2014 Volume 57 Issue 3 Pages 276-282
Purpose: The effects of the storage conditions of resin pastes on their mechanical properties were investigated by measuring flexural strength, Knoop hardness and width of contraction gap.
Methods: Estelite Σ Quick, BeautifilⅡ, Filtek Supreme Ultra, Solare and an injectable resin composite MI Fill were used. The storage conditions employed were 5℃ (cold condition), 23℃ (room condition), or 45℃ by using a composite softener (heat condition). Flexural strength, elastic modulus, and Knoop hardness were measured. Contraction gap widths of the restorations filled into the cavities in the bovine teeth were measured.
Results: Flexural strength and elastic modulus were higher for the specimens stored at the room and heat conditions. Knoop hardness was higher for the specimens stored at the room and heat conditions, but different between resin pastes used. Contraction gap formations were observed for the cold condition, and the gap width decreased with higher temperature.
Conclusion: Mechanical properties and contraction gap formation were affected by the storage temperature of resin pastes.
