Bioactive Two-step Approach: Promising Bonding Strategy for a One-step Self-etch Universal Adhesive

Area of Science:

• Dental Materials Science
• Adhesive Dentistry
• Biomaterials Engineering

Background:

• One-step self-etch universal adhesives are widely used in restorative dentistry.
• Enhancing the bond strength and longevity of these adhesives remains a clinical challenge.
• Novel hydrophobic adhesive resins offer potential for improved interfacial properties.

Purpose of the Study:

• To evaluate the efficacy of two experimental hydrophobic adhesive resins (BZF210, BZF21) in enhancing the bond strength of a universal adhesive.
• To investigate the effect of incorporating bioactive zinc fluoride glass into these resins.
• To compare the performance of experimental resins with established universal adhesives.

Main Methods:

• Three universal adhesives (GPB, SBU, SE2) and two experimental resins (BZF210, BZF21) were tested.
• Adhesives were applied to dentin, and microtensile bond strength (μTBS) was measured after 24-hour water storage.
• Fracture modes and interfacial structures were analyzed using SEM and SEM-EDS.

Main Results:

• Additional application of BZF210 and BZF21 significantly increased GPB's μTBS compared to GPB alone.
• Cohesive and mixed failures were more prevalent with experimental resins, indicating improved bonding.
• SEM-EDS confirmed the presence of zinc in the experimental resin group (GPB+BZF21).

Conclusions:

• The experimental hydrophobic adhesive resins BZF210 and BZF21 significantly improve the bond strength of the one-step self-etch universal adhesive GPB.
• Incorporating a bioactive hydrophobic layer can enhance the bonding efficacy of universal adhesives.
• These findings suggest expanded clinical applications for universal adhesives with additional hydrophobic layers.