Microshear bonding effectiveness of different dentin regions.

Area of Science:

• Dental Materials Science
• Biomaterials Engineering
• Adhesion Science

Background:

• Optimizing the bond strength of dental adhesives is critical for the longevity and success of dental restorations.
• Dentin's complex structure, including tubule orientation, can influence adhesive interactions and bond durability.
• Multimode adhesive systems offer versatility but their performance may vary across different dentin substrates.

Purpose of the Study:

• To investigate the effect of dentin tubule orientation on the bond strength of a multimode adhesive system.
• To compare the bond strength of a multimode adhesive on occlusal versus proximal human dentin.
• To evaluate the influence of different application modes (etch-and-rinse and self-etch) on adhesive performance.

Main Methods:

• Human molars were prepared to create distinct occlusal and proximal dentin regions.
• A multimode adhesive system was applied using both etch-and-rinse and self-etch modes.
• Microshear bond strength (μSBS) testing was conducted on cylindrical restorations bonded to prepared dentin surfaces.

Main Results:

• No significant difference in bond strength was observed between the etch-and-rinse and self-etch application modes (P = 0.19).
• Dentin region significantly affected microshear bond strength (μSBS) (P < 0.05).
• Proximal dentin exhibited higher bond strength values compared to occlusal dentin.

Conclusions:

• Dentin surface and tubule orientation play a significant role in the bonding effectiveness of multimode adhesive systems.
• The location of dentin preparation (occlusal vs. proximal) influences bond strength, with proximal dentin yielding better results.
• Understanding dentin morphology is essential for predicting and enhancing adhesive performance in clinical applications.