Background: Corticotomy-assisted orthodontic treatment is done to induce a state of increased tissue turnover and transient osteopenia, which is followed by a faster rate of orthodontic tooth movement. It considered as an adjunct treatment option for orthodontic treatment of adults. The aim of this Study was to elucidate the effectiveness of a new surgical approach for acceleration of maxillary canine retraction in human with laser assisted flapless corticotomy and evaluate its effect on vitality of pulp and gingival sulcus depth. Materials and methods: the sample comprised of 15 Iraqi patients (9 females and 6 males; mean age 21.7), who were required extraction for their maxillary first premolars followed by retraction of the canines as part of their orthodontic treatment plan. The study was designed as a split-mouth study. Decortications were done in the second stage of orthodontic treatment using Er:YAG laser to perform series of holes mesially and distally to the canine at the side with more space between the canine and second premolar without reflecting a surgical flap. The net canine movements and molar anchorage loss were calculated after six weeks. Vitality test, radiographical assessment and gingival sulcus depth were investigated. Results and Conclusions: The canines on the laser corticotomy side showed statisticaly higher mean value of retraction than their controls during six weeks period. Pulp vitality response and post surgery gingival sulcus depth showed no significant difference between the pre-laser and post-laser surgery. Based on the result of our study, flapless laser assisted corticotomy can be considered for acceleration of orthodontic tooth movement in humans.
Due to the dramatic environmental impact of sulfur emissions associated with the exhaust of diesel engines, last environmental regulations for ultra-low-sulfur diesel require a very deep desulfurization (up to 15 ppm), which cannot be met by the conventional hydrodesulfurization units alone. The proposed method involves a batch ultrasound-assisted oxidative desulfurization (UAODS) of a previously hydrotreated diesel (containing 480 ppm sulfur) so as to convert the residual sulfur-bearing compounds into their corresponding highly polar oxides, which can be eliminated easily by extraction with a certain highly polar solvent. The oxidizing system utilized was H2O2 as an oxidant, CH3COOH as a
... Show MoreThis paper aims to develop a technique for helping disabled people elderly with physical disability, such as those who are unable to move hands and cannot speak howover, by using a computer vision; real time video and interaction between human and computer where these combinations provide a promising solution to assist the disabled people. The main objective of the work is to design a project as a wheelchair which contains two wheel drives. This project is based on real time video for detecting and tracking human face. The proposed design is multi speed based on pulse width modulation(PWM), technique. This project is a fast response to detect and track face direction with four operations movement (left, right, forward and stop). These opera
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The research investigates the term innovation and its role in elaborating architectural practice based on diffusion. The complexity of the architectural field compared with other fields shows a problem in explaining how innovations in architecture diffuse as a thought and act in a certain context of practice. Therefore, the research aims to build an intellectual model that explains the way personal thoughts resembled by unique models introduced by creative and innovator designers diffuse in a certain pattern elaborate these models into a state of prevailing thought resembled by the movement in architecture. The research will apply its model to the more comprehensive movement in architecture, which is the modern movement,
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The research, which was drawn from his doctoral thesis (People's Policy towards Vietnam 1949-1979), discussed the roots of the connections between the Chinese and Vietnamese communists since the 1920s, the presence of Ho Chi Minh and other Vietnamese communists in China, their influence by the revolutionary struggle of the Chinese Communist Party and their establishment of a group of The Vietnamese Revolutionary Societies and the Indo-Chinese Communist Party until the outbreak of the Vietnamese Revolution and their success in declaring the establishment of the Democratic Republic of Vietnam in 1946. Keywords: Ho Chi Minh, Chinese Communist Party, Indo-Chinese Communist Party, Democratic Republic of Vietnam, Chou En Lai.
Background: The long term survival of dental implants is evaluated by the amount of crestal bone loss around the implants. Some initial loss of bone around dental implants is generally expected. There is reason to believe that reflecting a mucoperiosteal flap promotes crestal bone loss in the initial phase after an implant has been inserted. The surgical placement of a dental implant fixture is constantly changing and in recent years, there has been some interest in developing techniques that minimize the invasive nature of the procedure, with flapless implant surgery being advocated. The purpose of this study was to compare the radiographic level of the peri- implant bone after implant placement between traditional flapped surgery and f
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Nanoparticle has pulled in expanding consideration with the developing enthusiasm for nanotechnology which hold potential as essential segments for development applications. In the present work, a copper nanoparticle is manufactured as a suspension in distilled water by beating a bulk copper target with laser source (532 nm wavelength, 10 ns pulse duration and 10 Hz repletion rate) via method. UV- visible absorption spectra and AFM analysis has been done to observe the effect of repetition rate for the pulsation of laser. Copper nanoparticles (Cu-NPs) were successfully synthesized with green color. The Cu- NPs have very high purity because the preparation was managed in aqueous media to eliminate ambient contaminations. Absorption
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An analytical method and a two-dimensional finite element model for treating the problem of laser heating and melting has been applied to aluminum 2519T87and stainless steel 304. The time needed to melt and vaporize and the effects of laser power density on the melt depth for two metals are also obtained. In addition, the depth profile and time evolution of the temperature before melting and after melting are given, in which a discontinuity in the temperature gradient is obviously observed due to the latent heat of fusion and the increment in thermal conductivity in solid phase. The analytical results that induced by laser irradiation is in good agreement with numerical results.
Background: Impacted teeth are frequent problem and one of the most affected teeth is the maxillary canine. The early diagnosis of impacted canines by radiographic evaluation is imperative. The aim of this study was to determine the prevalence of impacted maxillary canines in patients attending the Oral diagnosis and Radiology clinic in College of Dentistry, University of Al-Basrah. Materials and Methods: 1280 patients attending the Oral Diagnosis and Radiology clinic in College of Dentistry University of Al-Basrah, between October 2013 and March 2015 were examined for the study. The age of the patients ranged from 15 to 55 years, with a mean age of 22.2 years. Results: The prevalence for maxillary impacted canines in all the cases was fo
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The main purpose of this work is the construction of an optical parametric amplifier (OPA) to generate a 629 nm pulsed laser. KTP nonlinear crystals were used for both parametric oscillation and amplification. A singly resonant parametric oscillator (OPO) is constructed to generate a signal of 1.54 μm and idler of 3.4 μm when the OPO system is pumped by 1.064 μm Q – switched Nd: YAG laser. The signal was then mixed with the pumping beam in OPA system to form the wanted wavelength. The obtained optical conversion efficiency was 60%.
An assembled pulsed Nd:YAG laser-robot system for spot welding similar and dissimilar metals is presented in this paper. The study evaluates the performance of this system through investigating the possibility and accuracy of executing laser spot welding of 0.2 mm in thickness stainless steel grade AISI302 to 0.5 mm in thickness low carbon steel grade AISI1008. The influence of laser beam parameters (peak power, pulse energy, pulse duration, repetition rate, and focal plane position on the final gained best results are evaluated. Enhancement of the experimental results was carried by a computational simulation using ANSYS FLUENT 6.3 package code.