A new method for assessment of marginal sealability of dental restorations

A new testing system was developed for assessment of marginal sealability of dental restorations. It was constructed with a thermocycle loading line and a leakage detecting line partitioned from each other by the restoration under evaluation. The hot and cold solutions of rhodamine B as a tracer were alternately circulated in the thermocycle loading line by the switching of six solenoid valves. Marginal leakage of the tracer into distilled water circulating in the detecting line was periodically monitored by a spectrometer while thermocycling the restoration. The leakage data could be analyzed on the basis of an empirical formula. In application of this method, the durability of a complete seal against thermal changes was estimated on three teeth each of which was restored with an inlay, an amalgam or a glass ionomer.