Irradiance effects on the mechanical properties of universal hybrid and flowable hybrid resin composites.

Abstract

OBJECTIVES:

A potential problem with high-intensity lights might be failure of polymer chains to grow and cross-link in a desired fashion, thereby affecting the structure and properties of the polymers formed. The purpose of this study was to evaluate mechanical properties of resin composites polymerized using four different light-curing units.

METHODS:

A conventional quartz-tungsten-halogen (QTH) light, a soft-start light, an argon-ion laser, and a plasma-arc curing light were used to polymerize disk-shaped (9.0mm diameter x 1.0 mm high) and cylinder-shaped (4mm diameter x 8 mm high) specimens of a universal hybrid and a flowable hybrid composite. Biaxial flexure strength, fracture toughness, hardness, compressive strength, and diametral tensile strength were determined for each composite.

RESULTS:

The use of the plasma-arc curing light, a high-intensity light, resulted in significantly lower hardness for the universal hybrid composite compared with the hardness obtained using the conventional QTH and the soft-start units. Hardness was the only mechanical property that was adversely affected by the use of a high-intensity light.

SIGNIFICANCE:

High-intensity lights might affect some resin composite mechanical properties, but this effect cannot be generalized to all resin composites and all properties.

• Authors: Annie J St-Georges, Edward J Swift, Jeffrey Y Thompson, Harald O Heymann
• Journal: Dental materials : official publication of the Academy of Dental Materials (Dent Mater) Vol. 19 Issue 5 Pg. 406-13 (Jul 2003) ISSN: 0109-5641 [Print] England
• PMID: 12742436 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Composite Resins
• Halogens
• Resin Cements
• Revolution (composite resin)
• Herculite XR
• Xenon

Topics

• Composite Resins (radiation effects)
• Compressive Strength (radiation effects)
• Dental Restoration, Permanent
• Dental Stress Analysis
• Halogens
• Hardness (radiation effects)
• Lasers
• Light
• Materials Testing
• Pliability (radiation effects)
• Resin Cements (radiation effects)
• Tensile Strength (radiation effects)
• Xenon