IADR Abstract Archives
Evaluation of Microhardness of Mineral Trioxide Aggregate Modified by Addition of Short Glass Fibers and Shredded Polyglycolic Acid Sutures
Objectives: The objective of this study was to test microhardness of mineral trioxide aggregate (MTA) modified by addition of short glass fibers (GF) and shredded polyglycolic acid (PGA) sutures .
Methods: Encapsulated MTA (MM-MTA, MicroMega, Besacon, France), modified using either short GF, length 140µm and diameter 6µm (Central Glass Co., Tokyo, Japan) or shredded PGA sutures, size 3/0 (Pegesorb, Dogsan Inc., Trabzon, Turkey), was used for the experiment. Four experimental groups (n=80) were as follows: control group (MTA) (n=20), MTA+5%GF (n=20), MTA+10%GF (n=20) and MTA+1%PGA (n=20). For the modified materials, MTA powder was removed from the capsule by 1%, 5% and 10% of weight and 1% PGA, 5% or 10% GF were added, respectively. The materials were mixed according to the manufacturer' s instructions and placed in custom made teflon molds, 6mm in diameter and 4mm in height. After seven days of incubation in phosphate-buffered saline, microhardness of samples was measured using a Vickers micorhardness testing machine (KB Prüftechnik GmbH, Hochdorf-Assenheim, Germany). A pyramid shaped diamond peak was used to apply pressure of 200 g during 10 seconds. Three indents were made on each tested sample and the mean Vickers hardness values were calculated and expressed in HV. For statistical analysis, Kolmogorov-Smirnov normality test and Student's t-test for independent samples were used, with level of significance set at 5%.
Results: The highest microhardness value was measured for MTA+10%GF (14.73±3.09) with statistically significant difference in comparison to other three groups (p<0.05). Both MTA+5%GF and MTA+1%PGA microhardness values (12.10±2.44 and 10.77±2.70, respectively) were statistically significantly different in comparison to control group (7.76±3.09), (p<0.05). There was no statistically significant difference in microhardness of MTA+5%GF and MTA+1%PGA (p>0.05).
Conclusions: Addition of both short GF and shredded PGA sutures significantly increased the microhardness of MTA. However, highest microhardness values were obtained by adding 10% of short GF to MTA.
Methods: Encapsulated MTA (MM-MTA, MicroMega, Besacon, France), modified using either short GF, length 140µm and diameter 6µm (Central Glass Co., Tokyo, Japan) or shredded PGA sutures, size 3/0 (Pegesorb, Dogsan Inc., Trabzon, Turkey), was used for the experiment. Four experimental groups (n=80) were as follows: control group (MTA) (n=20), MTA+5%GF (n=20), MTA+10%GF (n=20) and MTA+1%PGA (n=20). For the modified materials, MTA powder was removed from the capsule by 1%, 5% and 10% of weight and 1% PGA, 5% or 10% GF were added, respectively. The materials were mixed according to the manufacturer' s instructions and placed in custom made teflon molds, 6mm in diameter and 4mm in height. After seven days of incubation in phosphate-buffered saline, microhardness of samples was measured using a Vickers micorhardness testing machine (KB Prüftechnik GmbH, Hochdorf-Assenheim, Germany). A pyramid shaped diamond peak was used to apply pressure of 200 g during 10 seconds. Three indents were made on each tested sample and the mean Vickers hardness values were calculated and expressed in HV. For statistical analysis, Kolmogorov-Smirnov normality test and Student's t-test for independent samples were used, with level of significance set at 5%.
Results: The highest microhardness value was measured for MTA+10%GF (14.73±3.09) with statistically significant difference in comparison to other three groups (p<0.05). Both MTA+5%GF and MTA+1%PGA microhardness values (12.10±2.44 and 10.77±2.70, respectively) were statistically significantly different in comparison to control group (7.76±3.09), (p<0.05). There was no statistically significant difference in microhardness of MTA+5%GF and MTA+1%PGA (p>0.05).
Conclusions: Addition of both short GF and shredded PGA sutures significantly increased the microhardness of MTA. However, highest microhardness values were obtained by adding 10% of short GF to MTA.