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Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_16 | Pages 21 - 21
1 Oct 2016
Melling GE Avery SJ Evans SL Waddington RJ Sloan AJ
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Demineralised dentine matrix (DDM) contains a myriad of growth factors and matrix proteoglycans, the bioactivity of which can utilised in dental restorations and bone augmentations. This study aimed to develop a novel antimicrobial, bioactive dental cement to promote reparative dentinogenesis and prevent infections, improving the longevity of current dental restorations. Nanocarriers containing DDM (extracted from non-carious dentine; 1–100 μg/mL), and triclosan (300 μg/mL) were made. Human dental pulp stem cells (hDPSCs) were treated with DDM nanocarriers (10 ng/mL-100 μg/mL) for 3, 9, 21 and 35 days. Cell proliferation and viability were assessed by cell counts, Caspase-Glo 3/7 (Promega) and MTT assays. qRT-PCR was used to examine the expression of osteogenic markers runx2 and osteocalcin at days 3, 9 and 21. A transwell chemotaxis/ migration assay was used to assess the ability of DDM nanoparticles to recruit hDPSC progenitors. Triclosan nanocarriers were tested using growth curves and zones of inhibitions for S. Anginosus and E. Faecalis. SEM and biomechanical testing was carried out on Vitremer (Henry Schein) dental cements containing loaded and empty nanocarriers. DDM nanocarriers were able to significantly recruit hDPSCs and induce the expression of osteogenic markers in hDPSCs after 9 days. DDM Nanocarriers had no effect on cell proliferation or survival. Triclosan nanocarriers were able to inhibit the growth of S. Anginosus and E. Faecalis. Nanocarriers had limited effect on the biomechanical integrity of Vitremer cements. Nanocarriers successfully delivered DDM to hDPSC, promoting their in vitro recruitment and osteogenic differentiation, and triclosan to endodontic bacteria inhibiting their growth. The nanocarriers were incorporated into cements with minimal physical artefacts, therefore a novel antimicrobial, bioactive dental cement was produced, which could be a useful tool for dental tissue engineering


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXXVI | Pages 58 - 58
1 Aug 2012
Richards B Bayston R Ashraff W
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Background. Antibiotic loaded bone cement spacers are used as an adjunct to treatment in 2-stage arthroplasty revisions. If release of the correct choice of antimicrobials is optimised, systemic therapy might be curtailed and emergence of resistance minimised. Aims: To determine the elution period of antimicrobials from bone cement with and without a copolymer, polyvinylpyrrolidone (PVP) and to limit resistance development by the use of two or more antimicrobials. Methods. Triclosan, gentamicin and clindamycin with and without (PVP) in CMW bone cement, was tested against six bacteria using serial plate transfer. Results. While there was little difference between clindamycin and clindamycin with PVP, and between gentamicin and gentamicin with PVP, there was marked enhancement of release of triclosan with PVP. Resistance developed when antimicrobials were used singly but not when used in combination. Conclusion. The addition of water soluble PVP was expected to enhance elution of antimicrobials from bone cement. This occurred with triclosan, a poorly water-soluble agent, but there was no significant difference for gentamicin and clindamycin, which as preferentially water -soluble. Other copolymers are being explored in an attempt to enhance their release. Triclosan used in combination extended the duration of activity against the test bacteria without development of resistance. Combinations of antimicrobials reduce the risk of paradoxical resistance in bone cement