Mayyadah Al-Mozainy, Professor from Saud University, Saudi Arabia, Doctor Mayyadah Al-Mozainy is a speaker at Dentistry-2015


Aim of this study: to compare the polymerization shrinkage and the water sorption values of different low shrinkage composite materials.
Materials and method: different commercially available composite resin materials were used in this study: Reflexions XP (BISCO, IL, USA), Kalore (GC CORPORATION, JP -Tokyo), AELITE LS (BISCO, IL, USA), Filtek P90 (3M, St. Paul, USA) and Tetric N-ceram (Ivoclar Vivadent, NY, USA). The data for water absorption were analyzed by two-way analysis of variance (ANOVA), followed by one way analysis of variance (ANOVA) and Tamhane test at 95% level of confidence.
Results: Tetric N-ceram showed the highest polymerization strain mean ( -12.52 ± 10.958 ) followed by Filtek P90 (-10.99 ± 9.188), Reflexions XP (-8.77 ± 6.662 ), GC Kalore ( -5.20 ± 3.185 ), and the least polymerization strain was recorded for Aelite LS ( -3.95 ± 2.717). Filtek P90 showed the highest mean growth (5.21 ± 5.71) among the tested materials. Comparing the mean of water absorption percentages of the tested materials to each other, Filtek P90, Aelite LS and GC Kalore showed no significant difference to each other with P=0.986. Aelite LS , GC Kalore and Reflexions XP were also not significant to each other with P=1.00. Tetric N-ceram and Reflexions XP were not significantly different from each other with P=0.411, although Tetric N-ceram was significantly different from all the other tested materials with P=0.000.
Conclusion: The results of the present study showed that the polymerization shrinkage for all the tested materials was the greatest during the light activation reaction and decreased after the curing light was turned off, and they all presented their highest readings during the first twenty seconds. The highest polymerization shrinkage strain was recorded for Tetric N-ceram followed by Filtek P90, Reflexions XP, GC Kalore and Aelite LS.