The effective minimum cement thickness of zinc phosphate cement for luted non‐precious crowns

Journal of Oral Rehabilitation - Tập 12 Số 3 - Trang 235-245 - 1985
Rafael Grajower1, Israel Lewinstein1, C. Zeltser1
1Hebrew University, Hadassah School of Dental Medicine, Jerusalem, Israel

Tóm tắt

SummaryNon‐precious metal crowns were prepared for natural teeth which were ground to a taper angle of 5°. The movement of the crowns on teeth during repeated try‐on seating was measured with a micrometer. Increasing the applied load from 2 to 10 kg resulted in an average crown movement of 63 μm. For most samples this movement continued when try‐on was repeated. Casting irregularities were found to create furrows on some regions of the axial tooth surface during try‐on seating. The diameter of the ADA specification consistency disk for zinc phosphate cement was found to depend strongly on the P: L ratio and the ambient temperature. The castings were cemented with zinc phosphate cement of controlled consistency. Cementation with a load of 10 kg gave rise to an average crown elevation of 54 μm and a range of measurements between −8 and 113 μm. The effective minimum cement thickness corresponding to this average was calculated to be 4.7 μm. Small negative values of elevation were attributed to deepening of tooth furrows during cementation. An analysis is given of data from the literature, relevant to the cement flow and irregularities in cement thickness.

Từ khóa


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Thông tin xuất bản

Journal of Oral Rehabilitation

Tập 12 Số 3

235-245

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