Dexamethasone-doped nanoparticles improve mineralization, crystallinity and collagen structure of human dentin

Objectives: Bioactive materials have been used for functionalization of adhesives to promote dentin reminerali-zation. This study aims to evaluate bonding ability and both mechanical and chemical behavior of demineralized dentin infiltrated with polymeric nanoparticles doped with dexamethasone (Dex-NPs).Methods: Dentin conditioned surfaces were infiltrated with NPs, Dex-NPs or Dex-Zn-NPs. Bonded interfaces were also created and stored for 24 h or 21d, and then submitted to microtensile bond strength testing. Dentin remineralization was analyzed by Nanohardness, Young's modulus and Raman analysis.Results: At 21d of storage, dentin treated with undoped-NPs attained the lowest nanohardness and Young's modulus. Dex-NPs and Zn-Dex-NPs increased dentin nanohardness and Young's modulus after 21d Raman analysis showed high remineralization, crystallinity, crosslinking and better structure of collagen when func-tionalized Dex-NPs were present at the dentin interface.Conclusions: Infiltration of dentin with Dex-NPs promoted functional remineralization as proved by nano -mechanical and morpho-chemical evaluation tests. Dexamethasone in dentin facilitated crystallographic matu-rity, crystallinity and improved maturity and secondary structure of dentin collagen.Clinical significance: Using dexamethasone-functionalized NPs before resin infiltration is a clear option to obtain dentin remineralization, as these NPs produce the reinforcement of the dentin structure, which will lead to the improvement of the longevity of resin restorations.

Automated summary

This study evaluated the bonding ability and mechanical and chemical behavior of demineralized dentin infiltrated with polymeric nanoparticles doped with dexamethasone. The results showed that dexamethasone nanoparticles improved the nanohardness and Young's modulus of dentin, and promoted remineralization and improved the structure of collagen.