Collagen cross linking increases its biodegradation resistance in wet dentin bonding

Area of Science:

• Biomaterials Science
• Dental Materials
• Polymer Chemistry

Background:

• Dentin collagen biodegradation at the adhesive/dentin (a/d) interface compromises dental restoration longevity.
• This degradation is a primary cause of composite restoration failure.

Purpose of the Study:

• To evaluate the efficacy of incorporating glutaraldehyde (GA), a cross-linking agent, into dental adhesives.
• To determine if GA enhances collagen biodegradation resistance within the a/d interface.

Main Methods:

• A model adhesive formulation with and without 5% GA was prepared.
• Dentin surfaces were acid-etched, and adhesives were applied and light-cured.
• Specimens were immersed in a collagenase solution for up to 30 days.
• Analysis was performed using Scanning Electron Microscopy (SEM) and micro-Raman spectroscopy.

Main Results:

• SEM revealed voids and collagen loss in the a/d interface for adhesives without GA after degradation.
• Micro-Raman spectroscopy confirmed collagen removal by decreased amide I band intensity.
• Adhesives containing GA prevented collagen degradation within the a/d interface, as confirmed by both SEM and Raman analysis.

Conclusions:

• Collagen fibrils in the a/d interface are vulnerable to biodegradation with current adhesive systems and wet bonding techniques.
• Directly incorporating cross-linking agents like GA into adhesives effectively protects collagen fibrils from degradation.
• This approach offers a promising strategy to improve the long-term durability of dental restorations.