J Korean Acad Pediatr Dent.  2019 Nov;46(4):392-399. 10.5933/JKAPD.2019.46.4.392.

Evaluation of the Changes in Polymerization of TheraCal LC with Various Light-curing Time and Distance

• Bae S
• Lee J
• Ra J

• KMID: 2467075
• DOI: http://doi.org/10.5933/JKAPD.2019.46.4.392

Abstract

The purpose of this study was to evaluate polymerization of TheraCal LC, one of the tricalcium silicate cements. To measure the Vickers hardness number (VHN), the specimens were cured at different light curing time and distance. As a result, the VHN of the upper surface was significantly higher than the lower surface's in all groups (p < 0.05). The VHN of the lower surface was increased significantly with the increase of the light curing time in all distance (p < 0.05). When the distance was more than 4.0 mm at all light curing time, the VHN of lower surface was significantly decreased (p < 0.05). When the specimen was light cured for 20 seconds, the VHN of the lower surface did not exceed 2, which corresponds to 10% of the upper surface's. These results suggested that the 20 second light curing time was not sufficient to polymerize the lower surface under specific conditions and that light-curing time should be increased.

Keyword

Polymerization; Vickers hardness; Tricalcium silicate cement

MeSH Terms

Hardness
Polymerization*
Polymers*
Silicates
Polymers
Silicates