Victoria Dawson
Lecturer, DDS, ph.d. Department of Endodontics, Faculty of Odontology, Malmö University, Malmö, Sweden.
Elisa Kristin ArnarsdÃ3ttir
DDS, MSc, Private Practice in Reykjavik, Iceland, Faculty of Odontology, University of Iceland, Reykjavik, Iceland.
Leona Malmberg
Lecturer, senior consultant, DDS. Department of Endodontics, Faculty of Odontology, Malmö University, Malmö, Sweden.
Homan Zandi
Assistant professor, DDS, ph.d. Department of Endodontics, Institute of Clinical Dentistry, University of Oslo, Oslo, Norway.
Merete Markvart
Associate professor, DDS, ph.d. Research area Cariology and Endodontics, Section of Clinical Oral Microbiology, Department of Odontology, University of Copenhagen, Copenhagen, Denmark.
Headlines
High clinical success rate is expected when each step of the root canal treatment adheres to high quality standard of care.
An aseptic working field is maintained throughout the treatment using a tightly placed rubber dam preventing microbial contamination.
Access cavity with adequate size and shape enables a straight-line entry to the root canals.
Chemomechanical preparation using chemically-active irrigants removes microbial products and dissolve necrotic tissues.
A root-filling material with adequate length and size without any voids obturate the root canals, and the final restoration is placed in a timely manner.
A successful outcome of the endodontic treatment is strongly associated with well performed treatment procedures. An adequate access cavity preparation which is correctly positioned, of adequate size and with straight-line access to the canals, is a prerequisite for the subsequent endodontic treatment procedures to be properly performed. Under aseptic conditions, after gaining access to the root canals, the working length is determined by electronic apex locator combined with radiographs, preferably after coronal flaring. The root canals are then cleaned and shaped, in the vast majority of cases rotary or reciprocating Ni-Ti instruments can be used. This is performed in conjunction with the use of an irrigation solution, usually sodium hypochlorite with a low concentration. Once the chemomechanical instrumentation has been thoroughly performed, the next essential step is filling of the root canals. A root filling of good quality, that is, ending within 2 mm from the radiographic apex and without any voids, is of significant importance for the outcome while the materials and techniques appear less important. Finally, the tooth should be permanently restored as soon as possible after root filling, to prevent fracture and reinfection. Provided that the treatment procedures have been adequately performed, high success rates can be expected.
Endodontic treatment aims to prevent or eliminate root canal infection and apical periodontitis (AP). A successful treatment, from the clinician's perspective, is usually defined as radiographic normal periapical conditions and the absence of clinical signs and symptoms, while retention of the root filled tooth, functionality and absence of pain are amongst the most important factors from the patient's perspective.
High success rates (normal periapical conditions) have been reported for teeth without preoperative AP whereas the rate is slightly lower for teeth with AP A successful outcome of the endodontic treatment is strongly associated with well-performed treatment procedures, from aseptic work to the final restoration. In such cases, most periapical diseases show signs of healing 1 year postoperatively; nonetheless, non-healed cases may be followed up to 4 years, allowing them enough time to heal [].
In the following article, the endodontic treatment procedures including their significance for the outcome will be reviewed.
Aseptic work
Current endodontic treatment protocols are aimed at eliminating microorganisms and preventing the introduction of new microorganisms into the root canal system. Since endodontic pathogens are mainly oral commensals, isolating the tooth from the oral environment with a rubber dam is a prerequisite for safe and effective endodontic practice []. To minimize the risk of contamination, the isolated tooth and rubber dam also need to be disinfected []. Furthermore, all materials and instruments used during root canal treatment should be applied in a sterile, or effectively disinfected, condition. Gutta-percha points should be disinfected before use by immersion in, for example, chlorhexidine, alcohol, or sodium hypochlorite prior to obturation
There is some evidence on contamination from the dentist to the root canal system, since skin commensals, such as Cutibacterium acnes and Staphylococcus aureus, have been identified in endodontic infections Bacterial numbers have also been found to be significantly increased on gloves, suggesting a risk of contamination Therefore, keeping good hand hygiene is of utmost importance. A no-touch policy should also be adopted, meaning that efforts should be made to avoid touching the parts of instruments and materials which come in contact with the root canals, to further decrease the risk of contamination.
Every measure taken to establish and preserve asepsis during treatment is of value, as any means of reducing the microbial burden may cumulatively increase the chance of a successful treatment outcome.
Access cavity preparation and locating the canals
The objective of access cavity preparation is to completely unroof the pulp chamber, remove the coronal pulp tissue, and locate all of the canals with straight-line access, while saving as much tooth structure as possible; for proper cleaning, shaping, and obturation of the root canal system []. If the access cavity prep
