No abstract available.
Prostheses and Implants* ; Sensation*

No abstract available.

No abstract available.
Prostheses and Implants*

No abstract available.
Temporomandibular Joint*

No abstract available.
Corrosion* ; Metals*

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

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

STATEMENT OF PROBLEM: The residual monomer of denture base materials causes hypersensitivity on oral mucosa and intereferes with the mechanical properties of the cured resin. The amount of residual monomer is influenced by materials, curing cycle, processing method, and etc. PURPOSE: The aim of this study was to investigate the residual methyl methacrylate(MMA) content of injection molded denture base polymer, and to compare this with the self-cured resin and the conventional compression molded heat-cured resin. MATERIALS AND METHODS: Disc shaped test specimens (50mm in diameter and 3mm thick) were prepared in a conventional flasking technique with gypsum molding. One autopolymerized denture base resins (Vertex SC. Dentimex. Netherlands) and two heat-cured denture base resins (Vertex RS. Dentimex. Netherlands, Ivocap. Ivoclar Vivadent, USA) were used. The three types of specimens were processed according to the manufacturer's instruction. After polymerization, all specimens were stored in the dark at room emperature for 7 days. There were 10 specimens in each of the test groups. 3-mm twist drills were used to obtain the resin samples and 650mg of the drilled sample were collected for each estimation. Gas chromatography (Agillent 6890 Plus Gas Chromatograph, Agillent Co, USA) was used to determine the residual MMA content of 10 test specimens of each three types of polymer. RESULTS: The residual monomer content of injection molded denture base resins was 1.057+/- 0.141%. The residual monomer content of injection molded denture base resins was higher than that of compression molded heat cured resin (0.867+/-0.169%). However, there was no statistical significant difference between two groups (p > 0.01). The level of residual monomer in self cured resin(3.675+/-0.791) was higher than those of injection molded and compression molded heat cured resins (p<0.01). CONCLUSION: With respect to ISO specification pass/fail test (2.2% mass fraction) of residual monomer, injection molding technique(1.057+/-0.141%) is a clinicaly useful and safe technique in terms of residual monomer.
Calcium Sulfate ; Chromatography, Gas ; Denture Bases* ; Dentures* ; Fungi* ; Hot Temperature ; Hypersensitivity ; Mouth Mucosa ; Netherlands ; Polymerization ; Polymers

No abstract available.
Denture, Complete* ; Finite Element Analysis* ; Tooth, Artificial*

The aims of this experiment were to investigate the strain and temperature changes simultaneously within autopolymerizing acrylic resin specimens. A computerized data acquisition system with an electrical resistance strain gauge and a thermocouple was used over time periods up to 180 minutes. The overall strain kinetics, the effects of stress relaxation and additional heat supply during the polymerization were evaluated. Stone mold replicas with an inner butt-joint rectangular cavity (40.0x25.0mm, 5.0mm in depth) were duplicated from a brass master mold. A strain gauge (AE-11-S50N-120-EC, CAS Inc., Korea) and a thermocouple were installed within the cavity, which had been connected to a personal computer and a precision signal conditioning amplifier (DA 1600 Dynamic Strain Amplifier, CAS Inc., Korea) so that real-time recordings of both polymerization-induced strain and temperature changes were performed. After each of fresh resin mixture was poured into the mold replica, data recording was done up to 180 minutes with three-second interval. Each of two poly (methyl methacrylate) products (Duralay, Vertex) and a vinyl ethyl methacrylate product (Snap) was examined repeatedly ten times. Additionally, removal procedures were done after 15, 30 and 60 minutes from the start of mixing to evaluate the effect of stress relaxation after deflasking. Six specimens for each of nine conditions were examined. After removal from the mold, the specimen continued benchcuring up to 180 minutes. Using a waterbath (Hanau Junior Curing Unit, Model No.76-0, Teledyne Hanau, New York, U.S.A.) with its temperature control maintained at 50degrees C, heat-soaking procedures with two different durations (15 and 45 minutes) were done to evaluate the effect of additional heat supply on the strain and temperature changes within the specimen during the polymerization. Five specimens for each of six conditions were examined. Within the parameters of this study the following results were drawn : 1. The mean shrinkage strains reached -3095mu epsilon, -1796mu epsilon and -2959mu epsilon for Duralay, Snap and Vertex, respectively. The mean maximum temperature rise reached 56.7degrees C, 41.3degrees C and 56.1degrees C for Duralay, Snap, and Vertex, respectively. A vinyl ethyl methacrylate product (Snap) showed significantly less polymerization shrinkage strain (p<0.01) and significantly lower maximum temperature rise (p<0.01) than the other two poly (methyl methacrylate) products (Duralay, Vertex). 2. Mean maximum shrinkage rate for each resin was calculated to ?31.8mu epsilon/sec, -15.9mu epsilon/sec and ?31.8mu epsilon/sec for Duralay, Snap and Vertex, respectively. Snap showed significantly lower maximum shrinkage rate than Duralay and Vertex (p<0.01). 3. from the second experiment, some expansion was observed immediately after removal of specimen from the mold, and the amount of expansion increased as the removal time was delayed. For each removal time, Snap showed significantly less strain changes than the other two poly (methyl methacrylate) products (p<0.05). 4. During the external heat supply for the resins, higher maximum temperature rises were found. Meanwhile, the maximum shrinkage rates were not different from those of room temperature polymerizations. 5. From the third experiment, the external heat supply for the resins during polymerization could temporarily decrease or even reverse shrinkage strains of each material. But, shrinkage re-occurred in the linear nature after completion of heat supply. 6. Linear thermal expansion coefficients obtained from the end of heat supply continuing for an additional 5 minutes, showed that Snap exhibited significantly lower values than the other two poly (methyl methacrylate) products (p<0.01). Moreover, little difference was found between the mean linear thermal expansion coefficients obtained from two different heating durations (p>0.05).
Acrylic Resins* ; Electric Impedance ; Fungi ; Heating ; Hot Temperature ; Kinetics ; Microcomputers ; Polymerization* ; Polymers* ; Relaxation