background and aims. marginal seal of the material is extremely important in fissure sealant therapy. the aim of this study was to investigate microleakage of flowable composite resins and conventional fissure sealants with or without dentin bonding agent. materials and methods. the occlusal surface of 60 intact extracted human premolars, divided into four groups, were cleaned with pumice/slurr...

The influence of the interaction among water-cement ratio, content expansion agent, water reducing and retarder on compressive strength new sealing material was studied. Design-Expert software used to design experiments, establish a quadratic polynomial regression model, draw response surface, optimize parameters. microstructure morphology sample is explored by scanning electron microscope (her...

The failure reasons of reciprocating sealing in OPI-1800AWS fracturing pump are analyzed by scanning electron microscope technology (SEMT). The lubrication mechanism of plunger seal friction pair is analyzed by hydrodynamic lubrication theory. During its discharge and suction stroke, the reciprocating sealing friction pair meets the conditions of hydrodynamic lubrication, a certain thickness of...

Sealing with waterborne clays is a rapid and low cost method of controlling seepage through porous media whenever the clay source is within economical shipping distance of the sealing site. But more must be learned about this method of sealing before it can be fully utilized. Water impedance of waterborne bentonites, as measured by water loss in the filter press test, was correlated with their ...

INTRODUCTION Mineral trioxide aggregate (MTA) was developed because existing materials did not have the ideal characteristics for orthograde or retrograde root-end fillings. MTA has been recommended primarily as a root-end filling material, but it has also been used in pulp capping, pulpotomy, apical barrier formation in teeth with open apexes, repair of root perforations, and root canal fillin...

Bone resorption by osteoclasts depends on the assembly of a specialized, actin-rich adhesive 'sealing zone' that delimits the area designed for degradation. In this study, we show that the level of roughness of the underlying adhesive surface has a profound effect on the formation and stability of the sealing zone and the associated F-actin. As our primary model substrate, we use 'smooth' and '...

Sealing occlusal pits and fissures in teeth is a common and highly effective preventive method. The main purpose of sealing the pits and fissures is to prevent plaque microflora and food debris accumulation in the fissures where saliva cannot reach and clean the debris, re-mineralise initial lesions, and buffer the acid produced by cariogenic bacteria. Resin-based sealants, as well as glass ion...

We can distinguish 3 generations of FES implants for activation of neural structures: 1. RF-powered implants with antenna displacement dependent stimulation amplitude; 2. RF-powered implants with stabilised stimulation amplitude; and 3. battery powered implants. In Vienna an 8-channel version of the second generation type has been applied clinically to mobilisation of paraplegics and phrenic pa...

This Account summarizes techniques for fabrication and applications in biomedicine of microfluidic devices fabricated in poly(dimethylsiloxane) (PDMS). The methods and applications described focus on the exploitation of the physical and chemical properties of PDMS in the fabrication or actuation of the devices. Fabrication of channels in PDMS is simple, and it can be used to incorporate other m...