In Vitro Cytotoxicity Assessment of an Orthodontic Composite Containing Titanium-dioxide Nano-particles

Area of Science:

• Biomaterials Science
• Dental Materials Science
• Nanotechnology in Medicine

Background:

• Orthodontic bonding systems aim to prevent enamel demineralization.
• Nanoparticles are explored for enhancing bonding system properties.
• Titanium dioxide (TiO2) nanoparticles are investigated for their potential benefits.

Purpose of the Study:

• To evaluate the cytotoxicity of Transbond XT orthodontic adhesive with 1 wt% TiO2 nanoparticles.
• To compare the biological effects of nano-TiO2-enhanced adhesive versus conventional adhesive.

Main Methods:

• Composite disks of conventional and TiO2-containing Transbond XT were prepared.
• Disks were aged in Dulbecco's Modified Eagle's Medium (DMEM) for up to 14 days.
• Extracts were tested on human gingival fibroblasts (HGF) and mouse L929 fibroblasts using the MTT assay.

Main Results:

• Both adhesives exhibited moderate initial toxicity to HGF cells.
• TiO2-containing adhesive showed significantly lower initial toxicity than the pure adhesive (P<0.05).
• Toxicity decreased significantly with increased pre-incubation time for both groups (P<0.001).

Conclusions:

• Orthodontic adhesive with 1 wt% TiO2 nanoparticles demonstrated comparable or lower cytotoxicity than its nanoparticle-free counterpart.
• Incorporating 1 wt% TiO2 nanoparticles into the composite structure does not introduce additional health hazards.
• TiO2 nanoparticles may offer a safer alternative in orthodontic bonding agents.