Morphological interface between hybrid ionomers and dentin with and without smear-layer removal

Area of Science:

• Dental Materials Science
• Biomaterials Interface Analysis
• Restorative Dentistry

Background:

• Understanding the dentin-restorative material interface is crucial for long-term clinical success.
• Hybrid ionomers and poly-acid-modified composites are widely used dental restorative materials.
• Micromorphological evaluation provides insights into material-tooth interaction.

Purpose of the Study:

• To compare the micromorphological interface between dentin and various hybrid ionomer restoratives.
• To evaluate the formation of hybrid layers and resin tags with different materials.
• To assess the effect of smear layer removal on hybridization.

Main Methods:

• Extracted human molar teeth were prepared to expose flat dentin surfaces.
• Five dental materials (Compoglass, Dyract, F2000, Fuji II LC, Photac-Fil) were applied.
• Scanning Electron Microscopy (SEM) was used to examine the dentin/material interface after specific sample preparation techniques, including acid etching and decalcification.

Main Results:

• Poly-acid-modified composite resins (Compoglass, Dyract, F2000) demonstrated hybrid layer formation and resin tags at the dentin interface.
• Removal of the smear layer significantly enhanced the hybridization of these poly-acid-modified composites.
• Resin-modified glass-ionomer Fuji II LC also produced a hybrid layer.
• Photac-Fil showed no evidence of hybridization at the dentin interface.

Conclusions:

• Poly-acid-modified composites and Fuji II LC exhibit favorable micromorphological bonding to dentin.
• Smear layer management is critical for optimizing the hybridization of poly-acid-modified composites.
• Photac-Fil may have limitations in achieving a micromechanical bond with dentin compared to other tested materials.