Date of Award
Spring 2010
Document Type
Thesis
Degree Name
Master of Science (MS)
Department
Dentistry
First Advisor
Bahcall, James K.
Second Advisor
Berzins, David W.
Third Advisor
Jaunberzins, Andris
Abstract
Introduction: The purpose of this study was to compare the setting of MTA with and without the application of a moist cotton pellet. Methods: Fifty samples of MTA were mixed according to manufacturer’s instructions, placed with an amalgam carrier, and condensed with a plugger into a custom metal block with a well depth of 3.5 mm. Twenty-five of the MTA samples had a moist cotton pellet placed in contact with MTA mixture and twenty-five MTA samples had no moist cotton pellet in contact with the MTA mixture. The samples were placed in 100% humidity at 37°C and evaluated for penetration resistance with a Vickers microhardness tester every 30 minutes for 6 hours and again at 1 and 3 days. A Gillmore needle was used to test the setting time of the MTA. Statistical analysis was completed using repeated measures ANOVA. Results: MTA without the application of a moist cotton pellet displayed significantly greater penetration resistance for 6 hours and set significantly (P<0.05) faster than MTA with the moist pellet. At 1 and 3 days, however, the MTA with the moist pellet was significantly (P<0.05) harder than the MTA without the moist pellet. Conclusions: Application of a moist cotton pellet on MTA affects setting time and the hardness of the cement.