Purpose: describe histological & microbiological findings in root filled teeth that exposed to caries & oral environment.
•N= 32 teeth
-Teeth included: operated by one DR, root fillings had been exposed to either extensive caries\oral exposure for at least 3 months. Root filled 3 years or more prior to extraction.
-At the onset of endodontic treatment, 17 had been diagnosed with a vital pulp & 14 teeth had a necrotic pulp of which 10 teeth had presented radiographic evidence of apical periodontitis.
-Before extraction, a radiograph of each tooth was taken for an evaluation of the periapical status.
-A standardized protocol followed, No attempts to remove smear layer. Different sealers with laterally compacted GP.
-Haematoxylin and eosin for assessment of inflammatory status, while a modified brown/brenn technique for staining of bacteria.
Most highlighted Results:
1.In (96%) bacteria were limited to the coronal 1/3 only and were not present in the apical portion of the canal.
2.In one root, bacteria were noted in the apical end while not being seen either in the mid-root portion or coronally.
3.Soft tissue attached to root tip displayed either a non-infiltrated tissue or small tissue infiltrates of MNLs associated with dispersed sealer particles. Distinct inflammatory infiltrates in 7 \39 roots suggesting microbial exposure.
Well-prepared and filled root canals resist bacterial penetration even upon frank and long-standing oral exposure by caries, fracture or loss of restoration.