In vitro comparison of filled and unfilled universal bonding agents of amalgam to dentin

In this study, four different adhesive amalgam systems were compared(Amalgambond Plus, Amalgambond Plus with HPA, All-Bond 2, and All-Bond 2 with Liner-F) regarding their ability to bond amalgam to freshly prepared dentinal surfaces. The two groups that yielded the highest mean bond strengths, Amalgambond Plus with HPA and All-Bond 2 with Liner-F, were the only two groups in comparison that were not statistically different (P > 0.05). The use of the filled resin bonding agents created significantly higher bond strengths between tooth and freshly triturated amalgam than the unfilled resin bonding agents. Further study is required to determine: a) the exact nature and mechanism of the bonds, and b) clinical in vivo presence and longevity of the bonds.