Objectives: This study measured the flexural strength of four dual cured materials Ensure, Nexus 2, RelyX ARC, and Lute It, allowed to polymerize with and without light curing. Methods: Flexural strength specimens measured 20.0 mm in length and 2.2 mm in thickness and depth. The provisional materials were mixed following manufacturers' directions and placed into lubricated split metal molds. The specimens were light cured (VLC) with a curing light (output >500mw/cm2) for 60 seconds. Chemically cured materials (CC) were allowed to set until the polymerization reaction was complete. After the materials polymerized, they were separated from the mold. Ten samples of each material were fabricated. Completed samples were stored in containers of deionized water until testing. Flexural strength was measured by placing the specimens into a three-point flexural test attached to an Instron 4411 machine and loaded until the specimen failed using a 1 mm/minute crosshead speed. The peak load at fracture was recorded and the flexural strength calculated. The flexural strength data were analyzed using a two Factor ANOVA and Tukey B post-hoc tests (p=.05). Results: The mean flexural strengths of the materials (MPa) were: Insure CC 64±11, Insure VLC 78±8, Nexus CC 66±11 Nexus VLC 73.2±3 , RelyX ARC VLC 76±9, RelyX ARC CC 66±7, Lute-IT VLC 75±5, Lute-It CC 64±10. Conclusions: Flexural strength of materials not light cured were significantly lower than light cured materials (p=.01). Light curing produces significantly stronger flexural strength of dual cured cements compared to no light curing.

Back to the Dental Materials: III - Ceramics and Cements Program
Back to the IADR/AADR/CADR 80th General Session (March 6-9, 2002)

Top Level Search