Evaluation of the marginal fit of metal copings fabricated on three different marginal designs using conventional and accelerated casting techniques: An in vitro study

• Main Authors: Sharad Vaidya, Hari Parkash, Akshay Bhargava, Sharad Gupta
• Format: Article
• Language: English
• Published: Wolters Kluwer Medknow Publications 2014-01-01
• Series: Indian Journal of Dental Research
• Subjects: Accelerated casting technique; conventional casting technique; finish line; marginal gap
• Online Access: http://www.ijdr.in/article.asp?issn=0970-9290;year=2014;volume=25;issue=5;spage=641;epage=647;aulast=Vaidya

Introduction: Abundant resources and techniques have been used for complete coverage crown fabrication. Conventional investing and casting procedures for phosphate-bonded investments require a 2- to 4-h procedure before completion. Accelerated casting techniques have been used, but may not result in castings with matching marginal accuracy. Aims and Objectives: The study measured the marginal gap and determined the clinical acceptability of single cast copings invested in a phosphate-bonded investment with the use of conventional and accelerated methods. Materials and Methods: One hundred and twenty cast coping samples were fabricated using conventional and accelerated methods, with three finish lines: Chamfer, shoulder and shoulder with bevel. Sixty copings were prepared with each technique. Each coping was examined with a stereomicroscope at four predetermined sites and measurements of marginal gaps were documented for each. Statistical Analysis: A master chart was prepared for all the data and was analyzed using Statistical Package for the Social Sciences version. Evidence of marginal gap was then evaluated by t-test. Analysis of variance and Post-hoc analysis were used to compare two groups as well as to make comparisons between three subgroups . Results: Measurements recorded showed no statistically significant difference between conventional and accelerated groups. Conclusion: Among the three marginal designs studied, shoulder with bevel showed the best marginal fit with conventional as well as accelerated casting techniques. Accelerated casting technique could be a vital alternative to the time-consuming conventional casting technique. The marginal fit between the two casting techniques showed no statistical difference.