Lasers in Medicine
Year:2008 | Volume:5 | Issue:1 (27)|Papers Count:6

Background and Objectives: Thermal simulation of laser-tissue interactions is useful for determining optimal treatment parameters during the treatment process. Since LITCIT has been used as a useful tool in different studies for treatment planning of thermotherapy of liver tumors, we taught to its use as a treatment planning tool in laser hair removal. In this study we evaluated this software for thermal simulation software for laser hair removal systems.Material and methods: Two articles were used as our references. Complete information about tissue such as optical-thermal properties and geometrical modeling and also laser system such as wavelength, spot size, pulse duration and fluence was extracted form these texts. Then, these conditions about tissue and system were entered in LITCIT simulation software. After that, we run the program and saved the results. Finally, we compare our results with the results in references and evaluated the.Results: Output results of the LITCIT showed that they were consistent with the results of references that were calculated with different thermal modeling. No significant difference was seen between LITCIT results and other mathematical methods. Such a less average error shows the accuracy of the software for simulation and calculating the temperature.Conclusions: This simulating software has a high ability for using as a treatment planning software of laser-tissue interaction of laser hair removal process. Thus, it can be used for optimization of treatment parameters and protocols before setting up a real treatment on patients.

Background and Objective: Low Level Laser Therapy (LLLT) appears to be an increasingly popular therapeutic option amongst physicians. General practitioners (GPs) have shown considerable interest about using LLLT in their employment. Our information about the use of LLLT by GPs and their educational requirements within mainstream medicine was not clear. This study aimed to determine the knowledge, attitude and practice towards, LLLT among GPs.Material and Methods: A questionnaire survey was performed in 384 GPs working in their office that randomly assigned among participants of continuous medical education (CME) courses in Tehran.Results: The mean age of participants was 37±7.2 years. 54.2% of them were male, 49.2% were graduated after 1996, 45.1% were educated in Tehran universities, 73.2% had practiced in Tehran and 36.6% had work experience less than five years. Our results showed that only 32.3% of participants' responses about applications of LLLT were correct. In spite of low information, overall attitude of them was not negative. As in many cases, they emphasized to need a special educational course in CME, use of insurance services for these instruments, emission of formal justification and need to supervision of health ministry also.Conclusion: Although, a minor number of participants used LLLT in practice, their high interest and lack of qualified educational programs should be noticed more. Therefore, it seems that we need to design appropriate scientific programs by competent individuals.

Today, Light cured dental composites have wide spread applications, due to their physical and mechanical properties, easy applicability and lack of side effects for patient and dentistry. In this project, the effect of different powers and irradiation time of laser and also percentage of different filler on physical and mechanical properties of dental composites were evaluated. The resin of this composites was made of Bis-GMA and TEGDMA mixture with a mass ratio of 65:35. The filler was SiO2 nano particles with primary particles size of 10nm added to first composite with 20% of weight and to second composite with 25%. Also 0.05% of comphoroqunone and di methyl amin ethyl metacrylate were added as photoinitiator. The composites were thencured by argon laser at 472 nm with 260 mW/cm2 and 340 mW/cm2 at different irradition times. The FTIR results showed that amount of degree of conversion of cured composites at 340 mW/cm2 was more than amount of degree of conversion of cured composites at 260 mW/cm2. The results of the flexural strength and flexural modulus tests of cured composites showed that the composites with 25% filler have higher value than the composites with 20% filler. The composite with 20% filler that was cured at 260 mW/cm2 showed the highest amount of water sorption and solubility and the composite with 20% filler that was cured at 340 mW/cm2 showed the highest amount of reaction temperature. The overall results show that the composite with 25% filler cured at 340 mW/cm2 has better physical and mechanical properties.

Eِِarly stage diagnosis of breast cancer reduces morbidity and mortality in women. The staging of breast cancer is based on tumor depth, size and invasion to adjacent tissue. In order to evaluate the effect of depth on signal intensity, small lesion embedded at a specified depth of a breast tissue was modeled using Agar sample containing 0.1 micrometer fluorescent microspheres. The microspheres were imaged under 532 nm excitation wavelength by a wide field epi-fluorescent optical set-up. The optical set-up consists of Nd-YAG double harmonic laser, dielectric filter, cut-off filter and cooled CCD camera. A full characterization of microspheres’ images was performed to obtain the variation of fluorescent intensity versus depth. Our results showed that from depth of 1mm up to depth of 4mm, the normalized fluorescent peak intensity was varied Between 4.2 to 3.1. Using these experiments, it was shown that the epi fluorescent wide field microscopy can be used as a straightforward diagnostic method which can determine precisely the depth of embedded tumor in tissue.

Background and Objective: This double blinded RCT was designed to investigate the impact of GaAlAs low level laser (685, 830 nm) on Gingival Index, Plaque Index, Pocket Depth, Attachment Loss, Pain severity and Healing index of periodontal flap surgery.Material and Methods: Six patients (5 female, 1 male) were enrolled in the study due to inclusion/ exclusion criteria. In each patient periodontal surgery was performed on both side of one jaw, one of them randomly allocated in laser group while the other served as placebo. Laser group received laser irradiation (685 nm, 1 J/cm2 followed by 830nm, 5 J/cm2) before and on 7,14 and 21 postoperative days .In placebo group laser irradiation was performed while the laser system was off. To keep patients blind, they were instructed to wear safety goggles. All other conventional treatments were the same in both groups. Gingival Index, Plaque Index, Pocket Depth, Attachment Loss, Pain severity and Healing index were assessed by an independent dentist before and on 7, 14, 21 and 28 days after surgery.Results: There was no significant difference between indexes of laser and placebo groups at the beginning of the study. Gingival index was lower in laser group at the 7th and 14th day after surgery and it was significant (p<0.05). Healing index was higher in laser group at the 7th, 14th and 21st day after surgery and it was significant (p<0.05).There was no significant difference between Plaque Index, Pocket Depth, Attachment Loss and Pain severity of laser and placebo groups during the study assessments.At the end of the study (28th day) there was no significant difference between laser and placebo groups in any of the indexes.Conclusions: LLLT seems to have some early beneficial effects on healing of periodontal surgery wounds via improvement of Gingival and Healing Index.