In vitro and in vivo fluoride release from orthodontic elastomeric ligature ties

Area of Science:

• Orthodontics
• Materials Science
• Biomaterials

Background:

• Enamel demineralization around orthodontic attachments is a clinical concern, occurring within one month.
• Fluoride release from elastomeric ligature ties may offer protection against decalcification.
• Incorporating fluoride into orthodontic materials is a strategy to enhance cariostatic effects.

Purpose of the Study:

• To compare the in vitro and in vivo fluoride release of fluoride-impregnated and nonfluoride elastomeric ligature ties.
• To evaluate the residual fluoride levels in elastomeric ligatures after one month of intraoral use.

Main Methods:

• A potentiometric analytical method was used to determine fluoride release.
• Fluoride and nonfluoride elastomeric ligature ties (n=520) were tested both in vitro and in vivo (n=6 patients).
• In vivo samples were worn for one month, then tested for residual fluoride release.

Main Results:

• In vitro, fluoride-impregnated ties released an average of 0.38 microgram/F/mL/elastomeric over one month, with a residual release of 0.02 microgram/F/mL/elastomeric.
• In vivo, after one month, fluoride-impregnated ties showed significantly higher residual fluoride (1.43 microgram/F/mL/elastomeric) compared to in vitro.
• Nonfluoride ties showed minimal measurable fluoride release both in vitro and in vivo, with in vivo levels (0.44 microgram/F/mL/elastomeric) higher than in vitro due to imbibition.

Conclusions:

• Fluoride-impregnated elastomeric ligature ties demonstrate fluoride release both in vitro and in vivo.
• Intraoral use leads to higher residual fluoride levels in both types of ties, suggesting imbibition.
• Further clinical investigation is needed to confirm the efficacy of fluoride-impregnated ties in preventing decalcification in plaque-present environments.