In Vitro Investigations On The Fracture Strength Of Anterior Bridges Make Of Ips Empress, Ips Empress 2 And New All Ceramic Materials

Six all-ceramic systems - three pressed ceramics, (IPS Empress, IPS Empress 2 and a new experimental pressed ceramic) and three milled ceramics (two new experimental milled ceramics and celay.aluminia blanks)- are the subject of the current work. The bending strength of the materials and the static breaking load of adhesively cemented three-unit anterior bridges on rigid metal casts have been examined. In addition, the fatigue behaviour of the three pressed ceramics was investigated using identical but conventionally cemented bridges on resilient casts. A diagonal load was applied for 1,200,000 load cycles. The new pressed glass-ceramic and the glass-infiltrated aluminium oxide core material exhibited the highest bending strengths of 426 MPa and 423 MPa respectively, followed by IPS Empress 2 with 322 MPa. This sequence was different for the results from the static load tests. Bridges made of the new pressed ceramic achieved the highest breaking load at 1222 N followed by the IPS Empress 2 and Cleay bridges at 1154 N and 823 N, respectively. After the maximum number of load cycles had been applied, no fractures were detected in the IPS Empress bridges loaded to 100 N, the IPS Empress 2 bridges loaded to 300 N and the bridges made of the new ceramic loaded to 250 N. The endurance limits of the materials are expected to be above these values.