Assessment of microstructure, microbial count with adherence and ion leaching of calcium hydroxide filled SPRG restorative material: A SEM and confocal analysis

Aim

This study investigates the characterization of a calcium hydroxide-filled SPRG (Surface Pre-Reacted Glass Ionomer) restorative material. The analysis focuses on the material's microstructure and antimicrobial properties, specifically its efficacy against Streptococcus mutans, a common oral bacterium. Using Scanning Electron Microscopy (SEM) and confocal microscopy, we examine the material's surface morphology, microbial adherence, and ion leaching capabilities. The goal is to assess the material’s suitability for deep caries management and its potential as a dentine replacement.

Methods and Materials

Discs of Calcium Hydroxide filled SPRG Restorative Material were prepared (10 mm x 2 mm). SEM was employed to observe the surface morphology and microstructural characteristics of the material. To evaluate microbial adherence and count, confocal microscopy was used with Streptococcus mutans cultured on the material. The leaching of calcium and fluoride ions was quantified using the Ion Selective Electrode (ISE) method.

Results

The results showed significant leaching of calcium and fluoride ions, indicating the material's potential for ion release. SEM analysis provided detailed insights into the microstructure of the SPRG restorative material, while confocal microscopy revealed a clear distinction between live and dead Streptococcus mutans colonies, suggesting that the fluoride and calcium ion leaching contributed to effective antimicrobial properties.

Conclusion

Calcium hydroxide-filled SPRG restorative materials show promise for dental applications, with ion release and effective antimicrobial properties making them strong candidates for managing deep caries and potentially replacing dentine. Ongoing research could optimize these materials for clinical use, advancing restorative dentistry.