A method for microleakage evaluation along the dentin/restorative interface

To present a simple non-abrasive protocol in conjunction with the silver-staining method, enabling unobstructed visualization of well-defined microleakage patterns within the demineralized dentin-restorative interface.

Class V preparations were made with an occlusal margin on bevelled enamel and a gingival margin on dentin/cementum. After restoration with All Bond 2/P-50 and Scotchbond 2/Silux, storage in water at 37 degrees C for 7 days and thermocycling 300 times between 5 degrees and 55 degrees C, the specimens were placed in silver nitrate solution. After silver fixation, demineralization and clearing in methyl salicylate, silver stain location was scored ordinally. In addition, a three dimensional portrait of leakage pathways was illustrated using photographic and computer digitization.

The Wilcoxon signed-rank test showed that the extent of silver penetration before and after acid demineralization was not significantly different (P > 0.05). This study also confirmed that microleakage is not uniform along the circumference of a restorative margin. Although the protocol is insensitive to microleakage occurring solely within enamel, the predominant concern over that occurring within dentin, in particular along the cervical restorative border, renders it a serviceable alternative for future investigation of the integrity of the marginal seal from clinically restored in vivo specimens.