Effect of rebonding and type of liner on amalgam microleakage

Objectives: Use of varnish and dentin bonding agents has reduced microleakage under amalgam restorations effectively. Also rebonding may probably pose a role on microleakage and its complications. The aim of this study was to evaluate the effect of two different sealer agents on microleakage of Class V amalgam restorations with and without resin rebonding. Methods: Six groups each consists of ten premolars were divided into three pairs of groups. Class V cavities were prepared on the facial surfaces of each tooth, coronal margins in enamel and apical margins in cementum (dentin). Three groups received Copalite, Scotchbond Multi-Purpose (SBMP) and no sealing agent respectively, whereas the other three groups received the same sealing agents in conjunction with a rebonding process. Amalgam was used as restorative material. Specimens were thermocycled, stained and sectioned. Microleakage was graded (0-3) using a stereomicroscope at 40 x magnification. A scanning electron microscope was used, including high resolution elemental analysis. Data were analyzed with Kruskal-Wallis, Mann-Withney and Wilcoxon pair wise statistical tests (á=.05). Results: The groups lined with SBMP show significantly less microleakage and the no lined groups showed highest microleakage (P= 0.001). It was observed significant difference in microleakage mean rank of enamel and dentin margins (P=0.048). Also insignificant, lower microleakage was observed in groups with rebonding (P> 0.05). Conclusions: Mlti-step adhesive system had a significant effect on microleakage of Class V amalgam restorations. Rebonding did not have a significant effect on microleakage.