Toward biomimetic direct restorations: A nanofiber-based interfacial strategy to approximate dentin-enamel junction...

Area of Science:

• Biomaterials Science
• Dental Materials Science
• Nanotechnology

Background:

• The dentin-enamel junction (DEJ) is crucial for stress dissipation between enamel and dentin.
• Current composite resin (CR) restorations fail to replicate the DEJ's functional biomechanics.
• Developing biomimetic strategies is essential for improved dental restorations.

Purpose of the Study:

• To evaluate if electrospun nanofibers can create a compliant interlayer mimicking the DEJ's biomechanical properties.
• To assess the mechanical characteristics of nanofiber-reinforced interfaces in dental restorations.
• To explore a novel biomimetic approach for direct restorative procedures.

Main Methods:

• Human molars were sectioned to obtain enamel, dentin, and DEJ specimens.
• Microhardness, Derjaguin-Müller-Toporov (DMT) modulus (AFM), and microtensile bond strength were measured.
• Four groups were compared: Control (natural DEJ), Adhesive, Flowable CR, and Nanofiber interlayer.

Main Results:

• Enamel was harder than dentin; CR was softer than enamel.
• The natural DEJ exhibited the lowest DMT modulus, indicating compliance.
• The nanofiber group showed DMT modulus values closer to dentin and the natural DEJ.
• Microtensile bond strength showed no significant differences, but the nanofiber group approached control values.
• Morphological analysis revealed a more integrated interface with the nanofiber layer.

Conclusions:

• Electrospun nanofibers can form a compliant interlayer with mechanical properties similar to the DEJ.
• Nanofiber interlayers show promise for biomimetic dental restorations.
• This approach may enhance compliant behavior at the resin-dentin interface in restorative dentistry.