The influence of posterior composite type and application technique on the fracture resistance of maxillary premolar teeth : an in vitro study

الملخص EN

Background : A restorative material with the potential to increase resistance to cuspal fracture is available to dentists and the packable composite is one of them.

This in vitro study was conducted to evaluate and compare the cuspal fracture resistance of weakened maxillary premolar teeth with MOD preparations restored with different composite materials and techniques.

Materials and Methods : Fifty maxillary premolar teeth were divided into five groups (n = 10).

Class II MOD cavities were prepared in forty specimens.

Group A, were sound.

Group B were prepared but not restored.

Group C and D were restored with successive cusp build up using Z250 micro hybrid for group C and P60 packable for group D.

Finally, Group E was restored with bulk using P60 packable.

A 5 mm diameter steel sphere contacted the buccal and lingual cusps of the tested teeth until fracture occurred.

The values obtained in this study were subjected to Analysis of Variance (ANOVA) and student t–test was carried out between the two types of posterior composite materials.

Results : there's a high significant improvement of the fracture resistance of restored teeth using posterior composite as compared to the unrestored ones, but ; there's no difference of the type of the posterior composite material used, or the type of placement technique used, while the sound teeth remained the strongest teeth compared with all the other groups.

Conclusions : the study concluded that Posterior composite resin restoration whatever type or technique used, showed a great improvement in the resistance to cuspal fracture.