Bond strength of Gluma CPS using the moist dentin bonding technique

Area of Science:

• Dental Materials Science
• Adhesive Dentistry
• Biomaterials Research

Background:

• Effective bonding to dentin is crucial for the longevity of dental restorations.
• Dentin surface moisture significantly influences the performance of dental adhesives.
• Gluma primers are used to enhance adhesion between dentin and restorative materials.

Purpose of the Study:

• To evaluate the impact of acetone- vs. water-based Gluma primers on dentin bonding efficacy.
• To compare bonding performance across different dentin surface moisture conditions: wet, dry, and rewetted.
• To assess cavity sealing and resin impregnation depth with varying primer solvents and techniques.

Main Methods:

• Human dentin was etched with 20% phosphoric acid and subjected to four moisture conditions: wet, conventional drying, dry, and rewetting.
• Shear bond strength (SBS) was measured after 24 hours using either water-based or acetone-based Gluma primers.
• Cavity sealing and resin impregnation depth were analyzed at the margins of prepared cavities.

Main Results:

• Wet and conventionally dried dentin yielded high SBS (approx. 18 MPa and 16.5 MPa, respectively), regardless of primer solvent.
• Acetone-based primers demonstrated superior performance with the rewetting technique, achieving high SBS.
• Acetone primers with the wet technique resulted in consistently gap-free margins and optimal resin impregnation depth (12.5 microns).
• Dry techniques led to significantly thinner resin-impregnated layers, especially with acetone primers.

Conclusions:

• Dentin surface moisture management is critical for achieving optimal bond strength and sealing with Gluma primers.
• Acetone-based Gluma primers, particularly when applied to rewetted dentin, offer excellent cavity sealing and resin impregnation.
• The choice of primer solvent and application technique significantly affects the bonding efficacy and marginal integrity in adhesive dentistry.