Journal of Research and Advancement in Dentistry
Official publication of Magadh University and Kolhan University, Government of Bihar and Jharkhand, India
Official publication of Magadh University and Kolhan University, Government of Bihar and Jharkhand, India
Year : 2020
Volume : Volume 11
Issue : Issue 1
Address for correspondence :
Dr. Sunitha Kollu.
sntchowdary@gmail.com
Background: To evaluate the marginal accuracy of metal margins fabricated with three commonly used alloys using a stereomicroscope. Materials and Methods: Samples were made in three metal groups of fifteen each. Total of forty-five metal copings was fabricated on a prefabricated metal die. We utilized three commercially available alloys, i.e., Mealloy, Star Loy N, Supranium. Metal copings were fabricated by standard casting procedures. The brass master die made similar to the shape and dimension of mandibular first molar preparation. The tooth preparation section of the metal die was made with a vertical dimension of 6 mm from the cavosurface line angle to the occlusoaxial line angle. All wax pattern was separated from the master die by attaching a wax sprue of 3 mm diameter and 6 mm length at the centre of the occlusal surface. Investment of wax patterns was completed by phosphate-bonded investment material. The measurement of fit of the metal copings was recorded by stereo photomicroscope at four different surfaces. Samples were placed steadily at the testing platform of the microscope for gap evaluation and quantification. Mean of the four measured surfaces were taken as final for that particular sample. Samples with any kind for casting defects were discarded, and the procedure was repeated for that sample. Results: All the recorded data and responses were compiled and sent for statistical evaluation using statistical software Statistical Package for the Social Sciences version 21. The vertical marginal discrepancy data obtained were tabulated. For the group, I (Mealloy) samples, the mean vertical gap was 55.322. For group II (Star Loy N) samples, the mean vertical gap was 35.659. For group III (Supranium) samples, the mean vertical gap was 46.062. All measurements were attempted by using a stereomicroscope in micron. For group III (Supranium), the P-value was significant (0.01). Conclusion: Within the limitations of the study design, it can be concluded that the vertical marginal gap at the margin of the casting and the die was minimum for Star Loy N and maximum for Mealloy. Keywords: Mealloy, Star Loy N, Supranium, dental casting techniques, marginal accuracy.
