# Self-healing dental biomaterials: bioinspired pathways to sustainable dentistry

## TL;DR

This review explores self-healing dental materials that can repair themselves, aiming to make dental restorations last longer and reduce environmental impact.

## Contribution

The paper reviews recent advances in self-healing dental biomaterials and their potential for sustainable dentistry.

## Key findings

- Self-healing systems in resin composites showed 65-77% fracture toughness recovery after 6 months in water.
- Dynamic networks and supramolecular systems offer repeatable healing and interface remineralisation.
- Self-healing aligns with green dentistry by reducing resource use and waste.

## Abstract

Resin composite restorations typically last 6–10 years but often fail due to mechanical fatigue, hydrolytic breakdown, and degradation at the interface. These failures result in frequent replacements, leading to significant clinical and environmental impacts. Extending restoration durability is essential for both patient care and sustainability. This review examines recent advances in self-healing dental biomaterials, emphasising the underlying chemical and physical mechanisms, their integration into resin composites, cements, and adhesives, and their relevance to sustainable restorative practice.

A narrative review methodology was employed to synthesise the current evidence. Studies on self-healing mechanisms, including extrinsic (capsule- or reservoir-based) and intrinsic (dynamic covalent, supramolecular, or shape-memory polymer) systems, were critically evaluated with emphasis on evidence relevant to dental resin composites, cements, and adhesives. Parallel insights from polymer and material sciences were included where dental-specific research was limited. Supplementary searches were conducted on Google Scholar for additional peer-reviewed articles, books, and preprints.

Experimental resin composites and cements incorporating microcapsule-based self-healing systems exhibited fracture toughness recovery between 65% and 77%, maintaining structural integrity after 6 months of water storage in deionised water at 37°C. Disulfide and Diels–Alder dynamic networks, though mostly investigated in polymer science, show potential for repeatable healing under mild triggers, while supramolecular hydrogen-bonding and bioactive fillers offer adaptive repair and remineralisation at adhesive interfaces. Self-healing strategies align with the four pillars of green dentistry, that is pollution prevention, water conservation, energy efficiency, and waste reduction by potentially halving procedural resource consumption through extended restoration lifespan.

Self-healing biomaterials designed and developed in accordance with sustainability principles have the potential to transform restorative dentistry by facilitating autonomous repair, prolonging restoration lifespan, and minimising the environmental footprint through reduced material usage and clinical waste generation.