酸化ジルコニウムセラミックス用レヤリング陶材の熱膨張に関する研究  [in Japanese] Thermal Expansion of Layering Porcelains for the Tetragonal Stabilized Zirconia  [in Japanese]

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Author(s)

    • 三浦 賞子 MIURA Shoko
    • 東北大学大学院歯学研究科口腔修復学講座咬合機能再建学分野 Division of Fixed Prosthodontics, Department of Restorative Dentistry, Graduate School of Dentistry, Tohoku University
    • 稲垣 亮一 INAGAKI Ryoichi
    • 東北大学大学院歯学研究科口腔修復学講座咬合機能再建学分野 Division of Fixed Prosthodontics, Department of Restorative Dentistry, Graduate School of Dentistry, Tohoku University
    • 依田 正信 YODA Masanobu
    • 東北大学大学院歯学研究科口腔修復学講座咬合機能再建学分野 Division of Fixed Prosthodontics, Department of Restorative Dentistry, Graduate School of Dentistry, Tohoku University
    • 木村 幸平 KIMURA Kohei
    • 東北大学大学院歯学研究科口腔修復学講座咬合機能再建学分野 Division of Fixed Prosthodontics, Department of Restorative Dentistry, Graduate School of Dentistry, Tohoku University

Abstract

目的: レヤリング法により製作するオールセラミック修復では, クラック発生を防止し, 強度のある修復物を製作する上で, コア材と前装用陶材の熱膨張率関係が重要であると考えられている.そこで, 酸化ジルコニウムを応用したオールセラミックシステム (cercon<SUP>®</SUP>smart ceramics, Degu Dent) で使用するコア材および前装用陶材について, 加熱時・冷却時の熱膨張の測定を行った.<BR>方法: 熱膨張の測定は, ISO規格9693に準じて行った. 試料数はコア材5個, 前装用陶材はデンティン色およびエナメル色を各10個, 合計25個用意した. コア材はCAMマシーンにてスキャニング後, 焼結を行った. 前装用陶材は, 焼成回数が2回と4回の試料を各5個製作した. 測定は, 赤外線縦型熱膨張計を使用し, ISO規格に準じて行った, 加熱時と冷却時の熱膨張収縮係数を算出し, その平均値の比較を行った.<BR>結果: コア材の熱膨張収縮係数は, 加熱時・冷却時ともに10.8×10<SUP>-6</SUP>/℃ であった. 前装用陶材の熱膨張収縮係数は, 9.3-11.1×10<SUP>-6</SUP>/℃ の範囲であった. コア材の熱膨張収縮係数は, 前装用陶材との間に-0.3-1.5×10<SUP>-6</SUP>/℃ の差がみられた.焼成回数が2回と4回の場合では, ほぼ同じ値を示した.<BR>結論: コア材と前装用陶材は亀裂発生の可能性が少ない熱膨張関係であることがわかった.

Purpose: The purpose of this study wasto investigate the coefficients of thermal expansion and shrinkage of an all-ceramic system (cercon<SUP>®</SUP>smart ceramics, Degu Dent) utilizing tetragonal stabilized zirconia.<BR>Methods: The coefficients of thermal expansion and shrinkage of the core material and the layering porcelains (dentin and enamel) used in this study were measured according to the ISO 9693 standard. Five specimens for the core material and ten specimens for each layering porcelain were tested. The core specimens were milled, sintered, ground and polished. Five of the specimens for each layering porcelain were fired two times, and the remaining five specimens were fired four times. The fired layering porcelain specimens were ground and polished.<BR>The coefficients of thermal expansion and shrinkage were evaluated using a push-rod dilatometer at a heating rate of 5°C/min over temperature ranges of 25-700°Cfor the core, and 25-550°Cfor the layering porcelain. For each specimen, the coefficients of thermal expansion was determined to be between 25 and 500°Cfrom the plotted curve of expansion versus temperature.<BR>Results: For the core material, the coefficients of thermal expansion and shrinkage showed almost the same value (10.8×10<SUP>-6</SUP>/°C). For the layering porcelains, the coefficients of thermal expansion and shrinkage ranged from 9.3-11.1×10<SUP>-6</SUP>/°C. The difference of the coefficients of thermal expansion and shrinkage between the core materials and the layering porcelains was-0.3-1.5×10<SUP>-6</SUP>/°C. The specimens fired two times and the specimens fired four times exhibited almost the same value for each layering porcelain.<BR>Conclusion: The core material and layering porcelains have a suitable relationship.

Journal

  • Nihon Hotetsu Shika Gakkai Zasshi

    Nihon Hotetsu Shika Gakkai Zasshi 51(3), 556-562, 2007-07-10

    Japan Prosthodontic Society

References:  18

Codes

  • NII Article ID (NAID)
    10029762390
  • NII NACSIS-CAT ID (NCID)
    AN00197911
  • Text Lang
    JPN
  • Article Type
    ART
  • ISSN
    03895386
  • Data Source
    CJP  J-STAGE 
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