Substantivity of chlorhexidine to human dentin.

Area of Science:

• Dental Materials Science
• Biomaterials Research
• Adhesive Dentistry

Background:

• Resin-dentin bond degradation is a significant clinical challenge.
• Chlorhexidine (CHX) is known to inhibit dentinal proteases, potentially improving bond longevity.
• Understanding CHX substantivity to dentin is crucial for optimizing its clinical application.

Purpose of the Study:

• To investigate the substantivity of chlorhexidine (CHX) to human dentin.
• To evaluate the retention of CHX in mineralized and demineralized dentin substrates over time.
• To assess the influence of CHX concentration and incubation period on its retention.

Main Methods:

• Human dentin disks were prepared in mineralized (MD), partially demineralized (PDD), and totally demineralized (TDD) states.
• Specimens were treated with 0.2% or 2% CHX solutions and incubated for up to 8 weeks.
• CHX concentration in eluates was quantified using spectrophotometry.

Main Results:

• Significant CHX retention was observed in all dentin substrates (MD, PDD, TDD) irrespective of applied dose or incubation time.
• High CHX retention on hydroxyapatite (HA) was noted only at the 2% concentration.
• Results indicate substantial CHX binding to dentin matrix components.

Conclusions:

• Chlorhexidine exhibits outstanding substantivity to human dentin.
• The prolonged retention of CHX on dentin supports its role in preserving resin-dentin bonds.
• CHX's substantivity, combined with protease inhibition, likely contributes to enhanced bond durability.