Repair of non-carious amalgam margin defects

This study investigated the microleakage associated with the repair of non- carious amalgam defects using flowable resin composite. Occlusal amalgam pr eparations were accomplished on 36 non-carious mandibular molars, A standar dized 40-micron marginal defect was made by condensing amalgam against a my lar matrix strip, Specimens then underwent a corrosion protocol designed to simulate intraoral corrosion seen with amalgam restorations. The resultant specimens were divided into three treatment groups: 1) No treatment (contr ol); 2) Air abrasion of the amalgam defect surface, acid etching of both am algam and enamel surfaces, then placement of a flowable composite and 3) Ai r abrasion of the amalgam defect, application of a fifth-generation dentin bonding agent and placement of the flowable composite. Specimens were therm ocycled, sealed with glass ionomer and fingernail polish to within 1 mm of repaired margins, then immersed in basic fuchsin for 24 hours. Specimens we re sectioned and microleakage assessed. Results indicated that a flowable r esin composite significantly reduced marginal microleakage compared to the control (p <0.05), There was no difference in microleakage between flowable resin composite repairs done with or without the use of a dentin-bonding a gent.