Chlorhexidine stabilizes the adhesive interface: a 2-year in vitro study

Area of Science:

• Biomaterials science
• Dental research
• Adhesive dentistry

Background:

• Endogenous dentin matrix metalloproteinases (MMPs) can degrade collagen within adhesive interfaces.
• Adhesive systems may activate these MMPs, potentially compromising long-term bond stability.
• Chlorhexidine digluconate (CHX) is explored for its potential to inhibit MMP activity.

Purpose of the Study:

• To evaluate the role of endogenous dentin MMPs in collagen auto-degradation at adhesive interfaces.
• To assess the effect of a specific adhesive (Adper Scotchbond 1XT, SB1XT) and CHX on dentin MMP activity.
• To determine if CHX pretreatment improves the long-term stability of adhesive interfaces.

Main Methods:

• Zymography was used to analyze dentin MMP activity after incubation with SB1XT on untreated or CHX-treated dentin.
• Microtensile bond strength and interfacial nanoleakage were assessed for SB1XT bonded interfaces.
• Assessments were performed immediately and after 2 years of storage in artificial saliva.

Main Results:

• SB1XT application increased MMP-2 activity in dentin.
• CHX pre-treatment (0.2-2%) inhibited all tested dentin gelatinolytic activity.
• CHX significantly reduced bond strength loss and nanoleakage in aged specimens.

Conclusions:

• Adper Scotchbond 1XT actively contributes to dentin MMP-2 activation.
• Chlorhexidine digluconate effectively inhibits dentin MMPs, even at low concentrations (0.2%).
• CHX pretreatment enhances the stability of resin-bonded interfaces over time.