Simulated Cuspal Deflection and Flexural Properties of Bulk-Fill and Conventional Flowable Resin Composites

Area of Science:

• Dental Materials Science
• Polymer Chemistry

Background:

• Flowable resin composites are widely used in dental restorations.
• Minimizing polymerization-induced stress, such as cuspal deflection, is crucial for restoration longevity.
• Bulk-fill composites offer simplified placement but their stress-reducing potential needs evaluation.

Purpose of the Study:

• To compare the simulated cuspal deflection and flexural properties of bulk-fill and conventional flowable resin composites.
• To investigate the relationship between flexural properties and cuspal deflection in these materials.

Main Methods:

• Five bulk-fill and six conventional flowable resin composites were tested.
• Simulated cuspal deflection was measured using a micrometer or confocal laser scanning microscope (CLSM) in aluminum blocks.
• Flexural properties were assessed, and materials were examined using scanning electron microscopy (SEM).

Main Results:

• Some bulk-fill flowable composites demonstrated significantly lower or similar cuspal deflection compared to conventional types.
• Statistically significant differences in flexural properties were observed among materials.
• No significant correlation was found between flexural properties and cuspal deflection.

Conclusions:

• Certain bulk-fill flowable resin composites can reduce cuspal deflection when placed using the bulk-fill technique compared to conventional composites placed incrementally.
• Both micrometer and CLSM are suitable for measuring simulated cuspal deflection.
• Flexural properties did not show a significant relationship with cuspal deflection in this study.