Long-term fluoride release from glass ionomer-lined amalgam restorations

Area of Science:

• Dental Materials Science
• Biomaterials Research
• Fluoride Chemistry

Background:

• Glass ionomer cements are used as liners beneath amalgam restorations.
• Fluoride release from dental materials can contribute to caries prevention.
• Evaluating long-term fluoride release is crucial for material selection.

Purpose of the Study:

• To quantify fluoride release from amalgam restorations lined with different glass ionomer materials over a 1-year period.
• To compare the fluoride release profiles of Ketac-Silver, GC Lining, and Miracle Mix when used as liners under amalgam.

Main Methods:

• In vitro study using 50 extracted human molars with Class V cavities.
• Restorations included amalgam alone, and amalgam with three different glass ionomer liners (Ketac-Silver, GC Lining, Miracle Mix).
• Fluoride release was measured weekly for 10 weeks and at 1 year using a fluoride ion-specific electrode after thermocycling.

Main Results:

• All glass ionomer-lined groups showed measurable fluoride release at 1 year.
• Fluoride release (µg/ml) at 1 year: Ketac-Silver (0.28), GC Lining (0.68), Miracle Mix (1.12).
• Miracle Mix and GC Lining released significantly more fluoride than Ketac-Silver (P < 0.002).

Conclusions:

• Glass ionomer liners significantly increase fluoride release from amalgam restorations.
• Miracle Mix and GC Lining demonstrate superior fluoride-releasing capabilities compared to Ketac-Silver over 1 year.
• These findings suggest potential for enhanced caries prevention with specific glass ionomer liners.