Development of functional fillers as a self-healing system for dental resin composite.

Objectives: To evaluate the incorporation of repairing capsules containing different monomers and polymerization modulators on the self-healing efficiency of an experimental photopolymerizable resin-based composite.
Methods: Self-healing capsules containing different monomers and polymerization modulators were prepared by emulsion polymerization: TC _DHEPT (TEGDMA and DHEPT), BTC _DHEPT (Bis-GMA, TEGDMA, and DHEPT), and BTC _BPO (Bis-GMA, TEGDMA, and BPO). The capsules were analyzed through Fourier transform infrared spectroscopy and scanning electron microscopy. The capsules were added into experimental photopolymerizable resin composites establishing the following groups: ER (Control without capsules), ER+BPO, ER+BPO+TC _DHEPT , and ER+BTC _BPO +BTC _DHEPT . Filtek Z350 resin composite (3 M ESPE) was used as a commercial reference. The materials were tested for degree of conversion (DC), flexural strength (σf), elastic modulus (Ef), fracture toughness (virgin K _IC ), self-healing efficiency (healed K _IC ), and roughness. For statistical analysis, the significance value was established at an a = 0.05 level.
Results: When compared to the control material, the incorporation of repairing capsules did not affect DC, σf, and Ef. Fracture toughness was statistically similar between the experimental groups (p ≤ 0.05). Healed K _IC was statistically different between the groups ER+TC _DHEP and ER+BTC _BPO +BTC _DHEPT ; the self-healing efficiency was higher for ER+TC _DHEPT . Surface roughness was statistically similar among all groups.
Conclusions: The use of self-healing capsules promoted repair of the material. Studies with material aging after the self-healing process are necessary to better demonstrate the effectiveness of this system.
Clinical Significance: The self-healing system seemed to be a promising technology to be used in self-repaired restorative materials, which may prevent restoration fractures.
Competing Interests: Declaration of Competing Interest The authors report no conflicts of interest in this work.
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