Chitosan nanoparticles suspension can minimize enamel loss after in vitro erosive challenge

Chitosan nanoparticles suspension (ChNPs) showed antimicrobial effects in the oral cavity, but its effects on enamel erosion prevention remain little explored.

This study synthesized ChNPs and evaluated their effect on enamel after erosive challenge.

ChNPs were synthesized by ionic gelation and characterized using scanning electron microscopy (SEM), infrared spectrophotometry (FTIR), dynamic light scattering methods (DLS) and zeta potential (ZP). In total, 56 human enamel blocks were divided into four groups (n=14/group): (i) ChNPs suspension (4.4mg/mL); (ii) 0.05% sodium fluoride solution (NaF); (iii) chitosan solution (5.0 mg/mL); and (iv) distilled water. After incubation in freshly collected human saliva (3h), the samples were exposed to erosive challenge in 1% citric acid (90s) and remineralizing solution (2h) performed four times a day. After the 1st and 4th acid exposures, solutions were applied for 2 min. After 7 days, % Vickers surface hardness change (% SMH) was obtained using 300 g load applied for 15s. Enamel surface loss was evaluated using optical profilometer by subtracting the final profile values from baseline ones. Data were analyzed by ANOVA and post-hoc T tests (α=0.05). Surface topography was obtained by optical profilometer.

SEM revealed the formation of spherical nanoparticles. DLS showed nanoparticles with 85.7±10.5 nm diameter and ZP value of +45.5±5.4mV. Enamel surface loss was significantly lower in ChNPs and NaF groups, exhibiting a less rough surface in the treated areas. ChNPs, NaF and chitosan groups showed lower % SMH values.

ChNPs suspension minimized enamel loss after in vitro erosive challenge and appears to be a promising material for enamel erosion prevention.