Antibacterial effects and tensile bonding strength of orthodontic adhesive containing nanohydroxyapatite

Abstract

Objective To evaluate the tensile bonding strength (TBS) and antibacterial properties when an orthodon⁃ tic adhesive was added with nanohydroxyapatite (nHAp). Methods Light cure orthodontic adhesive (Grengloo) was blended with 2% TiO2 containing nHAp nanoparticles by 0%、10%、20%、30% (w/w), while the control was not blended with nHAp. Brackets were bonded to extracted premolars by these new adhesives. TBS of 5groups were determined, and the adhesive remnant index (ARI) scores were assessed. Composite discs specimen were prepared, incubated with bacte⁃ rial suspension for 48 h, and tested for antibacterial properties. Results No significant difference was found in ARI. The colony unit counts and lactate productionof the groups containing 2% TiO2 were significantly reduced. The colony unit counts and lactate production were without relationship with nHAp. The tensile bonding strength drastically de⁃ creased when containing more than 10% nHAp. Conclusion nHAp might not enhance the antibacterial effects of Gren⁃ gloo.

Keywords

• Nanohydroxyapatite
• TiO2
• Orthodontic adhesive
• Antibacterial
• Tensile bonding strength