Immediate versus water-storage performance of Class V flowable composite restoratives

Area of Science:

• Dental Materials Science
• Polymer Chemistry
• Biomaterials Engineering

Background:

• Flowable resin composites are widely used in restorative dentistry.
• Understanding factors influencing their mechanical properties and marginal integrity is crucial for clinical success.
• Water storage and finishing time can impact composite performance.

Purpose of the Study:

• To evaluate the effect of 24-hour water storage and finishing time on the mechanical properties and marginal adaptation of modern flowable resin composites.
• To compare the performance of flowable composites against control materials (microfilled and hybrid).

Main Methods:

• Eight flowable composites and two controls were tested.
• Specimens were subjected to immediate (3 min) or delayed (24 h) interfacial polishing after setting.
• Marginal gap formation was measured in Class V cavities.
• Shear bond strength to enamel and dentin, flexural strength, and flexural modulus were also determined after 3 min and 24 h water storage.

Main Results:

• A 24-hour water storage significantly enhanced shear bond strength, flexural strength, and flexural modulus for most materials.
• Delayed polishing (24 h) resulted in a significantly reduced number of marginal gaps for only three of the flowable composites.
• Immediate polishing led to a higher incidence of marginal gaps compared to delayed polishing for most materials.

Conclusions:

• A 24-hour post-cure interval generally improves the mechanical and adhesive properties of flowable dental composites.
• Delayed polishing may contribute to reduced marginal gap formation, but this approach deviates from typical clinical procedures.
• Clinical recommendations should consider the potential benefits of extended curing/storage before finishing.