Polymerization Kinetics of Pre-heated Composite
M. Daronch1,2,
F.A. Rueggeberg2,*,
M.F. De Goes1,3, and
R. Giudici4
1 Department of Dental Materials, School of Dentistry, University of São Paulo, São Paulo, SP, Brazil;
2 Dental Materials Section, Department of Oral Rehabilitation, Medical College of Georgia, Augusta, GA 30912-1260, USA;
3 Department of Restorative Dentistry, Dental School of Piracicaba at UNICAMP, Piracicaba, SP, Brazil; and
4 Department of Chemical Engineering, Polytechnic School, University of São Paulo, São Paulo, SP, Brazil
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Figure 1. Conversion with time at the top surface and at 2-mm depth with 20-second exposure duration at pre-selected composite temperatures. n = 5 specimens per experimental group. Coefficient of variation ranged from 0.3 to 3.0%.
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Figure 2. Conversion rate with time at the top surface and at 2-mm depth, at selected temperatures and exposure durations: (A) 40 sec, (B) 20 sec, (C) 10 sec, and (D) 5 sec, (E) natural log of Rpmax as a function of inverse temperature. A linear fit to the data was used to determine the activation energy (15.6 kJ/mol). (F) Natural log of conversion rate as a function of inverse temperature and monomer conversion at the top surface and (G) at 2-mm depth. For A–D, data at each one-second time point represent the mean of 5 replications; coefficient of variation ranged from 3.1 to 17.6%.
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Figure 3. Conversion rate as a function of monomer conversion obtained at the top surface and at 2-mm depth for various temperatures and exposure durations: (A) 40 sec, (B) 20 sec, (C) 10 sec, and (D) 5 sec. Each datapoint represents mean of 5 replications; coefficient of variation ranged from 6.0 to 36.4%.
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