Study on CT values in CBCT effective for bone quality diagnosis for implant treatment

2023 Fiscal Year Final Research Report

• Project/Area Number: 18K09636
• 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: Osaka University
• Principal Investigator: Sogo Motofumi 大阪大学, 大学院歯学研究科, 招聘教授 (70314391)
• Co-Investigator(Kenkyū-buntansha): 和田 誠大 大阪大学, 大学院歯学研究科, 准教授 (20452451)
• Project Period (FY): 2018-04-01 – 2024-03-31
• Keywords: CT値 / MDCT / CBCT / FOV / はみ出し

Outline of Final Research Achievements

The image density value of medical CT (MDCT) is called the "CT value" and is an index for clinical bone quality diagnosis for dental implants, but it has been said that dental CT (CBCT) cannot output CT values. However, based on the hypothesis that "CT values can be obtained even with CBCT if CT reconstruction is proper," direct proof is difficult, so we used the conjunctive proof method to verify that "CT values cannot be obtained under conditions that are also MDCT." went. Furthermore, we considered the condition that affects the CT value as ``protrusion of the subject from the field of view (FOV)'' and verified it in various protrusion environments. However, the CT value for water ≠ 0 and the graph specific to CBCT were not shown, indicating that either the hypothesis was incorrect or the condition settings were not able to imitate living organisms.

Free Research Field

歯科補綴

Academic Significance and Societal Importance of the Research Achievements

歯科用CT（CBCT）であっても医科用CT（MDCＴ)と同様にCT値が出力できることが証明されれば，歯科インプラント治療における臨床的骨質診断がCBCTでも可能となる．2009年頃調査した7機種のCBCTでは，1装置（アメリカ製）のみがMDCTと類似したCT値を示した．これを契機に，独自の再構成技術の研究を進めるが，CT値が出ない原因を簡単に証明するため本検証を発想した．各企業の努力は必要ではあるが，もし証明出来ればCBCTの機種に関わらず臨床的骨質診断ができるようになり，ひいては骨粗しょう症のスクリーニング検査にも応用できるようになると考えた．