[Root canal filling after apicoectomy, as seen on the scanning electron microscope]

The radiologically controled apicectomy shows frequently unsuccessful results. In histological examinations of the root apex area after apicectomy chronic inflammation is regularly seen even in negative radiologic findings. Examination of the most frequently used root filling material (zincoxyphosphate with guttapercha point) by scanning electron microscopy shows a porous surface and between the canal wall and the root filling material there appears regularly a deep groove as no contact is achieved. The rough surface structure, the chemical composition and the loose contact of the components in this area are considered irritative factors and reasons of failure in treatment.