Authors : Mehran Motamedi, Mohammad Joulaei, Ali Asghar Alavi and Nasrin Kiani Manesh
Abstract: In restorative procedures of subgingival cavities with tooth-colored restorative materials, it is necessary to choose a material with low technique sensitivity which is easy to use in such cavities because tooth-colored materials are highly technique sensitive. In the present study, microleakage of MTA and glass-ionomer was evaluated and compared in two open and closed sandwich technique procedures. Class II cavities were prepared on the mesial and distal surfaces of 24 human premolars. The cavities were filled with MTA and glass-ionomer up to 3 mm occluso-gingivally; in order to restore the remaining portion of the cavity with composite resin the teeth were randomly divided into two groups. In groups 1 and 2 closed and open sandwich techniques were used, respectively. Subsequent to thermocycling, the samples were immersed in 2% methylene blue for 24 h and sectioned under a stereomicroscope for microleakage evaluation. In the open sandwich group, microleakage was evaluated at dentin and junctional interfaces; in the closed sandwich group microleakage was evaluated only at dentin interface. Inter-group microleakage comparison (between open and closed techniques) was carried out by Mann-Whitney U test. Intra-group microleakage comparison (between MTA and glass-ionomer in the two open and closed techniques) was carried out by Wilcoxon signed-rank tests. Inter-group comparison did not reveal any significant differences in microleakage between the two open and closed sandwich techniques. In the intra-group comparison in the closed sandwich technique, no significant differences in microleakage were observed between MTA and glass-ionomer. In the open sandwich technique, MTA exhibited significantly less microleakage at dentin interface compared to glass-ionomer, however no significant differences were observed between the two materials at junctional interface. In composite resin restorations with open and closed sandwich techniques MTA can be as efficacious as glass-ionomer in decreasing microleakage.
Mehran Motamedi, Mohammad Joulaei, Ali Asghar Alavi and Nasrin Kiani Manesh, 2011. Comparison of MTA and Glass-Ionomer Microleakage in Two Open and Closed Sandwich Techniques in Class II Composite Resin Restorations. Research Journal of Biological Sciences, 6: 327-332.