A multi-functional dentine bonding system combining a phosphate monomer with eugenyl methacrylate.

Area of Science:

• Dental Materials Science
• Polymer Chemistry
• Biomaterials Engineering

Background:

• Tooth-resin composite interfaces are prone to failure due to microbial invasion and degradation.
• Developing durable dentine bonding systems (DBS) is crucial for long-term dental restorations.
• Antimicrobial monomers offer a potential strategy to enhance interface longevity.

Purpose of the Study:

• To design and evaluate experimental DBS incorporating eugenyl methacrylate (EgMA) for improved antimicrobial properties and resistance to degradation.
• To assess the impact of EgMA concentration on the physical, chemical, and mechanical properties of the DBS.
• To investigate the ability of the EgMA-containing DBS to inhibit matrix metalloproteinases (MMPs) and enhance hybrid layer stability.

Main Methods:

• Experimental adhesives with varying EgMA concentrations (0, 10, 20 wt%) were synthesized.
• Two-step self-etch DBS were formulated using bis[2-(methacryloyloxy)ethyl] phosphate (BMEP) in the primer.
• Properties evaluated included curing, thermal behavior, wettability, hybrid layer formation, microtensile bond strength (µTBS), nanoleakage, and MMP inhibitory activity via in situ zymography.

Main Results:

• EgMA incorporation reduced polymerisation exotherm and increased glass transition temperature (Tg) without compromising the degree of conversion.
• Higher EgMA concentrations led to significantly lower water sorption and solubility.
• The EgMA20 formulation exhibited the highest µTBS after water storage and the lowest nanoleakage after 6 months, with minimal MMP activity observed.

Conclusions:

• The hydrophobic EgMA monomer and increased cross-linking density effectively reduce water uptake and polymerisation heat.
• EgMA-containing DBS, combined with BMEP in a self-etching system, can inhibit MMP activity.
• This approach enhances the longevity and durability of the dentine-resin composite interface, offering a promising solution for dental restorations.