Dependencies of hydrogen-water on mineral-based hardness, temperatures and the container materials, and effects of the oral washing and drinking.

Widely distributed electrolytic-generators for hydrogen-water are not fully considered for the dependencies of post-electrolytic values of the dissolved hydrogen concentration (DH) and the oxidation-reduction potential (ORP) on the properties of the pre-electrolytic water. We investigated the dependencies of DH and ORP on mineral-based hardness, temperatures and the container materials, and effects on the oral cavity by oral washing or drinking. Along with an increase in mineral-based water-hardness, DH decreased from 960 to 870 μg/L and the ORP unexpectedly increased from -460 to -320 mV.

Development of a new direct core build-up method using a hollow fiber-reinforced post.

We have developed a new direct construction method for core build-up starting with the hypothesis that an improvement in pullout strength and a decrease in the number of voids in the restorative material will become possible by filling a hollow fiber reinforced post with the restorative material from the bottom of the root canal. For the pullout test, the hollow post was fixed to the head of a mixing tip and inserted into the bottom of a cylinder. The restorative material was then injected through the hollow post.

Failure morphology of all-ceramic prostheses.

The aim of this study is to investigate the internal morphology of all-ceramic prostheses before seating. Micro X-ray CT was used to inspect three dimensionally the locations and sizes of pores within experimentally fabricated all-ceramic crowns as well as measure the veneer and core thickness. Scanning electron microscopy (SEM) was used to examine the fracture sites of clinically failed prostheses.

Surface modification of poly (L-lactide) by atmospheric pressure plasma treatment and cell response.

This study investigated the influence of atmospheric pressure plasma treatment on the surface properties and cell response of poly(L-lactide) (PLLA) samples. The samples were analyzed by means of X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), micro- and nanosurface roughness, water contact angle, and zeta potential. Furthermore, cell adhesion assay and cell proliferation assay on the samples were carried out using MC3T3-E1 cells.

Improvement of cell adhesion on poly(L-lactide) by atmospheric plasma treatment.

The purpose of this study is to elucidate the interaction between the cell and the surface of poly(L-lactide) (PLLA) samples, which were modified using a low-temperature plasma treatment apparatus at atmospheric pressure. The plasma treatments were carried out in the atmospheres of air, carbon dioxide (CO2), and perfluoro propane (C3F8) gas. The PLLA samples before and after the plasma treatment were analyzed by XPS and their contact angles with water.

Fabrication of porous particulate for the scaffold by applying solution spraying method.

A simple and novel method--in the form of solution spraying--was developed to fabricate biodegradable, porous poly(L-lactic acid) (PLLA) particulates for scaffold. PLLA pellets were dissolved in an organic solvent. Then, 5 % PLLA-dioxane solution was sprayed using an air-assisted atomizer with a nozzle diameter of 2.

Surface modification of pure titanium by plasma exposure and its bonding to resin.

The purpose of this study was to investigate the effects on shear bond strength to resin after pure titanium (Ti) was exposed to plasma under different kinds of gas atmosphere. Polished Ti samples were treated using a plasma exposure apparatus in gas atmospheres of air, CO2, and C3F8. Surface analysis of Ti exposed to plasma was achieved through surface free energy and XPS measurements.

Bamboo charcoal inhibits growth of HeLa cells in vitro.

The purpose of this work was to investigate the far infrared spectral characteristics of bamboo charcoal powder and its effect on cancer cells for use in the dental field. To analyze the effects of the powder, HeLa and WI-38 cells were used and then assessed by cell adhesion assay and WST-1 assay. The powder emitted far infrared rays at wavelengths between 4 to 16 microm.

Retention force of complete palate coverage and palate-less dentures in vitro.

The purpose of this study was to investigate the retention force of complete palate coverage and palate-less dentures made with three polymerization systems (DS system, SR-Ivocap system, microwave polymerization system) in vitro. The retention force between each denture and a polyurethane model by intervening artificial saliva was measured using a tensile tester. In addition, discrepancies between the denture base and the stone cast were measured at several points.