Dentin Cross-linking Effect of Carbodiimide After 5 Years

Area of Science:

• Dental Materials Science
• Biomaterials Engineering
• Adhesive Dentistry

Background:

• Carbodiimide (EDC) primers are used in dentin bonding to preserve hybrid layer (HL) integrity.
• Long-term aging effects (>1 year) of EDC on HL stability are not well-documented.
• Understanding long-term performance is crucial for durable dental restorations.

Purpose of the Study:

• To evaluate the 5-year aging effects of EDC-based dentin primers on hybrid layer integrity.
• To assess the impact of EDC on dentin bond strength, enzymatic activity, and chemical profile.
• To determine the persistence of EDC's cross-linking effect over time.

Main Methods:

• Human molars were treated with EDC primer or without, then restored with two different bonding systems.
• Microtensile bond strength (µTBS), in situ zymography, and Raman spectroscopy were performed at baseline and after 5 years of aging in artificial saliva.
• Statistical analysis included three-way ANOVA and Tukey's post hoc test.

Main Results:

• EDC pretreatment significantly improved microtensile bond strength and reduced gelatinolytic activity after 5 years.
• EDC-treated groups showed higher bond strength and lower enzymatic activity compared to controls at 5-year aging.
• Raman spectroscopy indicated better collagen preservation in EDC-treated specimens, with less defined amide III peaks in controls.

Conclusions:

• The cross-linking effect of EDC persists in the hybrid layer for at least 5 years.
• EDC pretreatment enhances long-term dentin bond durability, collagen preservation, and reduces enzymatic degradation.
• EDC-based primers represent a promising strategy for improving the longevity of dental adhesive restorations.