Adhesion to primary dentin: microshear bond strength and scanning electron microscopic observation

Area of Science:

• Dental Materials Science
• Adhesive Dentistry
• Pediatric Dentistry

Background:

• Bond strength to primary dentin is crucial for restoration longevity.
• Evaluating new adhesive materials for pediatric restorations is essential.
• Understanding material performance in primary teeth informs clinical practice.

Purpose of the Study:

• To compare the bond strength of a self-adhesive resin composite, a self-etch adhesive, and a glass-ionomer cement to human primary dentin.
• To assess bond durability using microshear bond strength (pSBS) testing and scanning electron microscopy (SEM).

Main Methods:

• 75 human primary molars were prepared into dentin slabs.
• Three groups were tested: self-adhesive composite (Vertise Flow), self-etch adhesive (Optibond All-in-One) with composite, and glass-ionomer cement (Ketac-Fil).
• Micro-shear bond strength tests and SEM analysis were performed after thermocycling.

Main Results:

• The self-etch adhesive group showed the highest bond strength (20.2 MPa), significantly higher than the self-adhesive composite (9.0 MPa).
• The glass-ionomer cement group exhibited the lowest bond strength (4.8 MPa).
• Predominantly adhesive failures were observed across all groups.

Conclusions:

• Self-etch adhesives offer superior bond strength to primary dentin compared to self-adhesive resin composites and glass-ionomer cements.
• Material selection impacts the reliability of restorations in primary teeth.
• Further research may explore long-term clinical performance.