The physical properties of accelerated Portland cement for endodontic use.
OBJECTIVE
To investigate the physical properties of a novel accelerated Portland cement.


METHODS
The setting time, compressive strength, pH and solubility of white Portland cement (Lafarge Asland; CEM 1, 52.5 N) and accelerated Portland cement (Proto A) produced by excluding gypsum from the manufacturing process (Aalborg White) and a modified version with 4 : 1 addition of bismuth oxide (Proto B) were evaluated.


RESULTS
Proto A set in 8 min. The compressive strength of Proto A was comparable with that of Portland cement at all testing periods (P > 0.05). Additions of bismuth oxide extended the setting time and reduced the compressive strength (P < 0.05). Both cements and storage solution were alkaline. All cements tested increased by >12% of their original weight after immersion in water for 1 day with no further absorption after 28 days. Addition of bismuth oxide increased the water uptake of the novel cement (P < 0.05).


CONCLUSIONS
The setting time of Portland cement can be reduced by excluding the gypsum during the last stage of the manufacturing process without affecting its other properties. Addition of bismuth oxide affected the properties of the novel cement. Further investigation on the effect that bismuth oxide has on the properties of mineral trioxide aggregate is thus warranted.
Camilleri
J
J
Department of Building and Civil Engineering, Faculty of Architecture and Civil Engineering, University of Malta, Malta. josette.camilleri@um.edu.mt
D000042:Absorption; D000468:Alkalies / Q000737:chemistry; D017607:Aluminum Compounds / Q000737:chemistry; D001729:Bismuth / Q000737:chemistry; D017610:Calcium Compounds / Q000737:chemistry; D002133:Calcium Sulfate / Q000737:chemistry; D019245:Compressive Strength; D003738:Dental Cements / Q000737:chemistry*; D004338:Drug Combinations; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008422:Materials Testing; D010087:Oxides / Q000737:chemistry; D012387:Root Canal Filling Materials / Q000737:chemistry*; D017640:Silicates / Q000737:chemistry; D012995:Solubility; D013314:Stress, Mechanical; D013997:Time Factors; D014867:Water / Q000737:chemistry
D000468:Alkalies; D017607:Aluminum Compounds; D017610:Calcium Compounds; D003738:Dental Cements; D004338:Drug Combinations; D010087:Oxides; D012387:Root Canal Filling Materials; D017640:Silicates; C472247:accelerated Portland cement; C086631:mineral trioxide aggregate; D014867:Water; C033301:bismuth oxide; D001729:Bismuth; D002133:Calcium Sulfate