No abstract available.
Fires*

No abstract available.
Fires ; Tracheostomy

No abstract available.
Fires* ; Relaxation*

To compare several porcelains made by various manufacturers in shrinkage after firing and investigate the effect of condensation on shrinkage, specimens were prepared and the volume of each body was measured by the phase-shifting profilometry. Baseplate wax was cut by 2.5cmx2cm and cast in nonprecious metal (Verabond, U.S.A.). then any surfaces of specimens were abrased and polished on the SiC abrasing papers, preparing 120 specimens. specimens were divided into six groups according to the porcelain used, and the porcelain used in each group were as follows. Group I : Ceramco dentin porcelain Group II : Creation dentin porcelain Group III : Creation margin porcelain Group IV : Vintage margin porcelain Group V : Vita dentin porcelain Group VI : Vintage dentin porcelain Porcelain was built up on the metal plates using a small spoon and then solution matching to each porcelain was added. The six groups are subdivided into a and b. In subgroup a, only excessive solution was absorbed with tissue and in subgroup b, porcelain was condensed sufficiently. When build-up was completed, the shape was measured using the phase-shifting profilometry. After that, specimens were fired in the furnace programed for each porcelain and then their changed shape were measured again. Using the difference between the two above measurements, the ratio of shrinkage was calculated. Obtained results were as follows ; 1. Regardless of condensation, the volume of fired specimens were not different significantly between the two subgroups a and b in the same group. 2. The ratios of shrinkage were significantly higher in the groups porcelain built-up was condensed than in the groups not condensed. 3. The ratios of shrinkage were in the range of 36.81-27.19% in the groups porcelain built up was condensed and 44.52-37.54% in the other groups not condensed.
Dental Porcelain* ; Dentin ; Fires*

PURPOSE: The purpose of this research was to evaluate the shear bond strength between zirconia core and veneer ceramic after surface treatment. MATERIAL AND METHODS: Zirconia cores (N = 40, n = 10, 10 mm x 10 mm x 3 mm) were fabricated according to the manufacturers??instructions and ultrasonically cleaned. The veneering ceramics (thickness 3 mm) were built and fired onto the zirconia core materials. Four groups of specimens with different surface treatment were prepared. Group I: without any pre-treatment, Group II: treated with sandblasting, Group III: treated with liner, Group IV: treated with sandblasting and liner. The shear bond strength was tested in a universal testing machine. Data were compared with an ANOVA and Scheffe post hoc test (P = .05). RESULTS: The shear bond strength of group VI was significantly higher than the other groups. CONCLUSION: Both mechanically and chemically treated simultaneously on zirconia core surface influenced the shear bond strength between the core and veneering ceramic in all-ceramic systems.
Ceramics ; Collodion ; Fires ; Zirconium

PURPOSE: The purpose of this study was to compare the fracture strength of the metal and the bond strength in metal-ceramic restorations produced by selective laser sintering (SLS) and by conventional casting (CAST). MATERIALS AND METHODS: Non-precious alloy (StarLoy C, DeguDent, Hanau, Germany) was used in CAST group and metal powder (SP2, EOS GmbH, Munich, Germany) in SLS group. Metal specimens in the form of sheets (25.0 x 3.0 x 0.5 mm) were produced in accordance with ISO 9693:1999 standards (n=30). To measure the bond strength, ceramic was fired on a metal specimen and then three-point bending test was performed. In addition, the metal fracture strength was measured by continuing the application of the load. The values were statistically analyzed by performing independent t-tests (alpha=0.05). RESULTS: The mean bond strength of the SLS group (50.60 MPa) was higher than that of the CAST group (46.29 MPa), but there was no statistically significant difference. The metal fracture strength of the SLS group (1087.2 MPa) was lower than that of the CAST group (2399.1 MPa), and this difference was statistically significant. CONCLUSION: In conclusion the balling phenomenon and the gap formation of the SLS process may increase the metal-ceramic bond strength.
Alloys ; Ceramics ; Fires

PURPOSE: This study aimed to present the clinical applicability of restorations fabricated by a new method, by comparing the bond strength of between ceramic powder with different coefficient of thermal expansion and alloys fabricated by Selective laser sintering (SLS). MATERIALS AND METHODS: Fifty Co-Cr alloy specimens (25.0 x 3.0 x 0.5 mm) were prepared by SLS and fired with the ceramic (8.0 x 3.0 x 0.5 mm) (ISO 9693:1999). For comparison, ceramics with different coefficient of thermal expansion were used. The bond strength was measured by three-point bending testing and surfaces were observed with FE-SEM. Results were analyzed with a one-way ANOVA (alpha=.05). RESULTS: The mean values of Duceram Kiss (61.18 +/- 6.86 MPa), Vita VM13 (60.30 +/- 7.14 MPa), Ceramco 3 (58.87 +/- 5.33 MPa), Noritake EX-3 (55.86 +/- 7.53 MPa), and Vintage MP (55.15 +/- 7.53 MPa) were found. No significant difference was observed between the bond strengths of the various metal-ceramics. The surfaces of the specimens possessed minute gaps between the additive manufactured layers. CONCLUSION: All the five powders have bond strengths higher than the required 25 MPa minimum (ISO 9693); therefore, various powders can be applied to metal structures fabricated by SLS.
Alloys* ; Ceramics* ; Fires ; Powders

PURPOSE: To evaluate an effect of additional firing process after sintering of monolithic zirconia crown on marginal and internal fit through three-dimensional analysis. MATERIALS AND METHODS: Ten monolithic zirconia crowns were fabricated using titanium abutment model. Monolithic zirconia crowns were designed, milled, and sintered as a control group, and additional firing with coloring was performed as a test group. Three dimensional analysis were performed by using triple-scan protocol, and cross-section analysis on mesio-distal and disto-lingual section was evaluated to measure marginal and internal fitness. Then, three-dimensional surface difference on between two groups was evaluated (α=.05). RESULTS: There was statistically significant difference between the control group (32.0 ± 24.3 µm) and the test group (17.0 ± 10.8 µm) in the mesial axial wall (P < .02) and the control group (60.2 ± 24.3 µm) and the test group (71.8 ± 21.5 µm) in the distal axial wall (P < .01). There was no statistically significant difference at the remaining point. CONCLUSION: There was no statistical significance on the deviation of inner surface of crown according to firing number, and the results of both group were considered clinically acceptable.
Crowns ; Fires ; Titanium

No abstract available.
Fires ; Open Access Publishing

An university student passed away by an unidentified bullet in a reserve force exercise. An X-ray could not find any bullet from the thorax. The post-mortem examination revealed that the victim had been killed by a 5.56 mm (diameter) bullet. The striation mark of the fatal bullet was coincided with a test fired bullet of a suspect's machine gun. However only blank cartridges had been fired according to the firing range records. Also, the examiner found that the mouth diameter of the fatal blank cartridge case is narrower than the others. In order to explain the strange happening, various situation of blank cartridge firing was considered. The examiner group noticed that the diameter of a blank cartridge mouth fired from an unexpelled bullet including gun may change. The authors test fired a blank cartridge case with a gun including an unexpelled bullet, and compared the shape of the mouth with the fatal blank cartridge case. The mouth shapes of two blank cartridges were coincided. The authors could conclude that the an unidentified suspect charged a bullet in the muzzle of the suspect's gun, and the bullet expelled by the gas pressure of the fatal blank cartridge case.
Autopsy ; Fires* ; Humans ; Mouth ; Thorax