One-year Adhesive Bond Durability to Coronal and Radicular Dentin Under Intrapulpal Pressure Simulation

Area of Science:

• Dental Materials Science
• Biomaterials Engineering
• Restorative Dentistry

Background:

• Dental adhesives are crucial for bonding restorative materials to tooth structure.
• Understanding the long-term stability of adhesive bonds under physiological conditions is essential for clinical success.
• Coronal and radicular dentin present different structural and chemical properties that may influence adhesive performance.

Purpose of the Study:

• To compare the microtensile bond strength (μTBS) of different dental adhesive systems to coronal and radicular dentin.
• To evaluate the effect of one-year storage in artificial saliva under simulated intrapulpal pressure (IPP) on adhesive bond strength.
• To determine if adhesive strategies are sensitive to dentin substrate location (coronal vs. radicular) and storage duration.

Main Methods:

• Three adhesive strategies (two-step etch-and-rinse, two-step self-etch, single-step self-etch) were tested on 36 premolar teeth.
• Adhesives were applied to standardized coronal and radicular dentin surfaces under simulated IPP.
• Specimens were stored in artificial saliva at 37°C for 24 hours or one year before μTBS testing.

Main Results:

• Adhesive strategy and storage period significantly affected μTBS (p<0.001).
• The two-step self-etch adhesive demonstrated superior μTBS compared to the other systems at both time points.
• A significant decrease in bond strength was observed for all adhesives after one year of storage, irrespective of dentin substrate.

Conclusions:

• Dental adhesive systems are not influenced by the structural differences between coronal and radicular dentin.
• All tested adhesive systems exhibit reduced bond strength after long-term storage under simulated physiological conditions.
• Storage duration significantly impacts the durability of dental adhesive bonds.