***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Background . Multiple laser systems are available for the purpose of hair removal . Objective . The purpose of this study was to determine the safety and long‐term efficacy of the 800 nm , pulsed diode laser at reducing hair count . Methods . Fifty volunteers , primarily Fitzpatrick skin types II and III , with dark brown or black hair , were treated with a diode laser ( 800 nm , 10–40 J/cm2 , 5–30 msec , 9 mm 9 mm , 5 ° C chilled h and piece ) . Each subject had eight treatment sites at varying fluences and pulse duration s , as well as a varying number of treatments and pulses . Hair counts were obtained at each site at baseline , 1 , 3 , 6 , 9 , and an average of 20 months after treatment . Results . After one treatment , hair regrowths ranged from 22 to 31 % at the 1‐month follow‐up visit , then remained stable between 65 and 75 % from the 3‐month to the averaged 20‐month follow‐up . After two treatments there were relatively longer growth delays , with hair regrowths plateauing beginning at 6 months after treatment and ranging from 47 to 66 % for the remainder of the follow‐up evaluations . Side effects were limited to pigmentary changes , transient in subjects with skin types II and III . Conclusions . This 800 nm diode laser with a chilled sapphire tip and variable pulse duration is safe and effective for long‐term hair reduction in individuals with skin types II and III Background . The C and ela alex and rite and the Coherent diode laser systems come equipped with built‐in skin cooling systems that are design ed to both protect the epidermis , allowing higher fluences , and to alleviate discomfort . Nevertheless , pain can be a significant problem especially with treatment of larger areas . Scatter of the laser beam is reportedly affected by the spot size . It is cl aim ed that larger spot sizes are more effective at identical fluences . Objective . This study evaluated the effectiveness of a topical 5 % lidocaine cream ( ELA‐Max ) to control pain and compared pain levels at identical fluences between the 8 mm and 12 mm spot size of the alex and rite laser and between the alex and rite and diode laser with its 9 mm spot size . Methods . The study was conducted in the axillae of 12 patients . Each axilla was divided in half for side‐by‐side comparison . Half of the right axilla was treated with the alex and rite 8 mm and the other half with the 12 mm spot size at identical fluences . The left axilla was treated at the maximum tolerated fluences with the alex and rite 12 mm spot size and the diode 9 mm spot size . Results . At identical fluences and other parameters , there was significantly more pain with the alex and rite 12 mm spot size than with the alex and rite 8 mm spot size , both with or without topical anesthesia . The alex and rite laser was significantly less painful than the diode laser both with and without topical anesthetic . The difference was most noticeable between the alex and rite 8 mm spot size and the diode 9 mm spot size . Topical 5 % lidocaine anesthesia was effective in reducing pain , though not completely , for both the alex and rite and the diode lasers . Conclusion . Topical 5 % lidocaine cream is a simple and effective method for reducing patient discomfort during laser hair removal procedures , even when a skin cooling device is being used . A larger spot size causes more pain than a smaller spot size at identical fluences . The 800 nm diode laser causes greater discomfort than the 755 nm alex and rite laser Promising clinical results have been obtained with the normal mode ruby laser for removal of unwanted hair . Melanin within the hair follicles is thought to act as target for the ruby laser pulses , whereas epidermal melanin is thought to be a competitive chromophore , responsible for potential side effects . This study aim ed ( i ) to objectify postoperative changes in skin pigmentation and texture and ( ii ) to evaluate the importance of variations in preoperative skin pigmentation for the development of side effects 12 weeks after 1 treatment with the normal-mode ruby laser . A total of 17 volunteers ( skin types I-IV ) were laser-treated in the hairy pubic region ( n = 51 test areas ) . A shaved test area served as control . Skin reflectance spectroscopical measurements , 3-dimensional surface contour analysis and ultrasonography objectified postoperative changes in skin pigmentation and texture . Blinded clinical assessment s revealed postoperative hyperpigmentation ( 2 % of test areas ) and hypopigmentation ( 10 % ) , whereas no textural changes were seen . Reflectance spectroscopically-determined pigmentary changes depended on the degree of preoperative skin pigmentation , fairly pigmented skin types experiencing sub clinical hyperpigmentation and darkly pigmented skin types experiencing sub clinical hypopigmentation . Three-dimensional surface profilometry documented similar pre- and postoperative surface contour parameters , indicating that the skin surface texture is preserved after laser exposure . Ultrasonography revealed similar skin thicknesses in laser-exposed and untreated control areas . It is concluded that normal-mode ruby laser treatment is safe for hair removal in skin types I-IV BACKGROUND AND OBJECTIVES The aim was to study hair removal efficacy , and possible side effects of two commercially available long pulsed diode lasers . The radiant exposure was selected to a value of 35 J/cm2 , which is frequently used in the clinic in accordance with manufacturer 's recommendations . STUDY DESIGN / MATERIAL S AND METHODS A prospect i ve clinical study was performed on twenty-nine patients with hair color ranging from light brown to black on the upper lip . One half of the upper lip was r and omly selected for treatment with the  MedioStar laser ; the contralateral half of the lip was treated with the LightSheer laser . Three treatments were performed at 6 - 8 week intervals . Percent hair reduction and acute- and long-term side effects were evaluated after treatment . RESULTS The average hair reductions 6 months after the first treatment were 49 % with the MedioStar laser and 48 % with the LightSheer laser . No scarring or pigmentary change of the skin was observed after any of the treatments with either laser . However , differences in acute side effects such as degree of erythema and burned hairs were observed . CONCLUSIONS No statistically significant differences in hair removal efficacy were observed . These results agree with mathematical modeling , which also offers a method to estimate hair removal efficacy and adverse effects for a range of hair characteristics and laser parameters BACKGROUND AND OBJECTIVE The aim was to investigate the efficacy , side effects , and the long-term results of a long pulsed Nd : YAG-Laser for hair removal in different hair colors and skin types . STUDY DESIGN / MATERIAL S AND METHODS We performed a prospect i ve clinical study with 29 volunteers . Treatment was performed on the lower leg with a long pulsed Nd : YAG-Laser . Five test areas were treated 1 - 5 times in monthly intervals ; one served as control . Follow-up investigations were performed at each session , and 3 , 6 , and 12 months after the last therapy . No depilatory treatment except shaving was allowed during the time of follow-up . Percentual hair loss , short- and long-term side effects , and pain during the treatment were evaluated . RESULTS After one month , a hair loss of greater than 50 % was found in 44.9 % of the areas treated once . With up to five treatments , this percentage increased up to 71.5 % . One year after therapy , a greater than 50 % hair reduction was still present in 40 % of the five-treatment- areas and in 0 % of the areas treated only once . There were no permanent side effects despite one small scar after a folliculitis . CONCLUSIONS The long pulsed Nd : YAG is suitable to remove hair for more than 12 months effectively , although 4 - 5 sessions are necessary for these results . Blond hair can also be removed , although much less effective . No lasting side effects could be seen . Darker skin types or tanned skin can also be treated without side effects . A cooling may be advisable due to the pain reported by the volunteers OBJECTIVE To determine the safety and effectiveness of a long-pulsed Nd : YAG laser at 1064 nm in effecting  long-term hair reduction in patients with darkly pigmented skin . DESIGN Nonr and omized before-after clinical and histological trial . SETTING Private practice , ambulatory care facility . PATIENTS Twenty women with skin phototypes IV through VI and dark brown to black terminal hair on the face , axillae , or legs . INTERVENTION A series of 3 long-pulsed ( 50-millisecond ) 1064-nm Nd : YAG laser treatments at fluences ranging from 40 to 50 J/cm(2 ) were delivered to the identified treatment areas on a monthly basis by a single operator . MAIN OUTCOME MEASURES Global clinical grading scores of comparable before-after treatment photographs were determined by 2 independent medical assessors during each laser session and 1 , 3 , 6 , and 12 months postoperatively . A dermatopathologist review ed unmarked histological specimens obtained at baseline , immediately after the initial laser treatment , and at 1 and 6 months after the final laser session . RESULTS Substantial hair reduction was seen after each of the 3 treatment sessions . Prolonged hair loss was observed 12 months after the final laser treatment ( 70%-90 % hair reduction ) . Axillary hair was substantially more responsive to laser irradiation than was hair located on the legs and face . Adverse effects included mild to moderate treatment pain and rare occurrences of vesiculation and transient pigmentary alteration without fibrosis or scarring . Histological tissue changes mirrored clinical response rates , with evidence of selective follicular injury without epidermal disruption . CONCLUSION The long-pulsed 1064-nm Nd : YAG laser is a safe and effective method of long-term hair reduction in patients with darkly pigmented skin Laser-assisted hair removal has been reported previously with the Nd : YAG laser , the long-pulse ruby laser , the long-pulse Alex and rite laser , and the short-pulse Alex and rite laser . Results with all these lasers have been successful ; however , it has been postulated that the long-pulse Alex and rite laser would have a lower complication rate and greater efficacy at identical fluences than the short-pulse Alex and rite laser . The authors chose to compare directly the pulsed Alex and rite lasers for speed of application , complications , and results . Eighteen patients who desired hair removal were entered into the study . There were 10 female and 8 male patients , with a mean age of 36 years . All skin types from Fitzpatrick classes I through VI were treated . The body areas treated consisted of the face , ears , neck , back , arms , upper thighs , bikini lines , legs , and breasts . One side of the body was treated with the short-pulse ( 2-msec ) Alex and rite laser ( Sharplan Epitouch 5100 ) . The other half was treated with a long-pulse ( 20-msec ) Alex and rite laser . Both lasers were set at the same fluence for each patient . Patients reported a 60 % to 80 % reduction in hair growth at 6 months . Both sides were identical with regard to return of hair growth and complications such as hypopigmentation . Both the long- and short-pulse Alex and rite laser systems yielded an effective method of hair reduction with minimal complications . Equal results and complications were obtained with the two systems . The only exception was that the length of the procedure was shorter with the short-pulse Alex and rite laser OBJECTIVE To determine the most effective treatment parameters for laser-assisted hair removal using a Q-switched neodymium : yttrium-aluminum-garnet ( Nd : YAG ) laser . DESIGN Prospect i ve study to determine the effectiveness of Q-switched ND : YAG laser-assisted hair removal under varying pretreatment protocol s. Hair growth was assessed after laser treatment , and the results were compared with those of wax epilation at 4 , 12 , and 24 weeks . SETTING A private ambulatory laser facility and academic referral center . INTERVENTION Laser-assisted hair removal was performed under 4 different pretreatment conditions . Eighteen areas of unwanted body and facial hair from 12 study subjects were divided into 4 quadrants . Wax epilation followed by application of a carbon-based solution and exposure to Q-switched Nd : YAG laser radiation was performed on 1 quadrant . A second quadrant was wax epilated and exposed to Q-switched Nd : YAG laser radiation without prior carbon solution application . A third quadrant was exposed to laser radiation alone , and a final quadrant was wax epilated to serve as the control . Follow-up evaluations at 1 , 3 , and 6 months consisted of photographic documentation , manual hair counts , and patient hair-density estimates . MAIN OUTCOME MEASURE Percentage of hair regrowth as assessed by objective hair counts and patient subjective evaluations . RESULTS Mean percentage of hair regrowth at 1 month was 39.9 % for the wax-carbon-laser quadrant , 46.7 % for the wax-laser quadrant , 66.1 % for the laser-alone quadrant , and 77.9 % for the wax control quadrant . The percentage of hair regrowth approximately doubled by 3 months but was significantly delayed in all laser-treated quadrants regardless of pretreatment protocol . Full hair regrowth in all anatomic locations was observed by month 6 . Patient subjective evaluations of hair density closely approximated hair count data . No adverse effects or long-term complications were observed . CONCLUSIONS A single hair-removal treatment with the Q-switched Nd : YAG las 
    Output:
    
There appeared to be a short-term effect of approximately 50 % hair reduction with alex and rite and diode lasers up to six months after treatment , whereas little evidence was obtained for an effect of intense pulsed light , neodymium : YAG or ruby lasers .
Long-term hair removal was not documented with any treatment .
Pain , skin redness , swelling , burned hairs and pigmentary changes were infrequently reported adverse effects .
Some treatments lead to temporary short-term hair removal .