Mineral trioxide aggregate solution inhibits osteoclast differentiation through the maintenance of osteoprotegerin expression in osteoblasts
ABSTRACT Mineral trioxide aggregate (MTA) is a therapeutic, endodontic repair material that is reported to exhibit calcified tissue-conductive activity. The aim of this study was to investigate whether MTA may prevent osteoclast differentiation in vitro. MTA solution, but not other commonly used retrofilling materials, such as Dycal, Super-EBA, or intermediate restorative material (IRM) solution, dose-dependently inhibited osteoclastogenesis in cocultures of mouse bone marrow cells (BMCs) with primary osteoblast cells (POBs) induced by 1α,25-dihydroxyvitamin D(3) [1α,25(OH)(2) D(3) ]. Exogenous CaCl(2) medium supplementation did not inhibit osteoclastogenesis in cocultures. Furthermore, MTA solution did not affect receptor activator of NF-κB ligand (RANKL)-induced osteoclastogenesis, suggesting that POBs are targets of MTA. MTA solution suppressed the 1α,25(OH)(2) D(3) -induced reduction of osteoprotegerin (OPG) mRNA and protein production without changing RANKL expression in POBs. Consistent with this result, MTA solution did not inhibit osteoclastogenesis in cocultures of BMCs and POBs from OPG-deficient mice. Therefore, the maintenance of OPG expression in POBs appears to be critical for the inhibitory effect of MTA solution on osteoclast differentiation.
- SourceAvailable from: Maria Giovanna Gandolfi[Show abstract] [Hide abstract]
ABSTRACT: The in vitro apatite-forming ability of experimental calcium-silicate hydraulic cements designed for dentistry was investigated.Two cements containing di- and tricalcium-silicate (wTC and wTC-TCP, i.e. wTC added with alpha-TCP) were soaked in different phosphate-containing solutions, namely Dulbecco's Phosphate Buffered Saline (DPBS) or Hank's Balanced Salt Solution (HBSS), at 37°C and investigated over time (from 24h to 6months) by SEM/EDX, micro-Raman and ATR-FTIR.The early formation (24h) of an aragonite/calcite layer onto both cements in both media was observed. Calcium phosphate deposits precipitated within 1–3days in DPBS; spherical particles (spherulites) of apatite appeared after 3–7days. wTC-TCP cement showed earlier, thicker and more homogeneous calcium phosphate deposits than wTC.In HBSS calcite deposits were mainly noticed, while phosphate bands appeared only after 7days; the presence of globular deposits after 14–28days was mostly detected on wTC-TCP.After 6months, an approx. 900micron carbonated apatite layer formed in DPBS whilst a 150–350micron thick calcite/apatite layer generated in HBSS. Also in HBSS the carbonated apatite coating was earlier and thicker on wTC-TCP than wTC.Calcium-silicate cements showed the formation of a bone-like apatite layer, depending on the medium composition and ageing time. The addition of alpha-TCP increases the apatite-forming ability of calcium-silicate cements.Calcium-silicate hydraulic cements doped with alfa-TCP represent attractive materials to improve apical bone healing.Materials Science and Engineering C 10/2011; 31(7). DOI:10.1016/j.msec.2011.05.012 · 3.09 Impact Factor
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ABSTRACT: Aim: To describe a technique for the placement of apical Mineral trioxide aggregate (MTA) plugs in canals with wide apices. Summary: A novel technique to fill root canals with an apical diameter larger than 0.4 mm is presented. The technique includes three main stages; three Thermafil carriers of increasing size, previously de-sheathed by removing the Gutta-percha coating, are selected to engage 1, 2 and 3 mm short of the apex. Their use allows the negotiation of acute curvatures and ledged canals. Subsequently, an MTA plug matching the apical gauge is pre-formed with a pellet block, placed and condensed using the modified carriers in sequence. The presented protocol for the management of teeth with apices of a diameter greater than 0.4 mm allows a favourable apical control of the MTA. Clinical cases completed using this methodology are presented. Key learning points: MTA placement in teeth with wide apices was facilitated by using de-sheathed Thermafil carriers, to create an appropriate seal and stable platform for Gutta-percha backfilling or subsequent fibre post placement. The use of de-sheathed Thermafil carriers of different sizes allows predictable placement of pre-formed MTA plugs. Gauging of Thermafil carriers enhances control of the condensation phase to limit the extrusion of MTA.International Endodontic Journal 11/2012; 46(1):n/a-n/a. DOI:10.1111/j.1365-2591.2012.02115.x · 2.97 Impact Factor
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ABSTRACT: This study demonstrates that octacalcium phosphate (OCP) is a suitable substrate for alendronate local action towards bone cells. The results of the structural, spectroscopic, and microscopic investigation show that soaking OCP into alendronate solutions provoked the deposition of long crystalline rod-shaped formations, most likely a calcium alendronate complex, onto the calcium phosphate. The amount of alendronate loaded onto OCP increased as a function of the bisphosphonate concentration in solution. Osteoblast and osteoclast response was tested in single and in co-cultures on OCP containing 6.4wt.% AL (OCP-AL), and for comparison on hydroxyapatite (HA) containing a similar amount (5.9wt.%) of AL (HA-AL), as well as on pure OCP and HA as reference materials. Alendronate loaded materials displayed a beneficial effect on osteoblast activity and differentiation, whereas they inhibited osteoclast proliferation and differentiation. Crosstalking between osteoblast-like MG63 cells and human osteoclasts enhanced their response to alendronate. Moreover, OCP displayed a greater stimulating effect than HA on osteoblast differentiation, and AL promotion of osteoblast differentiation and mineralization was enhanced in OCP-AL with respect to HA-AL.Bone 08/2012; 51(5):944-52. DOI:10.1016/j.bone.2012.07.020 · 3.97 Impact Factor