Influence of the method of storage on the microleakage of primary teeth restored with different bonding systems: in vitro study

Abstract

The influence of the method of storage of teeth and the effect of two kinds of dentin-bonding agents on the microleakage at the axial and cervical walls of composite restorations, in primary second molars, were evaluated. The samples were divided in three groups: Dehydrated, Hydrated and Frozen. The Dehydrated group was kept dry, the Hydrated group was stored in physiological saline solution under refrigeration, and the Frozen group was kept in the freezer, also immersed in physiological solution. The samples received two vertical slot preparations: a mesio-occlusal and a disto-occlusal one. In the mesio-occlusal cavities, Scotchbond Multi-Use adhesive system was used, whereas in the disto-occlusal cavities Prime & Bond 2.1 system was used, and all cavities were filled with Solitaire composite resin. The groups were then thermocycled and immersed in silver nitrate solution. Microleakage was measured by means of a digitized image system and the values were submitted to statistical analysis. The results showed that the method of storage had no statistically significant influence on marginal microleakage. Microleakage at the cervical wall was significantly greater than that at the axial wall, with 99,9% of certainty. The adhesive systems did not show significant influence on microleakage, in the studied methods of storage. However, there was statistical difference in the Dehydrated group samples, with the use of Prime & Bond 2.1 adhesive, when considering the margins of the restoration (axial and cervical).