Dental CAD/CAM revolution by introducing AM technology to make zirconia crown - Challenge to condition optimization -

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K09991
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 57050:Prosthodontics-related
• Research Institution: Hokkaido University
• Principal Investigator: UEDA YASUO 北海道大学, 歯学研究院, 准教授 (30241342)
• Co-Investigator(Kenkyū-buntansha): 山口 泰彦 北海道大学, 歯学研究院, 教授 (90200617)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: ジルコニア・クラウン / AM / 3Dプリント / ジルコニア・セラミックス / 液槽光重合 / vat photo-polymerization

Outline of Final Research Achievements

This study aimed to establish a process for producing crowns from a mixture of zirconia and resin by 3D printing, dewaxing, and sintering. Two types of zirconia ceramic powders with different particle sizes and two types of castable resin were used to mold the mixtures using the vat photo-polymerization 3D printers, and the resin incineration (dewaxing) process was investigated under various conditions. As a result, it was found that in both cases, it was generally possible to dewax at temperatures up to 400°C. However, problems such as cracking and peeling were observed even when the temperature increase rate was reduced to 20°C/min, indicating that measures such as further reduction of the temperature increase rate at the temperature around which the resin softens to gasification or temporary suspension at a fixed temperature for a fixed time were necessary.

Free Research Field

歯科補綴学

Academic Significance and Societal Importance of the Research Achievements

ジルコニアの粉末材料は，日本メーカーが世界に供給して大きなシェアを持っている．価格は１kgあたり１万円台であるが，１本の歯冠に必要とする量は２g程度である．ジルコニアはチタンと同族の元素のジルコニウムの酸化物で，生体親和性がよく，歯科治療においてクラウンやブリッジ（いわゆる「被せ物」）に利用した場合の金属アレルギーの懸念がほぼ無い．一方，3Dプリントは，歯冠のような小さい物では，大量生産による大幅なコストダウンが可能である．
このため，クラウンやブリッジの製作に際し，AM（3Dプリント）技術を活用してジルコニアを加工できれば，安価で高品質で安心・安全な医療を国民に提供できるようになる．