Nanoindentation-induced interlayer bond switching and phase transformation in carbon nanotubes (CNTs) and graphite are simulated by molecular dynamics. Both graphite and CNTs experience a soft-to-hard phase transformation at room temperature at compressive stresses of 12 and 16 GPa, respectively. Further penetration leads to the formation of interlayer sp(3) bonds, which are reversible upon unl...

statement of problem: in some clinical situations, repair of composite restorations is treatment of choice. improving the bond strength between one new and old composite usually requires increased surface roughness to promote mechanical interlocking since chemical bonding might not be adequate. similarly, the treatment of a laboratory fabricated resin composite restoration involves the same pro...

o bjectives: the purpose of this study was to evaluate the effect of salivary ph on the shear bond strength (sbs) of orthodontic brackets to tooth surface. materials and methods: eighty intact premolars were randomly divided into four groups of 20.  after bonding a bracket on each tooth, the groups one to four were stored in artificial saliva at a ph of 3.8, 4.8, 5.8, and 6.8, respectively for ...

objective: a clinical challenge of using zirconia frameworks is to achieve adequate bond with different substrates. this study aimed to evaluate the effect of bioglass and silica coating of zirconia substrates on microshear bond strength of resin cement to tetragonal zirconia. methods: this laboratory experimental study was conducted on zirconia discs. a total of 120 ytzp zirconia (zirkonzahn) ...

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: as the use of different irrigants to eliminate residual debris and smear layer in the field of endodontic is unavoidable, by considering the effect of irrigants on the bond strength of resin composite restorations, this study was designed to evaluate the effect of a mixture of a tetracycline isomer, an acid, and a detergent (mtad) on the shear bond strength of two self-etch adhesive...

In this work, the strength of cold roll bond of the commercially pure titanium (CP Ti) sheet and the effect of TiO2 nanoparticles on bond strength was investigated. Through the accumulative roll bonding process, which is considered among the important severe plastic deformation processes, the creation of suitable bonds plays a significance role in the ultimate strength of the bond. Thus, resear...

Background and Aim: Er,Cr:YSGG laser irradiation has been suggested as an effective method of cavity preparation and surface treatment to enhance the bond strength. The aim of this study was to assess the microshear bond strength of Fuji II LC glass ionomer (GI) cement to primary dentin following bur preparation and Er,Cr:YSGG irradiation. Materials and Methods: This in vitro, experimental stu...

this study compared the push-out bond strength of endosequence root repair material (errm) and bioaggregate (ba), new bioceramic materials, to that of mineral trioxide aggregate (mta) after incubation in phosphate-buffered saline (pbs), a synthetic tissue fluid, for either 1 week or 2 months.one-hundred and twenty root sections were filled with proroot mta, ba, or errm. each tested material was...

immediate restoration after vital pulp therapy is essential in order to create and maintain effective coronal seal.the aim of this study was to evaluate the shear bond strength of recently used pulp capping materials: white mineral trioxide aggregate (mta), and calcium enriched mixture cement (cem) to composite resin with the use of etch-and-rinse and self-etch adhesive systems and compare them...