Composite resins in the 21st century

Area of Science:

• Dental Materials Science
• Biomaterials Engineering
• Restorative Dentistry

Background:

• Current composite resins require evaluation against established physiologic standards for posterior restorations.
• Human enamel and dentin serve as crucial benchmarks for material performance.
• Assessing surface roughness, hardness, modulus, strength, wear, and radiographic opacity is vital.

Purpose of the Study:

• To establish physiologic standards for evaluating composite resins in posterior dental applications.
• To define critical material properties for optimal composite resin selection.
• To identify promising composite resin formulations for contemporary restorative dentistry.

Main Methods:

• Comparative analysis of composite resin properties against human enamel and dentin standards.
• Evaluation of surface roughness (Ra), nanoindentation hardness, and Young's modulus.
• Assessment of compressive and fracture strength, in vivo wear rate, and radiographic opacity.

Main Results:

• Composite resins should have surface roughness ≤ human enamel (Ra = 0.64 microns).
• Filler particle hardness should not exceed hydroxyapatite (3.39 GPa), and Young's modulus should match or exceed dentin (18,500 MPa).
• Wear rates comparable to enamel (39 microns/y) and radiographic opacity exceeding enamel (198% Al) are necessary.

Conclusions:

• Ultrafine compact-filled composite resins align well with established physiologic and mechanical standards for posterior restorations.
• These materials offer a potential solution for durable and biocompatible dental restorations.
• Adherence to these criteria ensures optimal performance and longevity in the oral environment.