Comparative study of the surface characteristics, microstructure, and magnetic retentive forces of laser-welded dowel-keepers and cast dowel-keepers for use with magnetic attachments

Chao, Yong-lie; Du, Li; Yang, Ling

doi:10.1016/j.prosdent.2005.02.006

Cited by 6 publications

(7 citation statements)

References 13 publications

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“…Recent studies have acknowledged that the surfaces of keeper cast made with nickel–chromium alloy or titanium gave rise to coarse grains, but no obvious changes appeared when cast with gold alloy. 13 However, the keeper surface, except the heat reaction zone, maintained its original metallographic structure after laser welding. With a metallographic structure of body-centered cubic, the keeper made of SUS444 was an α-Fe-based interstitial solid solution.…”

Section: Discussionmentioning

confidence: 99%

“…13 Briefly, the keeper was first placed in the centre of a stainless steel mould (10-mm inner-diameter, 2.0-mm height). The remaining space was then filled with fusing wax (casting wax; Nissin Dental Products, Kyoto, Japan) by the wax-melting method (Figure 1a), and a sprue was fused at the bottom edge of the wax pattern.…”

Section: Methodsmentioning

confidence: 99%

“…In the laser-welded dowel-keeper group, keepers were removed from wax patterns to leave a concave after the wax-melting. After investment casting, the keepers were welded into the reserved concave of the specimen surface in argon atmosphere 13, 27, 28 by the semi-automatic micro spot welder (Primotec phaser; Primotec, Pforzheim, Germany).…”

Section: Methodsmentioning

confidence: 99%

“…The keeper could be cast or laser-welded into a dowel and coping as described in our previous study. 13 …”

Section: Introductionmentioning

confidence: 99%

“…22, 23 The keeper complex usually consists of two different metals by diverse fabrication methods such as casting and laser-welding processes. The relevant factors related to the corrosion of dental metal materials include their types, components, craftsmanship and more, 13, 24, 25, 26 all of which could have an influence on their original characteristics.…”

Section: Introductionmentioning

confidence: 99%

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Corrosion behaviours of the dental magnetic keeper complexes made by different alloys and methods

Song

Liu

et al. 2016

Int J Oral Sci

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The keeper and cast dowel–coping, as a primary component for a magnetic attachment, is easily subjected to corrosion in a wet environment, such as the oral cavity, which contains electrolyte-rich saliva, complex microflora and chewing behaviour and so on. The objective of this in vitro study was to examine the corrosion resistance of a dowel and coping-keeper complex fabricated by finish keeper and three alloys (cobalt–chromium, CoCr; silver–palladium–gold, PdAu; gold–platinum, AuPt) using a laser-welding process and a casting technique. The surface morphology characteristics and microstructures of the samples were examined by means of metallographic microscope and scanning electron microscope (SEM). Energy-dispersive spectroscopy (EDS) with SEM provided elements analysis information for the test samples after 10% oxalic acid solution etching test. Tafel polarization curve recordings demonstrated parameter values indicating corrosion of the samples when subjected to electrochemical testing. This study has suggested that massive oxides are attached to the surface of the CoCr–keeper complex but not to the AuPt–keeper complex. Only the keeper area of cast CoCr–keeper complex displayed obvious intergranular corrosion and changes in the Fe and Co elements. Both cast and laser-welded AuPt–keeper complexes had the highest free corrosion potential, followed by the PdAu–keeper complex. We concluded that although the corrosion resistance of the CoCr–keeper complex was worst, the keeper surface passive film was actually preserved to its maximum extent. The laser-welded CoCr– and PdAu–keeper complexes possessed superior corrosion resistance as compared with their cast specimens, but no significant difference was found between the cast and laser-welded AuPt–keeper complexes. The Fe-poor and Cr-rich band, appearing on the edge of the keeper when casting, has been proven to be a corrosion-prone area.

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Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%