No abstract available.
Prostheses and Implants* ; Sensation*

No abstract available.
Prostheses and Implants*

No abstract available.

No abstract available.
Corrosion* ; Metals*

No abstract available.
Temporomandibular Joint*

No abstract available.
Acidosis, Renal Tubular* ; Humans ; Infant, Newborn*

No abstract available.
Tooth*

A precise fit of the implant prosthesis is one of the most important factors in preventing mechanical complications. To analyze the degree of the misfit of implant prosthesis, a modal testing experiment was accomplished. And to interpret the modal testing analysis mathematically, three-dimensional finite element models were established. In the experimental modal testing analysis, with a laser displacement meter, FFT analyzer, impact hammer, etc., natural frequencies of the models with various degree of prosthesis fit were determined after the frequency response function were calculated. In the finite element analysis, the natural frequencies and mode shapes of the models which simulated those of experimental modal testing were computed. The results were as follows : 1. Natural frequencies of the prosthesis-abutment were related to the contact state between components. 2. In the modal testing experiment, the natural frequencies increased from 50micrometer to 200micrometer gap and reached a plateau. 3. In the finite element analysis, the natural frequencies decreased gradually according to the increase of the gap size. 4. In the finite element analysis, the mode shapes of model 1 with misfitting prosthesis showed different patterns from those without misfitting prosthesis. 5. The devices including a laser displacement meter used in this study were useful for measuring the natural frequencies of an implant prosthesis which had various degrees of fit.
Finite Element Analysis ; Prostheses and Implants*

The fracture of acrylic resin dentures remains an unsolved problem. Therefore, many investigations have been performed and various approaches to strengthening acrylic resin, for example, the reinforcement of heat-cured PMMA resin using glass fibers, have been suggested over the years. The aim of the present study was to investigate the effect of short glass fibers treated with silane coupling agent on the transverse strength of heat-polymerized PMMA denture base resin. To avoid fiber bunching and achieve even fiber distribution, glass fiber bundles were mixed with PMMA powder in conventional mixer whose blade was modified to be blunt. Composite of glass fiber (11micrometer diameter, 3mm & 6mm length, silane treated) and PMMA resin was made. Transverse strength and Young's modulus were estimated. Glass fibers were incorporated with 1%, 3%, 6% and 9% by weight. Plasticity and workability of dough was evaluated. Fracture surface of specimens was investigated by SEM. The results of this study were as follows 1. 6% and 9% incorporation of 3mm glass fibers in the PMMA resin enhanced the transverse strength of the test specimens (p<0.05). 2. 6% incorporation of 6mm glass fibers in the PMMA resin increased transverse strength, but 9% incorporation of it decreased transverse strength (p<0.05). 3. When more than 3% of 3mm glass fibers and more than 6% of 6mm glass fibers were incorporated. Young's modulus increased significantly (p<0.05). 4. Workability decreased gradually as the percentage of the fibers increased. 5. Workability decreased gradually as the length of the fibers increased. 6. In SEM and LM, there was no bunching of fibers and no shortening of fibers.
Denture Bases ; Dentures ; Elastic Modulus ; Glass* ; Plastics ; Polymethyl Methacrylate*

The clinical spectruni of epidermolysis bullosa acquisita(EBA) is much broader than originally thought. Although the full extent of the clinical presenation is still being defined, it is now known that EBA include the followings: a non-inflammatory mechanobullous condition equating wit,h classical EBA; an inflammatory vesiculosullous eruption mimicking bullous pernphigoid; and a mucosal-centered disease with sarring similar to cicatricial pemphigoid. Among the nine cases of EBA, aged between 34 to 70 year-old, seen in recent years, three patients had mechanobullous lesions with skin fragilities and scarrings; three patients had inflammatory bullous eruptions, and three other patient had combined features of mechanobullous/inflammatory bullous lesions. Mucous membrane lesions were recognized in sex cases, and the rnos! frequent site of involvement was the oral mucosae. According to observations of these patients episodes of inflammatory bullous eruptions appeared to be present in seven cases and have been considered as early sympoms of the disease. It has been noted, however, that in two cases lesions develop d as an non-inflammatory mechanobullous from thonset. Based on the ability of EBA to mimick bullous pemphigoid or cicatricial pernphogoid and the fact that such cases have perhaps been missed, we feel EBA is more common than past literature has suggested.
Aged ; Blister ; Cicatrix ; Epidermolysis Bullosa Acquisita* ; Epidermolysis Bullosa* ; Humans ; Mouth Mucosa ; Mucous Membrane ; Pemphigoid, Benign Mucous Membrane ; Pemphigoid, Bullous ; Skin