Evaluation of Vertical Marginal Adaptation of Provisional Crowns by Digital Microscope

Abstract

Objective: To investigate and compare the degree of vertical marginal discrepancy of four provisional crown materials by digital microscope. Materials and Methods: A total of 100 provisional crowns were fabricated on standardized resin dies by direct technique of provisional fabrication, using four different provisional materials (n = 25): Provisionals Fabricated by Systemp® c and b II, ivoclar vivadent, Schaan, Liechtenstein (group A); ProtempTM Plus, 3M ESPE, Neuss, Germany (group B); Success CD, PROMEDICA, Neumunster, Germany (group C); and Trim® Plus, Bosworth Company, Illinois, USA (group D). The provisional crowns were finished, tried, and locked with a customized device under 15N of vertical axial force. The vertical marginal discrepancy between the crown margin and the resin die was measured in micrometers using digital microscope (KH-7700, Hirox-USA, Inc., NJ, USA) at mid of buccal, lingual, mesial, and distal margin areas by a trained technician. Results: The mean values obtained for each group were as follows: group A = 129.10 ± 41.64, group B = 123.36 ± 40.94, group C = 89.67 ± 25.34, and group D = 107.24 ± 38.32. Assessment by post hoc Tukey’s test at 5% significance level showed a statistically significant difference (P < 0.05) between group C and group D with the other groups. Results of one-way ANOVA showed a statistically nonsignificant difference (P > 0.05) between the means of the four areas of measurement for each group. Conclusion: Marginal discrepancy of the group C (Success CD) was the lowest among the provisionals tested. The mean vertical marginal gap values for the materials tested were found to be with in the clinically acceptable range (<130 μm).

Keywords: Crowns, crown margins, marginal adaptability, provisional restorations, provisionals, temporary crowns