IADR Abstract Archives
Effect of Particle Size on Bioactivity of Novel Dental Composite.
Objectives: Bioactive glass (BAG) is well-known to possess antimicrobial and remineralising properties. By incorporating BAG in dental restorative materials, the release of remineralising ions will promote the formation of apatite. This is a desirable property at the tooth-restoration interface, as it protects against secondary caries and minimizes any microleakage due to polymerization shrinkage. The aim of this study is to investigate the effect of different particle sizes of novel BAG to form apatite.
Methods: Three Bioactive Glasses with different particle sizes (D50= 4μm, 8μm,12μm) containing SiO2-P2O5-CaO-CaF2-Na2O-K2O-MgO-SrO-ZnO were prepared using the melt quench technique at 1400C. Glass powder added in the resin matrix composed of BisEMA, UDMA, and TEGDMA and light-cured for the 20s. Samples were stored at 37C in different Artificial Saliva pH=7, pH=4, and TRIS-Buffer (AS7, AS4, and TRIS) for varying time intervals (1,3,7,30,90,180days). All synthesized samples were analyzed by doing pH measurement, Fourier Transform Infrared Spectroscopy (FTIR), Degree of conversion, and X-ray Diffraction (XRD).
Results: FTIR spectra and XRD patterns of all bioactive composites showed characteristic peaks for the formation of apatite in AS4, AS7, and TRIS which increases with time. 4µm is the most reactive and forms apatite relatively quicker compared to 8µm and 12µm. The degree of conversion of dental composite ranges between 66-76% in the order of 4 µm >8 µm >12µm. All samples showed an increase in pH favorable for apatite precipitation, especially in AS4 within 24hrs which corresponds to the XRD and FTIR results.
Conclusions: It appeared that this novel small size of BAG filler particles can have rapid apatite formation in Artificial saliva and Tris-buffer. Hence, it can be used as a smart clinical restorative material that can neutralize acid challenges and promote remineralization with enhanced biomineralization properties.
Methods: Three Bioactive Glasses with different particle sizes (D50= 4μm, 8μm,12μm) containing SiO2-P2O5-CaO-CaF2-Na2O-K2O-MgO-SrO-ZnO were prepared using the melt quench technique at 1400C. Glass powder added in the resin matrix composed of BisEMA, UDMA, and TEGDMA and light-cured for the 20s. Samples were stored at 37C in different Artificial Saliva pH=7, pH=4, and TRIS-Buffer (AS7, AS4, and TRIS) for varying time intervals (1,3,7,30,90,180days). All synthesized samples were analyzed by doing pH measurement, Fourier Transform Infrared Spectroscopy (FTIR), Degree of conversion, and X-ray Diffraction (XRD).
Results: FTIR spectra and XRD patterns of all bioactive composites showed characteristic peaks for the formation of apatite in AS4, AS7, and TRIS which increases with time. 4µm is the most reactive and forms apatite relatively quicker compared to 8µm and 12µm. The degree of conversion of dental composite ranges between 66-76% in the order of 4 µm >8 µm >12µm. All samples showed an increase in pH favorable for apatite precipitation, especially in AS4 within 24hrs which corresponds to the XRD and FTIR results.
Conclusions: It appeared that this novel small size of BAG filler particles can have rapid apatite formation in Artificial saliva and Tris-buffer. Hence, it can be used as a smart clinical restorative material that can neutralize acid challenges and promote remineralization with enhanced biomineralization properties.