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Relative hardness of composite buildups polymerized with two different LED lights
Hassan El-Shamy1, Omar El-Mowafy
1Department of Operative Dentistry, Faculty of Dentistry, Misr University for Science and Technology, October City, Egypt. dr_hassanelshamy@yahoo.com
The International Journal of Prosthodontics
|January 26, 2010
Summary
This study compared the relative hardness of five dental composites polymerized with LED lights. Z100 composite demonstrated superior hardness, making it ideal for dental core buildups.
Area of Science:
- Dental Materials Science
- Polymer Chemistry
- Biomaterials Engineering
Background:
- Dental composites are widely used restorative materials.
- Assessing the mechanical properties, such as hardness, is crucial for clinical performance.
- LED polymerization is the standard for composite curing.
Purpose of the Study:
- To evaluate the relative hardness (RH) of five different dental composite materials.
- To compare the effectiveness of two LED curing lights (Smartlite-IQ2 and DEMI LED) on composite hardness.
- To determine the optimal polymerization time for achieving desired hardness.
Main Methods:
- Five composite materials (Artiste, Filtek Supreme, Z100, LuxaCore) were prepared into disk specimens.
- Specimens were polymerized for 10 and 20 seconds using Smartlite-IQ2 and DEMI LED lights at a distance of 8 mm.
- Knoop hardness was measured on top and bottom surfaces immediately and 24 hours post-polymerization.
- Ten RH values per group were calculated and statistically analyzed.
Main Results:
- Relative hardness generally increased with longer polymerization times.
- The DEMI LED light produced significantly higher RH values compared to the Smartlite IQ2.
- Z100 composite exhibited >80% RH under most conditions and showed the highest hardness among all tested materials.
Conclusions:
- Polymerization time and LED light type significantly influence composite relative hardness.
- Z100 composite demonstrates superior hardness properties, indicating its suitability for dental core buildup procedures.
- Further research may explore long-term stability and other mechanical properties of these composites.
