within the MTA and MTA-like materials' composition has been associated with tooth discoloration, which has led to the invention of different materials with similar compositions that will not induce discoloration.
As a first step appropriate amount of analytical grade bismuth oxide
; Bi2O3 (98% pure) was dissolved in 63 wt.
Previous studies have shown that bismuth oxide
, the radiopacifying agent in ProRoot MTA and MTA-Angelus, decreased the mechanical properties of the cement (1, 7) and caused discolouration (8, 9).
Thus, studies were carried out to detect the component involved in this interaction and bismuth oxide
was found to be associated with tooth discoloration.
Matsumara, "Synthesis, characterization and photocatalytic performance of visible light induced bismuth oxide
nanoparticle," Journal of Alloys and Compounds, vol.
In another series of composite (YIG + [Bi.sub.2][O.sub.3]) material synthesis experiments, amorphous-phase films of thickness near 500 nm were deposited, in which the excess volumetric fraction of bismuth oxide
was near 20 vol.%.
In the literature, there are many studies which evaluate the radiopacity of many agents as bismuth oxide
, zinc oxide, barium sulfate, calcium tungstate, and zirconium oxide [12,13].
An independent analysis reveals that MTA is identical to Portland cement with the addition of bismuth oxide
. Initially, MTA was formulated as a grey powder, but white MTA was later developed to overcome tooth discolouration by the grey formula (Dammaschke et al 2005).
MTA has Portland cement as the main component in its composition and bismuth oxide
([Bi.sub.2][O.sub.3]) to promote radiopacity [5, 6].
They are lead based glazes, alkaline based glazes containing feldspars and/or frits, and alkaline earth based glazes containing calcium, magnesium, barium, strontium, beryllium oxide, zinc oxide, cadmium oxide and bismuth oxide
Specific topics include transient liquid phase bonding of alumina to alumina via a bismuth oxide
interlayer, the effect of pulse electrodeposition on properties of nanocrystalline nickel coatings, electrospun nanofibrous mats for local antibiotic delivery, the vibrational behavior of piezoelectric nano-beams, and synthesizing hard carbon as anode material for a lithium ion battery.