MICROLEAKAGE OF AMALGAM RESTORATIONS USING DENTIN BONDING SYSTEM PRIMERS

Purpose: To evaluate and compare in vitro microleakage of etched and n on-etched Class I amalgam restorations lined with various dentin bondi ng system primers to amalgam restorations with or without a Copalite l iner. Materials and Methods: Class I amalgam preparations were made in 140 extracted molars and divided into 14 groups of 10 teeth each. Per mite C dispersed phase alloy restorations were placed after the follow ing treatments: Group 1: No liner; Group 2: Lined with two coats of Co palite; Group 3(A): Lined with Amalgambond AA and 3(B): Etched with 35 % Ultra-etch and lined with Amalgambond AA; Group 4(A): Lined with Sco tchbond Multi-Purpose Primer and 4(B): Etched and lined with the prime r; Group 5(A): Lined with ProBond and 5(B): Etched and lined with the primer; Group 6(A): Lined with All-Bond 2 Primer A & B and 6(B): Etche d and lined with the primer; Group 7(A): Lined with OptiBond and 7(B): Etched and lined with the primer; Group 8(A): Lined with Permagen Pri mer and 8(B): Etched and lined with the primer. All primers were appli ed per manufacturers' specifications. After storage in water for 24 ho urs, all restorations were polished and then aged in water at 37 degre es C for 90 days. The specimens were then thermocycled for 300 cycles at 5 degrees C and 55 degrees C in basic fuchsin dye with a 30-second dwell time, mounted in epoxy rings, sectioned longitudinally, mesiodis tally and buccolingually into four sections, then evaluated at x100 an d the extent of dye penetration at the tooth/amalgam interface scored (two scores for each section, eight for each specimen). Results: The u nlined and Copalite-lined groups and all non-etched groups showed cons iderable marginal leakage. All the etched restorations were significan tly more effective in reducing microleakage than the non-etched, no li ner and Copalite-lined groups. Etching prior to application of the pri mers is significantly more effective than nonetching, however the effe ctiveness of the primer alone to seal the dentin needs to be evaluated . Overall, Amalgambond AA had the least microleakage of all the groups .