Non-thermal CO2 Laser Therapy (NTCLT): A Novel Photobiomodulative Approach for Immediate Pain Relief of Patchy Oral Mucositis Due to Chemotherapy of Solid Tumors.

Introduction: Chemotherapy-induced oral mucositis (COM) is a prominent complication of chemotherapy (CT). Non-thermal CO2 laser therapy (NTCLT) has been demonstrated as an innovative and safe photobiomodulative approach in some kinds of painful oral lesions. The purpose of this study was to evaluate the palliative effects of one session of NTCLT on COM lesions. Methods: Patients with painful COM (WHO grade:≥2) were included in this before-after clinical trial based on the eligibility criteria. The oral lesions were irradiated with a CO2 laser (power: 1 W, scanning the lesions with the rapid circular motion of the defocused handpiece) through a thick layer (3-4 mm) of a transparent gel containing a high-water content. The severity of pain in the lesions was self-assessed using a 0-to-10 visual analogue scale (VAS) for 7 consecutive days. The evaluating physician visited the patients on the 3rd and 7th days in search of any kind of complications. Results: Seventeen adult patients with 35 patches of OM due to chemotherapy of solid tumors completed the trial. Immediately after NTCLT, the mean for non-contact VAS pain scores of the lesions significantly declined from 4.91±2.356 to 0.29±0.622 (P<0.001) and the mean for contact VAS pain scores from 7.77±1.57 to 1.31±1.18 (P<0.001). The mean VAS pain scores of the lesions showed statistically significant differences between the follow-up periods compared to the baseline (P<0.001). The process was completely pain-free and required no anesthesia. After NTCLT, no kind of thermal adverse effects such as irritation, destruction, aggravation and even erythema were observed. Conclusion: Based on the results of this before-after clinical trial, NTCLT has the potential to be considered as a non-invasive and safe palliative option for the pain management of patchy OM due to chemotherapy of solid tumors.

Clinical Effect of Non-Thermal CO2 Laser Therapy (NTCLT) on Pain Relief of Oral Aphthous Ulcers of Behçet's Disease.

Introduction: Behçet's disease (BD) is a debilitating and chronic vasculitis which can affect multiple organs. Recurrent oral aphthosis is the most common clinical feature of BD. The remarkable pain associated with painful oral ulcers can exert a major impact on the patients' quality of life. Relieving pain of these oral ulcers is an essential approach in the management of mucocutaneous lesions of BD. Non-thermal CO2 laser therapy (NTCLT) as a novel photobiomodulative approach has recently been used for significant and immediate pain reduction of some types of painful oral lesions such as recurrent aphthous stomatitis, pemphigus vulgaris, and so on. In this procedure by some considerations, the conventional CO2 laser is used as a non-surgical, non- thermal, photobiomodulative laser without any visible thermal adverse effects. In this article, we report our experiences about the analgesic effects of NTCLT on painful oral aphthous ulcers of BD. Case Presentation: We report four cases of BD, whose painful oral aphthous ulcers were irradiated with NTCLT. Immediately after NTCLT, the pain of the lesions was significantly relieved with no visible complications. Conclusion: The results of this study suggest that NTCLT could be proposed as a hopeful procedure for significant and instant pain relief of oral aphthous ulcers of BD without any visible thermal adverse effects.

The Immediate Pain-Relieving Effects of Non-Thermal CO2 Laser Therapy on Genital Ulcers of Behcet's Disease: A Case Report.

Behçet's disease (BD) is a chronic, relapsing, systemic vasculitis of unknown etiology. Oral and genital aphthous ulcers are considered as the hallmarks of BD. The genital ulcers of BD may be extremely painful and often refractory to multiple treatments. In addition, they exert a negative impact on the patient's quality of life. Some investigations have demonstrated the significant and immediate pain-relieving effects of NTCLT (non-thermal CO2 laser therapy) on some oral lesions with no visible adverse effects. In this paper, we report a case of BD whose painful genital ulcers were irradiated with NTCLT and the patient's pain caused by the ulcers relieved immediately and significantly with no visible complications.

Quantitative Analysis of Skin Erythema Due to Laser Hair Removal: A Diffusion Optical Spectroscopy Analysis.

Introduction: Laser hair removal needs an accurate understanding of tissue structure and chromophores content in order to optimize the selection of laser irradiation parameters. None of the optimized laser therapy might lead to side effects in skin tissue such as severe erythema, burn, scar etc. Therefore, guidance by a noninvasive real-time diagnostic method like optical spectroscopy technique is beneficial. The purpose of this survey is to analysis the skin hemoglobin spectrum quantitatively before and after hair removal laser irradiation to minimize the side effects of the procedure. Methods: To carry out a spectroscopy study, a halogen-tungsten light source was used in the wavelength region of 400-700 nm on an ocean optic device. The measurements were made on the facial area under identical conditions. Total 19 volunteers for laser hair removal by gentle laser Candela, ranging 14- 49 years old, were included in the study. A total of 18 spectra were taken from each person, 9 spectra before hair removal as a reference and 9 subsequent spectra. Colorimetry was done for all acquired before and after spectrums using Origin software (version 8.6). Then, the erythema index derived for each spectrum. Statistical analysis of correlation and normalization in colorimetry data were done using data analysis by SPSS (version 16). Results: Spectra analysis, before and after optical reflectance spectrums in laser hair removal procedure, revealed the subpeak derivation, and concentration on special visible wavelength 510- 610 nm. We studied the changes of skin chromophores absorption. The derived erythema index [E] and colorimetry parameters a*, b*, l* were compared and correlated statistically. There was a statistically considerable direct linear correlation between a* and E while inverse linear correlation was observed for l* and E and no correlation for b* and E. Conclusion: Diffuse reflectance spectroscopy showed its potency as an accurate, noninvasive realtime as complementary method for laser treatment to detect erythema as a complication of the method, in order to optimize the parameters based on the tissue characteristics in various candidates.

Relieving Pain in Oral Lesions of Pemphigus Vulgaris Using the Non-ablative, Non-thermal, CO2 Laser Therapy (NTCLT): Preliminary Results of a Novel Approach.

Introduction: Pemphigus vulgaris (PV) is a chronic, serious autoimmune mucocutaneous bullous disease. Oral lesions in PV may be extremely painful. This pain may adversely affect the patients' oral intake and quality of life. This before-after clinical trial was designed to assess the pain relieving effects of single session of non-ablative, non-thermal CO2 laser therapy (NTCLT) in oral lesions of PV. Methods: Fifty painful oral lesions of fourteen patients with PV were illuminated by CO2 laser (power: 1 W, scanning the lesions with rapid circular motion of the handpiece) passing through a thick layer of transparent gel with high water content. The pain severity of the oral lesions was reported by the patients up to the fourth postoperative day. They were also asked to continue their existing systemic treatment during the course of this study as a precondition for the participation. Results: The severity of contact and non-stimulate (non-contact) pain declined immediately and significantly after NTCLT (P < 0.001). The pain relieving effect was sustained during the four successive days of follow-up. The procedure was pain free and no kind of analgesics was required. Following NTCLT, there were no visible thermal complications such as destruction, ablation or irritation of the oral lesions. Conclusion: The results of the trial proposed that single session of NTCLT could immediately and significantly relieve pain in oral lesions of PV, without any visible thermal complications.

Effects of low-level laser irradiation on the pathogenicity of Candida albicans: in vitro and in vivo study.

OBJECTIVE: The purpose of this study was to evaluate the effects of low-level laser irradiation (LLLI) on the in vitro growth characteristics and in vivo pathogenicity of Candida albicans in a murine model in the absence of a photosensitizer. BACKGROUND DATA: C. albicans is an opportunistic commensal organism that causes a wide variety of diseases in human beings, ranging from superficial infections to life-threatening invasive candidiasis. The incidence of C. albicans infection is increasing, because of the greater frequency of acquired immunodeficiency conditions. A high recurrence rate has been reported for vulvovaginal and oral candidiasis, despite the best available treatments. Therefore, the search for new treatment modalities seems quite rational. METHODS: Candida culture plates were exposed to common clinical energies of LLLI: 3, 5, 10, and 20 J at 685 nm (BTL Laser 5000, Medicinos Projektai, Czech Republic, Prague, max power output 50 mW) and 3, 5, 10, 30, and 50 J at 830 nm (BTL Laser 5000, Medicinos Projektai, Czech Republic, Prague, max power output 400 mW). RESULTS: Following LLLI with energies >10 J at both 685 and 830 nm wavelengths, statistically significant effects were observed in vitro on the turbidimetric growth kinetics of C. albicans and in vivo on the survival rate of infected mice (p value ≤ 0.05). Therefore, this energy could be considered a threshold for clinical investigation. CONCLUSIONS: Translating our data into the clinical setting, it can be proposed that a direct laser-based approach without using a photosensitizing dye can significantly reduce the pathogenicity of Candida albicans. It can also be concluded that laser light at specific wavelengths could be a possible promising novel treatment for superficial and mucocutaneous C. albicans infections.

Promoting wound healing in minor recurrent aphthous stomatitis by non-thermal, non-ablative CO(2) laser therapy: a pilot study.

BACKGROUND AND OBJECTIVE: This randomized controlled clinical trial (RCT) was designed to evaluate the effects of non-thermal, non-ablative CO(2) laser therapy (NACLT) to promote wound healing in minor recurrent aphthous stomatitis (miRAS). STUDY DESIGN/MATERIALS AND METHODS: Ten patients with 20 minor aphthous ulcers completed this study. Each patient had two discrete aphthous ulcers that had developed within 72 h before enrollment. One of the ulcers was randomly allocated to be treated with NACLT and the other one served as placebo. Before laser irradiation, a layer of transparent, non-anesthetic oral gel with high water content was placed on the laser and placebo lesions both. The CO(2) laser device was operated using 1 W power in defocused continuous mode, scanning rapidly over the lesion. The placebo lesion was irradiated with the same laser, but with an inactive probe. The healing times of the lesions were recorded by a blinded physician. RESULTS: The healing period was significantly shorter in ulcers treated by NACLT than in those treated with placebo (p=0.02). The process was not painful and anesthesia was not required. There were no visible side effects after NACLT and during follow-up periods. CONCLUSIONS: The results of this RCT suggest that single session of NACLT could be used to promote wound healing in minor aphthous ulcers, with no visible side effects.

Thermal damage patterns of diode hair-removal lasers according to various skin types and hair densities and colors: a simulation study.

BACKGROUND AND OBJECTIVE: It is important to prevent unwanted side effects of diode hair-removal lasers especially in dark skin tones. This study simulates the thermal damage patterns caused by diode hair-removal lasers in different skin types, hair colors, and hair densities. MATERIALS AND METHODS: LITCIT software has been used with the tissue modeled as two components, the skin and the hair. The absorption coefficients of various skin types (f(mel)=5%, 10%, 15%, and 20%), laser parameters, and optothermal properties of tissue were inputs. RESULTS: For all skin types there was a significant unwanted thermal damage to the epidermis as a result of fluence increase. Using longer pulse durations is accompanied by effective thermal damage to the hair follicle, while preserving the epidermis in skin types II and III, an effect not achieved in darker skins. Regardless of pulse duration, when the distance between hair follicles is ≤ 0.5 mm, there is a significant increase in thermal damage to interfollicular epidermis with high fluences compared with lower hair densities (interfollicular space ≥ 1 mm). In lighter hairs, while using longer pulse durations, higher fluences are needed in order to obtain the same level of thermal damage in the hair follicle as shorter pulse widths. CONCLUSIONS: In lighter skin types, lengthening the pulse duration of diode lasers (up to 400 ms) increases efficacy while preserving epidermis from unwanted thermal damage. However, it is necessary to use lower fluences while using longer pulse duration to avoid irreversible thermal damage to epidermis in darker tones, as is also true for locations with higher hair densities.

Simulation of heat distribution and thermal damage patterns of diode hair-removal lasers: an applicable method for optimizing treatment parameters.

OBJECTIVE: We simulated the heat distribution and thermal damage patterns of diode hair-removal lasers for different spot sizes, pulse durations, and fluences as a guide for optimization. BACKGROUND: Recently, the concept of thermal damage time as a reference for pulse duration has become a subject of debate. METHODS: Laser-Induced-Temperature-Calculation-In-Tissue (LITCIT) was used for the simulations. Skin was modeled as two homogenous layers of epidermis/dermis and two coaxial cylinders as the hair shaft/ follicle. Opto-thermal coefficients of the components and the radiant parameters of the laser (diode, 810 nm) were defined. RESULTS: At constant fluences and pulse durations, the damage occurred deeper when larger spot sizes were used. At constant pulse duration, high fluences caused significant damage to the hair follicle and epidermis. By using longer pulse durations (≤ 400 ms) at constant fluences, there was more effective damage to the hair follicle while sparing the adjacent epidermis and dermis. Because of the time-dependent temperature profiles, an increased pulse duration creates a moderate, gradual rise in the target's temperature. Pulse durations > 400 ms are accompanied by unwanted dermis damage. CONCLUSIONS: Our results show that using very long pulse durations near the tissue damage time (≤ 400 ms) creates better efficacy in treating unwanted hairs while avoiding unwanted damage.

A randomized clinical trial on the effect of low-level laser therapy on chronic diabetic foot wound healing: a preliminary report.

BACKGROUND AND OBJECTIVES: Low-level laser therapy (LLLT) has been shown to promote chronic wound healing in conditions of reduced microcirculation. In this preliminary study, we report the results of using LLLT to heal foot ulcers in patients with diabetes mellitus. MATERIALS AND METHODS: Twenty-three patients with a diabetic foot wound for at least 3 months were included in this double-blind randomized clinical trial. Patients were randomized to receive placebo treatment (n = 10) or LLLT (n = 13) (685 nm, energy density 10 J/cm(2)) in addition to conventional therapy. Patients were followed for 20 weeks. Ulcer size reduction and the number of patients with complete healing were compared between the LLLT and placebo groups. RESULTS: There were no significant differences in baseline characteristics of patients and foot ulcers receiving LLLT and placebo treatment. At week 4, the size of ulcers decreased significantly in the LLLT group (p = 0.04). After 20 weeks, in the LLLT group, eight patients had complete healing and in the placebo group only three patients experienced complete wound healing. The mean time of complete healing in LLLT patients (11 weeks) was less than that in placebo patients (14 weeks) though the difference was not statistically significant. CONCLUSIONS: The study provides evidence that LLLT can accelerate the healing process of chronic diabetic foot ulcers, and it can be presumed that LLLT may shorten the time period needed to achieve complete healing.

Relieving pain in minor aphthous stomatitis by a single session of non-thermal carbon dioxide laser irradiation.

This randomized controlled clinical trial was designed to evaluate the efficacy of single-session, non-thermal, carbon dioxide (CO(2)) laser irradiation in relieving the pain of minor recurrent aphthous stomatitis (miRAS) as a prototype of painful oral ulcers. Fifteen patients, each with two discrete aphthous ulcers, were included. One of the ulcers was randomly allocated to be treated with CO(2) laser (1 W of power in de-focused continuous mode) and the other one served as a placebo. Before laser irradiation, a layer of transparent, non-anesthetic gel was placed on both the laser lesions and the placebo lesions. The patients were requested to grade their pain on a visual analog scale up to 96 h post-operatively. The reduction in pain scores was significantly greater in the laser group than in the placebo group. The procedure itself was not painful, so anesthesia was not required. Powermetry revealed the CO(2) laser power to be 2-5 mW after passing through the gel, which caused no significant temperature rise or any visual effect of damage to the oral mucosa. Our results showed that a low-intensity, non-thermal, single-session of CO(2) laser irradiation reduced pain in miRAS immediately and dramatically, with no visible side effects.

Photodynamic therapy of head and neck basal cell carcinoma according to different clinicopathologic features.

BACKGROUND AND OBJECTIVES: We aimed to treat different pathologic types of basal cell carcinomas (BCCs) using photodynamic therapy (PDT). STUDY DESIGN/MATERIALS AND METHODS: Thirty lesions in six patients underwent PDT. The photosensitizer used was Photoheme, a hematoporphyrin derivative IX. It was injected intravenously at the dose of 2-3.25 mg/kg. After 24 hours, the lesions were illuminated by laser light (lambda = 632 nm, light exposure dose = 100-200 J/cm2). Lesions were evaluated pre and post-operatively and at follow-up sessions (of up to 6 months). RESULTS: After a single session of PDT, the average response rate in different histopathologic kinds of basal cell carcinoma (e.g., ulcerative, superficial, nodular, and pigmented forms) were 100%, 62%, 90%, and 14%, respectively. In patients who responded completely, the cosmetic results were excellent and there were no recurrence at 6th month of follow-up. CONCLUSION: Although PDT seems to be an effective treatment modality for superficial, ulcerative, and nodular BCCs, it is not recommended for pigmented lesions.