J Adv Prosthodont.  2018 Apr;10(2):128-131. 10.4047/jap.2018.10.2.128.

Precision of the milled full-arch framework fabricated using pre-sintered soft alloy: A pilot study

• Woo HW
• Cho SA
• Lee CH
• Lee KB
• Cho JH
• Lee DH

• KMID: 2409632
• DOI: http://doi.org/10.4047/jap.2018.10.2.128

Abstract

PURPOSE
This study aimed to evaluate the marginal discrepancy of full-arch frameworks in implant-supported prostheses fabricated using pre-sintered soft alloy (PSA).
MATERIALS AND METHODS
Full-arch metal frameworks were fabricated on the edentulous implant model using casting alloy (CA), fully-sintered hard alloy (FHA), and PSA (n = 4 in each group). To evaluate the misfit of the framework to the abutments, the absolute marginal discrepancy (AMD) values of the frameworks were measured in cross-sectional images that had been drawn as part of the triple-scan protocol. The AMD values were compared among the tested alloy groups using the Kruskal-Wallis test, with a post hoc Mann-Whitney U test (α=.05).
RESULTS
The FHA and PSA groups showed lower marginal discrepancies than the CA group (P < .001). However, the FHA group did not differ significantly from the PSA group.
CONCLUSION
Soft alloy milling is comparable to hard alloy milling, and it is more precise than casting in terms of the marginal fit of implant-supported, full-arch prostheses.

Keyword

Precision; Full arch framework; Pre-sintered soft alloy; Marginal discrepancy; Triple scan technique

MeSH Terms

Alloys*
Pilot Projects*
Prostheses and Implants
Alloys

Figure

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  Fig. 1 Workflow of study.

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  Fig. 2 Study model with implant-supported bar framework.

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  Fig. 3 Triple-scan technique of the marginal fit analysis. The framework image (a) and model image (b) are aligned with the framework/model image (c) to superimpose the images (d). The cross-sectional image (f) is obtained by virtual sectioning of the combined model (e).

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  Fig. 4 Overall absolute marginal discrepancy in the three groups. *Significant difference.

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