In Vitro Study Of Fracture Strength Of Provisional Crown Materials

This study aimed at investigating the influence of fabrication method  and material on the fracture strength of temporary  crowns.

Method:

A CrCo-alloy master model with 1 crown (abutment tooth 25 ) was manufactured. The master model was scanned and the data set transferred to a CAD/CAM unit (Cercon Brain Expert, Degudent, Hanau, Germany) for Ondent group and fort he ther groups  temporary crown produced by direct fabrication (Imident, Temdent, Structur Premium, Takilon, Systemp c&b ll, Acrytemp). 10 crown per experimental group were subjected  to water storage at 37 ◦C for 24h and then  thermocycled (TC, 1000×, 5–55 ◦C, 1 week). Maximum force at fracture (Fmax) was determined in a universary test machine at 1 mm/min. Data was analyzed using parametric statistics (p< 0.05).

Result:

F max values ranged from 777.6 to 1499.6 N. In PMMA groups Temdent showed the lowest values and Takilon showed the highest values. In composite groups Structur Premium showed the highest values and Acrytemp showed the lowest values. Composite groups showed significant  higher values than PMMA groups (p< 0.05).

Conclusion:

Composite based materials showed significantly high fracture strength than PMMA based materials.