UNLABELLED The penetration of a sealant into the tooth fissures can establish longer retention time for a pit and fissure sealant restoration. AIM This in vitro study was to evaluate the penetration ability of two low-viscosity resin materials, a composite and a compomer, applied with and without their bonding agents in comparison to an unfilled resin sealant. METHODS Forty premolars with s...

OBJECTIVES The aim of the study was to evaluate two ceramic materials as possible substitutes for enamel using two wear simulation methods, and to compare both methods with regard to the wear results for different materials. METHODS Flat specimens (OHSU n=6, Ivoclar n=8) of one compomer and three composite materials (Dyract AP, Tetric Ceram, Z250, experimental composite) were fabricated and s...

We report the true left-handed transmission of a composite metamaterial (CMM) consisting of periodically stacked split-ring resonator (SRR) and wire elements. The negative permeability (m < 0) gap is demonstrated explicitly by comparing SRR and closed-ring resonator structures. We confirm experimentally that the plasma cut-off frequency of the CMM is determined by the combined dielectric respon...

PURPOSE Sealants form a physical barrier between the oral environment and deep fissures that contribute to caries prevention. It is postulated that sealants possessing antibacterial properties are advantageous. The purpose of this study was to evaluate the antibacterial properties of four pit and fissure sealants using direct contact test (DCT) and agar diffusion test (ADT). METHODS For the D...

OBJECTIVES In auditory neuropathy (AN) children with hearing aids (HAs) or cochlear implant (CI), the speech perception improvement may not be in a significant degree. These children may perform speech perception after a few repeats. This condition may show that these children had difficulties in receiving and processing speech sounds. If the children with AN cannot distinguish the heard tones ...

Background. The chronic recommendation of pediatric drugs could exhibit erosive and cariogenic problems. Objective. To evaluate the effects of different pediatric drugs on the color stability of various restorative materials. Methods. Five specimens (1 mm × 3 mm) were prepared and immersed in ten different pediatric drugs and agitated every 8 hours daily for 2 min up to 1 week. Between immersio...

We consider electrons in two dimensions in a strong magnetic field at half filling of the lowest Landau level using the Chern-Simons approach. Starting from a lattice Hamiltonian for the electrons, we derive a path integral (PI) formulation for the composite fermions (CF) which respects the order of the operators. We use a time lattice with intermediate times in order to have a PI expressed in ...

BACKGROUND AND AIMS Effect of surface treatments on repair bond strength of aged composite resins might be different due to their dissimilar fillers. The aim was to evaluate the effect of different surface treatments on repair micro-shear bond strength (µSBS) of silica- (Spectrum TPH) and zirconia-filled (Filtek Z250) composite resins. MATERIALS AND METHODS Twenty-seven composite resin blocks...

OBJECTIVES Different light curing units are used for polymerization of composite resins. The aim of this study was to evaluate the degree of conversion (DC) and temperature rise in hybrid and low shrinkage composite resins cured by LED and Argon Laser curing lights. MATERIALS AND METHODS DC was measured using FTIR spectroscopy. For measuring temperature rise, composite resin samples were plac...

In order to replicate the fracture behavior of the intact human skull under impact it becomes necessary to develop a material having the mechanical properties of cranial bone. The most important properties to replicate in a surrogate human skull were found to be the fracture toughness and tensile strength of the cranial tables as well as the bending strength of the three-layer (inner table-dipl...