Effect of Different Curing Modes on the Degree of Conversion and Vickers Microhardness of Commercial Composites

Abstract

Objective: The aim of this study was to evaluate and compare the effect of different curing modes (soft start, ramped and delayed polymerization modes) on the degree of conversion and Vickers micro hardness of commercial composites.

Study Design: Experimental study

Place and Duration of Study: This study was conducted at COMSAT, Lahore in October 2015 till April 2016 for a period of six months.

Materials and Methods: Two commercially available hybrid and nano-hybrid composite i.e. Te-Econom plus (Ivoclar vivadent, Liechtenstein) and Coltene NT Premium (Whaladent, Altstätten, Switzerland) respectively were evaluated. All samples were prepared in brass molds by using three different modes of polymerization. Degree of conversion and Vickers micro hardness of the samples was evaluated by FTIR (Thermo Nicolet P6700 USA) technique and Vicker’s hardness indentor (MicroMet 6040, Buehler, Germany).

Results: Degree of conversion and Vickers microhardness of both dental composites showed the sequence, delayed curing > ramped curing > soft start curing. However, Coltene NT Premium showed better results comparatively.

Conclusion: Delayed mode of curing showed better degree of conversion and Vickers micro hardness comparatively. However, there was insignificant difference between the findings of both composites.