[A novel reactive polymer bonding composite resin to ground tooth substrates]

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Dental Materials

Background:

• Dental adhesives aim to bond restorative materials to tooth structure.
• Current adhesives often rely on monomer infiltration and polymerization, which can lead to potential drawbacks like pulp irritation.
• A novel approach using reactive polyelectrolytes for adhesion is explored.

Purpose of the Study:

• To prepare and evaluate the adhesion of a methyl methacrylate (MMA)-p-styrene sulfonic acid (MS) copolymer to ground tooth substrates.
• To elucidate the adhesion mechanism of the MS copolymer.
• To assess the bonding strength of different resin systems to the MS-treated tooth surface.

Main Methods:

• Preparation of MMA-p-styrene sulfonic acid copolymer (MS).
• Evaluation of MS adhesion to ground enamel and dentin, focusing on crosslinking with Ca2+.
• Testing bonding strength of MMA-TBB and MMA-BPO.DMPT resins to MS-treated teeth.
• Utilizing a photocurable liner (TEGDMA-CQ.NPG) for high bond strength assessment.

Main Results:

• MS adheres to tooth surfaces via crosslinking with Ca2+ from hydroxyapatite, a mechanism distinct from monomer interpenetration.
• MMA-TBB resin showed high bonding strength (11-12 MPa) to MS-treated teeth, while MMA-BPO.DMPT resin showed lower strength (2.5 MPa) due to disturbed polymerization.
• TEGDMA-CQ.NPG liner achieved 10-11 MPa bond strength, with no observed interpenetration into dentin.

Conclusions:

• The polymer reaction of MS with Ca2+ is crucial for effective adhesion to tooth substrates.
• MS acts as a reactive polyelectrolyte, providing strong adhesion and preventing monomer penetration, thus mitigating pulp irritation.
• This copolymer represents a promising material for enhanced dental adhesion applications.