Fluoride and chlorhexidine release from filled resins.

Area of Science:

• Dental Materials Science
• Polymer Chemistry
• Biomaterials Engineering

Background:

• Resin-based materials are developed to release fluoride or chlorhexidine for caries inhibition.
• The potential interaction and release dynamics of co-incorporated fluoride and chlorhexidine remain uninvestigated.
• Understanding these interactions is crucial for developing effective dual-action dental materials.

Purpose of the Study:

• To investigate the effect of fluoride-to-chlorhexidine ratios and storage medium pH on the release of these agents from a resin composite.
• To test the hypothesis that agent ratios and pH influence co-release kinetics.
• To explore potential synergistic or antagonistic interactions between fluoride and chlorhexidine release.

Main Methods:

• Resin composites were formulated with varying weight ratios (8/2, 5/5, 2/8) of calcium fluoride to chlorhexidine diacetate, with a total filler content of 23 wt%.
• Agent release was quantified using acetate buffers at pH levels of 4, 5, and 6.
• Ion chromatography and spectrophotometry were employed to measure fluoride and chlorhexidine concentrations, respectively.

Main Results:

• The release rate of both fluoride and chlorhexidine increased significantly as the pH of the storage medium decreased.
• The presence of fluoride salt markedly reduced the release of chlorhexidine from the resin.
• Conversely, a specific concentration of chlorhexidine was found to significantly enhance fluoride release, indicating a complex interaction.

Conclusions:

• The release of fluoride and chlorhexidine from resin-based materials is significantly influenced by the pH of the surrounding environment.
• A notable interaction exists between fluoride and chlorhexidine release, where fluoride suppresses chlorhexidine release, and chlorhexidine enhances fluoride release.
• These findings suggest that the co-release of fluoride and chlorhexidine can be modulated through material formulation and environmental pH, offering opportunities for optimizing therapeutic efficacy in dental applications.