ABSTRACT
Marginal adaptation is an important factor for long term clinical success of the restoration. This study aims to evaluate and compare the marginal adaptation of zirconium coping and nickel-chromium coping using the shoulder finish line design. For the purpose of this study 30 master dies were fabricated. A total of 30 copings were fabricated in which 15 zirconia copings and 15 Ni-Cr copings were fabricated. The copings obtained were seated on the die and marginal discrepancy between the metal die and the copings were then measured with Scanning electron microscope at magnification of ×50 and the findings were statistically analyzed. Mean and standard deviation values of marginal discrepancy of cervical margins of zirconia copings were 39.32 and 2.66 µm and Ni-Cr copings were 129.98 and 2.57 µm. Higher mean marginal gap (µm) is recorded in Ni-Cr copings compared to zirconia copings. The difference in mean marginal gap (µm) between the two copings is found to be statistically significant (P < 0.001). Within the limitation of this study it was concluded that higher mean marginal gap (µm) was recorded in Ni-Cr copings compared to zirconia copings. The difference in mean marginal gap (µm) between the two copings is found to be statistically significant (P < 0.001).
ABSTRACT
Post and core therapy is regarded as the treatment of choice for restoring severely damaged endodontically treated teeth. Critical control of endodontic materials in the coronal third of the canal and pulp chamber is essential in order to maintain its colour and translucency. In addition to this, the duplication of the optical characteristics of an intact tooth, including shade translucency and fluorescence is often made difficult by the use of metal infrastructures. As a result of this tooth colored posts have gained popularity especially in aesthetic areas. Besides aesthetics, the post is also responsible for transmitting the occlusal forces to the remaining tooth structure making the mechanical properties of the post critical. However, there is no clear consensus regarding an ideal system as far as strength of the post is concerned. Hence this study aims to analyses and compares the fracture strength of traditional prefabricated glass fibre posts with zirconium oxide posts constructed using CAD CAM technology.
ABSTRACT
During treatment planning it is important to recognize different gingival biotypes and forms, because they can affect the esthetic outcome of the treatment. This review provides an insight into the different gingival biotypes, their response to inflammation and trauma; significance in different prosthodontic modalities like esthetic rehabilitation and implant therapy.
