A comparison of four in vitro marginal leakage tests applied to root surface restorations

Marginal leakage associated with a variety of restorative materials, placed in root surface cavities of extracted teeth, was assessed by immersing the teeth in either acidified gelatin, eosin dye, silver nitrate or a solution of radiocalcium. The allocation of a score, dependent on the depth of tracer penetration at the interface, allowed comparisons to be made between the leakage tests employed. The rank order of the four leakage tests was generally consistent. Eosin resulted in the most severe leakage, followed by silver nitrate and radiocalcium, whilst acidified gelatin was the least sensitive method for demonstrating marginal leakage. Differences in leakage scores were not, however, always statistically significant. None of the four tests investigated was ideal, although eosin dye was considered to be the most appropriate method of demonstrating marginal leakage associated with root restorations.