Alireza Amir

Background: In anterior endodontically treated teeth a better esthetic can be achieved by using all-ceramic post -core restorations instead of metal post systems. Maximum retention and fracture resistance of the post are the criteria upon which selection of a post system is based. The aim of this study was to evaluate the fracture resistance and retention of two all-ceramic post and core systems including IPS Empress 2 post-core system and IPS Empress 2 core connected to Zirconium Cosmopost, and comparing these features among the two groupsMaterial and methods:  Eighty extracted maxillary central incisors and canines were divided into two groups of 40 including IPS Empress 2 and zirconium Cosmopost. To evaluate retention, shear force was applied to the cement at the crosshead speed of 0.5 mm/min; force was applied until the post was detached from the canal.  To measure the fracture resistance, the samples were loaded at 45-degrees to the horizon at the crosshead speed of 5 mm/min un...

The aim of the present randomized clinical trial was to evaluate marginal bone loss around two types of implants modified at the neck area: Nobel Active and Nobel Replace Groovy, both manufactured by Nobel Biocare. A total of 25 Nobel Active and 21 Nobel Replace Groovy implants were included in the present study. The implants were placed based on the relevant protocol and patient inclusion and exclusion criteria. The amount of bone loss around implants was compared at 6 and 12-month intervals using digital periapical radiographs. The mean bone loss values in the Nobel Active and Nobel Replace Groovy groups were 0.682 mm and 0.645 mm, respectively, with no statistically significant difference based on the results of independent t-test (P=0.802). Use of both implant types yielded favorable results, with high durability. The two implant types exhibited no superiority over each other in terms of bone loss.