A comparison of fracture loads in the in vitro studies revealed no significant difference between cast and direct posts and cores .
Meta- analysis of the data suggested that there is no difference in fracture behavior associated with the 2 treatment modalities .
Direct  post- and -core restorations with prefabricated posts are becoming increasingly popular .
A literature review was conducted to compare the clinical and in vitro performance of cast posts and cores to that of direct cores with prefabricated posts in single-rooted teeth .
Survival rate and fracture strength of endodontically treated maxillary incisors with moderate defects restored with different post-and-core systems: an in vitro study.
PURPOSE This study compares the survival rate and fracture strength of endodontically treated maxillary incisors with moderate coronal defects restored with different post- and -core systems after exposure to an artificial mouth . MATERIAL S AND METHODS Sixty-four caries-free human maxillary central incisors were selected for st and ardized size and quality , endodontically treated , and decoronated 2 mm coronal to the cementoenamel junction . Group 1 was restored with titanium posts and composite cores , group 2 received zirconia posts and a composite core , and in group 3 zirconia posts with a heat-pressed ceramic core were used . Teeth restored with cast posts and cores served as controls . All teeth were prepared and restored with complete cast crowns . All sample s were exposed to 1.2 million cycles in a computer-controlled chewing simulator with simultaneous thermocycling . In addition , the sample s were loaded until fracture in a static testing device . RESULTS The survival rates of the different groups were : 94 % for titanium/composite , 63 % for zirconia/composite , 100 % for the all-ceramic post and core , and 94 % for the cast post and core . The following mean fracture strengths were obtained : titanium/composite = 425 + /- 155 N , zirconia/composite = 202 + /- 212 N , zirconia/ceramic = 378 + /- 64 N , cast post and core = 426 + /- 178 N. The lower fracture load in the group with zirconia posts and composite cores was statistically significant . The use of zirconia posts result ed in fewer oblique root fractures . CONCLUSION Prefabricated titanium posts with composite cores , zirconia posts with heat-pressed ceramic cores , and cast posts and cores yield comparable survival rates and fracture strengths for the restoration of crowned maxillary incisors with moderate coronal defects .  Survival rates and fracture strengths for zirconia posts with composite cores are significantly lower , so this combination can not be recommended for clinical use
A comparison of fracture loads in the in vitro studies revealed no significant difference between cast and direct posts and cores .
Meta- analysis of the data suggested that there is no difference in fracture behavior associated with the 2 treatment modalities .
Direct  post- and -core restorations with prefabricated posts are becoming increasingly popular .
A literature review was conducted to compare the clinical and in vitro performance of cast posts and cores to that of direct cores with prefabricated posts in single-rooted teeth .