Dual application of dentin bonding agents: effect on bond strength

Area of Science:

• Biomaterials Science
• Dental Materials
• Adhesive Dentistry

Background:

• Dentin bonding agents (DBAs) are critical for the success of dental restorations.
• Provisional cements are often used between dental procedures, potentially affecting DBA performance.
• Understanding the interaction between DBAs and provisional cements is essential for predictable clinical outcomes.

Purpose of the Study:

• To investigate the impact of a dual application strategy for dentin bonding agents (DBAs) on shear bond strength.
• To evaluate how an intermediate provisional cement layer influences the bond strength of DBAs to dentin.

Main Methods:

• Human dentin surfaces were treated with a first layer of various DBAs (All-Bond 2, ART Bond, Syntac, P-Bond).
• A provisional cement was applied, removed after 24 hours, and the dentin surface cleaned.
• A second DBA application and composite cylinder were applied, followed by thermal cycling and shear bond strength (SBS) testing.

Main Results:

• Dual DBA application significantly increased SBS compared to single application after provisional cement use.
• P-Bond demonstrated consistently high SBS values with dual application, comparable to fresh dentin.
• All-Bond 2 showed consistently low SBS values, irrespective of the provisional cement used.

Conclusions:

• A dual application of certain dentin bonding agents, with an intermediate provisional cement step, substantially improves shear bond strength.
• The P-Bond DBA shows promising results for dual application, maintaining high bond strength after provisional cement removal.
• All-Bond 2's performance is negatively impacted by the tested protocol, suggesting limitations in its use with provisional cements.