Dual delivery of platelet-derived growth factor and bone morphogenetic factor-6 on titanium surface to enhance the early period of implant osseointegration.

OBJECTIVE: To test the surface properties and in vitro effects of a new sequential release system on MC3T3-E1 cells for improved osseointegration. BACKGROUND: BMP6-loaded anodized titanium coated with PDGF containing silk fibroin (SF) may improve osseointegration. METHODS: Titanium surfaces were electrochemically anodized, and SF layer was covered via electrospinning. Five experimental groups (unanodized Ti (Ti), anodized Ti (AnTi), anodized + BMP6-loaded Ti (AnTi-BMP6), anodized + BMP6 loaded + silk fibroin-coated Ti (AnTi-BMP6-SF), and anodized + BMP6-loaded + silk fibroin with PDGF-coated Ti (AnTi-BMP6-PDGF-SF)) were tested. After SEM characterization, contact angle analysis, and FTIR analysis, the amount of released PDGF and BMP6 was detected using ELISA. Cell proliferation (XTT), mineralization, and gene expression (RUNX2 and ALPL) were also evaluated. RESULTS: After successful anodization and loading of PDGF and BMP6, contact angle measurements showed hydrophobicity for TiO2 and hydrophilicity for protein-adsorbed surfaces. In FTIR, protein-containing surfaces exhibited amide-I, amide-II, and amide-III bands at 1600 cm-1 -1700 cm-1 , 1520 cm-1 -1540 cm-1 , and 1220 cm-1 -1300 cm-1 spectrum levels with a significant peak in BMP6- and/or SF-loaded groups at 1100 cm-1 . PDGF release and BMP6 release were delayed, and relatively slower release was detected in SF-coated surfaces. Higher MC3T3-E1 proliferation and mineralization and lower gene expression of RUNX2 and ALPL were detected in AnTi-BMP6-PDGF-SF toward day 28. CONCLUSION: The new system revealed a high potential for an improved early osseointegration period by means of a better factor release curve and contribution to the osteoblastic cell proliferation, mineralization, and associated gene expression.

ABM/P-15 modulates proliferation and mRNA synthesis of growth factors of periodontal ligament cells.

OBJECTIVE: Periodontal regeneration is histologically defined as regeneration of the tooth supporting structures, including alveolar bone, periodontal ligament, and cementum. Cells in the remaining periodontal tissues need optimal conditions if they are to perform their functions in the regeneration process. The present study is an investigation of the molecular effects of ABM/P-15 on human periodontal ligament cells (PDL) in vitro. MATERIAL AND METHODS: PDL cells obtained from healthy subjects were used for in vitro experiments. Cell proliferation, morphology, and mineralization using Von kossa staining were evaluated. mRNA expressions for transforming growth factor-beta (TGF-beta), insulin-like growth factor-I (IGF-I), basic fibroblast growth factor (b-FGF), vascular endothelial growth factor (VEGF), bone morphogenic protein-2 (BMP-2), platelet-derived growth factor (PDGF), and type 1 collagen (COL1) were assessed on days 3 and 7 using RT-PCR. RESULTS: ABM/P-15 enhanced proliferation of cultured PDL cells. It increased the mRNA expression of TGF-beta and BMP-2 in cultured PDL cells on days 3 and 7. IGF-I and b-FGF mRNA expressions showed a slight decrease, while PDGF expression was observed to have increased on day 3. VEGF and COL1 mRNA expressions were found not to be different on days 3 and 7. No differences were observed in the mineralization properties of cultured PDL cells treated with or without ABM/P-15. CONCLUSIONS: Based on the results of this in vitro study, it may be concluded that ABM/P-15 enhanced the regenerative capacity of PDL by regulating specific gene expressions of cells during early wound healing.

Intentional replantation for periodontally involved hopeless teeth.

The aim of this study was to evaluate the clinical and radiographic results of intentional replantation of periodontally involved teeth after conditioning of root surfaces with tetracycline-HCl. Thirteen patients (seven female, six male; age range: 35-52 years) with 15 periodontally involved hopeless teeth were included in this study. During the replantation procedure, the affected teeth were gently extracted, then the granulation tissues, calculus, remaining periodontal ligament and necrotic cementum on the root surfaces were removed. Tetracycline-HCl, at a concentration of 100 mg ml(-1), was applied for 5 min to the root surfaces. The teeth were then replaced into the socket and splinted. Patients were clinically and radiographically evaluated at baseline (time of surgery) and 6 months after the surgery. The following measurements were recorded: probing depth (PD), gingival recession (R), the amount of bone loss (BL) and bone gain (BG). Results indicated a reduction in PD and in the amount of bone loss and healthy gingiva. Mean PD was decreased from 5.25 to 2.36 mm, gingival recession was increased from 3.73 to 4.0 mm, and BL was reduced from 73.20 to 56.86%. At the end of 6 months, no root resorption or ankylosis was observed radiographically. Even during the short period of evaluation, it may be suggested that intentional replantation can be an alternative approach to extraction in cases where advanced periodontal destruction is present and no other treatments could be considered.