IADR Abstract Archives
Stabilization Time of Chemical Bonds in Restorative Glass-Ionomer/Glass-Hybrid Cements
Objectives: This research aimed to investigate the chemical reactions and the stabilization time of chemical bonds during setting process in restorative glass-ionomer/glass hybrid cements.
Methods: Four materials have been tested (n=5); two glass-hybrid cements: Equia Forte (GC, Japan) and Equia Forte HT (GC, Japan), and two restorative glass-ionomer cements: Ketac Universal (3M ESPE, Germany) e Riva Self Cure (SDI, Australia). Therefore, after manipulation following the manufacturer's recommendations, the cement was placed on the crystal for reading by Attenuated Total Reflectance Spectroscopy (ATR). Spectra were collected by averaging 10 scans. The resolution used was 4 cm-1 and the spectral region adopted was between 4000 and 400 cm-1. The initial reading was in 20s and from there a reading was taken every 10 seconds for 30 minutes. Time Behavior displays a profile exponential, so the function y(t) = y1 exp[-t/τ] + y0 was adopted to obtaining the characteristic time (τ). Results were analyzed with descriptive statistics and ANOVA.
Results: The results showed the formation of peaks present at the beginning of the mixture of the glass ionomer cement and over time, allowing to identify the reactions that occur in this material. GICs undergo a rapid initial setting reaction, but continue to change for some time after this initial hardening. A mathematical analysis of the materials temporal evolution showed that Riva had lower time (in seconds) to chemical bonds stabilization (393±58), followed by Equia Forte (709±36), Equia Forte HT (740±35) and Ketac Universal (747±92).
Conclusions: It was concluded that there were variations in the time of stabilization of the chemical bonds among GICs. The longer GIC takes to stabilize the chemical bonds during the setting process, the greater the amount of chemical bonds and it could be responsible for increasing the mechanical properties of the material.
Methods: Four materials have been tested (n=5); two glass-hybrid cements: Equia Forte (GC, Japan) and Equia Forte HT (GC, Japan), and two restorative glass-ionomer cements: Ketac Universal (3M ESPE, Germany) e Riva Self Cure (SDI, Australia). Therefore, after manipulation following the manufacturer's recommendations, the cement was placed on the crystal for reading by Attenuated Total Reflectance Spectroscopy (ATR). Spectra were collected by averaging 10 scans. The resolution used was 4 cm-1 and the spectral region adopted was between 4000 and 400 cm-1. The initial reading was in 20s and from there a reading was taken every 10 seconds for 30 minutes. Time Behavior displays a profile exponential, so the function y(t) = y1 exp[-t/τ] + y0 was adopted to obtaining the characteristic time (τ). Results were analyzed with descriptive statistics and ANOVA.
Results: The results showed the formation of peaks present at the beginning of the mixture of the glass ionomer cement and over time, allowing to identify the reactions that occur in this material. GICs undergo a rapid initial setting reaction, but continue to change for some time after this initial hardening. A mathematical analysis of the materials temporal evolution showed that Riva had lower time (in seconds) to chemical bonds stabilization (393±58), followed by Equia Forte (709±36), Equia Forte HT (740±35) and Ketac Universal (747±92).
Conclusions: It was concluded that there were variations in the time of stabilization of the chemical bonds among GICs. The longer GIC takes to stabilize the chemical bonds during the setting process, the greater the amount of chemical bonds and it could be responsible for increasing the mechanical properties of the material.