Introdution: The aim of this research was optimization curcumin characteristics for oral hygiene application. Curcumin-loaded starch nano-particles were developed for enhancing adhesion propery with enamel surface and best anti-bacterial effect against Streptococcus mutans. Methods: The study was the experimental one. The nanoparticles synthesize was based on precipitation and ionic gelation method. Nanoparticles characterization was done by scanning electron microscopy, dynamic light scattering and determination of zeta potential. In addition, minimum inhibitory concentration (MIC) was assessed to evaluate the antimicrobial properties of nanoparticles against Streptococcus mutans. The binding amount of nanoparticles to hydroxyapatite was evaluated and finally, the curcumin release from the nanoparticles was also assayed. Results: The average size of optimized starch nanoparticles were 61.1 nm. Also, zeta potential was -14.7, mV. Loading contents of nanoparticles were 24.59% measured by optical density from standard calibration curve of curcumin. In addition, minimum inhibitory concentration (MIC) of nanoparticles against Streptococcus mutans, was 0.204 and 0.438 mg/mL for starch nanoparticles and pure curcumin, respectively. It was also found that starch nanoparticles had inhibitory effect on bacterial biofilm. Conclusion: Curcumin-loaded starch nano-particles improve adhesion properties and interactions with enamel and prevent dental caries of Streptococcus mutans.