A Fluorescent Dye Method for Demonstrating Leakage around Dental Restorations

¹ Indiana University, School of Dentistry, Indianapolis, Indiana

A simplified technique for testing and scoring microleakage around dental restorations was presented. Eighty-seven class V cavities were prepared in 32 bovine mandibular incisor teeth. The cavities were divided into 4 groups and restored with representative fillings known to furnish good seal or known to be prone to microleakage. The filled teeth were immersed in fluorescein and rhodamine B for periods of 5 to 12 minutes and 1 hour. The teeth were sectioned with separating disks and viewed under ultraviolet light. With one exception, the dyes showed marginal leakage satisfactorily. The 24-hour amalgam fillings showed considerable leakage. Amalgams plus cavity varnishes showed reduced marginal leakage. All gutta percha restorations showed gross leakage. The fluorescent dyes tested did not show microleakage around zinc oxideeugenol restorations because of a "quenching" of the fluorescence. Sound enamel of bovine and human teeth was impermeable to the fluorescent dyes tested. Fluorescein showed the most promise for future research. It is inexpensive, nontoxic, and contrasts sharply with the natural fluorescence of teeth.