Quantitative microleakage evaluation of amalgam repair with different surface treatments

Materials and Methods: 50 defect-free human molar teeth were restored with amalgam occlusally. The teeth were thermocycled (1000X) between 5oC and 55oC with a dwell time of 30 seconds. Mesial and buccal parts of the amalgam fillings were removed out leaving only middle part of amalgam. One side of the cavity was finished with course diamond bur and the other part of the amalgam is finished with fine diamond bur. Then the samples were randomly divided into 5 groups (n=10/group) to receive the following adhesive systems: Group1: All Bond3 (Bisco); Group2: Clearfil SE Bond+Alloy Primer (Kuraray); Group3: Kuraray DC Bond (Kuraray); Group4: Xeno V (Dentsply); Group5: XP Bond (Dentsply). All the cavities were restored with resin composite (TPHSpectrum, Dentsply). All the materials were used according to the manufacturers' directions. The specimens were re-thermocycled (1000X), sealed with nail-varnish, stained with 0,5% basic fuchsin for 24h, sectioned mesiodistally and photographed digitally. The extent of dye penetration on resin-tooth and resin-amalgam interface was measured by image analysis software (ImageJ) for both course- and fine-finished surfaces. The data were analyzed statistically with one-way ANOVA and post hoc Tukey tests (p=0.05). Two randomly-selected sections from each group were observed under SEM.

Results: All Bond3 and XP bond (etch&rinse groups) produced the best results at each section statistically. All materials except All Bond3 exhibited more microleakage at amalgam interface then tooth interface. Surface finishing with different burs did not statistically affect microleakage.

Conclusion: Etch&Rinse adhesives may be preferred for amalgam repair in terms of microleakage prevention.