introduction: this study aimed to evaluate the effect of pretreatment with a neutral fluoride agent on shear bond strength (sbs) and microleakage of orthodontic brackets, and to investigate any significant relationship between sbs and microleakage. methods: forty intact premolars were selected and randomly divided into 2 groups. group 1 served as the control, while group 2 underwent treatment w...

background: many of the problems and composite filling failures are due to dentists' inadequate and passing acquaintance with bonding principles. the aim of this study is to assess dentists' acquaintance with the bonding principles and different adhesive application that are going to be used in educational programs. methods: in this descriptive and cross-sectional study, a valid and r...

dft and qtaim computations have been performed on numbers of pure nitrogen cluster speciesi.e. nn (n = 4, 6) for investigating the structure and bonding. this study is critical since thesemolecules have been nominated as the good synthetic targets of high energy materials (hem).0nthe other hand the decomposition mechanism is closely depends on the bonding pattern. thislatter concept was searche...

Wire bonding has been used in integrated circuit (IC) packaging for many years. However, there are many challenges in wire bonding for optoelectronics packaging. These challenges include bonding on sensitive devices, bonding over cavity, bonding over cantilevel leads and bonding temperature limitations. The optoelectronics package design brings another challenge, which requires wire bonding to ...

polymeric yarns for reinforcing cement composites have got great interest in all over the world. in this research the performance of bonding between nylon tire cord grad yarns, and one kind of cement composite called fine grained concrete was studied. two kinds of nylon cord yarns, nylon 6 and 66, with different finesse were selected. the durability of yarns with time in alkaline media was inve...

introduction: retention of fiber reinforced composite posts depends on the bond strength between post and cement, and cement and root dentin. the aim of this study is to evaluate the bond strength of one type of fiber post to radicular dentin with different adhesive cements. materials and methods: crowns of 44 caries-free, human premolar were removed 2 mm below the cej and the roots were endodo...

we present detailed theoretical studies of the h-bonded complexes formed from interaction between 5-fluorouracil and various six-membered cyclic nitrosamine compounds. in this study, an investigation on intermolecular interactions in x-nu (x = ch2, sih2,bh, alh, nh, ph, o and s) complexes is carried out using density functional theory. the calculations are conducted on b3lyp/6-311++‏‏g** level ...

enaminones are those structures made up three various functional groups including carbonyl, alkeneand amine groups which arelocated along with each other in a conjugate fashion. these compoundsare of much attention due to special characteristics and numerous applications. in the paper, sixvarious enaminone structures were theoretically optimized and after concluding, were compared withequivalen...