PURPOSE: This study examined the effects of glass infiltration treatments on the shear bond strength (SBS) between zirconia core and ultra low-fusing porcelain veneer. MATERIALS AND METHODS: The zirconia specimens were classified into 4 groups (n = 12): Untreated zirconia (group Z), zirconia coated ZirLiner (group ZL), glass-infiltrated zirconia (group ZG), glass-infiltrated and sandblasted zirconia (group ZGS). A cylinder of ultra low-fusing veneer porcelain was build up on each disk (6 mm × 3 mm). SBS was measured using a universal testing machine. Scanning electron microscope and Energy Dispersive X-ray spectroscopy were used to evaluate the surface of zirconia and failure pattern after SBS. RESULTS: SBS value of group ZGS was significantly lower than that of other groups (P < .05). No significant differences were detected among group ZL, group Z and group ZG. CONCLUSION: Glass infiltration is not effective to the bond strength between zirconia and ultra low-fusing porcelain veneer. Sandblasting also dramatically decreased the bonding strength.
Dental Porcelain* ; Glass ; Spectrometry, X-Ray Emission

STATEMENT OF PROBLEM: In order to increase preload with reducing the friction coefficient, abutment screws coated with pure gold and Teflon as dry lubricant coatings have been introduced. But the reported data indicate that if screw repeated tightening and loosening cycle, an efficiency of increasing preload was decreased by screw surface wearing off. PURPOSE: This study was to evaluate the influence of tungsten carbide/carbon coating, which has superior hardness and frictional wear resistance, on the preload of abutment screws and the stability of coating surface after repeated closures. MATERIAL AND METHOD: The rotational values of abutment screws and the compressive forces between abutment and fixture were measured in implant systems with three different joint connections, one external butt joint and two internal cones. Moreover, the stability and the alteration of coating surface were examined by comparison of the compressive force and the removable torque values during 10 consecutive trials, observation with scanning electron microscope and analyzed the elemental composition with energy dispersive x-ray spectroscopy. RESULTS AND CONCLUSION: 1. Application of coating resulted in significant increase of compressive force in all implant systems(P<.05). The increasing rate of compressive force by coating in external butt joint was greater than those in internal cones(P<.05). 2. Coated screw showed the significant additional rotation compared to non-coated screw in all implant systems(P<.05). There were no significant differences in the increasing rate of rotation among implant systems(P>.05). 3. Removable torque values were greater with non-coated screw than that with coated screw (P<.05). 4. Coated screw showed insignificant variations in the compressive forces during 10 consecutive trials(P>.05). 5. After repeated trials, the surface layer of coated screw was maintained relatively well. However, surface wearing and irregular titanium fragments were found in non-coated screw.
Friction ; Hardness ; Joints ; Polytetrafluoroethylene ; Spectrometry, X-Ray Emission ; Titanium ; Torque ; Tungsten*

OBJECTIVE: The objective of the study was to evaluate the practicality and the validity of different surface treatments of self-drilling orthodontic mini-implants (OMIs) by comparing bone cutting capacity and osseointegration. METHODS: Self-drilling OMIs were surface-treated in three ways: Acid etched (Etched), resorbable blasting media (RBM), partially resorbabla balsting media (Hybrid). We compared the bone cutting capacity by measuring insertion depths into artificial bone (polyurethane foam). To compare osseointegration, OMIs were placed in the tibia of 25 rabbits and the removal torque value was measured at 1, 2, 4, and 8 weeks after placement. The specimens were analyzed by optical microscopy, scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS). RESULTS: The bone cutting capacity of the etched and hybrid group was lower than the machined (control) group, and was most inhibited in the RBM group (p < 0.05). At 4 weeks, the removal torque in the machined group was significantly decreased (p < 0.05), but was increased in the etched group (p < 0.05). In the hybrid group, the removal torque significantly increased at 2 weeks, and was the highest among all measured values at 8 weeks (p < 0.05). The infiltration of bone-like tissue surface was evaluated by SEM, and calcium and phosphorus were detected via EDS only in the hybrid group. CONCLUSIONS: Partial RBM surface treatment (hybrid type in this study) produced the most stable self-drilling OMIs, without a corresponding reduction in bone cutting capacity.
Calcium ; Microscopy ; Microscopy, Electron, Scanning ; Osseointegration* ; Phosphorus ; Rabbits ; Spectrometry, X-Ray Emission ; Tibia ; Torque

PURPOSE: The purpose of the current in vitro study was to evaluate the transfer of metal to both alumina and cobalt-chrome (Co-Cr) heads that were scraped by a titanium alloy surface under different load conditions. MATERIALS AND METHODS: Alumina and Co-Cr heads were scraped by an acetabular metal shell under various loads using a creep tester. Microstructural changes in the scraped area were visualized with a scanning electron microscope and chemical element changes were assessed using an energy dispersive X-ray spectrometry. Changes in the roughness of the scraped surface were evaluated by a three-dimensional surface profiling system. RESULTS: Metal transfer to alumina and Co-Cr heads began to be detectable at a 10~15 kg load, which could be exerted by one-handed force. At loads of 30, 50 kg, fissures occurred on the head surfaces in addition to metal transfer. CONCLUSION: This study reveals that metallic debris was transferred from the titanium alloy acetabular shell to both alumina and Co-Cr heads by minor scraping. When the contact force increased, scratching of the head surface occurred in addition to the transfer of metal. The results of this study suggest that the greatest possible effort should be made to protect femoral heads, regardless of material, from contact with metallic surfaces during total hip arthroplasty.
Acetabulum* ; Alloys ; Aluminum Oxide* ; Arthroplasty, Replacement, Hip ; Head* ; Spectrometry, X-Ray Emission ; Titanium

PURPOSE: To report pathological, histochemical, ultrastructural, and spectrographic analysis of explanted hydrophilic acrylic intraocular lenses obtained from patients who had visual disturbances caused by postoperative opacification of the IOL. METHODS: Forty-three hydrophilic IOLs (ACRL-160, Ophthalmed Inc.) were explanted from 39 patients with decreased visual acuity because of opacification of the IOL itself. All explanted IOLs were examined grossly and by light microscopy. Full-thickness sagittal sections of the optics of the randomly selected 10 IOLs were stained with the von kossa method (special stains for calcium). One of these sectioned IOLs was not stained, and submitted for scanning electron microscopy and energy dispersive X-ray spectroscopy. RESULTS: Microscopic analysis revealed multiple fine, granular deposits within the lens optics and haptics, and these deposits were stained positively with the von Kossa method. They were varible in size, and unevenly distributed in the optics on the scanning electron microscopy, and energy dispersive X-ray spectroscopy of the internal substance of IOL demonstrated the presence of calcium within the deposits. CONCLUSIONS: We evaluated 43 explanted opacified ACRL-160 lenses, and have demonstrated that the opacification was caused by the presence of granular deposits within the IOL. The deposits have the component of calcium.
Calcium ; Coloring Agents ; Humans ; Lenses, Intraocular* ; Microscopy ; Microscopy, Electron, Scanning ; Spectrometry, X-Ray Emission ; Visual Acuity

OBJECTIVE: The aim of this study was to evaluate the remineralization of interdentally stripped teeth after fluoride gel or hydroxyapatite paste application. METHODS: After interdental stripping, 1.23% fluoride gel or 10% hydroxyapatite paste was applied three times a day, with a duration of four minutes, for a week. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) were used to compare the change of surface contents and crystal structures before and after the application of fluoride gel or hydroxyapatite paste. RESULTS: EDS analysis indicated that calcium contents were increased after 10% HAp paste application on stripped enamel (p < 0.01). SEM view showed that enamel surfaces in groups of 1.23% APF gel or 10% HAp paste application were smoother than those of control group, which was regarded as filling of the pore structure. And pores between crystal structures in groups treated with 1.23% APF gel or 10% HAp paste were smaller than those of control group. CONCLUSIONS: Application of APF or HAp on stripped enamel could positively influence on the surface contents or crystal structure.
Calcium ; Dental Enamel ; Durapatite ; Fluorides ; Microscopy, Electron, Scanning ; Spectrometry, X-Ray Emission ; Tooth

PURPOSE: The aim of this study was to evaluate changes in the bearing surface of an alumina head and cup insert after difficult intraoperative reduction of the head. MATERIALS AND METHODS: In two consecutive cases, where the force required for reduction caused scratching on the edge of the acetabular metal shell and marginal cracking of the adjacent portion of the alumina insert, the reduced alumina head was dislocated and retrieved with the alumina cup insert. The changes of the bearing surface were evaluated by gross inspection and by scanning electron microscopy(SEM) and energy dispersive x-ray spectrometry (EDAX). RESULTS: In both cases, the scratched area of the alumina head was found to have discolored. SEM and EDXA showed the discoloration to be the result of metallic debris from the titanium alloy shell. The metallic debris that was transferred from the head also stained the bearing surface of the alumina insert. CONCLUSION: Metallic debris might increase bearing surface wear. If the cracked ceramic fragments from the cup insert are neglected, it is also possible that they could be trapped between bearing surfaces and increase wear.
Acetabulum ; Alloys ; Aluminum Oxide ; Arthroplasty, Replacement, Hip* ; Ceramics ; Head* ; Spectrometry, X-Ray Emission ; Titanium

OBJECTIVE: The aim of this study was to evaluate the effect of remineralization and inhibition to demineralization after fluoride gel (acidulated phosphate fluoride, APF) or hydroxyapatite (HAp) paste application on interdentally stripped teeth. METHODS: After interdental stripping, 1.23% APF or 5%, 10% HAp paste were applied for 7 days for remineralization. Afterwards, teeth were exposed to lactate carbopol buffer solution for demineralization. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) were used to compare change in surface contents and crystal structures after remineralization, and then after demineralization. RESULTS: EDS analysis indicated that calcium (p < 0.001) and phosphate (p < 0.01) contents were increased after 10% HAp paste application on stripped enamel, calcium (p < 0.05) and phosphate (p < 0.01) contents were increased after 5% HAp paste application, and fluoride (p < 0.01) contents were increased after 1.23% APF application. SEM image showed that enamel surfaces became smoother and crystal structures became small and compact after APF or HAp application. After demineralization, calcium (p < 0.05) and phosphate (p < 0.05) contents remained increased on the enamel remineralized with 10% HAp paste, and phosphate (p < 0.05) contents remained increased on the enamel remineralized with 5% HAp paste. After demineralization, surfaces looked less destroyed in the enamel remineralized beforehand than those of the control, and small pores between crystal structures, formed by remineralization were remained. CONCLUSIONS: Hydroxyapatite paste and fluoride gel were helpful to remineralize and inhibit deminerlization on stripped enamel.
Calcium ; Dental Enamel ; Durapatite ; Fluorides ; Lactic Acid ; Microscopy, Electron, Scanning ; Polyvinyls ; Spectrometry, X-Ray Emission ; Tooth

OBJECTIVETo investigate the permance index ofof portable X-ray fluorescence spectrometer in the determination of lead on filter membrane and to provide data for the determination of lead in workplace air.

METHODSIrradiated with X-ray, the lead would emit specific X-ray fluorescence during the process from the excited state back to the ground state. Rapid determination of lead was completed using fluorescence energy and wave length for qualitative analysis and fluorescence intensity for quantitative measurement. Under set conditions, a series of customized calibration samples were measured to create a standard curve for quantitative analysis of lead on filter membrane.

RESULTSThe regression equation obtained using a portable X-ray fluorescence spectrometer to determine the lead on filter membrane was y=0.004x-0.182 (r2= 0.9999). The linear range was 0.00 -10.40 mg/m3, the minimum detectable concentration was 0.53 µg/m3, and the minimum quantifiable concentration was 1.76µg/m3. The relative standard deviation (RSD) of within-run precision of samples with different concentrations was 0.48%-6.22%, the RSD of between-run precision was 2.51%-5.09%, and the degree of accuracy was in the calibration range of standard samples.

CONCLUSIONPortable X-ray fluorescence spectrometry is a simple, rapid, repeatable, and accurate method for the determination of lead on filter membrane.

The purpose of this study was to evaluate the effect of acid-treatment conditions on the surface properties of the RBM (Resorbable Blast Media) treated titanium. Disk typed cp-titanium specimens were prepared and RBM treatments was performed with calcium phosphate ceramic powder. Acid solution was mixed using HCl, H2SO4 and deionized water with 4 different volume fraction. The RBM treated titanium was acid treated with different acid solutions at 3 different temperatures and for 3 different periods. After acid-treatments, samples were cleaned with 1 % Solujet solution for 30 min and deionized water for 30 min using ultrasonic cleanser, then dried in the electrical oven (37℃). Weight of samples before and after acid-treatment were measured using electric balance. Surface roughness was estimated using a confocal laser scanning microscopy, crystal phase in the surface of sample was analyzed using X-ray diffractometer. Surface morphology and components were evaluated using Scanning Electron Microscope (SEM) with Energy Dispersive X-ray spectroscopy (EDX) and X-ray Photoemission Spectroscopy (XPS). Values of the weight changes and surface roughness were statistically analyzed using Tukey-multiple comparison test (p=0.05). Weight change after acid treatments were significantly increased with increasing the concentration of H₂SO₄ and temperature of acid-solution. Acid-treatment conditions (concentration of H₂SO₄, temperature and time) did not produce consistent effects on the surface roughness, it showed the scattered results. From XRD analysis, formation of titanium hydrides in the titanium surface were observed in all specimens treated with acid-solutions. From XPS analysis, thin titanium oxide layer in the acid-treated specimens could be evaluated. Acid solution with 90℃ showed the strong effect on the titanium surface, it should be treated with caution to avoid the over-etching process.
Calcium ; Ceramics ; Microscopy, Confocal ; Photoelectron Spectroscopy ; Spectrometry, X-Ray Emission ; Surface Properties ; Titanium ; Ultrasonics ; Water