Following furcal perforation, bacteria may colonize the defect and cause inflammation and periodontal destruction. This study used confocal laser scanning microscopy (CLSM) to evaluate Enterococcus faecalis colonization and proliferation in furcal perforations repaired with different materials. Furcal perforations created in 55 extracted human mandibular molars were repaired using either MTA-Angelus, Endocem, or Biodentine and coronally subjected to E. faecalis suspension for 21 days. The specimens were then stained using a LIVE/DEAD Viability Kit and visualized by CLSM. The minimum and maximum depths of bacterial penetration into the dentinal tubules were 159 and 1790 μM, respectively, with a mean of 713 μM. There were significantly more live than dead bacteria inside the dentinal tubules (p = 0.0023) in all groups, and all three repair materials exhibited a similarly sized stained area (p = 0.083). However, there were significant differences in the numbers of dead bacteria at the circumference of the perforation defect (p = 0.0041), with a significantly higher ratio of live to dead bacteria in the MTA-Angelus group (p = 0.001). Following perforation repair, bacteria may colonize the interface between the repair material and dentin and may penetrate through the dentinal tubules. The type of repair material has a significant effect on the viability of the colonizing bacteria.
Correlative imaging of biological tissues with apertureless scanning near-field optical microscopy and confocal laser scanning microscopy
