EFFECT ON HARDNESS OF REUSED CAST COBALT CHROME ALLOY USING FLAME CENTRIFUGE CASTING METHOD

  • Mehreen Imran BDS, MPH, MPhil, Assistant Professor, Department of Dental Materials, Peshawar Dental College, Warsak Road Peshawar, Riphah International University.
  • Amjid Hanif BDS, MSc (UK), Assistant Professor, Department of Dental Materials, Peshawar Dental College, Riphah International University.
  • Bilal Zaman Babar BDS, MSc (UK), Assistant Professor& HOD, Department of Dental materials, Rehman College of Dentistry
  • Hafiz Muhammad Raza BDS, FCPS (Prosthodontics) Associate Professor, Peshawar Dental College, Riphah International University.
  • Nuzhat Ayub BDS, FCPS (Prosthodontics), Assistant Professor, Peshawar Dental College, Riphah International University.
  • Zia Ur Rehman BDS, MSc, Assistant Professor, Community and preventive dentistry, Peshawar Dental College, Riphah International University.
Keywords: Cobalt Chromium Alloy, Hardness, Reuse

Abstract

In dentistry lost wax casting method requires more alloy than needed to produce indirect restoration. The surplus casting alloy is re-used in routine. The aim of the present study was to assess the micro-hardness of the commercially available Cobalt-Chromium alloy, when 50 wt. % re-used alloy is added to it; up till six times. The study sample was divided into four groups (n=5). Group 1 was the control group with 100% fresh alloy cast once. In group 2, 3 and 4, a 50 wt.% cut off of previous castings were mixed to the fresh alloy. All the samples were cast using oxy-acetyl flame with broken arm centrifuge casting method. The hardness measurements were carried out under 500 gram force load for 10 second (ASTM-E 384) using micro hardness tester: Model: HVS-1000. Three indents were made on each specimen. The means of micro-hardness in study groups were compared using one-way ANOVA. The group1 had the maximum mean hardness (340+10); followed by group 2 with 305+11; group 3 had 334+10 and group 4 had the least hardness 303+15. F-test was non-significant at 5% level of significance (p-value=0.094) suggesting there was no difference among the hardness of the four groups.

Published
2020-01-01
How to Cite
Mehreen Imran, Amjid Hanif, Bilal Zaman Babar, Hafiz Muhammad Raza, Nuzhat Ayub, & Zia Ur Rehman. (2020). EFFECT ON HARDNESS OF REUSED CAST COBALT CHROME ALLOY USING FLAME CENTRIFUGE CASTING METHOD. Pakistan Oral & Dental Journal, 39(4), 381-385. Retrieved from http://podj.com.pk/index.php/podj/article/view/498
Section
Dental Material