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|Latin||canalis radicis dentis|
A root canal is the space within the root of a tooth. Part of a naturally occurring space within a tooth, it consists of the pulp chamber (within the coronal part of the tooth), the main canal(s), and more intricate anatomical branches that may connect the root canals to each other or to the surface of the root.
History of root canal surgery 
Nunn et al trace the history of root canal surgery (endodontic therapy) back to 1756, when Philip Pfaff published his work on gold as a filler material. A web page at the Oregon State School of Dentistry has a fuller account of the history.
Tooth structure 
At the center of every tooth is a hollow area that houses soft tissues, such as the nerve, blood vessels, and connective tissue. This hollow area contains a relatively wide space in the coronal portion of the tooth called the pulp chamber. These canals run through the center of the roots, similar to the way pencil lead runs through a pencil. The pulp receives nutrition through the blood vessels, and sensory nerves carry signals back to the brain.
Dental pulp 
The space inside the root canals is filled with a highly vascularized, loose connective tissue, the dental pulp. The dental pulp is the tissue of which the dentin portion of the tooth is composed. The dental pulp helps complete formation of the secondary teeth (adult teeth) one to two years after eruption into the mouth. The dental pulp also nourishes and hydrates the tooth structure, making the tooth more resilient, less brittle and less prone to fracture from chewing hard foods. Additionally, the dental pulp provides a hot and cold sensory function.
Root canal is also a colloquial term for a dental operation, endodontic therapy, wherein the pulp is cleaned out, the space disinfected and then filled.
Root canal anatomy 
Root canal anatomy consist of pulp chamber and root canals.Both contain the dental pulp. The smaller branches, referred to as accessory canals, are most frequently found near the root end (apex), but may be encountered anywhere along the root length. The total number of root canals per tooth depends on the number of the tooth roots ranging from one to four, five or more in some cases. Sometimes there are more than one root canal per root. Some teeth have a more variable internal anatomy than others. An unusual root canal shape, complex branching (especially the existence of horizontal branches), and multiple root canals are considered as the main causes of root canal treatment failures. (e.g. If a secondary root canal goes unnoticed by the dentist and is not cleaned and sealed, it will remain infected, causing the root canal therapy to fail).
Root canal anatomy in cross-section 
Root canals presenting an oval cross-section are found in 50%-70% of root canals. In addition, canals with a "tear-shaped" cross section are common whenever a single root contains two canals (e.g., mesial roots of lower molars). Nevertheless, these aspects of root-canal anatomy are not seen or recognized in conventional 2D radiographs, as the long axis of their flat cross section is usually directed in parallel to the direction of the x-ray beam. With the increased use of Cone Beam Computerized Tomography (CBCT), these shapes are likely to be increasingly more often seen and recognized not only by endodontists but also in the clinical environment of general practice.
When rotary NiTi files are used in canals with flat-oval or tear-shaped cross sections, a circular bore is created, while the buccal and/or lingual recesses remain un-instrumented. It takes (a) the awareness that a given canal is flat and (b) expertise in creative use of hand instruments to try to overcome this problem.
Tissue or biofilm remnants along such un-instrumented recesses may lead to failure due to both inadequate disinfection and the inability to properly obturate the root-canal space.
See also 
- American Association of Endodontists
- Dental Implants
- Oral surgery
- Ralph Frederick Sommer, an early developer of endodontics
- Nunn JH, Smeaton I, Gilroy J. (1996). "The development of formocresol as a medicament for primary molar pulpotomy procedures.". ASDC J Dent Child. 63: 51–53.
- German wiki of Philip Pfaff
- History of Endodontics page at Oregon State School of Dentistry
- What are Root Canals? DentalDiseases.org - Root Canal Therapy.
- Wu et al Int Endodod J. 2001
- De Deus et al J Endod 2010
- DeDeus et al J Endod 2006 & 2008
|Wikimedia Commons has media related to: Root canal|
- Root Canals at WebMD
- Video on Direct Pulp Capping, an alternative to Root Canal therapy
- Comparison of antibacterial and toxic effects of various root canal irrigants.
- Does a root canal hurt?