Sealing efficacy of therapeutic varnishes used with silver amalgam restorations

The sealing abilities of three therapeutic varnishes were compared with that of a conventional copal varnish in vitro under Tytin silver amalgam restorations. The therapeutic varnishes comprised two commercial fluoride varnishes and one experimental chlorhexidine-containing varnish. Leakage was traced using a basic fuchsin dye and was found to be considerable, particularly on root surfaces. The therapeutic varnishes performed as well as, and in some cases better than, the control. It is suggested that the use of preventive therapeutic varnishes in operative dentistry merits attention and further study.