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1.
目的探讨计算机辅助设计/计算机辅助制造(CAD/CAM)切削表面形貌对氧化锆瓷与饰瓷结合强度的影响。方法将40个Upcare氧化锆基底材料以CAD/CAM切削烧结瓷块试件,随机等分为4组。其中对照组按常规操作进行打磨、喷砂及抛光等处理。实验组均采用CAD/CAM时预设程序,分别使切削产生的刀路与剪切强度测试加力方向呈垂直(A组)、平行(B组)及突起(C组),并对试件进行喷砂处理。测量并比较各组试件的表面粗糙度和剪切强度。扫描电镜观察断裂界面的情况。结果各组的剪切强度分别为:A组(27.64±4.24)MPa、B组(27.12±5.32)、C组(36.86±7.21)MPa、对照组(24.14±2.74)MPa,其中对照组与A组、B组之间差异均无统计学意义(P>0.05),对照组与C组之间的差异具有统计学意义(P<0.05)。各组的表面粗糙度分别为:A组(5578.34±1165.58)Ra、B组(5227.98±1440.29)Ra、C组(5699.97±1234.28)Ra、对照组(5964.92±1013.834)Ra,各组之间的差异无统计学意义(P>0.05)。Pearson相关性分析显示,试件表面粗糙度与剪切强度之间无线性相关关系(P>0.05)。扫描电镜观察显示C组较其他组氧化锆瓷与饰瓷结合更致密,未见气泡,无孔隙存在。结论固位突起的锆瓷表面形貌可有效增加锆瓷与饰瓷间的结合强度,而表面粗糙度对界面的结合强度无明显影响。  相似文献   

2.
目的:评价选择性激光熔覆(selective laser melting,SLM)技术制作的钴铬合金与瓷粉的结合强度。方法:根据YY 0621-2008标准采用三点弯曲法测试比较SLM和传统失蜡铸造法的钴铬合金的金瓷结合强度,采用Vita瓷粉和Noritake瓷粉,对金瓷界面进行扫描电镜观察。结果:无论Vita瓷粉或Noritake瓷粉,SLM制作法的钴铬合金的金瓷结合强度均大于传统铸造法的金瓷结合强度(P<0.05)。SEM检测显示SLM钴铬合金的金瓷渗透深度均大于传统铸造钴铬合金的金瓷渗透深度。结论:SLM钴铬合金的金瓷结合强度大于YY0621-2008标准(25 MPa),也大于传统失蜡铸造法所获得的金瓷结合强度。  相似文献   

3.
目的 比较铸造钴铬合金与选区激光熔化(SLM)钴铬合金金瓷结合强度的差异。方法 用铸造法和SLM技术制作钴铬合金试件各10个,在中间1/3区域熔附瓷粉,采用剪切力试验测试金瓷结合强度并观察断裂类型。采用SPSS 13.0软件中的t检验对结果进行统计学分析。结果铸造组、SLM组剪切力分别为(33.11±4.98)、(30.94±5.98) MPa,二者间差异无统计学意义(P>0.05)。样本的断裂类型为复合断裂。结论 SLM钴铬合金修复体精密度较高,其金瓷结合强度与铸造钴铬合金相近。  相似文献   

4.
Abstract

Aims. The aim was to compare the fracture strength of porcelain fused to metal crowns with copings fabricated in Co-Cr using different manufacturing techniques (casting, milling and laser-sintering) with crowns manufactured in a high-gold alloy. Methods. A total of 50 identical crowns were fabricated and sub-divided into five groups; cast Co-Cr, milled Co-Cr, two groups of laser-sintered Co-Cr and a control group cast in a high-gold alloy. After thermocycling (5000 cycles, 5–55°C) and pre-load (30–300 N, 10,000 cycles) the crowns were loaded until fracture. Load (N) and fracture mode were recorded. Results. There was a significant difference (p < 0.05) in fracture strength between the control group and one of the laser-sintered groups. The mean values (N) for the groups were as follows: cast Co-Cr, 1560 ± 274; milled Co-Cr, 1643 ± 153; laser-sintered Co-Cr 1, 1448 ± 168; laser-sintered Co-Cr 2, 1562 ± 72; control group, 1725 ± 220. Conclusion. There is no difference in strength between Co-Cr crowns produced using the different production technologies: casting, milling or laser-sintering. Metal ceramic crowns made with copings fabricated in a high-gold alloy present numerically higher fracture strength than crowns made with copings fabricated in Co-Cr alloys. The difference is confirmed when analyzing the fracture surfaces, but the difference in fracture strength value is limited and is only significant with regard to one of the two laser-sintered groups.  相似文献   

5.
This study compared the bond strength between metal alloys and 5 ceramic systems. Ceramic systems (Vita VMK68, Ivoclar IPSd. SIGN, Ceramco II, Matchmaker and Finesse) were fired onto either Ni-Cr or Co-Cr base metal alloy. Metal-ceramic interfaces were subjected to shear loading until failure. The ceramic type significantly affected the bond strength results (p<0.05). For Ni-Cr alloy, the results ranged between 15.4-25.3 MPa and for Co-Cr alloy between 13.3-19.0 MPa. The highest mean bond strength value was obtained with the combination of Ni-Cr alloy-Ceramco II (25.3 MPa), the lowest bond strength was received from the combination of Co-Cr alloy-Ivoclar IPS d.SIGN ceramic (13.3 MPa). Adhesive failures between metal and ceramic were significantly more frequent with Ni-Cr alloy (31 out of 50) than with Co-Cr (20 out of 50) (p<0.05). Ceramco II presented the highest bond strength with both Ni-Cr and Co-Cr being significantly different from one another.  相似文献   

6.

Statement of problem

An annealing procedure is a heat treatment process to improve the mechanical properties of cobalt-chromium (Co-Cr) alloys. However, information is lacking about the effect of the annealing process on the bonding ability of ceramic to Co-Cr alloys fabricated by rapid prototyping.

Purpose

The purpose of this in vitro study was to evaluate the effects of the fabrication techniques and the annealing procedure on the shear bond strength of ceramic to Co-Cr alloys fabricated by different techniques.

Material and methods

Ninety-six cylindrical specimens (10-mm diameter, 10-mm height) made of Co-Cr alloy were prepared by casting (C), milling (M), direct process powder-bed (LaserCUSING) with and without annealing (CL+, CL), and direct metal laser sintering (DMLS) with annealing (EL+) and without annealing (EL). After the application of ceramic to the metal specimens, the metal-ceramic bond strength was assessed using a shear force test at a crosshead speed of 0.5 mm/min. Shear bond strength values were statistically analyzed by 1-way ANOVA and Tukey multiple comparison tests (α=.05).

Results

Although statistically significant differences were found among the 3 groups (M, 29.87 ±2.06; EL, 38.92 ±2.04; and CL+, 40.93 ±2.21; P=.002), no significant differences were found among the others (P>.05). The debonding surfaces of all specimens exhibited mixed failure mode.

Conclusions

These results showed that the direct process powder-bed method is promising in terms of metal-ceramic bonding ability. The manufacturing technique of Co-Cr alloys and the annealing process influence metal-ceramic bonding.  相似文献   

7.

Statement of problem

Direct metal laser sintering (DMLS) and direct metal laser melting (DMLM) have become popular for fabricating the metal frameworks of metal-ceramic restorations. How the type of layered manufacturing device, layer thickness, and alloy powder may affect the bond strength of ceramic to metal substructure is unclear.

Purpose

The purpose of this in vitro study was to evaluate the bond strength of dental porcelain to metal frameworks fabricated using different layered manufacturing techniques (DMLS and DMLM), Co-Cr alloy powders, and layer thicknesses and to evaluate whether a correlation exists between the bond strength and the number of ceramic remnants on the metal surface.

Material and methods

A total of 75 bar-shaped metal specimens (n=15) were fabricated using either DMLS or DMLM. The powder alloys used were Keramit NP-S and EOS-Cobalt-Chrome SP-2 with layer thicknesses of 20 μm and 30 μm. After ceramic application, the metal-ceramic bond strength was evaluated with a 3-point-bend test. Three-way ANOVA followed by the Tukey honest significance difference test were used for statistical analysis (α=.05). De-bonding surface microstructure was observed with scanning electron microscopy. Energy dispersive spectroscopy analysis was conducted to evaluate the correlation between ceramic remnants on the metal surface and bond strength values.

Results

The mean bond strength value of DMLS was significantly higher than that of DMLM. While no statistically significant difference was found between layer thicknesses, alloy powders closely affected bond strength. Statistical comparisons revealed that the highest bond strength could be achieved with DMLS-Cobalt-Chrome SP2-20μm, and the lowest bond strength was observed in DMLS-Keramit NP-S-20μm (P≤.05). No correlation was found between porcelain remnants on the metal surface and bond strength values.

Conclusions

The layered manufacturing device and the alloy powders evaluated in the current study closely affected the bond strength of dental porcelain to a metal framework. However, layer thickness did not affect the bond strength.  相似文献   

8.
目的 比较激光选区熔化(selective laser melting,SLM)技术与传统方法制作的钴铬合金(Co-Cr)和钛合金(Ti6Al4V)在金瓷结合性能方面的差异。方法 分别采用传统方法(铸造法和锻造法)和SLM技术制作4组直径10 mm、厚1 mm的圆形片状试件,每组各10个,分别记为铸造Co-Cr(CC)组、锻造Ti6Al4V(DT)组、SLM Co-Cr(SC)组、SLM Ti6Al4V(ST)组。流水下打磨抛光试件,氧化铝喷砂剂喷砂后,激光扫描共聚焦显微镜(CLSM)检测试件表面粗糙度。室温下干燥后分别烧结瓷粉,采用剪切强度测试法测定各组的金瓷结合强度,并进行统计学分析。体视显微镜观察瓷层断裂模式。场发射扫描电镜(FE-SEM)对金瓷结合界面形貌进行分析。结果 各组试件表面粗糙度未见明显差异(P > 0.05)。CC组和SC组的剪切强度无明显差异,分别为(25.949 ± 2.708)MPa和(26.707 ± 1.559)MPa,均显著高于DT组[(18.259 ± 1.882)MPa]和ST组[(21.504 ± 3.019)MPa](P < 0.05),其中DT组低于ST组(P < 0.05)。各组剪切强度测试后金瓷断裂模式均为混合断裂。FE-SEM下观察显示SC组和CC组金瓷界面结合紧密,DT组和ST组金瓷界面偶见气孔和裂隙。结论 SLM技术制作的Co-Cr金瓷结合强度与传统铸造法相当,SLM技术制作的Ti6Al4V金瓷结合强度明显高于传统锻造法。SLM技术作为一种新型的激光3D打印技术,在口腔修复学领域有极大的应用潜力。  相似文献   

9.
Statement of problemSelective laser melting (SLM), an additive manufacturing technology, is expected to replace the traditional lost-wax casting process used in producing removable partial denture (RPD) frameworks. However, studies comparing the accuracy of RPD frameworks and the effects of process parameters are lacking.PurposeThe purpose of this in vitro study was to optimize SLM process parameters and use a quantitative analysis method to improve the accuracy of 3D-printed RPD frameworks.Material and methodsThe orientation and support structure of Kennedy Class II RPDs were designed in various ways by using 2 different software programs, CAMbridge and Magics. The optimum melt-pool parameters, including laser power, scan speed, hatch distance, and layer thickness, were determined empirically before manufacturing 12 RPD frameworks with 4 different process designs by using SLM (n=3). The accuracy of the RPD frameworks was determined by 3D scanning and comparing the 3D scan data with the original standard tessellation language (STL) RPD design with the best-fit algorithm of the Geomagic software program.ResultsOptimum melt-pool parameters were found with the function of density, surface roughness, and productivity (P=180 W, v=1200 mm/s, h=60 μm, t=30 μm). RPD frameworks fabricated by the optimized process parameters (167 ±105 μm) showed significantly better (P<.05) mean ±standard deviation accuracy than the 3 other groups of RPD frameworks manufactured by using the nonoptimized process parameters (180 ±121 μm to 222 ±136 μm). The best accuracy was found with the transverse orientation and interconnected support structure.ConclusionsWith the optimized design of process parameters, clinically acceptable RPD frameworks were produced. The accuracy of RPD frameworks fabricated by using SLM varied according to the design of the process parameters, indicating that SLM technology can replace the traditional lost-wax casting process.  相似文献   

10.
Shear bond strength of a ceramic to Co-Cr alloys   总被引:2,自引:0,他引:2  
STATEMENT OF PROBLEM: Different combinations of Co-Cr alloys bonded to ceramic have been used in dentistry; however, the bond strength of ceramic to metal can vary because of different compositions of these alloys. PURPOSE: The purpose of this study was to evaluate the shear bond strength of a dental ceramic to 5 commercially available Co-Cr alloys. MATERIAL AND METHODS: Five Co-Cr alloys (IPS d.SIGN 20, IPS d.SIGN 30, Remanium 2000, Heranium P, and Wirobond C) were tested and compared to a control group of an Au-Pd alloy (Olympia). Specimen disks, 5 mm high and 4 mm in diameter, were fabricated with the lost-wax technique. Sixty specimens were prepared using opaque and dentin ceramics (VITA Omega 900), veneered, 4 mm high and 4 mm in diameter, over the metal specimens (n=10). The shear bond strength test was performed in a universal testing machine with a crosshead speed of 0.5 mm/min. After shear bond testing, fracture surfaces were evaluated in a stereomicroscope under x25 magnification. Ultimate shear bond strength (MPa) data were analyzed with 1-way ANOVA and the Tukey HSD test (alpha =.05). RESULTS: The mean (SD) bond strengths (MPa) were: 61.4 (7.8) for Olympia; 94.0 (18.9) for IPS 20; 96.8 (10.2) for IPS 30; 75.1 (12.4) for Remanium; 71.2 (14.3) for Heranium P; and 63.2 (10.9) for Wirobond C. Mean bond strengths for IPS 20 and IPS 30 were not significantly different, but were significantly (P<.001) higher than mean bond strengths for the other 4 alloys, which were not significantly different from each other. CONCLUSIONS: Bond strength of a dental ceramic to a Co-Cr alloy is dependent on the alloy composition.  相似文献   

11.
目的:探讨不同钛基底表面处理对钛与树脂粘接强度的影响。方法将纯钛试件随机平均分组:光滑组(A组)、酸蚀组(B组)、喷砂组(C组)、喷砂+酸蚀组(D组)、微弧氧化组(E组)、氮化钛涂层组(F组)。根据以上分组,对试件进行相应的表面处理,用粗糙度仪进行钛表面粗糙度测量,后与Cemerage冠桥树脂结合,扫描电子显微镜(SEM)观察试件表面形貌,能谱分析仪(EDS)对表面元素进行分析,万能试验机检测试件与Cemerage冠桥树脂的粘接强度。结果各组的粗糙度分别为A组(0.370±0.039)μm;B组(1.456±0.044)μm;C组(2.044±0.019)μm;D组(1.970±0.047)μm,E组(0.683±0.023)μm;F组(2.195±0.066)μm。各组的剪切强度分别为A组(5.84±0.30)MPa;B组(10.22±0.63)MPa;C组(10.78±0.45)MPa;D组(12.24±0.46)MPa;E组(13.82±0.61)MPa;F组(16.81±0.74)MPa。结论钛基底表面喷砂结合酸蚀,微弧氧化及氮化钛涂层处理均可有效提高树脂与钛的粘接强度。  相似文献   

12.
目的研究3D打印和铸造钴铬合金的耐蚀性及腐蚀对其力学稳定性的影响。 方法采用3D打印技术中选择性激光熔融技术(SLM)和传统铸造技术共制作钴铬合金试件72个,根据是否腐蚀采用随机数字法随机平均分为12组(每组6个),各组用于不同的测试及进入腐蚀。采用静态浸泡腐蚀法对试件进行腐蚀实验,激光扫描共聚焦显微镜(CLSM)检测试件表面粗糙度(Ra)及表面形貌,显微硬度计测量显微维氏硬度(VHN),万能测试机测试拉伸强度(TS)及弯曲强度(BS)。工艺和腐蚀对Ra、VHN、TS、BS等值的影响采用双因素析因方差分析进行分析(α= 0.05),Bonferroni法进行组间两两比较。 结果工艺和腐蚀对Ra和BS无交互效应(FRa= 2.989,PRa= 0.099;FBS= 0.480,PBS= 0.496)。两因素对Co-Cr合金的Ra值的主效应均有统计学意义(F工艺=6.262,P工艺=0.021;F腐蚀= 6.581,P腐蚀= 0.018),3D组的Ra值[(0.084 ± 0.026)μm]低于铸造组[(0.111 ± 0.024)μm],对照组的Ra值[(0.084 ± 0.025)μm]低于腐蚀组[(0.111 ± 0.025)μm]。两因素对Co-Cr合金的BS值的主效应均有统计学意义(F工艺= 6.753,P工艺= 0.013;F腐蚀= 7.384,P腐蚀= 0.017),3D组的BS值[(1651 ± 242)MPa]高于铸造组[(1371 ± 252)MPa],对照组的BS值[(1645±183)MPa]高于腐蚀组[(1377±310)MPa]。两因素对VHN和TS有交互效应(FVHN=5.018,PVHN=0.037;FTS= 5.903,PTS= 0.025)。Bonferroni法组间两两比较结果显示,3D对照组VHN值和TS值[VHN3D=(469 ± 4)HV,TS3D=(1010 ± 46)MPa]与铸造对照组[VHN铸造=(418 ± 4)HV,TS铸造=(827 ± 25)MPa]比较,差异有统计学意义(PVHN<0.001,PTS<0.001);3D腐蚀组VHN值及TS值[VHN3D=(418±3)HV,TS3D=(985 ± 30)MPa]与铸造腐蚀组[VHN铸造=(375 ± 5)HV,TS铸造=(728 ± 45)MPa]比较,差异有统计学意义(PVHN<0.001,PTS<0.001);3D对照组VHN值与3D腐蚀组比较差异有统计学意义(P<0.001),3D对照组TS值与3D腐蚀组比较差异无统计学意义(P= 1.000);铸造对照组VHN值及TS值与铸造腐蚀组差异有统计学意义(PVHN<0.001,PTS= 0.001)。 结论3D打印钴铬合金较铸造钴铬合金耐蚀性更优;前者TS、BS的稳定性均大于后者,两者的VHN稳定性相当。  相似文献   

13.
Objective:To determine and compare the longitudinal and transverse roughness parameters of the enamel surface of bovine teeth and evaluate the influence of these parameters on bond strength.Materials and Methods:Ninety bovine incisors were used. The surface roughness of enamel was measured with a profilometer. For each tooth, five readings were taken in the longitudinal plane and five were taken in the transverse plane of the long axis of the tooth in an area equal to the size of the bracket base. The metal brackets were bonded with Transbond XT, and bond strength was evaluated in a universal test machine.Results:There was a statistical correlation (P < .01) between the longitudinal and transverse roughness measurements. There was no correlation between roughness measurements (longitudinal and transverse) and bond strength (P > .05), nor was there a correlation between total roughness (longitudinal Ra and transverse Ra) and bond strength. The Student''s t-test showed that there was a statistically significant difference (P < .05) between longitudinal and transverse roughness.Conclusion:The transverse roughness is greater than the longitudinal roughness, there is a strong correlation between longitudinal and transverse roughness, and there is no correlation between enamel roughness and bond strength.  相似文献   

14.

Statement of problem

The clinical applications of high-translucency monolithic zirconia restorations have increased. Chairside and laboratory adjustments of these restorations are inevitable, which may lead to increased roughness and reduced strength. The influence of grinding and polishing on high-translucency zirconia has not been investigated.

Purpose

The purpose of this in vitro study was to compare the roughness averages (Ra) of ground and polished zirconia and investigate whether roughness influenced strength after aging.

Material and methods

High-translucency zirconia disks were milled, sintered, and glazed according to the manufacturer’s recommendations. Specimens were randomized to 4 equal groups. Group G received only grinding; groups GPB and GPK received grinding and polishing with different polishing systems; and group C was the (unground) control group. All specimens were subjected to hydrothermal aging in an autoclave at 134°C at 200 kPa for 3 hours. Roughness average was measured using a 3-dimensional (3D) optical interferometer at baseline (Ra1), after grinding and polishing (Ra2), and after aging (Ra3). A biaxial flexural strength test was performed at a rate of 0.5 mm/min. Statistical analyses were performed using commercial software (α=.05).

Results

Group G showed a significantly higher mean value of Ra3 (1.96 ±0.32 μm) than polished and glazed groups (P<.001), which showed no statistically significant difference among them (GPB, 1.12 ±0.31 µm; GPK, 0.88 ±0.31 µm; C: 0.87 ±0.25 μm) (P>.05). Compared with baseline, the roughness of groups G and GPB increased significantly after surface treatments and after aging, whereas aging did not significantly influence the roughness of groups GPK or C. Group G showed the lowest mean value of biaxial flexural strength (879.01 ±157.99 MPa), and the highest value was achieved by group C (962.40 ±113.84 MPa); no statistically significant differences were found among groups (P>.05). Additionally, no significant correlation was detected between the Ra and flexural strength of zirconia.

Conclusions

Grinding increased the roughness of zirconia restorations, whereas proper polishing resulted in smoothness comparable with glazed surfaces. The results provide no evidence that grinding and polishing affect the flexural strength of zirconia after aging.  相似文献   

15.
PurposeTo compare the effects of airborne-particle abrasion protocols on the surface morphology, the phase transformation and the resin bond strength of highly translucent zirconia (M) and conventional zirconia (Z).MethodsThirteen groups (N = 12) of Z and M specimens were prepared. Except for the control group, the specimens were sandblasted with conditions involving different grit sizes (50 μm or 110 μm), treatment times (10 s or 20 s) and pressures (0.1 MPa, 0.3 MPa or 0.6 MPa). The surface morphology was analyzed using scanning electron microscope (SEM) and the phase analysis was conducted with X-ray diffraction (XRD). The Ra and the shear bond strength (SBS) were measured and statistically analyzed, and the failure mode was determined by optical microscope.ResultsThe surface morphologies were strongly dependent on treatment conditions. Larger particle size and higher pressure resulted in higher Ra for both materials. Longer blasting time resulted in higher Ra for Z but not M. Overall, the SBS increased with increasing Ra; the highest average SBS was achieved by M and exceeded 18 MPa. The monoclinic transformation was not found in any treatment for M, but was found in Z.ConclusionsZ and M showed different dependence on the airborne-particle abrasion parameters in terms of Ra, SBS and phase transformation. The conditions for maximizing SBS included a 110 μm particle size and 20 s treatment for both, with pressures of 0.3 MPa and 0.6 MPa for the M and Z, respectively.  相似文献   

16.

Statement of problem

Heat treatment has been used to reduce the residual stress of alloys fabricated by selective laser melting (SLM) to avoid deformation. Co-Cr metal-ceramic alloys are used to fabricate metal-ceramic restorations and removable partial dentures (RPDs) on the same substrate by SLM. A heat treatment that enables the fabrication of metal-ceramic restorations and RPDs with excellent mechanical properties should be evaluated.

Purpose

The purpose of this in vitro study was to determine the effects of 2 heat treatments on the mechanical properties of SLM Co-Cr metal-ceramic alloys intended for the fabrication of thin RPDs.

Material and methods

Tensile bars were manufactured using cast metal-ceramics (C-MC group), RPD alloys (C-RPD group), and SLM Co-Cr metal-ceramic alloys. The SLM specimens were subjected to 2 different heat treatments, L1 at 880°C and L2 at 1100°C, and were further divided into subgroups (L1-MC, L1-RPD, L2-MC, and L2-RPD). Thirty-six tensile specimens were prepared in C-RPD, L1-RPD, and L2-RPD (simulated partial denture alloys for clinical use) and in C-MC, L1-MC, and L2-MC (simulated metal-ceramic alloys); 18 metal-ceramic bond strength specimens were prepared in C-MC, L1-MC, and L2-MC groups (n=6). The tensile test and 3-point bend test were conducted using a universal testing machine. The fracture surfaces of the L2-RPD tensile bar were examined using a scanning electron microscope. The Student t test (α=.05) was used for statistical analysis.

Results

No significant differences were observed between the bond strengths of L1-MC and C-MC (P=.74) or between those of L2-MC and C-MC (P=.124). The 0.2% yield strength (σ0.2) and elongation of all SLM specimens exceeded the minimum requirements required for the fabrication of thin RPDs as prescribed in ISO 22674:2016. The σ0.2 value of L1-MC and L2-MC was significantly higher than that of C-MC. Significant differences in σ0.2 values were found among the 3 RPD groups, L1-RPD>L2-RPD>C-RPD. For the elongation, significant differences were found among the 3 groups, L2-RPD>C-RPD>L1-RPD. The fracture surface of L2-RPD showed clear submicroscale dimples with fusion defects.

Conclusions

When Co-Cr metal copings and RPD frameworks were fabricated on the same substrate simultaneously using SLM, heat treatment at 1100°C was found more suitable than at 880°C to release residual stress, considering the toughness required for dental prostheses.  相似文献   

17.
PurposeThe aim of this study is to evaluate the effect of fusion sputtering surface treatment on the microshear bond strength of zirconia and self-adhesive MDP-containing resin cement.MaterialsThirty-six zirconia discs received one of the following treatments: fusion sputtering, airborne particle abrasion with 50-μm aluminum oxide particles, while as-sintered specimens served as a control. Four treated zirconia samples from each group were examined using 3D laser scanning microscope to assess the surface roughness and scanning electron microscope to study the surface topography. The specimens of each group were bonded to composite micro discs using MDP-containing self-adhesive resin cement (Panavia SA cement plus). The specimens were thermocycled for 5000 cycles between 5 and 55 °C. Microshear bond strength test was performed using universal testing machine until bonding failure. Failure modes and fracture surfaces was evaluated using scanning electron microscope.ResultsThe fusion sputtering surface treatment significantly influenced zirconia-resin bond strength (p < 0.001). The highest mean microshear bond strength value was observed in fusion sputtering treatment (23.18 ± 4.38). The lowest value was observed in as-sintered zirconia surfaces (7.23 ± 6.26).SignificanceFusion sputtering surface treatment enhanced the microshear bond strength of zirconia and resin cement.  相似文献   

18.
目的 评价不同氢氟酸处理时间对玻璃陶瓷表面与树脂粘接耐久性的影响,以期为玻璃陶瓷表面氢氟酸处理时间的正确选择提供临床参考.方法 可切削玻璃陶瓷(PmCAD)表面接受4.8%氢氟酸处理0 s(对照组)、30 s(30 s氢氟酸处理组)和60 s(60 s氢氟酸处理组),每组32个陶瓷片.使用三维激光共聚焦显微镜测量陶瓷片表面粗糙度参数(Ra)和表面积.陶瓷片与4种粘接套装(硅烷偶联剂和树脂粘接剂:A:Monobond S和Variolink Ⅱ;B:Clearfil Ceramic Primer和Clearfil Esthetic Cement;C:GC Ceramic Primer和Linkmax HV;D:Porcelain Liner M和SuperBond)粘接形成粘接试件,每组16个陶瓷片直接测量粘接强度,16个陶瓷片经30 000次冷热循环后测量粘接强度.结果 对照组、30和60 s氢氟酸处理组Ra值[分别为(3.89±1.94)、(12.53±0.80)、(13.58±1.10)μm]及表面积[分别为(7.81±2.96)、(30.18±2.05)、(34.16±1.97)mm2]随着氢氟酸处理时间的延长而显著增加(P<0.05).同种粘接套装相同氢氟酸处理时间下冷热循环后试件的粘接强度均显著低于冷热循环前(P<0.05).冷热循环后粘接套装A、B的粘接强度随着氢氟酸处理时间的延长而显著增加[A:分别为(3.59±3.51)、(16.18±2.62)、(20.33±2.45)Mpa;B:分别为(4.74±2.08)、(7.77±1.55)、(13.45±3.75)Mpa];粘接套装D 30 s氢氟酸处理组的粘接强度[(22.00±1.64)Mpa]显著高于相应对照组[(12.96±4.17)Mpa],但与60 s氢氟酸处理组[(20.42±3.01)Mpa]相比,差异无统计学意义(P>0.05);氢氟酸处理时间未对粘接套装C的粘接强度产生显著影响.结论 氢氟酸处理能提高玻璃陶瓷与树脂的粘接耐久性,氢氟酸处理时间的选择不仅取决于陶瓷表面结构的变化,也取决于所使用的粘接套装.  相似文献   

19.
PurposeStudying the effect of surface roughness and thermal cycling on titanium–ceramic bonding.MethodsOne hundred fourteen samples in the form of bar for the C.P. titanium and Ti–6Al–4V alloy were used. They were divided into two groups according to the type of bar. Each group was then subdivided according to the type of surface treatment to three subgroups, control, airborne-particle abrasion and silica coated. Each subgroup was subdivided into two classes according to the type of test (surface roughness and bond strength). Samples used for the bond strength test were veneered. These samples were subdivided into two subclasses according to thermal cycling; whether without thermal cycling or after 6000 thermal cycles.ResultsThe surface roughness test results showed that silica coating recorded the highest surface roughness. Also C.P. titanium gave higher value of surface roughness than Ti–6Al–4V alloy. As regard the bond strength, the airborne-particle abrasion classes and the silica coated classes recorded bond strength values above the acceptable limit of 25 MPa determined in ISO 9693. As regard thermal cycling, the results showed that aging by thermal cycling decreased the metal–ceramic bond strength.ConclusionsThe airborne-particle abrasion and the silica coating are acceptable treatments for titanium–ceramic restorations. Increasing surface roughness of C.P. titanium and Ti–6Al–4V alloy not necessarily results in an increase in their bond strength to ceramics. Aging affects the metal–ceramic bond strength.  相似文献   

20.
Statement of problemThe extrinsic characterization with pigments and glaze application on the surface of ceramic restorations promotes individualization and esthetics. However, whether this characterization is resistant to toothbrushing abrasive wear is unclear.PurposeThe purpose of this in vitro study was to investigate the abrasive wear resistance of characterized and glazed resin-modified ceramic with different surface treatments before characterization.Material and methodsEighty rectangular specimens (10×8×6 mm) were precision cut from Vita Enamic and randomly divided in 4 groups as per the surface treatment before the characterization technique. These groups included the following: no additional treatment or polishing only, acid etching, airborne-particle abrasion, and self-etching silanization. For each surface treatment, 2 subgroups were created considering the presence or absence of the glaze layer after shade characterization, totaling 8 groups (n=10). The specimens were submitted to toothbrushing simulation (150 000 cycles, 2.45-N, 180 strokes per minute) with a soft and straight toothbrush and a solution of toothpaste and distilled water (250 g/L). After each 50 000 cycles, the wear of the characterized surface was measured by using a contact profilometer in μm which was equivalent to 5, 10, and 15 years of simulated toothbrushing. The rates were analyzed by using 3-way ANOVA and the post hoc Tukey test (α=.05). Scanning electron microscopy analysis was performed to access the surface profile between the evaluated periods.ResultsThe mean wear rate (Rz) of the characterized surface was affected by the isolated factors, including surface treatment, glaze, and time (P<.001), with no interactive effects noted. A higher mean value of Rz was observed for polishing only (12.9 ±4.4 μm), followed by airborne-particle abrasion (10.2 ±4.5 μm), acid etching (9.4 ±2.4 μm), and then self-etching silanization (7.6 ±2.9 μm). Mean wear rate was also increased by the glaze (11.1 ±4.7 μm) compared with its absence (9 ±3.2 μm) and by the length of time, with 15 years (11.3 ±4.5 μm) followed by 10 years (9.8 ±4.0 μm) and 5 years (9 ±3.6 μm). The scanning electron microscopy images showed similar worn surfaces for each subgroup, glaze removal after 150 000 cycles, and surface homogeneity in function of time.ConclusionsSelf-etching silanization was found to be the treatment suitable for reducing the wear of characterized resin-modified ceramic during prolonged brushing of more than 5 years. Glaze application did not protect the characterization from surface wear, regardless of the ceramic surface treatment performed on the specimens.  相似文献   

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