Accelerating the Setting of Portland Cement Based Dental Materials Using Calcium Sulphates


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Mineral trioxide aggregate (MTA) is a Portland cement (PC) based material used for sealing root canals however it has a long setting time which is undesirable for dental applications. This study investigated the effect of three different calcium sulphate additions for accelerating the initial setting of a PC based dental material, whilst attempting to maintain its high compressive strength and low relative porosity. Anhydrous calcium sulphate (CaS), Plaster of Paris, calcium sulphate hemihydrate (PoP) and Gypsum, calcium sulphate dihydrate (Gyp) were each added to PC at 5wt%, 10wt% and 20wt%. Initial setting times, compressive strengths and relative porosity were measured using the Gilmore Needles Test, a universal testing machine and a helium pycnometer respectively. Scanning electron microscopy (SEM) was used to observe any microstructural changes in cements. PoP and CaS had the most profound influence on the setting of PC. 20wt% CaS had the greatest effect on the setting time of PC (10min) although decreased the compressive strength by up to 40%, which may have arisen from the formation of microcracks, observed by SEM analysis. Additions of 10wt% PoP and CaS may have the potential to reduce the long setting time of PC based dental materials.



Key Engineering Materials (Volumes 361-363)

Main Theme:

Edited by:

Guy Daculsi and Pierre Layrolle




J.L. O’Beirne et al., "Accelerating the Setting of Portland Cement Based Dental Materials Using Calcium Sulphates", Key Engineering Materials, Vols. 361-363, pp. 343-346, 2008

Online since:

November 2007




[1] K. S. Coomaraswamy, P. J. Lumley and M. P. Hofmann: J Endod 33(2007), pp.295-98.

[2] M. P. Walker, A. Diliberto and C. Lee: J Endod 32 (2006), pp.334-36.

[3] C. Main, N. Mirzayan, S. Shabahang and M. Torabinejad: J. Endod 30; 2 (2004), pp.80-83.

[4] P. Kogan, J. He, G. N. Glickman and I. Watanabe: J. Endod 32; 2 (2006), pp.569-72.

[5] E. A. Bortoluzzi Norberto Juárez Broon, M. A. H. Duarte, A. C. Cardoso de Oliveira Demarchi and C. Bramante: J Endod 32; 12 (2006), pp.1194-97.

[6] M. Tanomaru-Filho, J. M. G. Tanomaru, D. B. Barros, E. Watanabe and I. Y. Ito: J. Oral Sci. 49 (2007), pp.41-45.

[7] ASTM-Standard C266-99: ASTM International (2002).

[8] Bundesverband der Gips- und Gipsplattenindustrie. Gips-Datenbuch, Bundesverband der Gips- und Gipsplattenindustrie, Darmstadt (1995), p.11.