Fracture properties of composite and glass ionomer dental restorative materials

✍ Scribed by Goldman, M.

• Publisher: John Wiley and Sons
• Year: 1985
• Tongue: English
• Weight: 767 KB
• Volume: 19
• Category: Article
• ISSN: 0021-9304
• DOI: 10.1002/jbm.820190705

✦ Synopsis

The double-torsion technique has been used to determine critical stress intensity factor (K1,) values for a range of composites and glass ionomer cements used in restorative dentistry. From these values and determined elastic modulus ( E ) and tensile strength (cT) values, two other fracture properties: G1,, the critical strain energy release rate and a,, the inherent flaw size, have been evaluated. Glass ionomers have low K1, and high a. values, coarse particle composites high K1, and high a, values, microfine materials low K1, and low a.

values and fine particle composites medium to high K1, values and medium to low a. values. Light curing materials have K1, values according to their group but tend to have lower a, values than their chemically curing analogues. Glass ionomers have very low GI, values; however, there is no significant difference between the GI, Values of the composite groups. The K1, and uo values have been used to predict relative performance of the materials in highly stressed restorations and wear.