title: Sprue design alterations and its effect on the properties of base metal alloy castings: An in vitro study.
abstract: BACKGROUND
  To study the effect of various sprue designs on the properties of base metal alloy castings. The base metal alloys are extensively used for their excellent properties such as an increase in hardness, high melting range, high elastic modulus, its compatibility with ceramic material and low cost. However, to improve the properties of the base metal alloys is an ongoing research leading to various modifications in their fabrication procedure - which include sprue designs and their mode of attachment to the wax pattern.
  
  
  OBJECTIVE
  Study compared the effect of three sprue designs viz. conical sprue, cylindrical sprue and bottleneck sprue on the properties of mass and microhardness of base metal alloy castings.
  
  
  METHODS
  A prefabricated wax mesh pattern was selected for the fabrication of the alloy test samples in the study. The cylindrical sprue design was connected to the mesh pattern with a straight attachment. The bottleneck sprue design was connected to the mesh pattern with a constricted attachment. The conical sprue design was connected to the mesh pattern with a flared attachment. In this manner, ten samples for each of the three different sprue designs were prepared.
  
  
  RESULTS
  The obtained value for mass and microhardness were subjected to statistical analysis. ANOVA test was performed to determine the difference between the sprue designs.
  
  
  CONCLUSIONS
  The bottleneck sprue, conical sprue, and cylindrical sprue designs did not exert any apparent influence on the mass and microhardness.
authors.affiliation: Department of Prosthodontics, Thai Moogambigai Dental College and Hospital, Chennai, Tamil Nadu, India.
authors.forename: K R
authors.initials: KR
authors.lastname: Geetha Prabhu
authors.affiliation: Department of Prosthodontics, Thai Moogambigai Dental College and Hospital, Chennai, Tamil Nadu, India.
authors.forename: R
authors.initials: R
authors.lastname: Prabhu
authors.affiliation: Department of Oral Medicine and Radiology, Maharana Pratap Dental College and Hospital, Madhya Pradesh, India.
authors.forename: H
authors.initials: H
authors.lastname: Maheswari
authors.affiliation: Department of Prosthodontics, Thai Moogambigai Dental College and Hospital, Chennai, Tamil Nadu, India.
authors.forename: M A
authors.initials: MA
authors.lastname: Eswaran
authors.affiliation: Department of Prosthodontics, Sibar Institute of Dental Sciences, Guntur, India.
authors.forename: G
authors.initials: G
authors.lastname: Phanikrishna
authors.affiliation: Consultant Prosthodontist, Dent plus dental clinic, Guntur, Andhra Pradesh, India.
authors.forename: B
authors.initials: B
authors.lastname: Deepthi
keywords: Base metal alloy castings; dental alloy castings; microhardness; sprue design