Advances in mechano-biological behavior of peridontal ligament during orthodontic tooth movement / 国际生物医学工程杂志

Orthodontic tooth movement (OTM) is a very complicate mechano-biological procedure which is accomplished by the remodeling of periodontal tissues via orthodontic force.As the connective tissue between alveolar bone and cementum,periodontal ligament plays a vital role in the response and conduction of orthodontic force.The susceptible response of periodontal ligament to orthodontic force during OTM is a critical factor on inducing and modulating periodontal tissue restitution.This article reviews the concrete role of periodontal ligament and its mechano-biological behavior during OTM,discusses its mechanical response and biological mechanism respectively on histological,cellular and moleucular levels.

The effects of 240 g/L EDTA gel on the attachment and proliferation of human periodontal ligment cells onto the root surface of teeth with periodontitis / 实用口腔医学杂志

Objective:To study attachment and proliferation of human periodontal ligment cells(HPDLCs) on demineralized root surface of teeth with periodontitis following EDTA gel application. Methods:44 single-rooted teeth extracted because of severe periodontitis were treated by scaling and root planing(SRP). Then the fragments(5 mm?4 mm) of experimental surfaces were prepared. The fragments were randomly divided into four groups.The root surfaces in group 1,2,3 and 4 were treated by 240 g/L of EDTA gel for 2,3 and 4 min respectively or without treatment(control). Then 1?104 cells were seeded on the surface of each fragment and routinely cultured for 1,3 and 5 days respectively after seeding, the specimens were prepared for microscopic observasion, the cells on the root surfaces were counted. Moreover the other eight fragments were prepared for SEM observasion. Results:HPDLCs attached to and proliferated on all treated surfaces.Group 1, 2 and 3 presented significantly more cells on the root surfaces than the control group did at day 1,3 and 5. The cells on the root surfaces in group 2 and 3 were more than those in group 1 at day 1, 3 and 5. There was no evident difference between group 2 and 3 at any time. The root surfaces in group 2 and 3 had a fibrillar texture associated with an increased diameter of the exposed dentinal tubule openings.Smear layer were observed on root surfaces in group 1. Conclusion:EDTA gel(at 240 g/L) application may enhance attachment and proliferation on root surface of HPDLCs.