Molar efficiency study of chlorinated NPG substitutes in dentin bonding

Area of Science:

• Dental Materials Science
• Polymer Chemistry
• Adhesion Science

Background:

• Dentin adhesive bonding is crucial for dental restorations.
• N-phenylglycine analogues are explored for their potential in improving dentin bonding.
• Electron-withdrawing substituents can influence the chemical properties and effectiveness of bonding agents.

Purpose of the Study:

• To evaluate and compare the efficacy of three N-phenylglycine analogues with varying electron-withdrawing substituents in dentin adhesive bonding.
• To determine the relationship between the electron-withdrawing nature of substituents and the resulting bond strengths.
• To identify optimal concentrations for effective dentin bonding.

Main Methods:

• An experimental three-step dentin-bonding protocol was employed.
• Three N-phenylglycine analogues, N-(4-chlorophenyl)-glycine (NCPG), N-methyl-N-(4-chlorophenyl)-glycine (NMNCPG), and N-(3,4-dichlorophenyl)-glycine (NDCPG), were tested at various concentrations.
• Tensile bond strengths of dentin-to-composite bonds were measured after storage in water and analyzed statistically.

Main Results:

• N-methyl-N-(4-chlorophenyl)-glycine (NMNCPG) showed the highest effectiveness at 5 x 10(-3) mol/L, outperforming NCPG and NDCPG.
• NCPG consistently performed better than or equal to NDCPG across tested concentrations.
• Increased electron-withdrawing substituents generally led to lower mean bond strengths and a narrower effective concentration range.

Conclusions:

• N-methyl-N-(4-chlorophenyl)-glycine (NMNCPG) is a promising candidate for enhancing dentin adhesive bonding.
• The degree of electron-withdrawing substitution significantly impacts the performance of N-phenylglycine analogues in dentin bonding.
• Optimizing the chemical structure of bonding agents is key to achieving robust and durable dentin-composite interfaces.