CHX Stabilizes the Resin/demineralized Dentin Interface

Area of Science:

• Dental Materials Science
• Biomaterials Engineering
• Adhesive Dentistry

Background:

• Microtensile bond strength (µTBS) is crucial for dental adhesive longevity.
• Dentin substrate condition (sound, caries-infected, caries-affected) can influence adhesive performance.
• Chlorhexidine digluconate (CHX) is an antimicrobial agent with potential effects on dentin matrix.

Purpose of the Study:

• To evaluate the effect of 2% chlorhexidine digluconate (CHX) on the microtensile bond strength (µTBS) of an adhesive system.
• To assess the influence of CHX on dentin bond durability over 1 year under different dentin conditions.
• To compare the µTBS of an adhesive system on sound, caries-infected, and caries-affected dentin with and without CHX pre-treatment.

Main Methods:

• Human third molars were prepared and divided into sound, caries-infected, and caries-affected dentin groups.
• Dentin surfaces were pre-treated with 2% CHX or served as controls, then bonded with Adper Single Bond 2.
• Specimens were stored in deionized water for 24 hours, 6 months, and 1 year before µTBS testing.
• Scanning Electron Microscopy (SEM) was used for interface analysis.

Main Results:

• Caries-infected dentin exhibited significantly lower µTBS compared to caries-affected and sound dentin, irrespective of storage time or CHX treatment.
• Long-term storage (6 months and 1 year) reduced µTBS in the control group.
• The 2% CHX pre-treatment maintained µTBS over the storage periods, showing no significant decrease between 24 hours, 6 months, and 1 year.

Conclusions:

• 2% chlorhexidine digluconate (CHX) application after etching enhances the durability of dentin-adhesive bonds.
• CHX pre-treatment mitigates the bond strength degradation typically observed over time, especially in compromised dentin substrates.
• The findings suggest CHX is a beneficial adjunct for improving long-term adhesive performance in restorative dentistry.