Resin-modified glass ionomer cements: fluoride release and uptake

Area of Science:

• Dental Materials Science
• Biomaterials Engineering
• Polymer Chemistry

Background:

• Glass ionomer cements (GIC) are widely used dental restorative materials.
• Resin-modified GIC (RM GIC) offer improved aesthetics and handling but their fluoride release characteristics require further investigation.
• Understanding fluoride release is crucial for assessing anticariogenic potential.

Purpose of the Study:

• To evaluate short- and long-term fluoride release from RM GIC.
• To determine the influence of post-curing fluoride treatment on fluoride release.
• To assess the impact of mix consistency and environmental pH on fluoride release.

Main Methods:

• Specimens of six RM GICs and one conventional GIC were prepared.
• Continuous exposure to running water followed by periodic immersion in deionized water for fluoride measurement.
• Fluoride release was quantified using a standard method at 24 hours, 1 month, 9 months, and 11 months.
• Fluoride treatment was applied to 9-month-old specimens.

Main Results:

• Four out of six RM GICs exhibited fluoride release equal to or greater than conventional GIC at 24 hours and 1 month.
• Fluoride treatment significantly increased fluoride release in four RM GIC brands and conventional GIC.
• Two RM GICs showed lower fluoride release initially, with minimal impact from fluoride treatment.
• Thinner mix consistency led to higher fluoride release in one RM GIC.
• Low environmental pH increased fluoride release across all tested materials.

Conclusions:

• RM GICs demonstrate substantial fluoride release, contributing to their potential cariostatic effect.
• Post-fabrication fluoride treatment can enhance fluoride release from most RM GICs.
• Environmental factors like pH and material properties such as mix consistency influence fluoride ion diffusion.