Effect of immediate and delayed finishing and polishing procedures on micro hardness and gloss of esthetic restorative materials

ABSTRACT

To study the immediate and delayed finishing and polishing procedures effects on surface micro hardness and gloss of different composite. Materials and The restorative materials included a Hybrid composite [Valux TM Plus], Nano resin composite [Filtek_ Z350] and a poly acid modified resin composite Dyract Extra [Dentsply Caulk, Milford, DE, USA]. 30 discs were fabricated from every restorative material and at random divided into three groups. The group one served as control. Group two was finished and polished immediately and the third group was finished and polished after 24 hours. Three Vickers micro hardness indentation were performed on every disc surface under 100g load and 10s dwell time. Gloss measurements were done using a small-area glossmetre. Data for surface micro hardness and gloss were analyzed by two-way ANOVA and Tukey test [P<.05]. With respect to material wise comparisons the lowest values of micro hardness were observed for every restorative material which was cured under Mylar strip [control]. The greatest values of micro hardness were observed when finishing and polishing of samples was delayed [P<0.05]. There was not significant difference in gloss measurements with respect to material and time. All three types of composites tested showed highest value of micro hardness when finishing and polishing procedures were delayed for 24 hours. There is no statistical difference in gloss measurements with respect to material and time