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Waddell JN, Deckhart I, Welge M, Ichim I, Swain MV. The influence of flame and furnace soldering method on the stress corrosion, fatigue resistance and fracture toughness of soldered bar attachment systems for implant overdentures. J R Soc N Z 2019. [DOI: 10.1080/03036758.2019.1681478] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- John Neil Waddell
- Sir John Walsh Research Institute, School of Dentistry, University of Otago, Dunedin, New Zealand
| | - Insa Deckhart
- Dental Technology, Faculty of Engineering and Computer Science, University of Applied Sciences, Osnabrueck, Germany
| | - Melanie Welge
- Dental Technology, Faculty of Engineering and Computer Science, University of Applied Sciences, Osnabrueck, Germany
| | - Ionut Ichim
- School of Dentistry, University of Western Australia, Crawley, Australia
| | - Michael V. Swain
- University of Sydney Dental School, C24 – Westmead Hospital, University of Sydney, Sydney, Australia
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Bratos M, Bergin JM, Rubenstein JE, Sorensen JA. Effect of simulated intraoral variables on the accuracy of a photogrammetric imaging technique for complete-arch implant prostheses. J Prosthet Dent 2018; 120:232-241. [DOI: 10.1016/j.prosdent.2017.11.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 11/01/2017] [Accepted: 11/01/2017] [Indexed: 10/17/2022]
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Corrosion in artificial saliva of a Ni-Cr-based dental alloy joined by TIG welding and conventional brazing. J Prosthet Dent 2015; 114:278-85. [DOI: 10.1016/j.prosdent.2015.01.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2014] [Revised: 01/28/2015] [Accepted: 01/28/2015] [Indexed: 11/17/2022]
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Bertrand C, Poulon-Quintin A. Temporal pulse shaping: a key parameter for the laser welding of dental alloys. Lasers Med Sci 2014; 30:1457-64. [PMID: 24913424 DOI: 10.1007/s10103-014-1606-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Accepted: 05/28/2014] [Indexed: 11/26/2022]
Abstract
This study aims to describe the effect of pulse shaping on the prevention of internal defects during laser welding for two dental alloys mainly used in prosthetic dentistry. Single spot, weld beads, and welds with 80 % overlapping were performed on Co-Cr-Mo and Pd-Ag-Sn cast plates with a pulsed neodymium-doped yttrium aluminum garnet (Nd:YAG) laser. A specific welding procedure using adapted parameters to each alloy was completed. All the possibilities for pulse shaping were tested: (1) the square pulse shape as a default setting, (2) a rising edge slope for gradual heating, (3) a falling edge slope to slow the cooling process, and (4) a combination of rising and falling edges. The optimization of the pulse shape is supposed to produce defect-free welds (crack, pores, voids). Cross-section SEM observations and Vickers microhardness measurements were made. Pd-Ag-Sn was highly sensitive to hot cracking, and Co-Cr-Mo was more sensitive to voids and small porosities (sometimes combined with cracks). Using a slow cooling ramp allowed a better control on the solidification process for those two alloys always preventing internal defects. A rapid slope should be preferred for Co-Cr-Mo alloys due to its low-laser beam reflectivity. On the opposite, for Pd-Ag-Sn alloy, a slow rising slope should be preferred because this alloy has a high-laser beam reflectivity.
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Affiliation(s)
- Caroline Bertrand
- Institut de la Chimie de la Matière Condensée de Bordeaux (ICMCB), C.N.R.S., UPR9048, Université Bordeaux, 87 Avenue du Dr. Albert Schweitzer, 33608, Pessac, France,
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Ghadhanfari HA, Khajah HM, Monaco EA, Kim H. Effects of soldering methods on tensile strength of a gold-palladium metal ceramic alloy. J Prosthet Dent 2014; 112:994-1000. [PMID: 24840906 DOI: 10.1016/j.prosdent.2014.02.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Revised: 02/10/2014] [Accepted: 02/10/2014] [Indexed: 11/28/2022]
Abstract
STATEMENT OF PROBLEM The tensile strength obtained by conventional postceramic application soldering and laser postceramic welding may require more energy than microwave postceramic soldering, which could provide similar tensile strength values. PURPOSE The purpose of the study was to compare the tensile strength obtained by microwave postceramic soldering, conventional postceramic soldering, and laser postceramic welding. MATERIAL AND METHODS A gold-palladium metal ceramic alloy and gold-based solder were used in this study. Twenty-seven wax specimens were cast in gold-palladium noble metal and divided into 4 groups: laser welding with a specific postfiller noble metal, microwave soldering with a postceramic solder, conventional soldering with the same postceramic solder used in the microwave soldering group, and a nonsectioned control group. All the specimens were heat treated to simulate a normal porcelain sintering sequence. An Instron Universal Testing Machine was used to measure the tensile strength for the 4 groups. The means were analyzed statistically with 1-way ANOVA. The surface and fracture sites of the specimens were subjectively evaluated for fracture type and porosities by using a scanning electron microscope. RESULTS The mean (standard deviation) ultimate tensile strength values were as follows: nonsectioned control 818 ±30 MPa, microwave 516 ±34 MPa, conventional 454 ±37 MPa, and laser weld 191 ±39 MPa. A 1-way ANOVA showed a significant difference in ultimate tensile strength among the groups (F3,23=334.5; P<.001). Follow-up multiple comparisons showed a significant difference among all the groups. Microwave soldering resulted in a higher tensile strength for gold and palladium noble metals than either conventional soldering or laser welding. CONCLUSION Conventional soldering resulted in a higher tensile strength than laser welding. Under the experimental conditions described, either microwave or conventional postceramic soldering would appear to satisfy clinical requirements related to tensile strength.
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Affiliation(s)
| | - Hasan M Khajah
- Consultant, Fixed Prosthodontics, Al-Amiri Dental Center, Kuwait City, Kuwait.
| | - Edward A Monaco
- Assistant Professor and Director, Postgraduate Prosthodontics, Department of Restorative Dentistry, School of Dental Medicine, State University of New York at Buffalo, Buffalo, NY
| | - Hyeongil Kim
- Assistant Professor, Postgraduate Prosthodontics, Department of Restorative Dentistry School of Dental Medicine, State University of New York at Buffalo, Buffalo, NY
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Al Jabbari YS, Koutsoukis T, Barmpagadaki X, El-Danaf EA, Fournelle RA, Zinelis S. Effect of Nd:YAG laser parameters on the penetration depth of a representative Ni-Cr dental casting alloy. Lasers Med Sci 2013; 30:909-14. [PMID: 24326743 DOI: 10.1007/s10103-013-1502-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Accepted: 11/25/2013] [Indexed: 11/26/2022]
Abstract
The effects of voltage and laser beam (spot) diameter on the penetration depth during laser beam welding in a representative nickel-chromium (Ni-Cr) dental alloy were the subject of this study. The cast alloy specimens were butted against each other and laser welded at their interface using various voltages (160-390 V) and spot diameters (0.2-1.8 mm) and a constant pulse duration of 10 ms. After welding, the laser beam penetration depths in the alloy were measured. The results were plotted and were statistically analyzed with a two-way ANOVA, employing voltage and spot diameter as the discriminating variables and using Holm-Sidak post hoc method (a = 0.05). The maximum penetration depth was 4.7 mm. The penetration depth increased as the spot diameter decreased at a fixed voltage and increased as the voltage increased at a fixed spot diameter. Varying the parameters of voltage and laser spot diameter significantly affected the depth of penetration of the dental cast Ni-Cr alloy. The penetration depth of laser-welded Ni-Cr dental alloys can be accurately adjusted based on the aforementioned results, leading to successfully joined/repaired dental restorations, saving manufacturing time, reducing final cost, and enhancing the longevity of dental prostheses.
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Affiliation(s)
- Youssef S Al Jabbari
- Dental Biomaterials Research and Development Chair, College of Dentistry, King Saud University, P.O. Box 60169, Riyadh, 11545, Saudi Arabia,
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Bertrand C, Poulon-Quintin A. Effect of temporal pulse shaping on the reduction of laser weld defects in a Pd-Ag-Sn dental alloy. Dent Mater 2010; 27:e43-50. [PMID: 21081247 DOI: 10.1016/j.dental.2010.10.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2009] [Revised: 07/29/2010] [Accepted: 10/21/2010] [Indexed: 10/18/2022]
Abstract
OBJECTIVES To describe the influence of pulse shaping on the behavior of a palladium-based dental alloy during laser welding and to show how its choice is effective to promote good weld quality. METHODS Single spots, weld beads and welds with 80% overlapping were performed on Pd-Ag-Sn cast plates. A pulsed Nd:Yag laser was used with a specific welding procedure using all the possibilities for pulse-shaping: (1) the square pulse shape as the default setting, (2) a rising edge slope for gradual heating, (3) a falling edge slope to slow the cooling and (4) a combination of a rising and falling edges called bridge shape. The optimization of the pulse shape is supposed to enhance weldability and produce defect-free welds (cracks, pores…) Vickers microhardness measurements were made on cross sections of the welds. RESULTS A correlation between laser welding parameters and microstructure evolution was found. Hot cracking and internal porosities were systematically detected when using rapid cooling. The presence of these types of defects was significantly reduced with the slow cooling of the molten pool. The best weld quality was obtained with the use of the bridge shape. SIGNIFICANCE The use of a slow cooling ramp is the only way to significantly reduce the presence of typical defects within the welds for this Pd-based alloy studied.
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Affiliation(s)
- C Bertrand
- Department of Prosthodontics, University Victor Segalen Bordeaux 2, France.
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Waddell JN, Payne AGT, Swain MV, Kieser JA. Scanning Electron Microscopy Observations of Failures of Implant Overdenture Bars: A Case Series Report. Clin Implant Dent Relat Res 2010; 12:26-38. [DOI: 10.1111/j.1708-8208.2008.00127.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Lin MC, Lin SC, Wang YT, Hu SW, Lee TH, Chen LK, Huang HH. Fracture resistance of Nd:YAG laser-welded cast titanium joints with various clinical thicknesses and welding pulse energies. Dent Mater J 2007; 26:367-72. [PMID: 17694746 DOI: 10.4012/dmj.26.367] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The purpose of this study was to evaluate the fracture resistance of Nd:YAG laser-welded cast titanium (Ti) joints with various clinical thicknesses and welding pulse energies. A four-point bending test was used to assess the effects of various specimen thicknesses (1-3 mm) and welding pulse energies (11-24 J) on the fracture resistance of Nd:YAG laser-welded Ti dental joints. Fracture resistance was evaluated in terms of the ratio of the number of fractured specimens to the number of tested specimens. As for the fracture frequencies, they were compared using the Cochran-Mantel-Haenszel test. Morphology of the fractured Ti joints was observed using a scanning electron microscope. Results showed that decreasing the specimen thickness and/or increasing the welding pulse energy, i.e., increasing the welded area percentage, resulted in an increase in the fracture resistance of the Ti joint. Where fracture occurred, the fracture site would be at the center of the weld metal.
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Affiliation(s)
- Mau-Chin Lin
- Department of Dental Laboratory Technology, Central Taiwan University of Science and Technology, Taichung 406, Taiwan
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Huang HH, Lin MC, Lin CC, Lin SC, Hsu CC, Chen FL, Lee SY, Hung CC. Effects of welding pulse energy and fluoride ion on the cracking susceptibility and fatigue behavior of Nd:YAG laser-welded cast titanium joints. Dent Mater J 2007; 25:632-40. [PMID: 17076339 DOI: 10.4012/dmj.25.632] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
In this study, the cracking susceptibility and fatigue behavior of Nd:YAG laser-welded cast Ti joints (welding pulse energy: 11, 15, and 18 J) in fluoride-containing (0 and 0.5% NaF) artificial saliva were evaluated using constant elongation rate test (CERT) and fatigue test (FT), respectively. Both CERT and FT were also carried out in open air as controls. Results showed that increasing the welding energy increased the elongation and fatigue life, but decreased the tensile strength, of cast Ti joints in open-air environment. With a welding energy of 11 J, the fluoride ions in the artificial saliva increased the cracking susceptibility and decreased the fatigue life of Ti joints. When the welding energy exceeded 15 J, the presence of fluoride ions still increased the cracking susceptibility, but did not reduce the fatigue life of Ti joints. Rupture of Ti joints--if it occurred--occurred only at the welded metal (versus the non-welded part).
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Affiliation(s)
- Her-Hsiung Huang
- Faculty of Dentistry, School of Dentistry, National Yang-Ming University, Taipei, Taiwan
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Zupancic R, Legat A, Funduk N. Tensile strength and corrosion resistance of brazed and laser-welded cobalt-chromium alloy joints. J Prosthet Dent 2006; 96:273-82. [PMID: 17052472 DOI: 10.1016/j.prosdent.2006.08.006] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
STATEMENT OF PROBLEM The longevity of prosthodontic restorations is often limited due to the mechanical or corrosive failure occurring at the sites where segments of a metal framework are joined together. PURPOSE The purpose of this study was to determine which joining method offers the best properties to cobalt-chromium alloy frameworks. Brazed and 2 types of laser-welded joints were compared for their mechanical and corrosion characteristics. MATERIAL AND METHODS Sixty-eight cylindrical cobalt-chromium dental alloy specimens, 35 mm long and 2 mm in diameter, were cast. Sixteen specimens were selected for electrochemical measurements in an artificial saliva solution and divided into 4 groups (n=4). In the intact group, the specimens were left as cast. The specimens of the remaining 3 groups were sectioned at the center, perpendicular to the long-axis, and were subsequently rejoined by brazing (brazing group) or laser welding using an X- or I-shaped joint design (X laser and I laser groups, respectively). Another 16 specimens were selected for electrochemical measurements in a more acidic artificial saliva solution. These specimens were also divided into 4 groups (n=4) as described above. Electrochemical impedance spectroscopy and potentiodynamic polarization were used to assess corrosion potentials, breakdown potentials, corrosion current densities, total impedances at lowest frequency, and polarization charge-transfer resistances. The remaining 36 specimens were used for tensile testing. They were divided into 3 groups in which specimen pairs (n=6) were joined by brazing or laser welding to form 70-mm-long cylindrical rods. The tensile strength (MPa) was measured using a universal testing machine. Differences between groups were analyzed using 1-way analysis of variance (alpha=.05). The fracture surfaces and corrosion defects were examined with a scanning electron microscope. RESULTS The average tensile strength of brazed joints was 792 MPa and was significantly greater (P<.05) than the tensile strength of both types of laser-welded joints (404 MPa and 405 MPa). When laser welding was used, successful joining was limited to the peripheral aspects of the weld. The welding technique did not significantly affect the joint tensile strength. Electrochemical measurements indicated that the corrosion resistance of the laser-welded joints was better than of the brazed ones, primarily due to differences in passivation ability. CONCLUSION Laser welding provides excellent corrosion resistance to cobalt-chromium alloy joints, but strength is limited due to the shallow weld penetration. Brazed joints are less resistant to corrosion but have higher tensile strength than laser welds.
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Affiliation(s)
- Rok Zupancic
- Department of Prosthodontics, University of Ljubljana, Faculty of Medicine, Division of Dental Medicine, Slovenia.
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Waddell JN, Payne AGT, Swain MV. Physical and metallurgical considerations of failures of soldered bars in bar attachment systems for implant overdentures: a review of the literature. J Prosthet Dent 2006; 96:283-8. [PMID: 17052473 DOI: 10.1016/j.prosdent.2006.07.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The purpose of this literature review was to identify the etiological factors of failure of soldered bars in bar attachment systems for removable implant overdentures. A search of MEDLINE using the key words "bar attachment systems" was performed of English language peer-reviewed journals published between 1975 and 2005. Clinical studies of implant overdentures with prosthodontic maintenance complications of bar attachment systems were identified to establish the perceived etiology of failure. A further search of MEDLINE using the key words "solder joint" was also performed of the fixed prosthodontic literature to identify specific factors affecting the strength, fatigue resistance, and quality of gold solder joints used for bar attachment systems. The first search on bar attachment systems produced evidence of low failure rates of interabutment bars, but higher failure rates of bars where distal cantilever extensions were used. There were no explanations or descriptions of the nature of those failures in the clinical studies reviewed. The second search on fixed prosthodontic literature identified multiple factors that could potentially relate to the failed solder joints with bar attachments. Two potential sites of failure in bar attachments with distal cantilevers were identified, and a simple estimate of the tensile stresses at the solder joints was performed. The values found are comparable to the fatigue failure stresses reported in the searched literature.
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Affiliation(s)
- J Neil Waddell
- Discipline of Dental Technology, Department of Oral Rehabilitation, Oral Implantology Area of Research Strength, School of Dentistry, University of Otago, Dunedin, New Zealand
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Shehab AH, Pappas M, Burns DR, Douglas H, Moon PC. Comparative tensile strengths of preceramic and postceramic solder connectors using high-palladium alloy. J Prosthet Dent 2005; 93:148-52. [PMID: 15674225 DOI: 10.1016/j.prosdent.2004.11.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
STATEMENT OF PROBLEM It is not known whether different high-palladium alloys of similar composition possess comparable tensile strength properties associated with connector soldering. PURPOSE The purpose of this study was to evaluate the tensile strength properties of 2 high-palladium alloys on soldered connectors under simulated pre-ceramic and post-ceramic soldering conditions. MATERIAL AND METHODS Eighty cylindrical castings were fabricated (Rx Naturelle Plus alloy and Option alloy). The 40 castings for each alloy were subdivided into 2 groups of 20 each. In the first group, castings for each alloy were randomly paired and soldered with presolder (SMG2) to produce 10 preceramic test connector specimens for each alloy. In the second group, castings were similarly paired and soldered with postsolder (490 fine) to produce 10 postceramic test connector specimens for each alloy. Each soldered connector was subjected to tensile force until failure in a universal testing machine. Statistical analysis using a Wilcoxon rank sums test was performed (alpha=.05) RESULTS No significant difference was found between the mean tensile failure stress for Rx Naturelle Plus preceramic solder (344.7 +/- 77.6 MPa) compared to Option preceramic solder (411.5 +/- 112.8 MPa) (P =.1202). However, the mean tensile failure stress for Rx Naturelle Plus postceramic solder (260.8 +/- 223.7 MPa) was significantly lower than the Option postceramic solder (312.6 +/- 120.8 MPa) (P =.0407). Not only did Rx Naturelle Plus postceramic solder connectors show evidence of lower strength, but also an increased variation among specimens. CONCLUSIONS Rx Naturelle Plus solder connectors provided better strength with the preceramic as opposed with the postceramic connectors. For postsolder connectors, Rx Naturelle Plus alloy had less acceptable strength and a wider variation, suggesting it is more technique sensitive than Option alloy connectors.
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Affiliation(s)
- Abdul-Hadi Shehab
- Virginia Commonwealth University School of Dentistry, Richmond, VA 23298-0566, USA
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Baba N, Watanabe I, Liu J, Atsuta M. Mechanical strength of laser-welded cobalt-chromium alloy. J Biomed Mater Res B Appl Biomater 2004; 69:121-4. [PMID: 15116400 DOI: 10.1002/jbm.b.10082] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The purpose of this study was to investigate the effect of the output energy of laser welding and welding methods on the joint strength of cobalt-chromium (Co-Cr) alloy. Two types of cast Co-Cr plates were prepared, and transverse sections were made at the center of the plate. The cut surfaces were butted against one another, and the joints welded with a laser-welding machine at several levels of output energy with the use of two methods. The fracture force required to break specimens was determined by means of tensile testing. For the 0.5-mm-thick specimens, the force required to break the 0.5-mm laser-welded specimens at currents of 270 and 300 A was not statistically different (p > 0.05) from the results for the nonwelded control specimens. The force required to break the 1.0-mm specimens double-welded at a current of 270 A was the highest value among the 1.0-mm laser-welded specimens. The results suggested that laser welding under the appropriate conditions improved the joint strength of cobalt- chromium alloy.
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Affiliation(s)
- N Baba
- Department of Developmental and Reconstructive Medicine, Division of Fixed Prosthodontics and Oral Rehabilitation, Course of Medical and Dental Sciences, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
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Scherrer SS, Wiskott AHW, Coto-Hunziker V, Belser UC. Monotonic flexure and fatigue strength of composites for provisional and definitive restorations. J Prosthet Dent 2003; 89:579-88. [PMID: 12815352 DOI: 10.1016/s0022-3913(03)00174-4] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
STATEMENT OF PROBLEM Ordinarily, the mechanical strength of composites is characterized by their flexural strength. Information as to the material's fatigue strength is seldom provided. PURPOSE The purpose of this study was to compare the flexural strength and the resistance to fatigue loading of composites and an acrylic resin for provisional and definitive restorations. MATERIAL AND METHODS Artglass, Colombus, and Targis (composites) and Jet, Protemp II, Protemp Garant, and Provipont DC (provisional restorations) were subjected to mechanical tests. Fatigue tests (MPa) (n = 30 specimens/group) were conducted with the rotating-bending cantilever design. Monotonic flexural strength (MPa) (n = 10) was determined in 3-point bending tests. Fatigue resistance was analyzed via the staircase procedure, and flexural strength was examined by use of the 2-parameter Weibull distribution (confidence intervals at 95%). RESULTS The mean fatigue resistances (S(50)) in MPa +/- SD were: Targis, 62.1 +/- 7.0; Artglass, 58.5 +/- 3.7; Colombus, 54.6 +/- 6.2; Provipont DC, 29.5 +/- 3.2; Protemp II, 23.1 +/- 5.3; Jet, 22.8 +/- 8.3; Protemp Garant, 19.6 +/- 4.6. The flexure strengths (Weibull's S(0)) in MPa and their shape parameters (m) were: Colombus, 145.2 (13.1); Targis, 110.3 (7.8); Artglass, 5.9 (5.4); Jet, 150.9 (17.3); Provipont DC, 97.3 (23.8); Protemp II, 57.9 (6.4); Protemp Garant, 54.2 (12.8). The S(50) of Targis was significantly higher than that of Colombus but not different from Artglass. In flexion, the S(0) of Colombus was significantly higher than that of Artglass and Targis. The S(50) ranged between 40% and 60% of the S(0) for the composites and between 15% and 30% for the provisional restorative materials. CONCLUSIONS Correlations between monotonic flexure strength and resistance to fatigue loading were weak. Because fatigue tests are considered more pertinent than monotonic tests as to their predictive value, it is concluded that flexure strength data alone may not provide relevant information for long-term clinical performance. The material's resistance to fatigue loading should also be determined.
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Goto Y, Brudvik JS. Custom precision attachment housings for removable partial dentures. J Prosthet Dent 2002. [DOI: 10.1067/mpr.2002.127603] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Thompson JY, Bayne SC, Swift EJ, Stamatiades P. Dental materials citations: Part A, January to June 1997. Dent Mater 1997; 13:270-85. [PMID: 11696907 DOI: 10.1016/s0109-5641(97)80039-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE A search was conducted in biomedical journals published from January 1997 to June 1997 to identify all dental materials publications and sort them into major categories. METHODS Tables of contents for 79 journals for the period of January to June, 1997 were inspected and divided into 17 categories. Citations were analyzed by both frequency in journals and in categories, as well as compared to frequencies for previous years. RESULTS A total of 445 citations were detected in 79 journals for the period January 1997 to June 1997. Certain journals (n = 19) demonstrated a higher citation frequency (> or = 10 citations for 6 months) and represented 77.8% of all citations. The greatest number of citations continued to involve bonding (n = 97), resin-based restorative materials (composites; glass ionomers) (n = 95), prosthodontic materials (n = 51), and pulp protection/luting materials (n = 48). Frequencies by category were very similar to those for the last four years. SIGNIFICANCE The compiled literature citations provide a supplement for researchers and academicians seeking information in existing electronic databases.
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Affiliation(s)
- J Y Thompson
- Department of Operative Dentistry, School of Dentistry, University of North Carolina, Chapel Hill, North Carolina, USA.
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