the fractionated, non-ablative neodymium-doped yttrium aluminum garnet 1064-nm picosecond laser with holographic optics and the fractional CO2 laser in treating atrophic acne scars. METHODS: One side of each patient's face was randomly allocated and treated with three sessions of the 1064-nm picosecond laser with holographic optics at 2-month intervals. In contrast, the other side was treated with the fractional CO2 laser. Participants were followed up 3 months after the final session. The primary outcome included the physicians' evaluation using the ECCA grading scale and a four-point scale to assess improvement. The patients' assessment of progress, their overall satisfaction and preferences, and the side effects were also evaluated. RESULTS: No significant difference was observed between the two lasers in terms of the mean ECCA scores after treatments (P = 0.209). The physicians' improvement assessment was more significant for the fractional CO2 laser (P = 0.001). The patients' evaluation of improvement and subjective satisfaction were consistent with physicians' four-point scale results. The picosecond laser side had fewer adverse effects (P < 0.001). CONCLUSION: The fractionated, non-ablative Nd: YAG 1064-nm picosecond laser with holographic optics and the fractional CO2 laser were effective and safe in treating atrophic acne scars. Significantly better clinical outcomes were observed with the fractional CO2 laser, whereas fewer adverse effects were noted with the 1064-nm picosecond laser with holographic optics.

Application of CO2-Laser Micro-Perforation Technology to Freeze-Drying Whole Strawberry (Fragaria ananassa Duch.): Effect on Primary Drying Time and Fruit Quality.

Freeze-drying (FD) processing preserves foods by combining the most effective traditional technologies. FD conserves the structure, shape, freshness, nutritional/bioactive value, color, and aroma at levels similar to or better than those of refrigerated and frozen foods while delivering the shelf-stable convenience of canned/hot-air-dehydrated foods. The mass transfer rate is the essential factor that can slow down the FD process, resulting in an excessive primary drying time and high energy consumption. The objective of this study was to reduce the FD processing time using CO2 laser technology to improve product competitiveness in the preservation of whole strawberries. The research process consisted of the selection and characterization of fresh strawberries, followed by preparation, pre-treatment, freeze-drying, a primary drying time assessment, and a quality comparison. Experiments were carried out using strawberries without micro-perforation and with five and eight micro-perforations. Quality parameters were determined for fresh, frozen/thawed, and freeze-dried/rehydrated strawberries. It was found that the primary drying time can be significantly reduced by 20% (95% CI) from 26.7 h for non-perforated fruits to 22.3 h when five micro-perforations are made on each strawberry. The quality parameters used to evaluate the strawberries did not show significant differences when comparing frozen/thawed fruits with freeze-dried/rehydrated fruits. The experiments conducted in this study showed that freeze-drying may efficiently compete with freezing technology when processing whole strawberries.

A comparative study of fractional CO2 laser with topical triamcinolone acetonide versus intralesional triamcinolone acetonide in the treatment of alopecia areata.

Introduction: Alopecia areata (AA) is a non-scarring alopecia of chronic autoimmune etiology with heterogenous severity against the anagen hair follicle over the scalp, beard, or any part of the body and is associated with a significant psychological morbidity in the mental status of the patients leading the patients to seek treatment for cosmetic reasons. The management of AA is very unpredictable and is associated with various cosmetic adverse effects. This study aimed at comparing the efficacy and safety of a novel procedure of laser-assisted drug delivery system of steroids with the first-line procedure of intralesional steroids (ILS) for the treatment of patchy AA. Aims and Objectives: To assess and compare the efficacy and safety of fractional CO2 laser in combination with topical triamcinolone acetonide aqueous solution and intralesional triamcinolone acetonide as a monotherapy and in the treatment of AA. Materials and Methods: A total of 60 patchy AA patients were included in this study. Patients were randomized into two equal groups: Group A and Group B with 30 patients in each group using a computer-generated block randomization. Patients in Group A received fractional CO2 laser with topical triamcinolone acetonide aqueous solution and Group B received ILS. Both groups received treatment for five settings with each setting a gap of 3 weeks. The efficacy and safety of treatment modalities in both groups were assessed using global photograph assessment (GPA)-scale, lesional area density score percentage of improvement (LAD score improvement %), visual discomfort scale (VDS), visual analogue scale, and documentation of adverse effects in each setting. Results: Efficacy of treatment modality-assessed using means score of GPA-scale and LAD score improvement % suggests quicker results to patients in Group B in initial settings but drastic improvement happens to patients in Group A in subsequent settings. At the end of 5th setting, GPA-scale and LAD score improvement % suggest maximum efficacy in patients in Group A and they are statistically significant (P-value < 0.001). The mean VDS in both groups suggests maximum discomfort in Group A, yet the patient satisfaction at the end of 5th setting was maximum with patients in Group A and they are statistically significant (P-value < 0.001). Cosmetic notable adverse effect of atrophy of skin was documented in 30% of patients in Group B. Conclusion: This study showed that fractional CO2 laser with topical triamcinolone acetonide is a better treatment modality than the intralesional triamcinolone acetonide for the treatment of AA with respect to efficacy, safety, and adverse events.

Treatment of Fordyce Spots with CO2 Laser: A Case Series of Three Patients.

The Fordyce spots are ectopic sebaceous glands, located at the lip's vermilion border or the oral mucosa. Clinically presents as tiny, discrete, white or yellowish, focally grouped papules. It is a common cosmetic disorder and is significantly associated with emotional stress. Herein, we describe three cases that showed satisfactory cosmetic results after the treatment of Fordyce spots using a CO2 laser. Patients were 21-year-old, 25-year-old, and 28-year-old males with Fordyce spots on the upper lip. They were treated with the CO2 laser and after 4 months of treatment, no recurrence was noted. Treatment with pinhole ablation with CO2 laser improves cosmetic results, reduces downtime, and minimizes side effects. To the best of our knowledge, no such case series have been reported to date from the Indian subcontinent.

[Papilloma excision. Scalpel or CO2 Laser? A case report].

A papilloma is a benign tumor arising from an epithelial surface. Mostly a papilloma appears as an asymptomatic intraoral lesion and is often associated with the human papilloma virus (HPV). In this case report two similar, verrucous papules, sessile bilateral on the back of the tongue, were surgically removed in a 65-year-old male patient. Thereby two different methods of treatment were compared. On the right side of the back of the tongue, excision by scalpel, as the gold standard treatment modality, was performed. On the left side a surgical removal by a CO2 laser was performed. In a photothermal procedure, without direct contact to the tissue, the laser beam is cutting through the mucosa. Secondary wound healing can take place. Both methods were compared in relation to their application, wound healing, quality of the biopsy and morbidity. Postoperative less discomfort and a slightly faster wound healing could be seen after scalpel removal. The histopathological examination was comparable for both methods.

Comparison of dual-plane micro-drop injection of botulinum toxin type A with two traditional methods for treating hypertrophic scars in the tension zone: A long-term clinical application study.

BACKGROUND: Patients with hypertrophic scarring tend to experience recurrence after treatment, which often occurs in areas of the body with high skin tension. AIMS: To evaluate better treatments aimed at reducing the risk of scar recurrence in areas of high skin tension. METHODS: Patients were randomly divided into the following three treatment groups: botulinum toxin type A (BTA) via dual-plane micro-drop injections, triamcinolone acetonide (TAC) suspension, and CO2 via fractional CO2 laser. Interventions were implemented in all three groups once a month for three consecutive sessions. After the final treatment, scarring was evaluated at 1, 3, 6, 12, and 24 months using the Patient and Observer Scar Assessment Scale (POSAS). RESULTS: The 3-month POSAS score for each scar indicator in the treatment groups was significantly lower than that in the preoperative groups (p < 0.001). The scar score in the TAC group decreased at 3 months and increased thereafter. For other groups, the scar score continually decreased at all time points according to the Patient Scar Assessment Scale. Based on the Observer Scar Assessment Scale, the scar score continuously decreased at all time points in the BTA group; in the TAC group, it decreased at 1 month and increased thereafter; and in the CO2 group, the scar score decreased at 3 months and subsequently stabilized. CONCLUSIONS: All three treatment methods were effective. However, the BTA group experienced a reduced risk of scar recurrence and maintained long-term treatment effects.

Simultaneous versus sequential fractional CO2 laser and subcision combination for management of post-acne atrophic scars: A split-face comparative study.

BACKGROUND: A combination of fractional CO2 laser and subcision is usually employed for the treatment of post-acne atrophic scars. However, the efficacy and safety of both simultaneous and sequential combination therapies should be explored. AIMS: To compare the efficacy and safety of simultaneous and sequential fractional CO2 laser and subcision combination therapies for post-acne atrophic scars. PATIENTS AND METHODS: This single-blind, split-face clinical trial included 34 patients with post-acne atrophic scars at our institution. Each patient underwent three sessions of subcision combined with fractional CO2 laser, with a 1-month interval between each session. The left side of the face was treated with simultaneous combination therapy, whereas the right side was treated with sequential combination therapy. Treatment efficacy was assessed at 4, 8, and 12 weeks; and 3 and 6 months after the last session. RESULTS: Simultaneous and sequential treatments demonstrated comparable efficacy. Regarding the adverse events, the side of the face undergoing simultaneous treatment experienced longer swelling duration, higher pain levels during laser treatment, and shorter downtime. CONCLUSIONS: Despite the longer swelling time and higher pain levels during laser treatment in the simultaneous treatment side, the effectiveness and satisfaction level of the CO2 fractional laser and subcision for treatment of the acne scars were comparable between the two combinations, with a shorter downtime for the simultaneous than for the sequential combination therapy.

Shedding Light on Acne Scars: A Comprehensive Review of CO2 vs. Erbium-Doped Yttrium Aluminium Garnet (Er:YAG) Laser Therapy.

Acne scars pose a significant cosmetic concern and can have a profound impact on individuals' self-esteem and quality of life. Laser therapy has emerged as a promising treatment modality for improving the appearance of acne scars by promoting collagen remodeling and tissue regeneration. This comprehensive review compares two commonly used laser modalities, CO2 and erbium-doped yttrium aluminum garnet (Er:YAG), focusing on their mechanisms of action, efficacy, safety profiles, and patient outcomes. While CO2 lasers offer deeper tissue penetration and the potential for more significant improvement in severe acne scars, Er:YAG lasers provide a gentler approach with a lower risk of post-inflammatory hyperpigmentation. Recommendations for clinical practice include tailoring treatment approaches to individual patient characteristics, educating patients about treatment expectations and post-treatment care, considering combination therapies for enhanced outcomes, and implementing regular follow-up care. Areas for further research include long-term outcome studies, investigation of laser therapy in ethnically diverse populations, exploration of combination therapies, and evaluation of emerging laser technologies. This review aims to provide clinicians and patients with valuable insights to inform treatment decisions and optimize outcomes in managing acne scars.

Comparison of promestriene with vaginal fractional CO2 laser and radiofrequency treatments of genitourinary syndrome of menopause.

OBJECTIVE: To compare the effects of fractional CO2 laser and microablative fractional radiofrequency treatment with promestriene topical estrogen on sexual function and genitourinary syndrome of menopause symptoms. METHODS: This was a prospective randomized open-label clinical trial conducted with 62 postmenopausal women assigned to three intervention groups: a) topical promestriene for 90 days (n = 17); b) fractional CO2 laser treatment (n = 24); and c) microablative fractional radiofrequency treatment (n = 21). Each of the latter two groups underwent three treatment sessions at 4-week intervals. At baseline and at the end of the study, all participants had a gynecological examination that included vaginal pH measurement, and the completion of the Vaginal Symptom Score, the Vaginal Health Index, and the Female Sexual Function Index. For the energy treatment groups, adverse effects were evaluated after each session. Group homogeneity was assessed at baseline, and results were evaluated over time (from baseline to the end of treatment) and between groups over time. RESULTS: All baseline parameters were similar among studied groups. At the end of the study, all 3 treatments had produced similar effects: a reduction of vaginal pH, and an improvement of vulvovaginal symptoms (Vaginal Symptom Score and Vaginal Health Index scores) as well as sexual function (higher total Female Sexual Function Index scores, and in the desire, arousal, lubrication and pain domain scores), with no differences observed between groups. Side-effects were slight for both energy treatment groups, mainly represented by vaginal discharge. CONCLUSION: The present study suggests that the two energy treatments were efficient along with promestriene at improving postmenopausal genitourinary and sexuality symptoms. Clinical trial identification numberNCT04717245.

Influence of Different Surface Treatments on the Bond Strength of Yttria-Stabilized Tetragonal Zirconia Ceramic.

Objective: This in vitro study evaluates the shear bond strength (SBS) of yttria-stabilized tetragonal zirconia (Y-TZP) and resin cement after different surface treatments. Materials and methods: Forty-eight ceramic cubes were divided into four groups (n = 12): G1 (control) sandblasting with Al2O3; G2-sandblasting with silica-coated Al2O3 (Rocatec); G3-Rocatec + CO2 laser; and G4-CO2 laser + Rocatec. A metallic primer was applied to the pretreated ceramic. A rubber ring was adapted on the central area, and then, the resin cement was inserted into the matrix and photoactivated. The samples were evaluated regarding surface roughness (Ra), SBS, failure type, and qualitatively with scanning electron microscopy (SEM). The data were analyzed by one-way analysis of variance followed by Tukey's test (p < 0.05). Results: The mean values of Ra (µm) were as follows: G1-4.52a, G2-4.24a,b, G3-4.10a,b, and G4-2.90b and the mean values of SBS (MPa) were as follows: G1-7.84a , G2-4.41b , G3-4.61b and G4-6.14a,b. SEM analyses showed superficial irregularities for all groups, being more prominent for G1. The presence of silica deposits was observed for G2, G3, and G4, but in the last two groups there were some linear areas, promoted by the fusion of silica, due to the thermomechanical action of the CO2 laser. Conclusions: The surface treatment with CO2 laser + Rocatec, using one MDP-based cement, can be an alternative protocol for the adhesion cementation of Y-TZP ceramic since it was as effective as the conventional pretreatment with aluminum oxide sandblasting.

Efficacy of Microneedling and CO2 Laser for Acne Scar Remodelling: A Comprehensive Review.

Acne scarring is a prevalent issue affecting millions worldwide, with significant psychological and social implications. Microneedling and CO2 laser therapy have emerged as promising modalities for acne scar remodelling. Microneedling induces controlled micro-injuries to stimulate collagen production, while CO2 laser therapy precisely ablates scar tissue. This comprehensive review evaluates the efficacy, safety, and comparative benefits of microneedling and CO2 laser therapy. Literature synthesis reveals both modalities to improve acne scars, albeit with different mechanisms and risks. Factors influencing treatment selection and the role of combination therapy are discussed. Future directions include optimising protocols and exploring novel techniques. Overall, microneedling and CO2 laser therapy offer valuable options for acne scar management, empowering individuals to address the physical and emotional burden of scarring.

Process Parameter Optimization for CO2 Laser Polishing of Fused Silica Using the Taguchi Method.

Fused silica was polished to a high quality by a CO2 laser beam with a rapid scanning rate. The rapid scanning rate produced a line laser heat source, resulting in a "polishing line" during the polishing process. The Taguchi method was used to evaluate the comprehensive influence of polishing process parameters on the polishing qualities. Four factors, namely the length of laser reciprocating scanning (A), laser beam scanning speed (B), feed speed (C), and defocusing amount (D), were investigated in this study. The optimal process parameter combination (A1B1C1D1) was obtained. The surface roughness of fused silica was reduced from Ra = 0.157 µm to 0.005 µm. Through analysis of variance (ANOVA), it was found that laser beam scanning speed (B) had a significant influence on the polishing quality. The interaction of the two factors plays a decisive role in the determination of the best process parameters, and the influence of other multi-factor interaction can be ignored; the interaction between A × B is the largest, with a contribution of 42.69%.

Current Treatment of Stress Urinary Incontinence by Bulking Agents and Laser Therapy-An Update.

Stress urinary incontinence (SUI) affects around 20% of women. In addition to the established suburethral sling insertion, two less invasive approaches are of interest today: urethral bulking agents and vaginal laser therapy. This review discusses articles through December 2023 identified by a PubMed literature search using the keywords "incontinence" and "bulking" or "laser". Although the two approaches are less effective than sling insertions, there are specific conditions in which one or the other technique is more advantageous. Injecting bulking agents into the urethra only takes some minutes and works without general anesthesia. The method is particularly suited for elderly, frail, or obese patients with multiple comorbidities, but is also applicable for all patients and in combination with other therapies. Generally, the safety profile is good but differs between bulking materials. Two laser types-the Erbium:YAG laser with SMOOTH-mode and the fractional ablative CO2 laser-deliver heat into the tissue to induce tissue tightening and regeneration. Intravaginal laser therapy improves mild to moderate SUI, while studies describe how intraurethral laser therapy is also beneficial for severe SUI. Young women between childbirths, as well as postmenopausal women, may benefit from laser therapy. The method is safe, can be performed on an outpatient basis, and does not require any artificial material.