ENDO, 01/2007

The root canal system is colonised with microorganisms in cases of apical periodontitis. Currently, it is impossible to totally eliminate these microbes purely with mechanical instrumentation. Therefore, irrigants are required to eradicate intraradicular infection. In this article, the different actions and interactions of the most commonly used irrigants are discussed and a clinical protocol suggested. At least two different irrigants should be used to achieve the most effective reduction of intraradicular microorganisms. Keywords: apical periodontitis, chlorhexidine, disinfection, smear layer, sodium hypochlorite

Ultrasound is sound energy with a frequency of more than 25 kHz; it can be useful during different stages of endodontic treatment. This article is an overview of the possible applications of ultrasound in endodontics. Keywords: endodontics, root canal, ultrasound

Due to the introduction of highly active antiretroviral therapy (HAART), HIV infection has gradually become more of a chronic immunodeficiency disease. In response to HAART, the CD4 cell count, in most cases, increases and thereby the HIV-infected patients are at a lower risk of developing opportunistic infections; this leads to an enhanced quality of life and a reduced mortality. Therefore, nowadays, the endodontist is more likely to encounter an HIV-infected patient in need of endodontic treatment. Unfortunately there is a lack of guidelines for the treatment of HIV-infected or AIDS patients. The intention of this overview is to evaluate current knowledge regarding endodontic treatment and its outcome in HIV-infected patients. Keywords: AIDS, CD4 cell count, HAART, infection control, Kaposi's sarcoma, prophylactic antibiotic treatment, treatment outcome

NiTi rotary systems are able to prepare root canals to excellent taper, with less canal transportation, greater preservation of tooth structure, and allow faster canal preparation than hand instruments. Since the capability of NiTi instruments to efficiently enlarge root canals depends on their surface properties, surface treatments of NiTi instruments are examined and the effects of NaOCl, sterilisation processes and electropolishing are discussed. Keywords: autoclave sterilisation, corrosion, NaOCl, NiTi, surface treatment

Accurate knowledge of canal anatomy is one of the keys to success when performing root canal treatment. A succuessful outcome depends on three-dimensional debridement and obturation of the root canal system, maintained by a good coronal seal. Intimate knowledge of canal confluency is very important in order to shape the root canal system in the best possible way, and appreciation of uncommon anatomy allows the endodontist to conserve dental tissue. Moreover, using nickel-titanium (NiTi) rotary files, apical confluences and the acute angles of root curvatures often carries a high risk of instrument separation. The aim of this paper is to describe the root canal anatomy of mandibular molars. Keywords: endodontic anatomy, NiTi instrument failure, root canals

In this case report, the non-surgical retreatment of a maxillary first molar is described. The management of a strip perforation is explained. Keywords: location, mesio-buccal root, strip perforation