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VOLUME 17 , ISSUE 2 ( February, 2016 ) > List of Articles

RESEARCH ARTICLE

Marginal Accuracy of Castings Fabricated with Ringless Casting Investment System and Metal Ring Casting Investment System: A Comparative Study

BG Prasanna, M Kalavathi, Bhuvana Sachin, TV Shreeharsha, B Praveen, Mallikarjuna Ragher

Citation Information : Prasanna B, Kalavathi M, Sachin B, Shreeharsha T, Praveen B, Ragher M. Marginal Accuracy of Castings Fabricated with Ringless Casting Investment System and Metal Ring Casting Investment System: A Comparative Study. J Contemp Dent Pract 2016; 17 (2):165-170.

DOI: 10.5005/jp-journals-10024-1821

Published Online: 01-02-2016

Copyright Statement:  Copyright © 2016; Jaypee Brothers Medical Publishers (P) Ltd.


Abstract

Background

The thermal expansion of the investment can be restricted by the metal casting ring because the thermal expansion of the ring is less than that of the investment. The ringless casting procedure is in use in clinical dentistry, though there is little scientific data to support its use in fixed partial dentures. In this study, marginal discrepancy of castings produced with the ringless casting technique and the conventional technique using the metal rings were compared.

Materials and methods

A total of 30 wax patterns were fabricated directly on a metal die. Optical stereomicroscope was used to measure the marginal discrepancy between the metal die and wax patterns. A total of 15 castings were invested using Bellavest T phosphate-bonded investment with the ringless technique and 15 were invested with the same investment with a metal ring; 30 castings were produced using a nickel-chromium ceramo-metal alloy. The internal surface of the castings was not modified and seated with finger pressure. The vertical marginal discrepancy was measured using an optical stereomicroscope at a magnification of 100×. The data obtained were statistically analyzed using students t-test (paired t-test and unpaired t-test).

Results

The castings of the ringless technique provided less vertical marginal discrepancy (240.56 ± 45.81μ) than the castings produced with the conventional metal ring technique (281.98 ± 53.05μ). The difference was statistically significant.

Conclusion

The ringless casting technique had produced better marginal accuracy compared with conventional casting technique. Ringless casting system can be used routinely for clinical purpose.

How to cite this article

Kalavathi M, Sachin B, Prasanna BG, Shreeharsha TV, Praveen B, Ragher M. Marginal Accuracy of Castings Fabricated with Ringless Casting Investment System and Metal Ring Casting Investment System: A Comparative Study. J Contemp Dent Pract 2016;17(2):165-170.


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