New initiator system for bonding to dentin using methylcyclohexanedione

Area of Science:

• Dental Materials Science
• Polymer Chemistry
• Biomaterials Engineering

Background:

• Dentin bonding is crucial for dental restorations.
• Effective polymerization initiator systems are vital for durable dental adhesives.
• The role of initiator systems in dentin bonding requires further investigation.

Purpose of the Study:

• To evaluate a novel polymerization initiator system comprising 2-methyl-1,3-cyclohexanedione (MCHD) and CuCl2 for dentin bonding.
• To assess the influence of dentin conditioners and CuCl2 concentration on the performance of MMA/PMMA resins.
• To determine the curing time and tensile bond strength of the new initiator system.

Main Methods:

• Resins were formulated with MMA, PMMA powder, MCHD (2 wt%), and varying CuCl2 concentrations (0.001-0.03 wt%).
• Bovine dentin surfaces were treated with six different acidic conditioners (phosphoric acid or citric acid) containing FeCl3 or CuCl2 (0-3 wt%).
• Curing time and tensile bond strength to dentin were measured under optimal conditions.

Main Results:

• The MCHD/CuCl2 initiator system demonstrated effective polymerization in MMA/PMMA resins.
• Optimal conditions resulted in tensile bond strengths of approximately 10 MPa.
• These bond strengths are comparable to highly effective existing dentin bonding resins, such as those initiated by tributylborane.

Conclusions:

• The MCHD/CuCl2 initiator system is highly effective for dentin bonding applications.
• The effectiveness is significantly enhanced when dentin is pre-treated with acidic conditioners containing ferric or copper chloride.
• This novel system offers a promising alternative for durable and reliable dental adhesive formulations.