NIOM was represented by senior scientist John Tibballs who contributed a poster:
Tibballs JE, Wellendorf H, Kopperud H “Flexural, flexural fatigue and flexural creep strength of four bulk-fill resin composites at room and body temperatures”.
Bulk-fill composites have gained increased interest during the past years. Earlier studies have examined monomer leaching, depth of cure and polymerization shrinkage and found them generally similar to equivalent, traditional materials. Depth of cure indicated however that, under sub-optimal curing conditions, longer curing times ought to apply to achieve full depth of hardening.
This study explored the flexural strength and fatigue properties of bulk-fill resin composites in standard testing and in a wet, 37°C environment.
Flexural strength and flexural fatigue strength of bulk-fill resin composites are found to depend so greatly on the test environment and loading conditions that the design strength of the material in the oral environment under masticatory forces is estimated to be 20-25 % of the flexural strength quoted as standard. Finite element analyses with simplified tooth models suggest, however, that this strength is adequate to sustain function at least for fillings subject to moderate biting forces.