Endowed Chair of Oral Technology, Rheinische Friedrich-Wilhelms-University, Welschnonnenstr. 17, 53111 Bonn, Germany.
J Biomech. 2011 Jul 28;44(11):2136-43. doi: 10.1016/j.jbiomech.2011.05.025. Epub 2011 Jun 15.
Periodontal diseases like gingivitis and periodontitis have damaging effects on the periodontium and commonly affect the mechanical properties of the periodontal ligament (PDL), which in the end might lead to loss of teeth. Monitoring tooth mobility and changes of the material properties of the PDL might help in early diagnosis of periodontal diseases and improve their prognosis. It was the aim of this study to develop a novel intraoral device to determine the biomechanical characteristics of the periodontal ligament. This includes the measurement of applied forces and resulting tooth displacement in order to investigate the biomechanical behaviour of the periodontium with varying loading protocols with respect to velocity and tooth displacement. The developed device uses a piezoelectric actuator to apply a displacement to a tooth's crown, and the resulting force is measured by an integrated force sensor. To measure the tooth displacement independently and non-invasively, two magnets are fixed on the teeth. The change in the magnetic field caused by the movement of the magnets is measured by a total of 16 Hall sensors. The displacement of the tooth is calculated from the movement of the magnets. The device was tested in vitro on premolars of four porcine mandibular segments and in vivo on two volunteers. The teeth were loaded with varying activation curves. Comparing the force progression of different activation velocities, the forces decreased with decreasing velocity. Intensive testing demonstrated that the device fulfils all requirements. After acceptance of the ethical committee, further testing in clinical measurements is planned.
牙周病，如牙龈炎和牙周炎，对牙周组织有破坏性影响，通常会影响牙周韧带（PDL）的机械性能，最终可能导致牙齿脱落。监测牙齿松动和 PDL 材料特性的变化有助于牙周病的早期诊断，并改善其预后。本研究旨在开发一种新型的口腔内设备，以确定牙周韧带的生物力学特性。这包括测量施加的力和由此产生的牙齿位移，以便研究牙周组织在不同加载方案下的生物力学行为，涉及速度和牙齿位移。所开发的设备使用压电致动器向牙齿的牙冠施加位移，并且通过集成的力传感器测量所产生的力。为了独立且非侵入式地测量牙齿位移，将两个磁铁固定在牙齿上。通过总共 16 个霍尔传感器测量由磁铁运动引起的磁场变化。通过磁铁的运动来计算牙齿的位移。该设备在四个猪下颌骨段的前磨牙上进行了体外测试，并在两名志愿者身上进行了体内测试。牙齿被加载有不同的激活曲线。比较不同激活速度的力进展情况，发现力随速度的降低而减小。经过强化测试，该设备满足所有要求。在伦理委员会接受后，计划进行进一步的临床测量测试。
