Repair of amalgam restorations with conventional and bonded amalgam: an in vitro study

Abstract

Purpose: This study evaluated microleakage on amalgam restorations repaired by amalgam and bonded amalgam. Methods: Thirty extracted human pre-molars were restored by amalgam. A simulated defect was prepared and assigned to two treatment groups (n=15): G1 - repaired by amalgam (Permite C-SDI); G2 - repaired by bonded amalgam (Caulk 34% Tooth Conditioner Gel – Dentsply + Prime & Bond 2.1 – Dentsply + Permite C- SDI). The teeth were immersed in a 50% silver nitrate solution, thermocycled and then, sectioned longitudinally through the restoration center and examined by 3 examiners using a stereomicroscope. Microleakage was evaluated in a 0-4 scale for dye penetration. Microleakage data were analyzed by Kruskal Wallis and Dunn test. Results: The bonded amalgam technique was significantly the most effective in repair/tooth interfaces sealing (score 0=53.3%, P=0.0012). For repair/restoration interfaces, conventional amalgam was also statistically more effective in the sealing (score 0=86.7%, P<0.001). Conclusion: None of materials eliminated microleakage completely. The use of adhesive systems had significant effect on the ability to seal the repair/tooth interface, however, for repair/restoration interface, it can increase microleakage.