Shear Bond Strength and Tooth-Composite Interaction With Self-Adhering Flowable Composites

Area of Science:

• Dental Materials Science
• Adhesive Dentistry
• Biomaterials

Background:

• Self-adhering flowable composites offer simplified application in dental restorations.
• Understanding their interaction with tooth structure and long-term bond durability is crucial for clinical success.

Purpose of the Study:

• To evaluate the tooth-composite interaction and shear bond strength (SBS) of self-adhering flowable materials.
• To compare the performance of different self-adhering flowables against a conventional system.

Main Methods:

• Class V cavities in human molars were restored with four different flowable composites (Vertise Flow, Fusio Liquid Dentin, experimental self-adhering flowable, Adper Prompt-L-Pop/Filtek Supreme XT Flowable).
• Microleakage and tooth-composite interface morphology were assessed.
• Shear bond strength was measured on prepared enamel and dentin substrates after water storage or thermocycling, with failure modes analyzed via SEM.

Main Results:

• Self-adhering flowables (EF, VF) exhibited lower microleakage at enamel margins compared to conventional systems.
• Dentin microleakage was lower with FLD and VF.
• Shear bond strength significantly decreased after thermocycling for all materials, with self-adhering flowables generally showing diminished bond strength.
• More cohesive failures were observed with the conventional system (PLP).

Conclusions:

• The tooth-composite morphology and bond strength results suggest cautious clinical application of self-adhering flowables.
• Long-term stability and bond degradation under thermal stress are significant concerns for self-adhering flowable composites.