Objective. To investigate the frequency and influencing factors of rubber dam usage for endodontic procedures among general dentistry practitioners and specialized practitioners (endodontist) in Tianjin. Methods. Three hundred questionnaires were distributed among practitioners from 3 different types of medical institutions in Tianjin. Data were collected and analysed using Chi-square tests. Re...

Spherical void expansion in plastics and rubber-modified plastics is investigated under radial traction conditions. The plastics are modeled as elastic-plastic pressure-sensitive materials and the rubbers are modeled as nonlinearly elastic materials. First, the growth of a spherical void in an infinite plastic matrix is investigated under remote radial traction conditions. The results show that...

Powdery mildew disease of rubber affects immature green leaves, buds, inflorescences, and other immature tissues of rubber trees, resulting in up to 45% losses in rubber latex yield worldwide. The disease is often controlled by dusting the diseased plants with powdered sulfur, which can have long-term negative effects on the environment. Therefore, it is necessary to search for alternative and ...

Opalized white tuff (OWT) with 40 μm average particle size and 39.3 m(2)/g specific surface area has been introduced into polyisoprene rubber (NR). Their reinforcing effects were evaluated by comparisons with those from precipitated silica (PSi). The cure characteristic, apparent activation energy of cross-link (E(ac)) and reversion (E(ar)), and mechanical properties of a variety of composites ...

Waste latex sludge from centrifuged residue, which is a null by-product of concentrated latex manufacturing, was digested to retrieve the rubber by using sulfuric acid. It was found that the acid concentration and digestion time have an effect on the amount and purity of the retrieved rubber. Sulfuric acid at concentrations of more than 10% by weight with a digestion time of 48 hours completely...

The purpose of this study was to test the hypothesis that more recently developed rubber dam systems (OptraDam ® Plus and OptiDam™) are faster and easier to handle, and that the quality of isolation is not decreased. The rubber dam systems were applied in standard conditions on a dental simulator in several model clinical situations. The time of preparation, application and removal were measure...

An investigation was conducted to determine the influence of recycled scrap tire rubber on the engineering properties of controlled low strength material (CLSM). With control over the ultimate compressive strength of CLSMs being key for applications such as backfilling utility trenches where re-excavation is often necessary, incorporation of scrap tire rubber into the CLSM mixture is a viable w...

Rubber material generally behaves as an electrical insulator, but vapor-grown carbon fiber (VGCF) is known for its electrical conductivity. Thus, we compounded styrene-butadiene rubber and carbon nanofiber (VGCF), and studied the relationship between strain and the DC electrical resistivity of vulcanized rubber filled with carbon nanofiber. No change of hardness was observed in hardness tests. ...

Electro-mechanical impedance (EMI) sensing technique based on smart piezoelectric materials has emerged as a potential tool for the implementation of an online monitoring system for structural health monitoring. Many nondestructive methods have limited capabilities in monitoring of the rubber aging in a continuous manner. In this study, the feasibility of the EMI sensing technique for the onlin...