Year : 2016

Volume : Volume 6

Issue : Issue 2s

Address for correspondence :
Dr. Asha M. Rathod
ashur.579@gmail.com

Abstract

Aim:  This study compared the marginal accuracy of the copings fabricated, single and multiple per ring, with conventional metal ring investing system and ringless investing system. Materials and method: The study consists of 40 samples (copings) which was mainly divided into two groups i.e. Group I- conventional metal ring investing system (20 copings) and Group II- ringless investing system (20 copings). Each group was further divided in two subgroups i.e. Group I-a, ten copings were fabricated using single wax pattern invested and cast individually with conventional metal ring investing system whereas Group I-b, ten copings were fabricated using ten wax patterns invested and cast together with conventional metal ring investing system. Group II-a, ten copings were fabricated using single wax pattern invested and cast individually with ringless investing system whereas Group II-b, ten copings were fabricated using ten wax patterns invested and cast together with ringless investing system. For measuring the marginal discrepancy, an optical microscope at a magnification of 100 x was used. Measurements were recorded on four surfaces of the die i.e. buccal, palatal, mesial and distal. The data was analysed with the T- test. Results: The marginal discrepancy of the ringless group was significantly less than that of the conventional metal ring investing system (P<0.00). There was no statistical significant difference between the two subgroups that is single coping and ten copings fabricated per ring (P > 0.05). Conclusion: The ringless technique may produce accurate castings for use in fixed prosthodontics, therefore further investigation is needed to develop a protocol for its use.

Keywords: Coping, marginal accuracy, investing, ringless, casting.