Microleakage of a dental amalgam alloy bonding agent.

Amalgambond (a 4-META derivative resin bond agent) was evaluated for its effectiveness in reducing microleakage compared to copal varnish and no lining agent in class 5 amalgam preparations restored with either an admix alloy (Dispersalloy) or a spherical alloy (Tytin). Teeth were thermocycled between 5 and 55 degrees C with two 4-META/amalgam groups additionally aged in 37 degrees C water for 30 days prior to thermocycling. Nonaged, 4-META/amalgam restorations showed significantly less microleakage (P < 0.