Optimization of Residual Stress Measurement Conditions for a 2D Method Using X-ray Diffraction and Its Application for Stainless Steel Treated by Laser Cavitation Peening.

As the fatigue strength of metallic components may be affected by residual stress variation at small length scales, an evaluation method for studying residual stress at sub-mm scale is needed. The sin method using X-ray diffraction (XRD) is a common method to measure residual stress. However, this method has a lower limit on length scale.

Effects of occlusal rest design on pressure distribution beneath the denture base of a distal extension removable partial denture-an in vivo study.

This study aimed to investigate the pressure distribution beneath the denture bases of removable partial dentures (RPDs) with different occlusal rest designs (ORDs) by in vivo measurement. Four types of detachable occlusal rests (mesial and distal, distal, mesial, and nonrest) were placed on the direct abutment teeth of distal extension RPDs in four patients with free-end edentulous mandibles. Pressure measurements were obtained by using thin and flexible tactile sensors.

Evaluation of thermal stress in hydroxyapatite film fabricated by powder jet deposition.

This study aimed to create a thick hydroxyapatite (HA) film on the surface of a human tooth via a powder jet deposition (PJD) device for dental handpieces, and to examine the microstructural and mechanical properties of the HA film. In particular, the effects of thermal stress on this film were evaluated. The HA film was created by blasting 3.

Effect of hydroxyapatite film formed by powder jet deposition on dentin permeability.

A powder jet deposition (PJD) process can be used to create a thick hydroxyapatite (HA) film on the surface of a human tooth. This study aimed to investigate in vitro the ability of an HA film, applied using PJD, to diminish dentin permeability. Discs of human coronal dentin were cut perpendicular to the tooth axis and the smear layer was removed by EDTA treatment.

Characteristics of hydroxyapatite film formed on human enamel with the powder jet deposition technique.

This study aimed to create hydroxyapatite (HAp) film by powder jet deposition with manipulating the blasting nozzle above human enamel and to examine the microstructural and mechanical properties of the HAp film and the bonding strength at the interface between the HAp film and the enamel substrate. HAp particles calcinated at 1200°C with an average size of 4.7 μm were used.

Fabricating nano ribbons and nano fibers of semiconductor materials by diamond turning.

Diamond turning tests have been made on single crystalline silicon wafers. It was found that chips removed from the material surface during machining consist of nano needles, nano ribbons and nano fibers, the shape and size of which depend on the undeformed chip thickness and the cutting edge geometry. Electron diffraction studies showed that the needle-type chips are micro-crystalline with slight amorphization; while the nano ribbons and nano fibers have been mostly transformed into the amorphous phase.

Dose-dependent osteogenic effect of octacalcium phosphate on mouse bone marrow stromal cells.

Octacalcium phosphate (OCP) has been advocated to be a precursor of biological apatite crystals in bones and teeth. Our previous studies showed that synthetic OCP stimulates bone regeneration, followed by the progressive conversion of OCP into hydroxyapatite (HA), when implanted in bone defects. However, the precise mechanism to induce the osteogenic phenotype in osteoblasts by OCP has not been identified.

The effect of microstructure of octacalcium phosphate on the bone regenerative property.

The present study was designed to investigate whether the microstructure of synthetic octacalcium phosphate (OCP) affects its intrinsic bone regenerative properties as a scaffold and its conversion process into hydroxyapatite (HA). Our previous studies indicated that an agregate of OCP crystals, consisting of randomly oriented plate-like crystals, are capable of enhancing both osteoblastic cell differentiation in vitro and bone regeneration. While the transformation of OCP into HA has been considered in relation to the stimulatory capacity of OCP in bone regeneration, little is known about the effect of the microstructure of OCP granules on these capabilities.

Effects of a removable partial denture and its rest location on the forces exerted on an abutment tooth in vivo.

The 3-dimensional forces exerted on an abutment tooth of a removable partial denture (RPD) were measured in vivo during clenching using a force-measuring device with a piezoelectric transducer. The device was mounted on the mandibular right second premolar of a subject with an edentulous maxilla. The magnitude of the forces was higher and the direction was more posterior without the RPD in place.