as it is seen, by passing the evolutionary process of banding of orthodontic attachments to the bonding ones, orthodontics have witnessed many developments, such as application of new adhesives, optimized base designs, new bracket materials, curing methods and more efficient primers. the studies often address the morphological, micro-leakage, and shear bond tests to evaluate bond efficacy. amon...

objectives : this experimental study evaluated the effect of bonding application time on the microshear bond strength of composite resin to different types of glass ionomer cements (gics). materials and methods: one-hundred and sixty specimens (two conventional and two resin-modified gics) were prepared and divided into 16 groups. the surface of all specimens was prepared using two different bo...

Two bonding models i.e cumullenic and acetylenic models have been proposed to account for thebonding patterns in linear carbon clusters while the bonding patterns in cyclic and 3D geometrieS of theseclusters have remained ambiguous.This work presents the bonding patterns in various C4 and C5 pure clusters at MP2/aug-cc-pVTZ level oftheory. This subject is studied in the light of modern bonding ...

mp2 calculations with cc-pvtz basis set were used to analyze intermolecular interactions in f3cx···yli···nccn and f3cx···nccn···liy triads (x = cl, br; y = cn, nc) which are connected via halogen and lithium bonds. those complexes with the role of liy as halogen acceptor and lithium donor show cooperativity with energy values ranging between -1.97 and -2.92 kj mol-1. those complexes with simult...

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...