Thermal Degradation of New Universal Composite Resin

Objectives: A new universal composite SOLARE Sculpt (SS, GC) was developed with three new technologies for enhanced durability; Full-coverage silane coating, Single dispersion nano fillers & High-performance pulverized CERASMART. As an in vitro measure of durability, the purpose of this study was to investigate resistance to thermal degradation of SS by comparing flexural strength with other universal composite resins.
Methods: SS, Filtek Z350 (Z350, 3M ESPE), Filtek Z250 (Z250, 3M ESPE) and Filtek Z100 (Z100, 3M ESPE) were examined in this study as universal composite resins. Flexural strength test specimens were prepared in accordance with ISO4049:2009. All specimens were divided into two groups, one group was stored in 37 oC water for 24 hours and performed flexural strength test (Control, n=5). In another group, flexural strength test was performed after thermal cycle (5 oC /55 oC, 10,000 cycles, n=5). Flexural strength test was performed with a crosshead speed of 1mm/min (AG-5KNXplus SHIMADZU). The data was analyzed by one-way ANOVA (p<0.01). All specimens were also observed by scanning electron microscope (SEM) after thermal cycling.
Results: The flexural strength of SS was maintained after thermal cycling with no significant difference between control and after thermal cycling. However, flexural strength of the other universal composite resins decreased after thermal cycling. Additionally, cracks and loss of filler on surface of Z350, Z250 and Z100 were observed by SEM under the condition of thermal cycling.
Conclusions: These results suggest that SS has higher durability against thermal degradation than other universal composite resins.