Chemical composition and physical
properties of Thai white Portland cements
and bismuth oxide mixed with calcium
chloride and methyl cellulose
Authors :
- Punyawee Werasopon D.D.S.
- Anchana Panichuttra D.D.S., M.Sc., Ph.D.
Abstract :
Objective To investigate the chemical composition and physical properties of Thai white Portland
cement with bismuth oxide mixing with calcium chloride and methyl cellulose compared to Thai white
Portland cement with bismuth oxide when mixed with sterile water and white ProRoot® MTA mixed
with sterile water.
Materials and methods Ten samples of Thai white Portland cements from two manufacturers with
bismuth oxide mixed with sterile water or liquid with additive (5% calcium chloride and 1% methyl
cellulose) and white ProRoot® MTA mixed with sterile water were prepared in each group. Chemical
composition of set cement was analyzed with X-ray diffractometer and morphological characteristic
was observed by SEM. The pH, setting time, radiopacity, compressive strength and solubility were
tested. The results were analyzed with one-way ANOVA at 0.05 level of confidence.
Results White ProRoot® MTA mixed with sterile water and Thai white Portland cement with bismuth
oxide mixed with calcium chloride and methyl cellulose or mixed with sterile water have the similar
chemical composition. However, particles of white ProRoot® MTA appeared smaller than the two
Portland cements. Small amount of calcium hydroxide was detected in white ProRoot® MTA mixed
with sterile water but not in other groups. The pH of all cements were rapidly increased after mixing.
White ProRoot® MTA showed the highest pH (12.07) when cements were fully set. White Portland
cements with calcium chloride and methylcellulose has the significantly higher pH than the groups
mixed with sterile water. The setting time of white Portland cements mixed with calcium chloride and
methylcellulose was statistically significantly shorter but higher compressive strength at 21 days when compared to the cements mixed with sterile water. White Portland cements mixed with calcium chloride and methycellulose have the statistically significant higher solubility than the cements mixed with sterile water in the first day but all cements have the similar solubility after 21 days.
Conclusion Thai white Portland cements with bismuth oxide mixing with calcium chloride and
methyl cellulose have shorter setting time but higher compressive strength when compared to those
mixed with sterile water, while, the solubility at 21 days and radiopacity are similar to those of white
ProRoot® MTA. However, their pH are slightly lower than white ProRoot® MTA. Overall physical
properties of Portland cement with calcium chloride and methycellulose is satisfactory and has
potential to be developed as a substitutable material in the future.
(CU Dent J. 2010;33:207-20)
Keywords :
calcium chloride; chemical composition; methyl cellulose; physical property; Portland
cement; white ProRoot® MTA
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