The authors concluded that the apical tissue of properly treated teeth with no signs of periapical changes is only rarely significantly inflamed. When the tissue is inflamed, microbial causes can always be demonstrated. Despite the presence of microorganisms coronally in nearly all cases, apical tissue is seldom affected.Research clearly demonstrates that apical cleaning and disinfection is of paramount importance and it is much better to be a pulp lover than an apical barbarian, see pic below: Case of the right is done by a pulp lover and the one on the left is done by an apical barbarian. READ FULL PAPER
Leaving the apical third under-cleaned and under-filled some opinion leaders encourage dentists to clean,disinfect and obturate lateral canals. Radiographs which show filled lateral canals look very impressive. Authors point out that lateral canals are rarely, if ever, completely cleaned
after preparation, regardless of the instrumentation technique and irrigants used (54–57).
This has been put into proper perspective in this classical study:
Fate of the Tissue in Lateral Canals and Apical Ramifications in Response to Pathologic Conditions and Treatment Procedures by Domenico Ricucci, Jose F Sequeira, JOE vol 36,Pages 1-15, January 2010
Conclusion of this study: Overall, the belief that lateral canals must be injected with filling material to enhance treatment outcome was not supported by literature review or by our histopathologic observations. READ FULL PAPER