The effect of the pulse-delay cure technique on residual strain in composites.
Polymerization-induced shrinkage of composites leads to residual stress in the final restoration. For composites with a high modulus of elasticity, the level of stress can have significant clinical consequences, including crack formation in the enamel or microscopic separations at the preparation/restoration interface. The pulse-delay cure technique cures composites by providing low-energy pulse initially (e.g., 200 mW/cm2 for 3 seconds), followed by a waiting period of 3 to 5 minutes for strain relief, during which the composite can be finished and polished. The final cure is obtained by exposure to a high-intensity light source of 500 mW/cm2 for the recommended time. In vitro data obtained by strain gauges show that the pulse-delay cure technique can reduce residual strain in the composite by as much as 34%.
Suh
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Bisco Dental Products, Schaumburg, Illinois, USA.
Feng
L
L
Wang
Y
Y
Cripe
C
C
Cincione
F
F
de Rjik
W
W
D003188:Composite Resins / Q000737:chemistry*; D018772:Dental Marginal Adaptation; D003799:Dental Stress Analysis; D004055:Differential Thermal Analysis; D004548:Elasticity; D006358:Hot Temperature; D008027:Light; D055095:Optics and Photonics; D011108:Polymers / Q000737:chemistry; D013314:Stress, Mechanical; D013674:Technology, Dental / Q000379:methods*; D014783:Viscosity
D003188:Composite Resins; D011108:Polymers