Quantitative microleakage evaluation around amalgam restorations with different treatments on cavity walls

The purpose of this in vitro study was to evaluate the dye penetration around amalgam restorations in dentin cavities by a quantitative test. Standardized circular cavities were prepared on the facial surface of 75 extracted human single-rooted teeth, and restored with dental amalgam. Different bonding/sealing treatments were used on the cavity walls before the restorations were placed. The specimens were thermo-cycled between 5 +/- 2 degrees C and 55 +/- 2 degrees C for 500 cycles with 1-minute dwell times, followed by immersion in a 2% methylene blue solution for 12 hours at 37 degrees C. The quantitative microleakage was evaluated by spectrophotometry and was expressed by microgram dye per tooth structure. The results showed that the use of bonded amalgam restorations was more effective in reducing microleakage.