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Effect of the Porosity of the Filler Aggregates on the Setting Expansion of Investment Material

Department of Dental Technology, Osaka University Faculty of Dentistry, 1-8, Yamadaoka, Suita, Osaka, Japan 565

M. Okazaki

Department of Dental Technology, Osaka University Faculty of Dentistry, 1-8, Yamadaoka, Suita, Osaka, Japan 565

H. Kimura

Department of Dental Technology, Osaka University Faculty of Dentistry, 1-8, Yamadaoka, Suita, Osaka, Japan 565

Y. Haeuchi

Department of Dental Technology, Osaka University Faculty of Dentistry, 1-8, Yamadaoka, Suita, Osaka, Japan 565

F. Kubo

Taisei Dental Mfg. Co. Ltd., 4-38-7, Hoshidakita, Katano, Osaka, Japan 576

Twenty experimental phosphate-bonded investments were prepared by the mixing of two types of fillers (spherical glass beads and irregularly shaped silica particles) with five types of filler aggregates of different porosities, and two different ratios of MgO to NH ₄H₂PO₄. These investments were mixed with three different liquids, and their setting expansion, time until setting expansion began (induction time), and fluidity were measured under constant experimental conditions. The following results were obtained: (1) The setting expansion was significantly related to bulk porosity of filler aggregates, not to packed porosity, despite variations in type of filler, ratio of MgO to NH₄H ₂PO₄ or type of liquid; and (2) the fluidity and the time until setting expansion began were also related to the bulk porosity of the filler aggregates.

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Journal of Dental Research, Vol. 67, No. 10, 1278-1283 (1988)
DOI: 10.1177/00220345880670100701


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This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Saved Citations Download to citation manager Request Permissions Request Reprints Add to My Marked Citations Citing Articles Citing Articles via Google Scholar Citing Articles via Scopus Google Scholar Articles by Takahashi, J. Articles by Kubo, F. Search for Related Content PubMed PubMed Citation Articles by Takahashi, J. Articles by Kubo, F. Social Bookmarking                         What's this?