Evaluation of Surface Roughness and Tensile Strength of Ni-Cr Alloys Used for Fixed Partial Prosthesis on Recasting (Recycling)- An in-Vitro Study

Casting is one of the primary techniques for producing shaped metals and alloys. Investigators had been making effort 
to recast the alloy up to many generations. The aim of present study was evaluation of surface roughness and tensile strength 
of  Ni-Cr  alloys  used  for  Fixed  Partial  Denture  on  recasting. The  alloys  are  divided  into  four  groups:  Group A-  Pure 
Alloys100%, Group B-75% New + 25% Once recast alloy, Group C-50% New +50% Once recast alloy and Group D-100% 
Once Recast alloy. Identical test specimens were prepared with the use of metal mold. The entire specimens were tested first 
for the surface roughness test by surface roughness tester and later for tensile strength test by UTM machine. ANOVA test 
(Analysis of Variance) was used for analyzing the result. Tensile strength of new alloy showed no statistically significant 
difference (p-value>0.05) from recast alloy whereas new alloy had statistically significant surface roughness (Maximum and 
Average surface roughness) difference (p-value<0.01) as compared to recast alloy. It is concluded that the tensile strength 
will not be affected by recasting of nickel-chromium alloy whereas surface roughness increases markedly.