Impact of PVM/MA Copolymer on Dentin Bond Durability

Area of Science:

• Dental Materials Science
• Adhesive Dentistry
• Polymer Chemistry

Background:

• Dental adhesives are crucial for bonding restorative materials to tooth structure.
• Understanding factors affecting bond strength and durability is essential for clinical success.
• Aging processes like thermocycling can compromise adhesive interfaces.

Purpose of the Study:

• To evaluate the effect of Polymethyl vinyl ether-co-maleic anhydride (PVM/MA) copolymer on the shear bond strength (SBS) of dental adhesives to dentin.
• To assess the influence of thermocycling aging on the bond performance of these adhesives.
• To compare the outcomes between an etch-and-rinse and two self-etch adhesive systems.

Main Methods:

• Three adhesive systems (Adper Single Bond Plus, Clearfil SE Bond, Fluorobond II) were tested.
• Polymethyl vinyl ether-co-maleic anhydride (PVM/MA) copolymer was incorporated into the adhesives at 50 mg/ml.
• Dentin specimens were bonded, light-cured, and tested immediately or after 20,000 thermal cycles (5-55 °C).

Main Results:

• The PVM/MA copolymer improved immediate bond strength for Clearfil SE Bond (CSE) and long-term stability for Adper Single Bond Plus (ASB) after thermocycling.
• CSE with PVM/MA showed the highest immediate bond strength (22.0±1.7 MPa).
• Thermocycling significantly reduced bond strength in most groups, except for ASB with PVM/MA.

Conclusions:

• Incorporating PVM/MA copolymer can enhance the performance and long-term stability of specific adhesive systems, particularly ethanol-based, hydrophilic agents.
• This strategy may improve the durability of the adhesive bond to dentin.
• Further research into PVM/MA copolymer applications in dental adhesives is warranted.