Sunday, 18 December 2016

Wednesday, 16 March 2016

What are the Irritants for Pulpal and Periapical Tissues?
The major causes of pulpal and periapical diseases are living and nonliving irritants. The latter group includes mechanical,
thermal and chemical irritants. The living irritants include various microorganisms including bacteria, yeasts and viruses.
When pathological changes occur in the dental pulp, the root canal space acquires the ability to harbor various irritants
including several species of bacteria, along with their toxins and byproducts. Investigations in animals and patients have
shown that pulpal and/or periradicular diseases do not develop without the presence of bacteria.1,2 Advanced culturing and
molecular biology techniques have shown that primary root canal infections are polymicrobial (10-30 bacterial species)
in nature and are dominated by obligate anaerobic bacteria.3 The variety of microorganisms present in root canal-treated
teeth with persistent periapical lesions is more restricted (1-3 species) in comparison to primary root canal infections, which
are dominated by E. faecalis, a facultative anaerobic gram-positive coccus that is resistant to