SEM evaluation of the interaction between a three-step adhesive and dentin.

Area of Science:

• Biomaterials Science
• Dental Materials Science
• Adhesion Science

Background:

• The interaction between resin tags/microtags and dentinal collagen fibrils is crucial for dental adhesion but poorly understood.
• Understanding this interaction can improve the longevity and effectiveness of dental restorations.

Purpose of the Study:

• To investigate the interaction between resin tags and microtags of an adhesive system with dentinal collagen fibrils.
• To elucidate the mechanisms underlying adhesion to dentin using a three-step adhesive system.

Main Methods:

• Human third molars were prepared into dentin disks, etched, and treated with Scotchbond Multi-Purpose adhesive and Z100 composite.
• Bonded specimens were aged, fractured, and analyzed using scanning electron microscopy (SEM) after acid treatment.
• SEM was used to examine the morphology and interaction of resin tags and microtags with dentinal collagen.

Main Results:

• A hybrid layer with resin tags (approx. 100 micrometers) and numerous fine, branching microtags was observed.
• Resin tags and microtags demonstrated intimate contact with dentinal collagen fibrils, extending into deeper dentin zones.
• These findings indicate a complex interaction between the adhesive system and the dentin substrate.

Conclusions:

• Dental adhesion involves both micromechanical retention and potential chemical interactions.
• The observed intimate contact suggests effective penetration and interaction of the adhesive system with dentinal collagen.
• This detailed understanding can inform the development of improved dental adhesive systems.