(Pages 81 - 86)
1. Assistant professor Ziauddin University.
Corresponding author: “Dr Nazish Fawad” Nazish_fawad@yahoo.com
Volume 24, Issue 2 (April - June 2015)
To investigate the effect of covering curing tip with multi protective layers on vicker’s hardness of different composite resins.
One hundred and twenty specimens were fabricated from a hybrid composite (ValuxTM Plus)(Group A), nano resin composite (Filtek- Z350)(Group B) and a nano ceramic composite (CeramoX)(Group C) by using polytetrafluoroethylene mold. Forty specimens of each material (Group A,B and C) were Forty specimen of each material (Group A,B and C)were then separated and divided in to four groups. Group A1/B1/C1 (control) cured with curing tip covered with Single wrap barrier; Group A2/B2/C2 cured with curing tip covered with two wrap barriers; Group A3/B3/C3 cured with curing tip covered with four wrap barriers; A4/B4/C4 cured with curing tip covered with eight wrap barriers. After finishing and polishing the specimens, microhardness test were performed using digital microhardness tester. The data collected were analyzed using ANOVA and Tukey’s post hoc analysis with SPSS version 21.
The mean micro hardness of micro hybrid composite was 71.58 ± 3.51 which was significantly less than micro hardness of nano composite and nano ceramic (P < 0.001). However, the micro hardness of both nano materials was not significantly different (P > 0.999). Sub groups analysis according to number of protective layers also showed significant difference. Microhardness of group A4/B4/C4 was significantly lowest than its other three counterparts.
Micro hardness was not affected by covering curing tip uptill four wrap barriers. On the contrary, a covering curing tip with eight wrap barriers reduced the micro hardness of all composite resins under study with maximum reduction observed in micro-hybrid group.
Composite, Micro hardness, Multi protective layers, curing.
How to CITE
Fatima N. Effect of Covering Curing Tip with Multi Protective Layers on Vicker’s Hardness of different composites. J Pak Dent Assoc 2015; 24(2):81-86.