Dentin-polymer bond promoted by Gluma and various resins

Area of Science:

• Dental Materials Science
• Adhesive Dentistry
• Polymer Chemistry

Background:

• Effective bonding between dentin and composite materials is crucial for durable dental restorations.
• Oxygen inhibition during polymerization can negatively impact adhesive bond strength on dentin surfaces.
• Marginal contraction gaps in fillings can lead to secondary caries and restoration failure.

Purpose of the Study:

• To evaluate the impact of resins containing specific additives on dentin-composite bond strength.
• To assess the effectiveness of these resins in preventing marginal contraction gaps.
• To investigate the role of oxygen inhibition in adhesive bonding to dentin.

Main Methods:

• Dentin surfaces were treated with Gluma and then coated with various resins.
• Shear and tensile bond strengths between dentin and microfilled composite were measured.
• Marginal contraction gaps around composite fillings were analyzed to assess bonding effectiveness.

Main Results:

• Resins containing propanal demonstrated shear bond strengths around 15 MPa.
• One resin formulation achieved tensile bond strengths exceeding 22 MPa, though composite rupture limited precise measurement.
• Fillings exhibited no contraction gaps in 30-70% of cases when using resins with propanal or p-toluenesulfinate.

Conclusions:

• Resins containing reducing agents, such as propanal, enhance shear and tensile bond strengths to dentin.
• These additives effectively reduce marginal contraction gaps, indicating improved adhesive performance.
• Reducing oxygen inhibition during polymerization is proposed as the mechanism for increased bonding effectiveness.