Endogenous Enzymatic Activity in Dentin Treated with a Chitosan Primer

Area of Science:

• Biomaterials Science
• Dental Research
• Polymer Chemistry

Background:

• Dentin matrix contains enzymes like matrix metalloproteinases (MMPs) that can degrade the hybrid layer.
• Chitosan is a biocompatible polymer with potential applications in dentistry.
• Controlling dentinal enzymatic activity is crucial for improving the longevity of dental restorations.

Purpose of the Study:

• To investigate the impact of varying chitosan concentrations on dentinal enzymatic activity.
• To assess chitosan's potential as a primer to inhibit MMPs in dentin.
• To evaluate the effect of chitosan on MMPs in both unrestored and restored dentin.

Main Methods:

• Human dentin powder was treated with different concentrations (1%, 0.5%, 0.1%) of chitosan.
• Gelatin zymography and in situ zymography were employed to detect and quantify proteolytic activity.
• Dentin proteins were extracted and analyzed using SDS-PAGE with fluorescein-labeled gelatin.
• Enzymatic activity was measured using UV light scanning and Image J software.

Main Results:

• Enzymatic activity was directly proportional to chitosan concentration, with higher activity at 1% and 0.5% concentrations.
• The 0.1% chitosan concentration demonstrated a significant reduction in enzymatic activity compared to higher concentrations.
• Restored dentin groups exhibited higher enzymatic activity than unrestored groups, except for the 0.1% chitosan primer.
• The 0.1% chitosan primer showed only faint expression of enzymatic activity.

Conclusions:

• Chitosan, particularly at a 0.1% concentration in water, effectively reduces dentinal matrix metalloproteinases (MMPs) activity.
• Low-concentration chitosan primers show promise for preserving bond strength in dental restorations over time.
• Chitosan's MMP-inhibiting properties make it a potential biomaterial for enhancing the durability of adhesive dentistry.