Fracture strength of copy-milled and conventional In-Ceram crowns.
The purpose of this study was to compare the fracture resistance of copy-milled and conventional In-Ceram crowns. Four groups of 10 uniform sized all-ceramic anterior crowns were fabricated for this test: (1) In-Ceram Spinell (2) In-Ceram Alumina (3) Celay In-Ceram Spinell, and (4) Celay In-Ceram Alumina crowns. All specimens were cemented on stainless steel master die with resin cement and stored in 37 degrees C water for one day prior to loading into a universal testing machine. Using a steel ball at a crosshead speed of 0.5 mm min-1, the crowns were loaded at 30 degrees C angle until catastrophic failure occurred. Mean fracture strength was analysed and compared. Under the conditions of this study and the materials used, the following conclusions were drawn: 1. The strength of Celay In-Ceram anterior crowns had a slightly higher fracture strength than conventional In-Ceram crowns. 2. In-Ceram Alumina crowns had a significantly higher fracture strength than In-Ceram Spinell crowns in both conventional and copy milling methods.
Hwang
J W
JW
Department of Prosthodontics, College of Dentistry and Dental Research Institute, Seoul National University, 28 Tonkon-Dong Chongro-Gu, Seoul, 110-749, Korea.
Yang
J H
JH
D000537:Aluminum Oxide; D003442:Crowns; D003775:Dental Polishing / Q000379:methods*; D003776:Dental Porcelain; D017267:Dental Prosthesis Design / Q000379:methods*; D003799:Dental Stress Analysis; D006801:Humans; D007180:Incisor; D008277:Magnesium Oxide; D008422:Materials Testing; D008669:Metallurgy
C111130:spinell; D003776:Dental Porcelain; C070870:In-Ceram; D008277:Magnesium Oxide; D000537:Aluminum Oxide