Biomechanical Characterization of the Periodontal Ligament: Orthodontic Tooth Movement

Biomechanical Characterization of the Periodontal Ligament: Orthodontic Tooth Movement Public Deposited

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Creator

Uhlir, Richard F.
- Affiliation: School of Dentistry, Department of Orthodontics

Abstract

The biomechanical characteristics of the dental periodontal ligament (PDL) are currently not completely known. Methods: A Dynamic Mechanical Analyzer (DMA) that detects small forces at resolutions of 0.002 N was utilized to characterize stress-strain behavior of PDL specimens sectioned from mandibular bovine incisors. Uniaxial tension tests using different force levels of 0.5, 1, and 3 N were completed for 37 samples. Young's modulus (E) values calculated from experimental data were compared to see the effects of anatomic location and force levels. The Mooney-Rivlin Hyperelastic (MRH) model was constituted to analyze experimental data and used in Finite Element Analysis (FEA) of orthodontic intrusion. Results: The modulus of PDL was approximately 66% greater at labio-lingual surfaces than at mesio-distal surfaces of roots. Force level was positively related to modulus. The MRH model well fit the non-linear stress-strain curve of PDL. MRH FEA predicted greater tipping effect and higher compressive stresses at the root apex of the intruded tooth than that computed from previous linear-elastic simulation. Conclusion: The PDL is well characterized by a hyperelastic constitutive equation independent of the applied force levels. The MRH model demonstrated a reasonable expected outcome of stress/strain patterns within the PDL and bone for intrusive mechanotherapy.

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