Improving Self-Healing Dental-Restorative Materials with Functionalized and Reinforced Microcapsules

Area of Science:

• Materials Science
• Biomaterials Engineering
• Polymer Chemistry

Background:

• Dental resin composites suffer from microcracks, limiting restoration lifespan.
• Self-healing microcapsules offer a solution to improve dental material durability.
• Optimizing microcapsule-matrix interactions is key to enhancing self-healing performance.

Purpose of the Study:

• To enhance self-healing dental resins by optimizing microcapsule-resin matrix physicochemical interactions.
• To investigate the effect of surface functionalization on poly(urea-formaldehyde) (PUF) microcapsules.
• To evaluate novel bilayer functionalization strategies for improved healing efficiency.

Main Methods:

• Poly(urea-formaldehyde) (PUF) microcapsules were reinforced and surface-functionalized using 3-aminopropyltriethoxysilane (APTES) and (3-mercaptopropyl)trimethoxysilane (MPTMS).
• A bilayer functionalization approach using tetraethyl orthosilicate (TEOS) in combination with APTES or MPTMS was employed.
• X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis (TGA) were used to characterize the functionalized microcapsules.

Main Results:

• Surface functionalization significantly increased the Si:C ratio, indicating successful silane grafting.
• The functionalization process preserved microcapsule integrity and healing agent volume.
• TEOS/MPTMS-functionalized microcapsules exhibited the highest healing efficiency, achieving up to 35% toughness recovery.

Conclusions:

• Novel silanization strategies using APTES, MPTMS, and bilayer functionalization with TEOS effectively enhance microcapsule performance in dental resins.
• The optimized microcapsules demonstrate superior self-healing capabilities, promising extended lifespan for dental restorations.
• This research presents a new pathway for developing advanced self-healing biomaterials.