COMPARATIVE STUDY OF THE MICROSHEAR BOND STRENGTH AND THE SOLUBILITY OF RESIN SEALER WITH AND WITHOUT THE ADDITION OF NANO SILVER

Aim: To compare the micro shear bond strength and the solubility of resin sealer with and without the addition of Nano silver.
Materials and Methods: This study was carried out on 30 human freshly extracted upper first premolars. After preparation of tooth surfaces for microshear bond strength test, The prepared teeth were assigned to three groups 10 of each: Group A: AH Plus sealer was used, Group B: AH Plus sealer with 0.2% Nano silver incorporated to the already mixed sealer was used, group C: AH Plus sealer in addition to 0.5% Nano silver incorporated to the already mixed sealer was used. A shear load with tensile mode of force was applied via materials testing machine, Micro-shear bond strength was measured. For solubility test 30 PVC rings with 20 mm in internal diameter and 5 mm in thickness were placed onto a thin cellophane sheet supported by a glass plate and filled with sealers as follows: Group A, 10 rings filled with AH Plus sealer mixed according to the manufacturer’s instructions. Group B, 10 rings filled with AH Plus sealer mixed according to the manufacturer’s instructions, in addition to 0.2% Nano silver incorporated to the already mixed sealer. Group C, 10 rings filled with AH Plus sealer mixed according to the manufacturer’s instructions, in addition to 0.5% Nano silver has incorporated to the already mixed sealer. The samples were kept in an environment with temperature of 37˚C for up to three times the setting time of each sealer group. After that, the samples were removed from the rings. Each sample was weighed on precision scale and suspended through the nylon thread inside a large opening flask containing 50 ml of ultrapure water and all samples were maintained into the incubator at 37˚C for 7 days. Then the samples were placed into desiccators for 24 hours for new weighing. The difference between the first and the second weight represents the mass loss for each of the specimens.
Results: Group A showed the highest mean value of microshear bond strength among all groups. Group B showed a mean value of microshear bond strength, lower than Group A and there was a statistically significant difference between them, but was higher than that of Group C and there was no statistically significant difference between these two groups B and C. Group C showed the least mean value of microshear bond strength among all groups, it showed statistically significant difference with group A, and although it was also lower than Group B but there was no statistically significant difference between them. For solubility test group C showed the least mean value of solubility among all groups, it showed statistically significant difference with group A, and although it was also lower than Group B but there was no statistically significant difference between them.
Conclusion: The results of the present study showed that the incorporation of 0.2%& 0.5% nano silver particles to the already mixed AH plus sealer although decreased the microshear bond strength to dentin but it increased the resistance of the sealer to solubility..