Effect of green tea-loaded chitosan nanoparticles on leathery dentin microhardness

Author(s)

Curylofo-Zotti, Fabiana Almeida ; Tedesco, Antonio Claudio ; Lizarelli, Gustavo Teodoro Costa ; Takahashi, Luandra Aparecida Unten ; Corona, Silmara Aparecida Milori

• Document type: Journal article
• Source: ODONTOLOGY; v. 109, n. 4, p. 8-pg., 2021-05-08.

Abstract

The purpose of this study was to assess the effect of a chitosan-based nanoformulation containing green tea on leathery (remaining) dentin subsurface microhardness. Size distribution, polydispersity index (PDI) and zeta potential (mV) of nanoformulations were previously determined by dynamic light scattering (DLS). Human dentin specimens were exposed to Streptococcus mutans for 14 d. Soft dentin were selectively removed by Er:YAG laser (n = 30) or bur (n = 30). Remaining dentin was biomodified with chitosan nanoparticles (Nchi, n = 10) or green tea-loaded chitosan nanoparticles (Gt + Nchi, n = 10) for 1 min. Control group (n = 10) did not receive any treatment. Subsurface microhardness (Knoop) was evaluated in hard (sound) and soft dentin, and then, in leathery dentin and after its biomodification, at depths of 30, 60 and 90 mu m from the surface. Nchi reached an average size of <= 300 nm, PDI varied between 0.311 and 0.422, and zeta potential around + 30 mV. Gt + Nchi reached an average size of <= 350 nm, PDI < 0.45, and zeta potential around + 40 mV. Soft dentin showed significantly reduced microhardness at all depths (p > 0.05). The subsurface microhardness was independent of choice of excavation method (p > 0.05). At 30 mu m from the surface, Gt + Nchi increased the leathery dentin microhardness compared to untreated group (p < 0.05). Nchi promoted intermediate values (p > 0.05). Both nanoformulations showed an average size less than 350 nm with nanoparticles of different sizes and stability along the 90-day period evaluated. Subsurface microhardness of bur-treated and laser-irradiated dentin was similar. At 30 mu m, the biomodification with Gt + Nchi improved the microhardness of leathery dentin, independently of caries excavation method used. (AU)

• FAPESP's process: 17/11582-1 - Dentin biomodification with phosphorylated chitosan nanoparticles (NanoPC) after selective removal of caries lesion by Er: YAG laser: Evaluation of antimicrobial and physicochemical properties
• Grantee: Fabiana Almeida Curylofo Zotti
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 13/50181-1 - Use of drugs containing nanocarriers with photosensitizers and/or other active compounds applied to cell therapy and treatment of central nervous system disorders
• Grantee: Antonio Claudio Tedesco
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 19/04807-2 - Functions of proanthocyanidins as nucleators of dentin biomineralization
• Grantee: Fabiana Almeida Curylofo Zotti
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor