What Are The Aesthetic Applications Of Pico Laser Treatments? Advanced Solutions For Skin And Tattoo Removal

Discover how Pico laser technology effectively treats tattoos, melasma, acne scars, and wrinkles with advanced photomechanical precision.

What Is A Pico Laser And How Does It Work? Master The Power Of Picosecond Pressure For Skin Rejuvenation

Learn how Pico laser's photomechanical effect shatters pigment and boosts collagen with minimal heat, ensuring fast recovery and superior results.

What Are The Steps Involved In A Laser Lipo Procedure? A Complete Guide To Precision Body Contouring

Learn the step-by-step process of Laser Lipo, from thermal fat liquefaction to recovery, for effective fat reduction and skin tightening.

What Are The Advantages Of Using Pico Lasers Over Q-Switched Lasers? Maximize Safety & Pigment Clearance Efficiency

Discover why Pico lasers outperform Q-switched systems by using picosecond technology to safely shatter pigment with minimal heat and faster results.

Which Specific Wavelengths Of The Q-Switched Nd Yag Laser Are Used? Master 532Nm & 1064Nm For Pigment Removal

Learn how Q-switched Nd:YAG 532nm and 1064nm wavelengths target epidermal vs. dermal lesions for safe and effective laser pigment removal.

How Does Pico Laser Treatment Reduce Skin Pigmentation? Achieve Clearer Skin With Advanced Photo-Acoustic Technology

Learn how Pico laser technology shatters melanin into microscopic particles for safe, effective pigmentation removal and skin rejuvenation.

Why Is Precise Energy Regulation Essential When Using Laser Equipment? Optimize Safety & Efficacy In Aesthetic Care

Learn why precise laser energy regulation is vital for anatomical areas like the vaginal wall to ensure safety and clinical efficacy.

Is The Q-Switched Nd:yag Laser Treatment Considered Safe? Expert Insights On Safety And Efficacy

Learn why Q-Switched Nd:YAG lasers are safe and effective. Explore side effects, healing timelines, and the importance of professional expertise.

What Are Common Side Effects Of Q-Switched Nd:yag Laser Treatment? Expert Aftercare Tips For Flawless Healing

Learn to manage side effects like redness and crusting after Nd:YAG laser. Get expert aftercare tips for safe, scar-free skin regeneration.

What Benefits Have Resulted From Recent Developments In Pico Laser Technology? Discover The Peak Of Clinic Efficiency

Learn how modern Pico laser advancements enhance safety, speed up patient recovery, and reduce operational costs for medical aesthetic clinics.

What Is Laser Lipolysis? Achieve Precision Body Contouring With Advanced Laser Fat Removal

Learn how laser lipolysis works to destroy fat cells, promote skin tightening, and contour the body with minimal downtime.

What Are The Key Benefits Of Q-Switched Laser Treatment? Advanced Pigment Removal And Skin Rejuvenation Solutions

Explore the benefits of Q-Switched Laser treatment, including precision tattoo removal, melasma management, and collagen-boosting rejuvenation.

What Is The Working Principle Of Picosecond Lasers For Tattoo Removal? Discover The Power Of Photoacoustic Technology

Learn how picosecond lasers use the photomechanical effect to shatter tattoo ink into microscopic dust for faster and safer removal.

What Is The Working Principle Of Laser Lipo? Discover The Advanced Science Behind Laser Lipolysis And Skin Tightening

Learn how Laser Lipo uses photothermal energy to liquefy fat, coagulate blood vessels, and stimulate collagen for superior body contouring results.

What Is The Primary Mechanism Of Action For Fractional Co2 Laser Equipment? Learn How It Repairs Atrophic Acne Scars.

Discover how fractional CO2 lasers use selective photothermolysis and MTZs to stimulate collagen and treat deep atrophic acne scars effectively.

What Is The Primary Function Of A Fractional Co2 Laser System? Master Advanced Skin Remodeling & Collagen Regeneration

Learn how Fractional CO2 Laser systems use micro-thermal zones to trigger collagen production and reverse signs of skin aging effectively.

What Is The Purpose Of Incorporating A Microlens Array (Mla) Into Picosecond Laser Technology For Scar Treatment? Achieve Deep Skin Remodeling

Discover how Microlens Array (MLA) optics and LIOB technology enable deep scar remodeling with minimal downtime and superior collagen regeneration.

Why Is It Mandatory To Use Eye Protection During Fractional Laser Operations? Essential Ocular Safety Standards

Learn why eye protection is critical in Fractional laser treatments to prevent thermal damage, retinal injury, and permanent vision loss.

What Are The Technical Advantages Of Non-Ablative Fractional Laser Technology In Improving Perifollicular Fibrosis?

Learn how non-ablative fractional lasers use thermal remodeling to reverse perifollicular fibrosis and restore hair follicle function effectively.

What Does Pico Do For Skin? Unlock Non-Invasive Skin Rejuvenation

Discover how Pico laser technology uses ultra-short pulses to shatter pigment, smooth texture, and boost collagen with minimal downtime.

Why Is A Fractional Ablative Er:yag Laser Used For Facial Angiofibromas? Precision Depth Control For Nodule Removal

Learn why the AF Er:YAG laser is the gold standard for treating residual angiofibroma nodules with precise depth control and minimal scarring.

Why Is It Necessary To Control The Pulse Duration Of Co2 Lasers To Under 1Ms? Achieve Safe And Precise Skin Ablation

Learn why sub-1ms CO2 laser pulse durations are critical to prevent collateral thermal damage and ensure precise skin vaporization via Selective Photothermolysis.

What Advantages Does The Erbium:yag Laser Offer Over Nd:yag For Becker's Nevus? Achieve Rapid Pigment Clearance

Learn why ablative Erbium:YAG lasers provide superior efficiency and faster pigment clearance for Becker’s Nevus compared to Nd:YAG systems.

What Is The Core Function Of Cooling Systems In Laser Hair Removal? Enhance Safety And Results In Your Clinic

Learn how integrated cooling systems protect the skin, reduce pain, and allow for higher laser energy to achieve permanent hair removal results.

What Is The Therapeutic Mechanism Of The 1540Nm Non-Ablative Fractional Laser? Rejuvenate Skin With Zero Downtime

Learn how the 1540nm non-ablative laser uses Microthermal Zones to stimulate collagen and treat photoaging without damaging the skin surface.

What Are The Technical Advantages Of Setting Specific Pulse Stacking (Smartstak)? Enhance Precision & Fast Recovery

Learn how pulse stacking (SmartStak) decouples treatment depth from thermal damage to maximize efficacy and minimize patient recovery time.

Why Is The 755 Nm Wavelength Preferred For Pigmented Lesions? Optimize Clearance With Picosecond Technology

Discover why the 755 nm wavelength is the gold standard for treating pigmented lesions, offering high melanin absorption and minimal skin damage.

How Do The Procedural Requirements Of Fractional Co2 Laser Compare To Vaginal Estrogen? Professional Treatment Guide

Compare episodic fractional CO2 laser therapy vs. daily estrogen suppositories. Learn about frequency, compliance, and long-term efficacy benefits.

What Are The Technical Advantages Of The Ablative Er:yag Laser? Precision Over Co2 In Pigment-Sensitive Skin Treatments

Learn why Er:YAG lasers offer superior precision and safety over CO2 lasers for Dowling-Degos disease through cold ablation technology.

What Role Do Ablative Lasers Play In Scar Remodeling? Transform Skin With Co2 & Erbium Technology

Learn how CO2 and Erbium lasers vaporize scar tissue and stimulate collagen synthesis for dramatic skin structural remodeling.

How Does Pico Work? Harnessing Ultra-Fast Light For Precise Skin Treatments

Discover how Pico laser technology uses picosecond pulses and photo-acoustic pressure to shatter pigment and tattoos with minimal heat and downtime.

How Does The Nd:yag Laser Work? Unlocking Deep-Tissue Precision For Medical Aesthetics

Discover the science behind Nd:YAG lasers: how a 1064nm wavelength enables deep, targeted treatments for hair removal, vascular lesions, and tattoo removal.

Why Must All Personnel Wear Professional Protective Eyewear During Laser Hair Removal? Ensure Total Ocular Safety

Understand why wavelength-specific eyewear is critical to prevent permanent retinal damage and blindness during laser hair removal procedures.

What Is The Primary Function Of The 1550 Nm Erbium-Doped Fractional Laser? Master Non-Ablative Skin Remodeling

Learn how the 1550nm laser creates Microscopic Thermal Zones (MTZs) to stimulate collagen regeneration without damaging the skin's surface.

How Do Cut-Off Filters In Professional Intense Pulsed Light (Ipl) Systems Optimize The Treatment Of Acne?

Learn how IPL cut-off filters optimize acne treatment by targeting sebaceous glands, reducing inflammation, and stimulating collagen for clear skin.

How Do Professional Hair Growth Machines Intervene In Biological Pathways To Reverse Hair Loss? Science-Backed Results

Learn how LLLT and LED technology reactivate Wnt/beta-catenin pathways and counteract blue light damage to restore the natural hair growth cycle.

What Is The Technical Mechanism Of Deep Fractional Handpieces For Burn Scars? Engineering Deep Tissue Release

Learn how high-precision deep fractional handpieces use vertical vaporization to release scar tension and remodel disorganized collagen fibers.

What Are The Technical Advantages Of Pico Laser For Treating Skin Hyperpigmentation? Advanced Pigment Shattering

Learn how Pico Laser's photo-mechanical effect shatters deep pigment into dust for safer, faster clearance of hyperpigmentation and skin darkening.

How Does F-Mount Packaging For High-Performance Laser Diodes Benefit Integration? Compact Power For Precision Lasers

Learn how F-Mount packaging streamlines compact laser systems through minimal footprints, integrated FAC, and efficient solid-state pumping.

What Is The Role Of The Specialized Handpiece And Scanning System In Co2 Vaginal Laser? Precision For Clinical Success

Learn how CO2 laser scanners and handpieces provide 360-degree coverage and microscopic point precision for consistent vaginal rejuvenation results.

What Are The Advantages Of Professional Ablative Fractional Lasers? Achieve Superior Remodeling For Mature Skin Grafts

Learn why ablative fractional lasers outperform non-ablative devices for skin graft remodeling through tissue vaporization and deep hyperplasia.

Why Is The 1064Nm Long-Pulse Nd:yag Laser Utilized As An Auxiliary Treatment For Hidradenitis Suppurativa?

Discover how 1064nm Nd:YAG lasers treat Hidradenitis Suppurativa by targeting follicles, reducing inflammation, and preventing disease progression.

How Does A Computer-Controlled Scanning System Enhance Laser Procedures For Skin Conditions? Precision And Automation

Learn how computer-controlled scanning systems improve laser precision, energy uniformity, and thermal safety for treating conditions like rhinophyma.

What Are The Unique Advantages Of Picosecond Laser Equipment? Master Stubborn Pigment Removal With Ease

Discover how Picosecond Lasers use photoacoustic effects to shatter pigment into dust-like particles for safe, effective skin clearance.

How Do Alexandrite Or Nd:yag Lasers Help Reduce Recurrence Rates? Expert Guide To Pilonidal Sinus Prevention

Learn how Alexandrite and Nd:YAG lasers eliminate the root cause of pilonidal sinus disease by targeting hair follicles with precision technology.

What Are The Core Technical Advantages Of Fractional Technology For Scar Repair? Elevate Clinical Precision

Discover how Fractional Technology outpaces traditional lasers for scar repair through deep penetration and rapid recovery.

How Do Co2 And Er:yag Lasers Differ In Afr Treatments? Choosing The Right Tech For Skin Resurfacing

Understand the differences between CO2 and Er:YAG lasers in AFR, focusing on water absorption, thermal damage, and coagulation for scar treatment.

Why Adjust Laser Parameters By Fitzpatrick Skin Type? Ensure Safety & Efficacy In Professional Laser Treatments

Learn why tailoring laser fluence and pulse duration to Fitzpatrick skin types is vital to prevent burns and pigment issues in clinical settings.

What Is The Primary Function Of The Long-Pulse 1064Nm Nd:yag Laser In Hs? Targeted Hair Follicle Destruction For Relief

Learn how the Long-pulse 1064nm Nd:YAG laser treats Hidradenitis Suppurativa by targeting hair follicles to reduce inflammation and prevent flares.

What Role Do 2940Nm Erbium Laser Systems Play In Cosmetic Permeability And Safety Research? Advanced Research Insights

Explore how 2940nm Erbium lasers enhance transdermal absorption and simulate extreme safety conditions for advanced cosmetic and toxicity research.

What Key Function Does High-Intensity Focused Ultrasound (Hifu) Perform In Transdermal Drug Delivery? Unlock Precision

Learn how HIFU acts as an active trigger for drug release through cavitation and thermal effects, ensuring precise and rapid dermal absorption.

Why Is It Necessary To Use Professional Surgical Blades For Laser Shaving? Ensure Safety And Maximize Treatment Results

Learn why professional shaving is crucial before laser irradiation to prevent skin burns and ensure maximum energy reaches the hair follicles.

What Is The Mechanism Of Action For The Long-Pulsed Mode? Master Deep Tissue Remodeling In Laser Protocols

Learn how Long-pulsed Mode laser treatment stimulates deep collagen and elastin synthesis through controlled thermal energy and protein denaturation.

Why Is The Precise Adjustment Of Dot Power And Dwell Time Critical During Fractional Co2 Laser Procedures? Master Safety

Learn why calibrating power and dwell time in CO2 laser treatments is vital for tissue remodeling, safety, and preventing thermal damage.

How Do Pulse Duration Settings In Medical Lasers Influence Vascular Treatment? Precision Thermal Confinement Explained

Master pulse duration and thermal relaxation time to optimize vascular laser treatments, ensuring vessel destruction without tissue damage.

How Do Microthermal Zones (Mtzs) Function? Unlock The Science Of Rapid Healing In Fractional Co2 Laser Resurfacing

Learn how Microthermal Zones (MTZs) create microscopic thermal injuries to stimulate collagen and speed up skin healing in Fractional CO2 treatments.

What Are The Equipment Advantages Of Non-Ablative Nd:yag Lasers? Discover Superior Deep Tissue Vaginal Remodeling

Learn why Nd:YAG lasers offer deeper tightening and faster recovery than CO2 lasers for vaginal mucosal remodeling through non-ablative technology.

What Are The Advantages Of A Co2 Laser Scanner For Scalp Adenomas? Precision And Speed For Large Lesions

Learn how high-precision scanning units in CO2 laser systems automate the treatment of large scalp sebaceous adenomas for superior aesthetic results.

How Does A Co2 Laser System Compare To Traditional Surgical Excision? Superior Precision For Facial Sebaceous Adenomas

Discover why CO2 lasers outperform traditional surgery for facial lesions, offering bloodless precision and superior aesthetic healing.

How Do Laser Wavelength Parameters Affect Gsm Treatment Penetration? Optimize Your Clinic's Aesthetic Results

Learn how 10,600nm and 2,940nm wavelengths dictate penetration depth and thermal diffusion for effective GSM and vaginal atrophy treatments.

What Is The Significance Of Standardized Co2 Laser Protocols? Enhance Clinical Practice Value And Safety

Learn how standardized CO2 laser treatment protocols eliminate uncertainty, maximize hardware performance, and ensure consistent clinical results.

Why Are Fractional Co2 Laser Systems Superior To Cryotherapy For Hair Regeneration? Deep Follicle Stimulation Benefits

Discover why Fractional CO2 Lasers outperform cryotherapy in hair regeneration through precision dermal targeting and superior follicle stimulation.

What Are The Advantages Of Combining Nd:yag And Ipl For Vascular Lesions? Boost Clinical Efficiency & Clearance

Learn how dual-modality Nd:YAG and IPL platforms treat deep and superficial vascular lesions simultaneously for superior clinical results.

How Do The 5Mm Spot Size And High-Frequency Settings Influence The Quality Of Laser Scar Treatment? Precision Guide

Discover how 5mm spot sizes and high-frequency settings optimize laser scar revision through uniform energy delivery and enhanced patient safety.

What Advantages Does A Fractional Co2 Laser Offer Over Traditional Systems? Superior Skin Resurfacing With Rapid Healing

Discover how Fractional CO2 lasers use MTZ technology to provide deep structural correction with faster recovery and lower risk than traditional ablation.

What Technical Advantages Do Picosecond Pulse Lasers Offer Over Traditional Nanosecond Lasers? Upgrade Your Clinic Now

Discover why picosecond lasers outperform nanosecond systems through photoacoustic technology, offering faster pigment removal and higher safety.

What Skin Conditions Can Laser Resurfacing Treat? Discover 10+ Benefits For Clinical Rejuvenation

Learn how laser resurfacing treats wrinkles, acne scars, pigmentation, and medical growths like actinic keratosis for flawless skin.

What Are The Unique Technical Advantages Of Carbon Dioxide (Co2) Laser Equipment In Managing Diffuse Actinic Cheilitis?

Discover how CO2 laser equipment uses precise depth control and selective photothermal action to effectively treat Actinic Cheilitis lesions.

What Is The Clinical Value Of Ultrashort Pulse Technologies Like Picosecond Or Nanosecond Lasers In Phototherapy?

Learn how picosecond and nanosecond lasers use photoionization to provide precise clinical results with minimal thermal damage to surrounding tissue.

What Are The Advantages Of A 1,064-Nm Picosecond Laser Vs Q-Switched? Advanced Pigment Shattering Tech

Learn why 1,064-nm picosecond lasers outperform Q-switched systems in pigment removal using photomechanical effects for safer, faster clearance.

What Is The Fundamental Difference Between Picosecond Lasers And Ablative Lasers? Photoacoustic Vs Photothermal Rejuvenation

Learn how picosecond lasers use photoacoustic shockwaves versus the photothermal heat of ablative lasers for effective skin remodeling and repair.

What Is The Difference Between Micro-Laser Liposuction And Cryolipolysis? Choose The Best Body Sculpting Tech

Compare micro-laser liposuction's thermal fat melting and skin tightening vs. Cryolipolysis's non-invasive freezing technology for body contouring.

What Precautions Should Be Taken Before A Fractional Co2 Laser Procedure? Essential Preparation Guide For Pros

Master the fractional CO2 laser prep timeline: UV avoidance, melanin resting, and antiviral protocols to ensure safety and prevent pigmentation.

What Are The Popular Types Of Cosmetic Laser Equipment And Their Primary Applications? Maximize Your Clinic's Potential

Explore the top cosmetic laser categories, from hair removal to skin resurfacing, and find the right equipment for your aesthetic practice.

How Do Pico Laser Machines Work? Discover The Revolutionary Photomechanical Technology For Skin Renovation

Learn how Pico laser machines use ultra-short pulses and pressure waves to shatter pigment and stimulate collagen without heat damage.

How Does Co2 Laser Resurfacing Work? Discover The Science Of Ablative Skin Renewal

Learn how CO2 laser resurfacing vaporizes damaged tissue and stimulates collagen for smoother, tighter, and rejuvenated skin.

In What Ways Does Laser Technology Improve Patient Safety Compared To Traditional Surgery? 5 Key Clinical Advantages

Learn how laser technology enhances patient safety by reducing trauma, minimizing anesthesia risks, and providing superior precision over surgery.

For Which Skin Types Is The Nd:yag Laser The Most Appropriate Choice? Safe & Effective Solutions For Darker Skin Tones

Learn why the Nd:YAG laser is the safest choice for Fitzpatrick skin types IV-VI. Ideal for hair removal, vascular lesions, and tattoo removal.

What Types Of Aesthetic And Dermatological Conditions Can Be Treated With An Nd Yag Laser? Versatile Skin Solutions

Discover the versatility of Nd:YAG lasers for tattoo removal, pigmentation, skin rejuvenation, and acne treatment for clinics and premium salons.

What Are The Primary Functions Of A Professional Nd:yag Laser Machine? Master Tattoo Removal And Skin Rejuvenation

Learn how professional ND:YAG laser machines work to remove tattoos, eliminate deep pigmentation, and stimulate collagen for skin rejuvenation.

Why Is A Cooling Or Icing Stage Essential During Laser Treatments? Ensuring Safety & Efficacy In High-Precision Lasers

Learn why cooling is critical for laser safety, preventing burns, reducing pain, and enabling higher energy for better clinical results.

What Are The Clinical Operational Advantages Of Non-Ablative Lasers Compared To Ablative Laser Equipment?

Explore why non-ablative lasers are the preferred choice for clinics seeking minimal downtime and high safety in dermal collagen stimulation.

Fractional Co2 Laser Vs. Steroid Injections For Alopecia Areata: Discover Superior Results And Safety

Compare Fractional CO2 Laser and steroid injections for Alopecia Areata. See why laser therapy offers higher hair density and avoids skin atrophy.

What Is The Primary Objective Of A 0% Overlap Setting In Fractional Laser Ablation? Master Safe Thermal Management

Learn how 0% overlap prevents thermal stacking, reduces burn risks, and ensures uniform results in fractional laser skin ablation procedures.

What Is The Mechanism Of Action For Medical-Grade Laser Systems In Treating Refractory Melasma? Advanced Laser Insights

Learn how Nd:YAG and fractional CO2 lasers treat refractory melasma through photoacoustic shattering and structural dermal remodeling.

What Are The Primary Functions Of Medical Coupling Gel? Optimize Safety And Efficacy In Laser Hair Removal

Learn how medical coupling gel acts as an optical bridge and thermal barrier to ensure safe, effective, and efficient laser hair removal.

How Do Nd:yag Laser Systems Facilitate The Removal Of Microencapsulated Tattoos? Unlock Advanced Pigment Clearance

Learn how Nd:YAG lasers use photomechanical energy to rupture microcapsule shells, enabling natural lymphatic pigment removal with minimal damage.

What Physical Mechanism Does A Micro-Ablative Fractional Co2 Laser System Use To Treat Gsm? Harnessing Thermal Repair

Learn how fractional CO2 lasers treat GSM through controlled thermal injury, triggering collagen production and mucosal restoration.

Why Control Treatment Density In Ladd? Optimize Fractional Co2 Laser Parameters For Maximum Drug Delivery Efficacy

Learn why precise energy and density control in fractional CO2 lasers is vital for effective Laser-Assisted Drug Delivery (LADD) and patient safety.

Why Is The Flexibility Of Parameter Adjustment In Fractional Laser Equipment Essential For Dark Skin Tones (Iv-Vi)?

Learn how adjustable laser parameters prevent PIH and burns in Fitzpatrick IV-VI skin by optimizing heat dissipation and energy density.

What Role Does Tor Play In Transdermal Drug Delivery? Unlock Deep Dermal Absorption With Fractional Laser Technology

Learn how the Temporary Opening of the Epidermal Barrier (TOR) uses fractional lasers to deliver large-molecule drugs directly into the deep dermis.

Why Is A Multi-Session Treatment Protocol Recommended For Laser Vaginal Tightening? Unlock Durable Results

Learn why a 3-session protocol spaced 6 weeks apart is essential for maximizing collagen remodeling and achieving long-term vaginal tightening.

What Are The Clinical Advantages Of High-Precision Laser Systems? Transform Your Clinic With Thermal Precision

Discover how high-precision lasers outperform traditional surgery with superior hemostasis, micron-level control, and faster patient recovery.

What Critical Protective Role Does A Sapphire Cooling Tip Play During Laser Irradiation? Ensuring Safety And Efficacy

Learn how sapphire cooling tips protect the epidermis, prevent burns, and enable higher energy for superior laser treatment results.

Why Is The Total Ablation Mode Of A Co2 Laser Necessary For Treating Non-Undermined Central Facial Skin?

Learn why Total Ablation Mode is essential for treating deep wrinkles and photoaging in non-undermined skin through aggressive reconstruction.

How Do Non-Ablative Fractional Laser Systems Function In The Treatment Of Atrophic Striae? Restore Skin Elasticity

Learn how non-ablative fractional lasers treat stretch marks by stimulating collagen through MTZs while keeping the epidermis intact for fast healing.

How Can The Initial Application Of An Ablative Laser Be Used To Enhance The Effects Of Topical Anesthesia Creams? Maximize Numbing

Discover how a low-energy laser pass increases skin permeability, allowing topical anesthesia to penetrate deeper for faster and more effective numbing.

Why Is An Integrated Visible Red Aiming Beam Critical During Ablative Laser Procedures? Ensuring Precision And Safety

Learn why the visible red aiming beam is vital for CO2 and Er:YAG lasers to ensure precise targeting and prevent accidental tissue damage.

What Specific Safety Concerns Does Sapphire Contact Cooling Technology Address? Secure Your Laser Hair Removal Treatments

Learn how sapphire cooling prevents burns, pigment changes, and plumes in laser hair removal by maintaining skin safety at 4°C.

What Technical Advantages Do Sapphire Cooling Lenses Offer Over Ice-Pack Cooling? Boost Clinic Safety And Efficiency

Discover why sapphire cooling lenses outperform ice packs by providing active, synchronous protection for higher energy laser hair removal efficacy.