POLYMERIZATION SHRINKAGE, DEGREE OF CONVERSION, DEPTH OF CURE, AND HEAT GENERATION OF NOVEL EXPERIMENTAL AND COMMERCIAL COMPOSITE

Abstract

Objective:
 To compare and characterise commercial and control composites. By characterising these composites, target properties for new experimental dental composites can be outlined.
 Materials and Methods:
 Three commercial, and two experimental composites were compared and investigated. The composition of commercial materials were provided from published literature and manufacturer’s information. The changes in intensity of spectral peaks that were involved in free radical addition polymerization were used to determine the degree of conversion using FTIR (n=6). The samples were prepared in 1 mm, and 4 mm thickness and cured for 40 s from top. Depth of cure, Polymerization shrinkage and heat generation were determined using conversion data, and equations.
 Results:
 The conversion for Gradia, and Z250 were significantly lower than the flowable Vertise flow, and experimental composites C-HEMA, and C-4 META in both 1 mm, and 4 mm depth. The shrinkage, and heat generation values suggests opposite trends to conversion. With the highest shrinkage, and heat generation associated with Vertise flow. Depths of cure of all materials were in the range of 2.28 to 2.49 mm at 20 s, and 40 s cure.
 Conclusion:
 The experimental composite with added monomers had the potential to compete with commercially available composites, without compromising the properties.