Prospective clinical study of monolithic zirconia crowns-Following morphology and function for long-term prognosis-

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K11739
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Prosthodontics/ Dental materials science and
• Research Institution: Meikai University (2018-2019); Tohoku University (2017)
• Principal Investigator: Shoko Miura 明海大学, 歯学部, 准教授 (60431590)
• Co-Investigator(Kenkyū-buntansha): 江草 宏 東北大学, 歯学研究科, 教授 (30379078)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: ジルコニア / CAD/CAM / モノリシック

Outline of Final Research Achievements

The purpose of this study was to examine the clinical performance of monolithic zirconia crowns in terms of short-term failure or complications. A prospective cohort study based on record evaluation and clinical examination of patients treated with tooth-supported monolithic zirconia crowns was performed in Japan. The crowns were prepared during the follow-up period from April 2014 to July 2018. The 3.5-year cumulative success and survival rates were set as primary endpoints.
During the study period, 40 monolithic zirconia crowns were placed. Four crowns experienced clinical complications. The estimated Kaplan-Meier 3.5-year success and survival rates were 90.5% and 92.8%, respectively.
The results of this study suggest that the molar application of monolithic zirconia crowns requires detailed attention to interocclusal clearance and the restoration of the antagonist tooth.

Free Research Field

クラウンブリッジ補綴学

Academic Significance and Societal Importance of the Research Achievements

本研究の結果から，モノリシックジルコニアクラウンの臼歯部への適用には，咬合面クリアランスと対合歯が部分的に修復されているかどうかに細心の注意が必要であることが明らかとなった．咬合面クリアランスは，0.5 mmではクラウン破折の可能性が高いため，支台歯形成時には削除量を0.8 mm以上確保する必要があると考えられた．成功率と生存率は約90％と高いため，モノリシックジルコニアクラウンは，臼歯部の修復に効果的なメタルフリー材料による補綴歯科治療の選択肢となると考えられた．しかしながら，追跡期間が短いため，今後さらなるエビデンスの蓄積が必要である．