Defense Date


Document Type


Degree Name

Master of Science



First Advisor

Dr. B. Ellen Byrne


The use of Mineral Trioxide Aggregate (MTA) is gaining popularity among clinicians. Despite the many ideal qualities it possesses, it is often difficult to manipulate and often requires a second appointment for placement of a restoration to allow for setting. If the time to set of MTA can be accelerated to a single appointment time frame without significantly altering its properties, then MTA may gain even wider acceptance. The purpose of this study is to identify the percentage of a Portland Cement Accelerator (PCA), that when added to MTA, will decrease the time to set of MTA towards a single appointment time frame. Ten Teflon sample molds were prepared to hold 20 standardized chambers in each. Three sample molds were prepared with a 5.0% (by weight of MTA) accelerator, 3 with 10.0% accelerator and 3 with 15.0% accelerator mixed with MTA and water. Another sample mold contained a mixture of MTA and water only and acted as the control. Samples were tested using a dial indicator microgauge apparatus that measured the depth of needle penetration starting at 2 minutes and then every minute up to 15 minutes. Samples were also tested at 3, 4, 24, 48 and 72 hours. A mixed-model repeated measures ANOVA showed the four accelerator groups were significantly different and there was a significant time trend. The 5.0% accelerator group set significantly faster compared to the 15.0% and the control at 15 minutes or less (p<0.05). In conclusion, it appears that 5.0% PCA when added to MTA can accelerate the setting reaction.


© The Author

Is Part Of

VCU University Archives

Is Part Of

VCU Theses and Dissertations

Date of Submission

June 2008