Effect of CO2 laser combined with AmF/NaF/SnCl2 solution on the prevention of human and bovine enamel erosion

Abstract: This in vitro study evaluated the potential of CO2 laser (10.6 μm) combined with a stannous/fluoride-containing solution for preventing erosion in human/bovine enamel. Forty-eight samples of each substrate were randomly allocated to four groups (n = 12): W - distilled water; E - AmF/NaF/SnCl2 solution; L - CO2 laser; and LE - CO2 laser+AmF/NaF/SnCl2 solution. After surface treatments, samples were submitted to a 5-day erosive challenge, alternating immersions in 0.5% citric acid (2 minutes, 6x/day) and in artificial saliva. Optical profilometry (μm) and scanning electron microscopy (SEM) were used to determine surface loss and surface morphology, respectively. Data were statistically analyzed by two-way ANOVA and Tukey's tests (p < 0.05). For human enamel, tissue loss was lower in group L (12.37 ± 4.46) than in group W (16.45 ± 2.76), and higher than in the groups treated with AmF/NaF/SnCl2 solution (E-5.44 ± 2.37; LE-5.55 ± 2.31). In group L, SEM images reveled a disorganized surface but fewer projections than in group W and LE showed fewer irregularities than W, E, and L. For bovine enamel, tissue loss in group L (13.90 ± 3.50) did not differ from that in group W (14.10 ± 2.98), and was higher than losses in groups E (5.70 ± 2.12) and LE (8.12 ± 2.56), which were statistically similar to each other. Groups W and L had similar aspects of demineralization, whereas groups E and LE showed homogenous surfaces. Surface-treated samples had no changes in their surfaces. CO2 laser was able to slightly prevent surface loss only on human enamel surface, but did not enhance the AmF/NaF/SnCl2 effect on the prevention of enamel erosion.

Terapia combinada de laser de CO2 e luz intensa pulsada no tratamento de lesões vasculares / Combined CO2 laser and intense pulsed light therapy in the treatment of vascular lesions

As lesões vasculares congênitas podem ser divididas em: tumores e malformações. Os hemangiomas são tumores vasculares benignos decorrentes da proliferação anormal de células endoteliais; já as manchas em vinho do Porto são malformações vasculares de provável herança autossômica dominante. Até o presente momento, não há estudos sobre a associação entre luz intensa pulsada e laser de CO2 como forma terapêutica destas patologias. A presente série de casos apresenta 10 casos de lesões vasculares tratadas com a combinação destas formas de irradiação. Conclui-se que esta terapia combinada pode ser efetiva na redução da espessura das lesões ou na atenuação da coloração

Congenital vascular lesions can be subdivided into tumors and malformations. Hemangiomas are benign vascular tumors resulting from the abnormal proliferation of endothelial cells, whereas port-wine stains are vascular malformations of a possible autosomal dominant inheritance. To date, there are no studies associating the use of intense pulsed light and CO2 laser as a therapeutic form for these pathologies. We present a series of 10 cases of vascular injuries treated with the combination of these forms of irradiation. This combined therapy can be effective in reducing the thickness of the lesions or in attenuating the color.

Xantogranuloma múltiplo do adulto: relato de caso de tratamento exitoso com laser CO2 / Multiple adult xanthogranuloma: case report of successful treatment with CO2 Laser

O xantogranuloma múltiplo do adulto é uma apresentação mais rara e tardia do xantogranuloma juvenil, uma histiocitose de células não Langerhans. No adulto, normalmente, é uma lesão única, sendo a manifestação por múltiplas lesões infrequente e pouco descrita na literatura. Relatamos um caso de xantogranuloma múltiplo do adulto, com falha terapêutica à isotretinoína e ótima resposta ao tratamento com laser CO2 no modo cirúrgico

Multiple adult xanthogranuloma is a rare and late variant of Juvenile xanthogranuloma, a non-Langerhans cell histiocytosis. It usually corresponds to a single lesion in adults, and the manifestation of multiples lesions is uncommon. We report a case of multiple adult xanthogranuloma, with Isotretinoin therapy failure and optimal response to CO2 Laser treatment in the surgical mode.

Tratamento de neurofibromatose NF-1 com laser de CO2 - Relato de caso / Treatment of neurofibromatosis NF-1 with CO2 laser - case report

neurofibromatose tipo 1 apresenta lesões cutâneas múltiplas e limitadas opções terapêuticas. O laser de CO2 é ferramenta útil na remoção de neurofibromas, a principal fonte de desfiguração cosmética nesses pacientes. Apresentamos o tratamento de neurofibromas com laser de CO2 em uma paciente ao longo de quatro anos e meio. A paciente apresentava lesões de diâmetro variável, distribuídas difusamente. Após 16 sessões com laser de CO2 constatou-se melhora clínica. Apesar de ser tratamento paliativo, a melhora estética obtida justifica o esforço e tempo demandados, tendo em vista os ganhos na esfera psicológica do paciente.

Type 1 neurofibromatosis has multiple cutaneous lesions and limited treatment options. CO2 laser is a useful tool for the removal of neurofibromas, the main source of cosmetic disfiguration for these patients. We present the treatment of neurofibromas with CO2 laser in a patient over 4.5 years. The patient had lesions with variable diameter, diffusely distributed. After 16 sessions of CO2 laser, we observed clinical improvement. Although it is a palliative treatment, the cosmetic improvement achieved substantiates the demanded effort and time in view of the psychological gains for the patient.

Therapeutic effect of different power CO2 laser on benign lesions of vocal cords / 中国基层医药

Objective@#To compare the efficacy between conventional laryngeal microsurgery and different power CO2 laser on benign vocal cord lesions for clinical reference.@*Methods@#From June 2016 to December 2018, 580 patients with benign vocal cord lesions admitted to Jiaxing Hospital of Traditional Chinese Medicine were divided into A, B, C, D, E group according to the random number table rule, with 116 cases in each group.A group was treated with conventional laryngeal microsurgery.B, C, D and E groups were treated with CO2 laser with the output power 2W, 3W, 4W, and 5W.All the patients were tested for phonological parameters (Jitter, Shimmer, F0, MPT, DSI) and Rosent simplified Voice Hand Index (VHI-10). The main vocal parameters and VHI-10 changes were compared among the five groups before surgery and 4 weeks after surgery.@*Results@#Four weeks after operation, Jitter, Shimmer, F0 and DSI of A, B, C, D and E groups decreased with the range B group>C group>D group>E group>A group[(2.42±0.21)% vs.(2.70±0.25)% vs.(2.91±0.31)% vs.(3.24±0.38)% vs.(3.58±0.42)%, F=27.603, P=0.000; (3.86±0.43)% vs.(4.18±0.48)% vs.(4.55±0.56)% vs.(4.87±0.58)% vs.(5.22±0.62)%, F=22.352, P=0.000; (168.50±20.13)Hz vs.(175.24±22.71)Hz vs.(180.65±24.68)Hz vs.(187.28±26.44)Hz vs.(195.55±28.35)Hz, F=18.193, P=0.000; (2.88±0.34) vs.(3.46±0.38) vs.(3.82±0.41) vs.(4.50±0.44) vs.(5.40±0.51), F=31.604, P=0.000]. The MPT of A, B, C, D and E groups were prolonged with the prolongation B group>C group>D group>E group>A group[(16.26±1.69)s vs.(15.65±1.67)s vs.(14.58±1.64)s vs.(13.85±1.60)s vs.(12.61±1.59)s, F=20.415, P=0.000]. Four weeks after operation, VHI-10 in A, B, C, D and E groups decreased with the extents B group>C group>D group>E group>A group[(7.23±0.74)points vs.(9.58±0.95)points vs.(11.48±1.17)points vs.(13.68±1.45)points vs.(15.46±1.74)points, F=27.467, P=0.000].@*Conclusion@#Low-power (2W) CO2 laser is the best treatment for benign vocal cord lesions, which is worthy of clinical promotion.

Therapeutic effect of different power CO2 laser on benign lesions of vocal cords / 中国基层医药

Objective To compare the efficacy between conventional laryngeal microsurgery and different power CO2 laser on benign vocal cord lesions for clinical reference.Methods From June 2016 to December 2018, 580 patients with benign vocal cord lesions admitted to Jiaxing Hospital of Traditional Chinese Medicine were divided into A,B,C,D,E group according to the random number table rule ,with 116 cases in each group.A group was treated with conventional laryngeal microsurgery.B,C,D and E groups were treated with CO 2 laser with the output power 2W, 3W,4W,and 5W.All the patients were tested for phonological parameters ( Jitter, Shimmer, F0, MPT, DSI) and Rosent simplified Voice Hand Index (VHI－10).The main vocal parameters and VHI －10 changes were compared among the five groups before surgery and 4 weeks after surgery.Results Four weeks after operation,Jitter,Shimmer, F0 and DSI of A,B,C,D and E groups decreased with the range B group ＞C group＞D group＞E group＞A group [(2.42 ±0.21)% vs.(2.70 ±0.25)% vs.(2.91 ±0.31)% vs.(3.24 ±0.38)% vs.(3.58 ±0.42)%,F＝27.603,P＝0.000;(3.86 ±0.43)%vs.(4.18 ±0.48)%vs.(4.55 ±0.56)%vs.(4.87 ±0.58)%vs.(5.22 ± 0.62)%,F＝22.352,P＝0.000;(168.50 ±20.13) Hz vs.(175.24 ±22.71) Hz vs.(180.65 ±24.68) Hz vs. (187.28 ±26.44)Hz vs.(195.55 ±28.35) Hz,F＝18.193,P＝0.000;(2.88 ±0.34) vs.(3.46 ±0.38) vs. (3.82 ±0.41) vs.(4.50 ±0.44) vs.(5.40 ±0.51),F＝31.604,P＝0.000].The MPT of A,B,C,D and E groups were prolonged with the prolongation B group ＞C group ＞D group ＞E group ＞A group [( 16.26 ±1.69 ) s vs. (15.65 ±1.67)s vs.(14.58 ±1.64)s vs.(13.85 ±1.60) s vs.(12.61 ±1.59) s,F＝20.415,P＝0.000].Four weeks after operation,VHI－10 in A,B,C,D and E groups decreased with the extents B group ＞C group＞D group＞E group＞A group [(7.23 ±0.74) points vs.(9.58 ±0.95) points vs.( 11.48 ±1.17 ) points vs.(13.68 ± 1.45)points vs.(15.46 ±1.74)points,F＝27.467,P＝0.000].Conclusion Low－power (2W) CO2 laser is the best treatment for benign vocal cord lesions ,which is worthy of clinical promotion.

Effect of fractional ablative carbon dioxide laser with lidocaine spray on skin flap survival in rats

BACKGROUND: Lidocaine spray is a local anesthetic that improves random-pattern skin flap survival. The fractional ablative carbon dioxide laser (FxCL) produces vertical microchannels that delivers topically applied drugs to the skin. In this study, we hypothesized that FxCL therapy would enhance the lidocaine effect to improve random-pattern skin flap survival in rats. METHODS: McFarlane random-pattern skin flaps were elevated in 48 rats, which were divided into four groups according to treatment: FxCL+lidocaine, FxCL, lidocaine, and nontreatment (control). On postoperative day 7, necrotic flap areas, the number of capillary vessels, and neutrophil count were evaluated. Anti-rat vascular endothelial growth factor (VEGF) and CD31 antibody activity were also evaluated by immunohistochemical staining. RESULTS: Flap survival rate was 53.41%±5.43%, 58.16%±4.80%, 57.08%±5.91%, and 69.08%±3.20% in the control, lidocaine, FxCL, and FxCL+lidocaine groups, respectively. Mean neutrophil count in the intermediate zone excluding the necrotic tissue was 41.70±8.40, 35.43±6.41, 37.23±7.15, and 27.20±4.24 cells/field in the control, lidocaine, FxCL, and FxCL+lidocaine groups, respectively. Anti-rat VEGF and CD31 antibody activity were the highest in the FxCL+lidocaine group. CONCLUSION: FxCL with lidocaine had a positive effect on random-pattern skin flap survival in rats. Thus, FxCL with lidocaine spray should be considered as a new treatment option to improve flap viability.

Evaluation of efficacy of microneedling radiofrequency for the treatment of facial acne scars / 中华皮肤科杂志

Objective To evaluate the efficacy and safety of microneedling radiofrequency in the treatment of facial acne scars.Methods A retrospective study was conducted.According to the inclusion and exclusion criteria,42 patients with acne scars receiving microneedling radiofrequency treatment (observation group) and 47 patients with acne scars treated with fractional CO2 laser (control group) in Guangzhou Institute of Dermatology were enrolled into this study from June 2016 to June 2017.Single-blind evaluation was conducted according to a four-grade scoring system and ECCA grading scale (échelle d'évaluation clinique des cicatrices d'acné) by two clinically experienced dermatologists to evaluate and compare the clinical efficacy between the 2 groups,based on the clinical photos before and after the treatment.Statistical analysis was done by using chi-square test,t test of two independent samples and paired Wilcoxon signed rank test.Results After treatment,no significant difference in the total response rate was observed between the observation group (92.9％,39 cases) and control group (89.4％,42 cases;x2 =0.042,P ＞ 0.05).Before the treatment,there was no significant difference in the ECCA score between the observation group (46.7 ± 16.3) and control group (45.7 ± 15.8,t =0.271,P ＞ 0.05).After the treatment,the ECCA score in the observation group and control group significantly decreased into 29.5 ± 15.1 and 31.3 ± 14.9 respectively (Z =-5.713,-6.086,respectively,both P ＜ 0.05).Conclusion Microneedling radiofrequency is effective for the treatment of facial acne scars,with high safety and less injuries.

Comparison of carbon dioxide laser versus high-frequency electroacupuncture in the treatment of steatocystoma multiplex: a self-controlled clinical study / 中华皮肤科杂志

Objective To compare the clinical efficacy and safety of carbon dioxide (CO2) versus high-frequency electroacupuncture based on the assistance of drilling and blunt dissection in the treatment of steatocystoma multiplex.Methods A randomized,self-controlled study was performed in 15 patients.The median line of the body served as the dividing line,and the lesions on the two sides of the median line of the body were randomly divided into 2 groups to be treated with CO2 laser or high-frequency electroacupuncture,which left micropathways into the cyst cavity.After the above treatment,contents in the cysts were squeezed out or drawn out with a mosquito clamp,and the cysts were bluntly dissected.The decrustation time,erythema subsiding time,adverse reactions and recurrence were compared among lesions at different sites or with different sizes.Results For the lesions at the same sites or with similar sizes after treatment,the decrustation time and erythema subsiding time were both significantly shorter in the CO2 laser group than in the high-frequency electroacupuncture group (both P ＜ 0.05).There were significant differences in the decrustation time and erythema subsiding time among lesions at different sites or with different sizes (all P ＜ 0.05).Mild pain occurred in the 2 groups,and no hematoma or secondary infection occurred.There were significant differences in the incidence of scar formation or pigmentation between the 2 groups (both P ＜ 0.05).During the follow-up of 6-18 months,relapse occurred in 1 patient in each group.Conclusion Compared with the high-frequency electroacupuncture,CO2 laser assisted by drilling and blunt dissection shows better efficacy in the treatment of steatocystoma multiplex,and it can remove lesions at various sites at one time.

Ultrapulsed fractional CO2 laser for the treatment of nine cases of porokeratosis in children / 中华皮肤科杂志

Objective To investigate the efficacy and safety of ultrapulsed fractional CO2 laser in the treatment of porokeratosis in children.Methods Clinical data were collected from 9 children with porokeratosis in the Department of Dermatology of Beijing Children's Hospital from January 2014 to December 2015,and analyzed retrospectively.These patients were all treated with ultrapulsed fractional CO2 laser in a dynamic superficial stripping (Active FX) mode.The initial energies were 100,200 and 300 mJ/cm2,and the frequencies ranged from 100 to 300 Hz.Before and after the treatment,as well as during the follow-up,confocal laser scanning microscopy was used to evaluate the severity and recovery of skin lesions.Results Of the 9 patients,7 were male,and 2 were female.Their average age was 4.19 ± 3.97 years.After the treatment with ultrapulsed fractional CO2 laser,all of the patients were considered to be cured based on the clinical standard.Some adverse reactions such as erythema,edema and erosion occurred in the 9 patients immediately after the treatment,but all completely regressed within 3-7 days.At 3,6 and 12 months after the treatment,no scars or skin discoloration was observed.The average duration of follow-up was 1 year,and the longest duration of follow-up was 2 year and 4 months.No relapse occurred during the follow-up.Conclusion Ultrapulsed fractional CO2 laser is effective and safe for the treatment of porokeratosis in children.

A retrospective analysis of CO2 laser and microdebrider for the treatment of severe juvenile on-set recurrent respiratory papillomatosis / 中华耳鼻咽喉头颈外科杂志

Objective@#Juvenile on-set recurrent respiratory papillomatosis (JORRP) can be an aggressive and potentially life-threatening disease. To emphasize the importance of complication prevention in local excision surgery, the single-center experience of RRP treatment in a group of patients with relatively short recurrence-free-interval (>4 times/yrs) was reported.@*Methods@#Data of 49 patients underwent papilloma resection during 2002-2013 were retrospectively analyzed. Combined techniques of laser microsurgery and microdebriders were used to remove papillomas, prevent the formation of scar tissue and improve respiratory distress. Forty-nine cases were followed up for 99.0[74.5; 121.0]months, ranging from 39 to 185 months. The age of disease onset was 2[1; 3] years old. Most of the patients had difficulty in breathing(42 of 49 cases). Seven patients had hoarseness.53.0% patients had subglottic or trachea papillomatosis spreading. The rate of complications, synechia formation, tracheal stenosis, needing for tracheostomy, mortality was recorded. Patients were followed up for at least three years. The characteristics of the patients, improvement in symptoms, recurrence-free interval, and the rate of tracheal extubation were evaluated. Wilcoxon signed ranks test and chi-square test were used for data comparation.@*Results@#Long-term relieve in disease(≤2 surgeries were needed/year) were achieved in 29(59.1%) subjects, in which 8(16.3%) of the subjects did not need surgical treatment for at least 3 years. Long-term relieve had been achieved in 25 of subjects who did not accept tracheostomy. Seven subjects did not need surgical treatment for at least 3 years. The rate of successful tracheal extubation was 53.8% in 13 patients who had undergone tracheostomy. Three cases dead of intrapulmonary spread.@*Conclusions@#Combined techniques of laser microsurgery and microdebriders are effective in improvement in both respiratory distress and voice quality. The combined technique are helpful to avoid inevitable long-term stenotic complications, ultimately affecting the quality of life.

The research progress of CO2 laser in the treatment of oral lichen planus / 中华口腔医学杂志

Oral lichen planus (OLP) is a common oral mucosal disease. The etiology of OLP is not clear. The treatment of OLP is difficult as some of the OLP patients have little effects to the conventional mucosal treatments. In recent years, laser therapy has been adopted to treat patients with OLP. The CO2 laser therapy has drawn much attention of doctors and scholars because of its advantages in treating the OLP. This review article mainly discusses the principle, effects and some state-of-the-art progresses in OLP treatment using CO2 laser.

Clinical and pathological analyses of 154 patients with white lesion of vocal cord / 中华耳鼻咽喉头颈外科杂志

Objective@#To investigate the clinical and pathological features and prognosis of white lesion of vocal cord.@*Methods@#One hundred and fifty-four cases of white lesion of vocal cord from January 2009 to February 2016 were retrospectively analysed. All the patients had undergone the resection of white lesion of vocal cord resection through retaining laryngoscope under general anesthesia with the specimens pathologically examined.@*Results@#There were 148 males and 6 females in this study. The ages ranged from 36 to 83 years, and the median age was 54.5.There were 103(66.88%) long-term smokers, and 64(41.56%) long-term drinkers. Postoperative pathology showed that chronic mucosal inflammation in 19 cases (12.34%), squamous epithelial hyperplasia in 56 cases(36.36%), mild dysplasia in 25 cases(16.23%), moderate dysplasia in 34 cases(22.08%), severe dysplasia in 12 cases(7.79%), carcinoma in situ in 6 cases(3.90%), and invasive carcinoma in 2 cases(1.30%). The recurrence rate and canceration rate of chronic mucosal inflammation were 0. The recurrence rate of squamous epithelial hyperplasia was 10.71%, the canceration rate was 0.The recurrence rate of mild dysplasia was 8.00%, the canceration rate was 0. The recurrence rate of moderate dysplasia was 20.59%, the canceration rate was 8.82%. The recurrence rate of severe dysplasia was 25.00%, the canceration rate was 16.67%.@*Conclusions@#White lesion of vocal cord is a predominantly male disease. Long-term smokering and drinking are one of common causes. The final diagnosis of white lesion of vocal cord relies on the pathology. Closed observation is necessary for theses dysplasia cases. The majority of which are benign, the operation effect is good.

Treatment of glottic cancer involving the anterior commissure by transoral CO2 laser surgery / 中华耳鼻咽喉头颈外科杂志

Objective@#To study the clinical outcome of transoral CO2 laser surgery for glottic cancer involving the anterior commissure.@*Methods@#Thirty-two cases of glottic cancer involving the anterior commissure treated by transoral CO2 laser surgery between March 2009 and December 2013 were retrospectively reviewed. Among these cases, 27 were T1bM0M0, 5 were T2N0M0. All cases were followed-up for more than 3 years.@*Results@#All the 32 cases were successfully treated. Perioperative complications included injuries in the soft palate mucosa(13/32, 40.63%), loose incisors(3/32, 9.38%) and subcutaneous emphysema in the neck(2/32, 6.25%). During the follow-up period, granulation was found in all cases. Three cases had local recurrence. Two patients treated by a secondary transoral CO2 laser surgery and the other case had total laryngectomy, all three cases were followed up for 5 years without recurrence. Two cases had regional recurrence but no primary site recurrence. One patient was treated by neck dissection, and followed up for 5 years without recurrence. The other patient died of supraclavicular and mediastinal lymph node metastasis and lung metastasis 40 months after operation. The overall 5-year survival rate was 90.6%. There was no significant difference in survival rate between T1bN0M0(92.6%) and T2N0M0(80.0%) (Log Rank χ2=0.788, P=0.375). The overall 5-year local regional control rate was 84.4%. In T1bN0M0 lesions, the 5-year local regional control rate was 92.6%, which was significantly higher than that in T2N0M0 lesions(40.0%) (Log Rank χ2=9.504, P=0.002).@*Conclusion@#With appropriate surgical indication, detailed preoperative evaluation, good surgical skill, transoral CO2 laser surgery may achieve satisfactory outcome in the treatment of glottic cancer involving the anterior commissure.

Treatment of Bartholin gland cyst with CO2laser / Tratamento do cisto da glândula de Bartholin comlaser de CO2

ABSTRACT Objective To describe the results of treatment with CO2 laser for Bartholin gland cysts. Methods Thirty-one women with Bartholin gland cysts were treated with CO2laser at an outpatient´s setting. Skin incision was performed with focused laser beam, the capsule was opened to drain mucoid content, followed by internal vaporization of impaired capsule. Results There were no complications. Five patients had recurrence of the cyst and were submitted to a second and successful session. Conclusion CO2 laser surgery was effective to treat Bartholin gland cysts with minimal or no complications, and can be performed at an outpatient´s setting.

RESUMO Objetivo Descrever os resultados do tratamento com laser de CO2 para o cisto da glândula de Bartholin. Métodos Foram tratadas 31 mulheres com cisto da glândula de Bartholin em regime ambulatorial com o laser de CO2. Foram realizados: incisão da pele com feixe de laser focalizado, abertura da cápsula com drenagem do conteúdo mucoide e vaporização interna da cápsula doente. Resultados Não ocorreram complicações. Cinco pacientes apresentaram recidiva do cisto, sendo submetidas à segunda sessão, com sucesso em todas. Conclusão A cirurgia com laser de CO2 foi efetiva para o tratamento do cisto da glândula de Bartholin, com mínima ou nenhuma complicação, podendo ser realizada em ambiente ambulatorial.

Lower energy and pulse stacking. A safer alternative for skin tightening using fractional CO2 laser

PURPOSE : To evaluate the effect of different energies and stacking in skin shrinkage. METHODS : Three decreasing settings of a fractional CO2 laser were applied to the abdomen of Twenty five Wistar rats divided into three groups. Group I (n=5) was histologically evaluated for microthermal zones dimensions. Groups II and III (n=10 each) were macroscopic evaluated with freeware ImageJ for area contraction immediately and after 30 and 60 days. RESULTS : No statistical significance was found within microthermal zone histological dimensions (Group I) in all settings studied. (Ablation depth: 76.90 to 97.18µm; Coagulation depth: 186.01 to 219.84 µm). In Group II, macroscopic evaluation showed that all settings cause significant immediate skin contraction. The highest setting cause significant more intense tightening effect initially, contracting skin area from 258.65 to 179.09 mm2. The same pattern was observed in Group III. At 30 and 60 days, the lowest setting significantly sustained contraction. CONCLUSION : Lower fractional CO2 laser energies associated to pulse stacking could cause consistent and long lasting tissue contraction in rats.

Action of AlGaInP laser and high frequency generator in cutaneous wound healing. A comparative study

ABSTRACT PURPOSE: To evaluate in a macroscopic, histological and histomorphometric manner the healing process of cutaneous wounds in mice. METHODS: The sample consisted of 40 male mice and was divided in four groups: 1st group (control, n=10), 2nd group (High Frequency Generator - HF, the maximum amplitude range, 120s, n=10), 3rd group (AlGaInP Laser 660 nm, 30mW power, 5 J/cm2, applying scan mode, 120s, n=10) and 4thgroup (AlGaInP Laser 660 nm, 30 mW power, 8 J/cm2, applying scan mode, n=10). The surgical incision was made with an 8 mm diameter punch perpendicularly to the back of the animal. The statistical analysis was achieved by the statistical test One Way Anova post hoc Tukey Test and significance at p<0.05 in GraphPad Prism program. RESULTS: It was observed that in the acute phase the AlGaInP Laser at 5 J/cm2 provided a greater stimulus to healing, and both lasers were effective in the remodeling phase. CONCLUSION: The AlGaInP lasers from 5 J/cm2 to 8 J/cm2 showed better biomodulatory results in the acute and remodeling phases respectively, however, the HF was less effective than the laser, providing significant benefits only in the acute phase of tissue repair.

Evaluation of efficacy and safety of a focal fractional laser for the treatment of atrophic acne scars / 中华皮肤科杂志

Objective To evaluate the efficacy and safety of focal fractional laser treatment(FFLT)for atrophic acne scars. Methods A randomized, self-controlled study was performed. A total of 20 patients with atrophic facial acne scars were enrolled into this study. Treatments were randomly administered in a split-face manner. Half of each subject′s face received FFLT(FFLT side), and the other half underwent full-face fractional CO2 laser resurfacing(control side), for one session. All the patients were followed up for 3 months after the treatment. Evaluation was based on the ECCA grading scale (échelle d′évaluation clinique des cicatrices d′acné)and patient satisfaction score. A VISIA skin detector was used to take photographs and evaluate skin texture. Moreover, physical parameters of the skin, including erythema index, melanin index and transepidermal water loss (TEWL), were measured. Adverse effects were recorded and evaluated. Statistical analysis was carried out by paired t test, Wilcoxon paired rank test, Fisher′s exact test and repeated-measure analysis of variance. Results The ECCA score decreased from 51.24 ± 17.61 at the baseline to 34.46 ± 14.99 at 3 months after the treatment at the FFLT side(t = 7.886, P 0.05). Compared with those before the treatment, skin texture scores decreased in both sides (both P 0.05)from 2 weeks to 3 months after the treatment(all P > 0.05). Conclusion FFLT can improve therapeutic outcomes in atrophic acne scars with reduced adverse reactions.

Fractional CO2 laser combined with a collagen dressing for the treatment of atrophic facial acne scars: a clinical observational study / 中华皮肤科杂志

Objective To evaluate the efficacy and safety of a collagen dressing for healing of wounds induced by fractional CO2 laser in patients with atrophic facial acne scars.Methods Seventy patients with atrophic facial acne scars were recruited to this study,and randomly divided into a treatment group and a control group.Both the two groups were treated by two sessions of fractional CO2 laser with an interval of one month.After each session of laser therapy,the treatment group were topically treated with a collagen dressing for 20 minutes once a day for 10 consecutive days,while the control group did not apply any collagen dressing.All the patients were followed for 6 months.Efficacy was evaluated by the degree of acute inflammatory reaction,time needed for crust shedding and patient comfort level.The length of downtime as well as incidence of post-inflammatory hyperpigmentation and other adverse reactions were also assessed.Results Compared with the control group,the treatment group showed a decrease in the score for acute inflammatory response (W =312,P ＜ 0.01),time needed for crust shedding (t =2.08,P ＜ 0.05),incidence rate of post-inflammatory hyperpigmentation (x2 =6.06,P ＜ 0.05),length of downtime (t =3.14,P ＜ 0.05),but an increase in self-reported comfort level (W =172,P ＜ 0.01).No new scar formed in any of these patients.Conclusion The collagen dressing is effective in reducing incidence of adverse reactions and improving satisfaction degree of patients with atrophic facial acne scars after fractional CO2 laser therapy.

Clinical curative effect observation of ultra pulse CO2 laser combined with collagen dressing in treatment of primary cutaneous amyloidosis / 中国医师杂志

Objective To investigate the clinical efficacy and safety of ultra pulse CO2 laser combined with collagen dressing in treatment of cutaneous amyloidosis.Methods A total of 68 cases of primary cutaneous amyloidosis patients according to the different treatment methods was divided into two groups:the control group (n =33 cases) that was given acitretin capsules oral and topical compound flumetasone ointment packet treatment,and observation group (n =35 cases) with ultra pulse CO2 laser combined with collagen dressing external treatment.Two groups were observed in patients with curative effect and adverse reaction.Results Disease of integral observation group after treatment was significantly lower than the control group(t =3.12,P ＜0.05).The observation group had the efficiency of [88.6％ (31/35)] that was significantly higher than that of control group[17/33(51.5％),x2 =11.23,P ＜.0.01].The observation group had significantly shorter healing time [(5.38 ± 1.81) d] compared to the control group [(10.75 ±2.06)d,t =11.39,P ＜ 0.01].The observation group did not have recurrence,which was significantly different from the control group (x2 =4.90,P ＜ 0.05).Conclusions Ultra pulse CO2 laser combined with collagen dressing in treatment of primary cutaneous amyloidosis is a kind of effective treatment methods with remarkable curative effect and less adverse reactions.It is worthy of clinical application.