Clinical performance of bonded amalgam restorations at 42 months

Background, Despite a lack of data based on clinical research, many positiv e characteristics have been attributed to the placement of amalgam restorat ions with an adhesive resin liner. Methods, For 42 months, the authors followed two groups of subjects who had amalgam restorations placed in a previous study. In this double-blind stud y, these subjects had been randomly assigned to have amalgam restorations p laced with an adhesive liner or with a copal varnish placed under all resto rations and a bulk base of zinc phosphate cement for deeper lesions. The au thors evaluated anatomical form, marginal adaptation, retention and the pre sence of secondary caries at six, 18, 30 and 42 months. Results, At 42 months, the authors found that all restorations in both grou ps still were retained, were free of secondary caries and were rated clinic ally acceptable. No difference between the groups was found for any categor y (P > .05; analysis). Conclusions, Placement of amalgam restorations with adhesive liners was fou nd to produce results equivalent to that of traditional methods over a 42-m onth period. Clinical Implications, Practitioners wary of using new methods that have no t undergone thorough clinical testing can feel comfortable placing adhesive liners under amalgam restorations.