Regeneration of early enamel errosion by crystal transition using low-temperature annealing

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K09998
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 57040:Regenerative dentistry and dental engineering-related
• Research Institution: Showa University
• Principal Investigator: Miyazaki Takashi 昭和大学, その他部局等, 特任教授 (40175617)
• Co-Investigator(Kenkyū-buntansha): 柴田 陽 昭和大学, 歯学部, 教授 (30327936)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: エナメル質 / ハイドロキシアパタイト / 漂白 / 再生

Outline of Final Research Achievements

The smallest structural motif of tooth enamel is composed of a hexagonal crystal structure of hydroxyapatite combined with a complex of enamel proteins. These nanocrystals are inherently susceptible to acid attacks and prone to demineralization at competitive grain boundary triple points, where they grow. When the triple points are eliminated through bleaching, a driving force prompts apatite crystals to recover their most stable state, inducing a transition in the crystal structure to a monoclinic form. Concurrently, the introduction of fluoride and strontium ions enables the maintenance of the monoclinic state, allowing the enamel to display its prenatal calcification capacity and leading to significant remineralization of early enamel caries. These findings suggest the potential for a novel caries restoration treatment, which diverges considerably from conventional dental procedures that rely on the removal of affected dentin.

Free Research Field

歯科理工学

Academic Significance and Societal Importance of the Research Achievements

齲蝕は予防できることが最も望ましいが，発生してしまった場合にはエナメル質表層下が侵食された状態のうちに進行を阻止することが有効な手段である．一般臨床で齲蝕の治療法は，国内外を問わず患部を機械的に除去後，レジンや金属などの修復材料を，接着システムを介して患部に接着する方法である．本研究の成功により，チェアーサイドにおいて，少なくとも初期齲蝕では機械的切削を行わず，エナメル質を再生することが可能になる．再石灰化治療が健全歯を増やし，歯科治療はこれまでの切削・充填中心の治療から，予防中心のケアに移行する可能性がある．本研究成果は，我が国の健康長寿に貢献する将来の歯科医療の中心になることが期待できる．