A Biomechanical Study Of Restorations Of Endodontically Treated Premolars

The restoration of endodontically treated premolars is a confusable problem, we can compare the different restorations of endodontically treated premolars to choose the best method from the point of biomechanics.Collected 50 pairs of symmetry maxillary first premolars from 50 patients then randomized divided into 10 groups, every group has 5 pairs, every pair received different treatment accordingly, embedded and fixed up. Then loaded by instron 4302 universal test machine in speed of 1mm/min to broken up, recorded the top load. The load angle is 45 degree to the long axis of the teeth, as the load is pointed to the middle of the lingual surface on the buccal cusp. Statistic the records in paired samples t test by SPSS11.5 software. The first part, measure the shape of the symmetry left and right first premolars, analysis the comparability. The second part is based on the occlusal cave, test one compare the full natural teeth and AgHg filled teeth, test two compare the full natural teeth and FX-â…¡ filled teeth, both fracture strength of the treated groups are lower than control groups. Test three compare the full natural teeth and full crowned teeth, the fracture strength of the treated group is higher than control group. The third part is based on the mesial-occlusal cave, test fourcompare the full natural teeth and full crowned teeth, the fracture strength of the treated group is lower than control group; test five compare the full natural teeth and post-crowned teeth, the fracture strength of the treated group is higher than control group. The forth part is based on the mesial-occlusal-distal cave, test six compare the full natural teeth and post-crowned teeth, the fracture strength of the treated group is lower than control group; test seven compare the crowned teeth and post-crowned teeth, the fracture strength of the post-crowned group is higher than the crowned without post group; test eight compare the fabricated post and cast post teeth, test nine compare the compounded post and cast post teeth, test ten compare the compounded post and fabricated post teeth, the fracture strength between the both groups have no statistically difference. From the point of biomechanics, the different trauma of the endodontically treated teeth fits to different restorations. The occlusion cave fits the full crown restoration mostly, the mesial-occlusal cave fits the post -crown restoration mostly, the mesial-occlusal-distal cave currently recommends the post -crown restoration mostly since no restorations are ideality.