title: In vivo measurements and numerical analysis of the biomechanical characteristics of the human periodontal ligament.
abstract: The periodontal ligament is a complex tissue with respect to its biomechanical behaviour. It is important to understand the mechanical behaviour of the periodontal ligament during physiological loading in healthy patients as well as during the movement of the tooth in orthodontic treatment or in patients with periodontal disease, as these might affect the mechanical properties of the periodontal ligament (PDL). Up to now, only a limited amount of in vivo data is available concerning this issue. The aim of this study has been to determine the time dependent material properties of the PDL in an experimental in vivo study, using a novel device that is able to measure tooth displacement intraorally. Using the intraoral loading device, tooth deflections at various velocities were realised in vivo on human teeth. The in vivo investigations were performed on the upper left central incisors of five volunteers aged 21-33 years with healthy periodontal tissue. A deflection, applied at the centre of the crown, was linearly increased from 0 to 0.15mm in a loading period of between 0.1 and 5.0s. Individual numerical models were developed based on the experimental results to simulate the relationship between the applied force and tooth displacement. The numerical force/displacement curves were fitted to the experimental ones to obtain the material properties of the human PDL. For the shortest loading time of 0.1s, the experimentally determined forces were between 7.0 and 16.2N. The numerically calculated Young's modulus varied between 0.9MPa (5.0s) and 1.2MPa (0.1s). By considering the experimentally and numerically obtained force curves, forces decreased with increasing loading time. The experimental data gained in this study can be used for the further development and verification of a multiphasic constitutive law of the PDL.
authors.affiliation: Endowed Chair of Oral Technology, Rheinische Friedrich-Wilhelms-University, Welschnonnenstr. 17, 53111 Bonn, Germany; Department of Prosthetic Dentistry, Preclinical Education and Materials Science, Rheinische Friedrich-Wilhelms-University, Welschnonnenstr. 17, 53111 Bonn, Germany. Electronic address: ludger.keilig@uni-bonn.de.
authors.forename: L
authors.initials: L
authors.lastname: Keilig
authors.affiliation: Endowed Chair of Oral Technology, Rheinische Friedrich-Wilhelms-University, Welschnonnenstr. 17, 53111 Bonn, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Drolshagen
authors.affiliation: Endowed Chair of Oral Technology, Rheinische Friedrich-Wilhelms-University, Welschnonnenstr. 17, 53111 Bonn, Germany.
authors.forename: K L
authors.initials: KL
authors.lastname: Tran
authors.affiliation: Endowed Chair of Oral Technology, Rheinische Friedrich-Wilhelms-University, Welschnonnenstr. 17, 53111 Bonn, Germany; Department of Prosthetic Dentistry, Preclinical Education and Materials Science, Rheinische Friedrich-Wilhelms-University, Welschnonnenstr. 17, 53111 Bonn, Germany.
authors.forename: I
authors.initials: I
authors.lastname: Hasan
authors.affiliation: Endowed Chair of Oral Technology, Rheinische Friedrich-Wilhelms-University, Welschnonnenstr. 17, 53111 Bonn, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Reimann
authors.affiliation: Experimental Dento-Maxillo-Facial Medicine, Rheinische Friedrich-Wilhelms-University, Welschnonnenstr. 17, 53111 Bonn, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Deschner
authors.affiliation: Helmholtz Institute for Radiation and Nuclear Physics, Rheinische Friedrich-Wilhelms-University, Nussallee. 14-16, 53115 Bonn, Germany.
authors.forename: K T
authors.initials: KT
authors.lastname: Brinkmann
authors.affiliation: Institute of Computational Science, University of Lugano, Via Giuseppe Buffi 13, 6906 Lugano, Switzerland.
authors.forename: R
authors.initials: R
authors.lastname: Krause
authors.affiliation: Institute of Computational Science, University of Lugano, Via Giuseppe Buffi 13, 6906 Lugano, Switzerland.
authors.forename: M
authors.initials: M
authors.lastname: Favino
authors.affiliation: Endowed Chair of Oral Technology, Rheinische Friedrich-Wilhelms-University, Welschnonnenstr. 17, 53111 Bonn, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Bourauel
mesh_terms: D000328:Adult; D019245:Compressive Strength / Q000502:physiology; D003198:Computer Simulation; D055119:Elastic Modulus / Q000502:physiology; D006244:Hardness / Q000502:physiology; D006801:Humans; D007180:Incisor / Q000502:physiology*; D008954:Models, Biological; D010513:Periodontal Ligament / Q000033:anatomy & histology* / Q000502:physiology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013314:Stress, Mechanical; D013718:Tensile Strength / Q000502:physiology; D055815:Young Adult
keywords: In vivo; Intraoral device; Loading device; Periodontal ligament; Young's modulus