Background and aims: Diverse gauges have been used to measure and determine Bracket height for correct Bracket positioning. The aim of the present study was to determine and compare Bracket positioning accuracy by using height Bracket positioning gauge (HBPG) and Boone gauge (BG).Materials and methods: Nineteen sets of stone models were prepared from one patient. One set was employed to determine the ideal position of Brackets, and the remaining nine pairs of sets for Bracket placement by nine clinicians using HBPG and BG. Teeth were then sectioned from the stone models and placed inside acrylic molds, photographs were taken and imported to a computer. In two groups, the position of each bonded Bracket was compared in three aspects of vertical, mesiodistal and angular with the ideal position of every Bracket. Finally, Bracket positioning errors were measured.Results: Mann-Whitney U test demonstrated significant differences in the means of vertical error between the HBPG group and BG groups (P<0.001), while there were no significant differences between mesiodistal and angular errors. Factorial ANOVA revealed that gauge and tooth type, and the position of tooth on the right and left side of the mouth play a ma-jor role in the rate of vertical error.Conclusion: Vertical accuracy of Bracket positioning by the use of HBPG is more than that by BG. However, there is no difference between two gauges in relation to the mesiodistal and angular errors.

We define a new function-valued inner product on L2(G), called j-Bracket product, where G is a locally compact abelian group and j is a topological isomorphism on G. We investigate the notion of j -orthogonality, Bessel's Inequality and j -orthonormal bases with respect to this inner product on L2(G).

Different techniques have been introduced for the removal of ceramic Brackets. Since the early 1990s, lasers have been used experimentally for debonding ceramic Brackets. The goal of this study is to give a comprehensive literature review on laser-aided ceramic Bracket debonding. PubMed and Google Scholar databases were used to identify dental articles with the following combination of key word: Ceramic Brackets, Debonding, and Laser. Sixteen English articles from 2004 to 2015 were selected. The selected studies were categorized according to the variables investigated including the intrapulpal temperature, shear bond strength, debonding time, enamel damage and Bracket failure. Most articles reported decreased shear bond strength and debonding time following laser irradiation without any critical and irritating increase in pulpal temperature. There were no reports of Bracket failure or enamel damage. Laser irradiation is an efficient way to reduce shear bond strength of ceramic Bracket and debonding time. This technique is a safe way for removing ceramic Bracket with minimal impact on intrapulpal temperature and enamel surface and it reduces ceramic Bracket failure.

Construction of welded moment resisting connection is common. These connections have high potential for brittle failure of welds if quality of welding is not controlled. In this research new bolted Bracket connection similar to Kaiser bolted Bracket connection is introduced. Kaiser connection has invention patent so construction society can’t utilize them without authority. Proposed connection of this paper can be manufactured by both casting and welding methods and can eliminate patent problems. In this evaluation connection performance, pretention force of bolts, height of Bracket, number of bolts and length of Bracket have been evaluated. In modeling of connection in order to accuracy of results between different connected area and bolts faces contact elements were created. The standard cyclic history was selected for loading of specimens. The results shows that proposed connection can be accepted by connection code for using in special moment resisting frames from both ductility and strength aspects. Findings are extended as hysteresis curves, released energy of connection, rupture index indicators and slip of bolts.

Background and objectives: Trametes species have been used for centuries in traditional medicine of Asian countries. Recently, some of the bioactive compound have been isolated and evaluated for therapeutic purposes from these species. The aim of this study was to report the isolation and structure elucidation of major sterols from fruiting bodies of Trametes gibbosa. Volatile compounds and antioxidant activities of the different mushroom extracts of mushroom were also examined. Methods: The fruiting bodies of T. gibbosa were extracted with n-hexane, methanol, and hot water, respectively. For isolation of sterols, the n-hexane extract was subjected to column chromatography and fractionated by step gradient of n-hexane: ethyl acetate. The volatile oil was prepared by hydrodistillation and analyzed by GC-MS. For evaluation of the antioxidant activity, 2, 2-diphenyl-1-picrylhydrazyl and ferric reducing antioxidant power assays were used. Moreover, the phenolic and carbohydrate contents were assessed using spectrophotometry methods. Results: The column chromatography of the n-hexane extract led to the isolation of three sterols. These compounds were identified for the first time in T. gibbosa as follows: ergosta-5, 7, 22-trien-3β,-ol (ergosterol),5, 8-epidioxy-ergosta-6, 22-dien-3-ol,5, 9-epidioxy-8, 14-epoxy-ergosta-6, 22-dien-3-ol. The most abundant volatile compounds were identified as aldehydes (29. 01%), fatty acids (21. 2%) and alcohols (12. 07%). Based on antioxidant results, methanol and hot water extracts showed the highest activities in DPPH (EC50=588. 56±, 36. 37 μ, g/mL) and FRAP (432±, 6. 6 mmol Fe2+/g DW) methods, respectively. Conclusion: Trametes gibbosa is a valuable source of mycochemicals such as sterols, carbohydrate and phenolics. Further investigations are required for evaluation of the therapeutic potentials of the isolated compounds.

CFRP composites have unique application qualities such as high resistance and durability to environmental conditions, having relatively low weight and easy to install in strengthening concrete structure elements. The Brackets should be strengthen sufficiently if they are not calculated and implemented well. Application of the CFRP is one of the methods for such purposes. The study involves using five different configurations of CFRP sheets as a means of strengthening Bracket, using finite element and non-linear dynamic analysis method within the ABAQUS software. Comparative analysis results of non-strengthened Bracket model, show a 24.06% increase in the load-carrying capacity of strengthened models using the CFRP compared with the initial model (without CFRP). Results further show an increase of 24.96% of energy absorption in the strengthened models compared with the non-strengthened model.

Background: This study investigated the effect of two different methods of bleaching during orthodontic treatment on Bracket bond strength. Materials and Methods: A total of 45 extracted premolar teeth were selected in this experimental study and divided into three groups (office bleaching with 35% hydrogen peroxide, home bleaching with 22% carbamide peroxide, and control). The color of the teeth was assessed initially before the application of bleaching agents and Thermocycling. Orthodontic Brackets were subsequently bonded on the treated surfaces. Bleaching procedures were then performed. A final color measurement was performed at two points on the buccal surface both underneath and adjacent to the Bracket base. The initial and final color measurements and the bond strengths were compared between the groups using the analysis of variance. P < 0. 05 was considered as statistically significant. Results: Bracket bond strength was significantly reduced in both bleaching groups compared with the control group (P < 0. 01). The color difference before and after the bleaching procedures was significant in the office bleaching group (P < 0. 01), while the control group did not demonstrate a statistical difference between initial and final color assessments (P > 0. 05). Conclusion: Bleaching procedures performed during orthodontic treatment reduce bond strength. Enamel beneath the Bracket base experiences a whitening effect though to a lesser degree compared with an uncovered surface.

Background and Aim: This study aimed to evaluate the effect of repeated bonding by self-etching primers (SEPs) and a conventional phosphoric acid-etchant on shear bond strength (SBS), adhesive remnant index (ARI), and enamel morphology at different debonding time points. Materials and Methods: In this experimental study, 120 premolars were randomly divided into six groups of 20. In the first three groups, the Brackets were bonded by Transbond XT, Transbond Plus, and Beauty OrthoBond, and were debonded after 30minutes. Adhesive remnants were removed from the enamel surface by a tungsten carbide bur. Rebonding was done with new Brackets as described. The remaining three groups were debonded after aging. The SBS, ARI, and enamel surface morphology were evaluated. The SBS data were analyzed by two-way analysis of variance (ANOVA). The ARI scores were compared by using Mann-U-Whitney and Kruskal-Wallis tests. Results: The SBS of Transbond XT in the first debonding was significantly higher than that of Transbond Plus. Transbond Plus showed a higher SBS than Beauty Ortho Bond. In the second debonding, the SBS values of Transbond XT and Transbond Plus were not significantly different, but their SBS values were significantly higher than that of Beauty Ortho Bond. SEPs showed a higher bond strength in the second bonding compared to the first bonding. Scanning electron microscopy (SEM) showed more porosity in the enamel surface before the second bonding compared to the first bonding. The SBS of Beauty Ortho Bond significantly decreased after aging, and SEM images showed a gap at the resin-enamel interface. Conclusion: SEPs are recommended for secondary bonding in the clinical setting due to a decreased chair time, less damage to enamel, and an adequate bond strength.