Effect of cavity varnish, amalgam liner or dentin bonding agents on the marginal leakage of amalgam restorations

The purpose of this in vitro study was to compare marginal leakage of Class II amalgam restorations lined with different agents (two new generation de ntin bonding systems, a cavity varnish and an amalgam liner). Forty freshly extracted human molar teeth were divided into five groups. Class II prepar ations were prepared in the mesial and distal surfaces of each molar. While the cavities in two groups were lined with two new generation bonding syst ems, the other two groups were treated with an amalgam lining material and a cavity varnish. Fifth group was used as control, without any lining. Amal gam was hand-condensed into each preparation. Specimens were thermocycled, stained and sectioned. Microleakage was graded using a stereomicroscope. Me an microleakage scores for occlusal and cervical margins were calculated an d analised. For the leakage values on occlusal margins, Kruskal-Wallis test indicated no significant difference in all groups. For the leakage values on cervical margins, Kruskal-Wallis test indicated significant difference i n four groups when compared with controls (P < 0.001). On the other hand, t here was no significant difference between the occlusal and cervical leakag e values in each group.