Clinical performance of bonded amalgam restorations at 42 months

Background, Despite a lack of data based on clinical research, many positive characteristics have been attributed to the placement of amalgam restorations 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 study, these subjects had been randomly assigned to have amalgam restorations placed with an adhesive liner or with a copal varnish placed under all restorations and a bulk base of zinc phosphate cement for deeper lesions. The authors evaluated anatomical form, marginal adaptation, retention and the presence of secondary caries at six, 18, 30 and 42 months. Results, At 42 months, the authors found that all restorations in both groups still were retained, were free of secondary caries and were rated clinically acceptable. No difference between the groups was found for any category (P > .05; analysis). Conclusions, Placement of amalgam restorations with adhesive liners was found to produce results equivalent to that of traditional methods over a 42-month period. Clinical Implications, Practitioners wary of using new methods that have not undergone thorough clinical testing can feel comfortable placing adhesive liners under amalgam restorations.