Fatigue of packable dental composites.
OBJECTIVE
The purpose of the study was to measure the fatigue properties of four dental resin composites using a dynamic mechanical analysis and to relate the results with viscoelastic properties.


METHODS
Dynamic torsional loading was conducted at resonance at 30-50Hz. Specimens were thoroughly cured and tested dry at 21 degrees C.


RESULTS
All of the specimens showed a loss of strength following repeated stress, due to material fatigue. The material with the highest shear modulus had the lowest damping and the highest fatigue strength.


CONCLUSIONS
Dental composites exhibit a modest loss of strength due to fatigue. Since mastication involves many cycles of stress during the life of a restoration, fatigue properties should be taken into account in restoration design.
Aristotle University of Thessaloniki, School of Dentistry, Department of Operative Dentistry, Thessaloniki, Greece. papady@dent.auth.gr
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Papadogiannis
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Lakes
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Palaghias
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Helvatjoglu-Antoniades
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Papadogiannis
D003187:Compliance; D003188:Composite Resins / Q000737:chemistry*; D003764:Dental Materials / Q000737:chemistry*; D003799:Dental Stress Analysis; D004548:Elasticity; D006801:Humans; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D008956:Models, Chemical; D019279:Resin Cements / Q000737:chemistry; D033081:Shear Strength; D012833:Siloxanes / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D014102:Torsion Abnormality; D014783:Viscosity
C406265:Alert composite resin; D003188:Composite Resins; D003764:Dental Materials; C438835:Filtek P60 Composite Resin; D008689:Methacrylates; D019279:Resin Cements; D012833:Siloxanes; C479084:admira; C485972:synergy compact resin cement