Effect of long-term water storage on dentin bonding

Area of Science:

• Dental Materials Science
• Biomaterials Engineering
• Restorative Dentistry

Background:

• Dental restorations require durable bonds between resin composites and tooth structure.
• Water degradation can compromise the integrity of adhesive interfaces over time.
• Assessing the long-term performance of dental adhesives is crucial for clinical success.

Purpose of the Study:

• To evaluate the impact of prolonged water storage on the bond strength and interfacial integrity of resin composite bonded to dentin.
• To compare the durability of All-Bond 2 and Amalgambond adhesive systems under simulated oral conditions.

Main Methods:

• Shear bond strength testing of All-Bond 2 and Amalgambond resin composite assemblies after 24 hours and 6 months of water storage at 37°C.
• Evaluation of marginal microleakage using eosin dye in Class V restorations.
• Assessment of interfacial integrity and gap formation using polyvinyl siloxane impressions.

Main Results:

• Significant reduction in shear bond strength was observed for both All-Bond 2 (32.68 to 23.29 MPa) and Amalgambond (26.03 to 12.90 MPa) after 6-month water storage (P < 0.05).
• No dye leakage or gaps were detected at the margins of any restorations, indicating absence of microleakage.
• Gaps were frequently observed at the floor of Amalgambond restorations, suggesting interfacial compromise.

Conclusions:

• Both adhesive systems demonstrated reduced bond strength after long-term water storage.
• Amalgambond showed a greater decrease in bond strength and exhibited interfacial gaps, indicating potential long-term durability issues.
• While microleakage was not evident, the interfacial integrity of Amalgambond restorations may be compromised over time.