Penetration of a dentin bonding agent into dentin

Area of Science:

• Dental Materials Science
• Biomaterials Engineering
• Adhesive Dentistry

Background:

• Effective bonding to demineralized dentin is crucial for durable dental restorations.
• Scotchbond Multi-Purpose (SMP) is a widely used dental adhesive system.
• Understanding the interaction between priming agents and demineralized dentin is key to optimizing bond strength.

Purpose of the Study:

• To investigate the effect of Scotchbond Multi-Purpose (SMP) priming agents on collagen wettability in demineralized dentin.
• To determine how priming agent application influences bonding monomer penetration and adaptation.
• To optimize the application protocol for SMP to enhance shear bond strength.

Main Methods:

• Bovine teeth were prepared and demineralized.
• Scotchbond Multi-Purpose (SMP) primer and Z100 resin were applied.
• Shear bond strength testing and scanning electron microscopy (SEM) were performed.
• Conventional air drying (CAD) and critical point drying (CPD) techniques were used for SEM evaluation.

Main Results:

• A statistically significant 26.3% increase in shear bond strength was observed with a second application of SMP primer.
• SEM revealed voids in the demineralized layer of conventionally air-dried specimens.
• Critical point drying (CPD) demonstrated that voids were filled with collagen fibrils, which were incorporated into the resin.
• Even with multiple applications, some unincorporated collagen fibrils were observed.

Conclusions:

• A second application of SMP primer enhances resin penetration and adaptation in demineralized dentin.
• The CPD technique provides superior visualization of resin-dentin interactions compared to CAD.
• Optimizing SMP application can improve micromechanical retention and overall bond strength in dental restorations.