TY - BOOK AU - Sarah Ahmed Elhussieny Ali AU - Eman Mohamed Anwar , AU - Rasha Nabil Sami , TI - Influence of preparation parameters and cement space width on the marginal and internal fit of a machinable all ceramic crown system / PY - 2012/// CY - Cairo : PB - Sarah Ahmed Elhussieny Ali , KW - Cement space KW - Ceramic crown KW - Marginal and internal N1 - Thesis (M.Sc.) - Cairo University - Faculty of Oral and Dental Medicine - Department of Prosthodontics; Issued also as CD N2 - The aim of the present study was to evaluate the effect of the preparation parameters and the cement space width on the internal and marginal fit of a machinable all ceramic crowns . The tested preparation parameters were : 1. two preparation heights : a. 4mm. b. 6mm . 2. two convergence angles : a. 12{u00B0} total convergence angle . b. 20{u00B0} total convergence angle . The tested cement spaces width were : a. 80 om. b. 120om ER -