Long-term bacterial leakage along obturated roots restored with temporary and adhesive fillings

The aim of this study was to examine whether obturated roots combined with several adhesive and temporary filling materials can be bypassed by bacteria. Standardized cavities were coronally prepared into 130 straight roots mimicking clinical access cavities. After obturation the roots were assigned to six test and three control groups and coronally sealed with either Clearfil, CoreRestore, IRM, Ketac Fil, or a combination of IRM/wax or Ketac Fil/wax. The roots were then fixed between a top and a bottom chamber each. The top chamber contained soy broth with 108 Staphylococcus epidermidis colony-forming units/ml, and the bottom chamber contained sterile soy broth. For I yr the mounts were checked on a regular basis for turbidity in their bottom chambers indicating bacterial growth. After 1 yr only three samples from the CoreRestore group and two samples from the Clearfil group resisted leakage. At termination there was no significant difference in number of leaking samples among the groups. At the beginning of the experiment IRM performed worst. Between months 5 and 10 Clearfil showed the least leaking samples; for some months this was statistically significant compared with IRM or Ketac Fil.