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Polymerization kinetic calculations in dental composites: a method comparison analysis
1Department of Operative/Restorative Dentistry, Periodontology and Pedodontics, Ludwig-Maximilians-Universität München, Goethestr. 70, 80336, Munich, Germany, nilie@dent.med.uni-muenchen.de.
Clinical Oral Investigations
|November 22, 2013
Summary
Real-time analysis of bulk-fill composites using FTIR and light transmission revealed that irradiance measurements are more sensitive to thickness changes than the degree of conversion (DC). This understanding aids in tailoring material properties.
Area of Science:
- Dental Materials Science
- Polymer Chemistry
- Spectroscopy
Background:
- Bulk-fill resin-based composites offer clinical advantages but require precise understanding of their polymerization dynamics.
- Real-time monitoring methods are crucial for characterizing the conversion process and identifying influencing parameters.
Purpose of the Study:
- To compare Fourier transform infrared (FTIR) spectroscopy and visible light transmission spectrometry for real-time analysis of polymerization in bulk-fill composites.
- To quantify parameters influencing polymerization, specifically degree of conversion (DC) and irradiance, across varying sample thicknesses.
Main Methods:
- Real-time DC measurement using attenuated total reflectance FTIR spectroscopy.
- Real-time irradiance variation recording during material irradiation.
- Statistical analysis including ANOVA and Pearson correlation on data from 2, 4, and 6 mm thick samples.
Main Results:
- No significant difference in DC was observed with increasing sample thickness.
- Irradiance transmission varied significantly with thickness and material, fitting a biexponential function representing gel and glass phases.
- FTIR accurately determined both gel and glass phase transitions, while irradiance measurements only detected the latter.
Conclusions:
- Visible light transmission (irradiance) is more sensitive to changes in sample thickness than DC, indicating greater alterations in translucency.
- Understanding polymerization kinetics through these methods allows for tailored material properties by manipulating different stages of the process.
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