2-HEMA-free dentin bonding system to prevent contraction gap

Area of Science:

• Dental Materials Science
• Polymer Chemistry
• Adhesive Dentistry

Background:

• 2-hydroxyethyl methacrylate (2-HEMA) is a common component in dental primers and bonding agents.
• Understanding its role is crucial for optimizing dentin bonding systems and minimizing adverse effects.

Purpose of the Study:

• To evaluate the effect of 2-HEMA in primers and dentin bonding agents on the efficacy of dentin bonding systems.
• To assess the formation of polymerization contraction gaps in resin composite restorations.

Main Methods:

• A commercial resin composite was restored in human molar dentin cavities.
• Polymerization contraction gap width was measured.
• Different priming strategies involving EDTA-conditioning and various monomers (including 2-HEMA) were tested.

Main Results:

• Gap formation was prevented with EDTA-conditioning followed by glyceryl mono-methacrylate, ethylene glycol, and 1,6-hexanediol priming, irrespective of 2-HEMA content in the bonding agent.
• 2-HEMA priming alone did not completely prevent gap formation.
• 2-HEMA demonstrated low bonding efficacy and potential for delayed allergic skin reactions.

Conclusions:

• 2-HEMA is not essential in either the primer or the dentin bonding agent for effective dentin bonding.
• Alternative priming solutions offer superior gap prevention.
• The use of 2-HEMA should be reconsidered due to its limited efficacy and adverse side effects.