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Study: Development of Novel Remineralizing Antimicrobial Brushite Cements

Posted on June 26, 2014

 

Cape Town, South Africa – Today, at the 92nd General Session & Exhibition of the International Association for Dental Research (IADR), held in conjunction with the IADR Africa/Middle East Regional Meeting, N.A. Ismail, University College London Eastman Dental Institute, England, will present a study titled “Development of Novel Remineralising Antimicrobial Brushite Cements.”

The objective of this study was to optimize brushite cement properties and assess the effect of incorporation of a novel polymeric antimicrobial (PAM). Cement powders were mixed with aqueous solutions at a powder to liquid ratio (PLR) of 3.3:1 or 4:1 to produce cement pastes and start the setting reaction. The powder consisted of 1g of monocalcium phosphate monohydrate (MCPM) and 1.23g of β - tricalcium phosphate (β-TCP). MCPM from two sources was employed (particles sizes of 53 and 65 micron). Additionally β-TCP particle size ranged from 4 to 34 micron. The liquid phase was prepared by dissolving PAM powder (0, 10, 20, 30, 40 or 50 wt%) in 800 mM aqueous citric acid. Biaxial Flexural strength was determined with a ball on ring jig and Instron frame. Setting kinetics and microstructure were examined using FTIR and SEM.

The viscosity of the brushite cements was advantageously lowered with MCPM of larger particle size. The largest particle size of β-TCP (34 micron) also gave cements of higher flexural strength (up to 30 MPa). Higher PLR increased strength by 5 – 7MPa. High levels of PAM could be added with only a minor reduction in the strength however setting time was delayed and less brushite formed. Adding PAM resulted in a more homogenous and less porous structure.

The researchers found that brushite cement strength can be raised by optimizing component particle size and raising powder content. High levels of PAM can be added without significant reduction in strength but the setting time is delayed and final brushite crystal microstructure altered.

This is a summary of abstract #206, “Development of Novel Remineralising Antimicrobial Brushite Cements,” to be presented by N.A. Ismail, Thursday, June 26, 2014: 10:45 a.m. - 12:15 p.m. in Ballroom West of the Cape Town International Convention Centre.