IADR Abstract Archives
Addition of Fluoride to MTA Boosts the Differentiation of Osteoblasts
Objectives: Although both mineral trioxide aggregate (MTA) and fluoride are widely recognized for their hard tissue formation inducing or fostering properties, respectively, little is known whether and how a combination of both influences bone cells.
Methods: MTA disks with and without addition of 0.5, 0.25 and 0.1% sodium fluoride were characterized for their surface roughness by laser scanning microscopy and for the adhesion of human alveolar osteoblasts by scanning electron microscopy. Using eluates from fluoride-enriched MTA disks, the cell proliferation was measured by monitoring the DNA incorporation of 5-bromo-2'-deoxyuridine. Further, gene expression was profiled by qPCR arrays, the extracellular matrix mineralization was quantified by absorption measurement of Alizarin red stains, and effects were calculated with repeated measures analysis and post hoc p-value adjustment.
Results: The cell adhesion was similar on MTA disks with and without fluoride addition, of which the surface roughness was comparable. Control osteoblasts showed a curvilinear proliferation pattern peaking at d5, which was leveled out by the incubation with MTA. The addition of fluoride resulted in a significant proliferation decrease at d7 for all concentrations. At the mRNA level, both the incubation with MTA only and fluoride-enriched MTA modulated a panel of genes involved in osteogenesis, bone mineral metabolism and extracellular matrix formation. Although MTA significantly impaired extracellular matrix mineralization compared to MTA-free controls, the addition of fluoride supported the formation of mineralized nodules in a dose-dependent manner.
Conclusions: The addition of fluoride clearly modulates the biocompatibility of MTA in terms of bone cell proliferation and hard tissue formation. Hence, fluoride enrichment is desirable for MTA-based clinical applications aiming at hard tissue formation.
Methods: MTA disks with and without addition of 0.5, 0.25 and 0.1% sodium fluoride were characterized for their surface roughness by laser scanning microscopy and for the adhesion of human alveolar osteoblasts by scanning electron microscopy. Using eluates from fluoride-enriched MTA disks, the cell proliferation was measured by monitoring the DNA incorporation of 5-bromo-2'-deoxyuridine. Further, gene expression was profiled by qPCR arrays, the extracellular matrix mineralization was quantified by absorption measurement of Alizarin red stains, and effects were calculated with repeated measures analysis and post hoc p-value adjustment.
Results: The cell adhesion was similar on MTA disks with and without fluoride addition, of which the surface roughness was comparable. Control osteoblasts showed a curvilinear proliferation pattern peaking at d5, which was leveled out by the incubation with MTA. The addition of fluoride resulted in a significant proliferation decrease at d7 for all concentrations. At the mRNA level, both the incubation with MTA only and fluoride-enriched MTA modulated a panel of genes involved in osteogenesis, bone mineral metabolism and extracellular matrix formation. Although MTA significantly impaired extracellular matrix mineralization compared to MTA-free controls, the addition of fluoride supported the formation of mineralized nodules in a dose-dependent manner.
Conclusions: The addition of fluoride clearly modulates the biocompatibility of MTA in terms of bone cell proliferation and hard tissue formation. Hence, fluoride enrichment is desirable for MTA-based clinical applications aiming at hard tissue formation.