title: Alternate metal framework designs for the metal ceramic prosthesis to enhance the esthetics.
abstract: OBJECTIVE
  The objective of the present study was to evaluate the effect of five different metal framework designs on the fracture resistance of the metal-ceramic restorations.
  
  
  METHODS
  For the purpose of this study, the central incisor tooth was prepared, and the metal analogue of it and a master die were fabricated. The counter die with the 0.5 mm clearance was used for fabricating the wax patterns for the metal copings. The metal copings with five different metal framework designs were designed from Group 1 to 5. Group 1 with the metal collar, Group 2, 3, 4 and 5 with 0 mm, 0.5 mm, 1 mm and 1.5 mm cervical metal reduction respectively were fabricated. Total of fifty metal ceramic crown samples were fabricated. The fracture resistance was evaluated with the Universal Testing Machine (Instron model No 1011, UK). The basic data was subjected to statistical analysis by ANOVA and Student's t-test.
  
  
  RESULTS
  Results revealed that the fracture resistance ranged from 651.2 to 993.6 N/m(2). Group 1 showed the maximum and Group 5 showed the least value.
  
  
  CONCLUSIONS
  The maximum load required to fracture the test specimens even in the groups without the metal collar was found to be exceeding the occlusal forces. Therefore, the metal frameworks with 0.5 mm and 1 mm short of the finish line are recommended for anterior metal ceramic restoration having adequate fracture resistance.
authors: Department of Prosthodontics, Government Dental College and Research Institute, Bellary, Karnataka, India.
authors: Naina Vilas
authors: NV
authors: Vernekar
authors: Prithviraj Kallahalla
authors: PK
authors: Jagadish
authors: Srinivasan
authors: S
authors: Diwakar
authors: Ramesh
authors: R
authors: Nadgir
authors: Manjunatha Revankar
authors: MR
authors: Krishnarao