24%EDTA gel on attaching and proliferation of human PDLCs

Objectives: To evaluate the attachment and proliferation of HPDLC on demineralized root surface following EDTA gel application at different time periods with scaling and root planning. In addition, to investigate the surface topography change. Methods:Attachment and proliferation of cultured human periodontal ligament cells on root surfaces treated by EDTA with SRP or SRP alone were observed. 44 single-rooted teeth extracted because of severe periodontitis were used. These samples were treated by SRP before fragments(5mm×4mm) were obtained from the experimental surfaces. Then they were randomly divided into four groups for root conditioning: EDTA 2min group; EDTA 3min group; EDTA 4min group; control group. At last 1×10⁴ cells were seeded on the top of each fragment.1,3,5 days after seeding, the specimens were prepared for microscopy analysis, and the cells were counted. Moreover the other eight fragments were prepared for SEM to observe the topography . Results: HPDLC attached and proliferated on all treated surfaces. Each EDTA group presented significantly more cells than did the control group at days 1 ,3 and 5. The cells of EDTA 3min and 4 min groups were more than did of EDTA 2 min group at day 3 and 5. There was no evident difference between EDTA 3 min group and 4 min group at any time. The root surfaces after 3-minute , 4 minute EDTA gel application had a fibrillar texture associated with an increased diameter of the exposed dentinal tubule openings. but areas of smear layer was observed on root surfaces treated by the 2-minute EDTA gel. Conclusions: Demineralized root surfaces following EDTA gel application at different time periods with SRP may enhance attachment and proliferation of HPDLC . Moreover, 3 min treatment may be recommended in clinic.