The retention of natural dentiton has a better out come than any replacemnet by prosthesis, such as bridge or even an implant can provide. The common reason for failure of root canals can be due to missed canals, short fillings (root canal under preparation), ledges, perforation transportation of canals. Root canal treatment in dentistry, is a common means of treating tooth, which are inflamed due to caries, or death has occured due to trauma, tooth cracks or even due to caries. Successful root canal treatment is characterised by absence of inflamation or clinical presence of infection of tooth.
Root canal is followed by short and long term complications, the short term complication include inflamation of the periapical area following root canal therapy, which is temporary, long term complication include draning sinus tract and recurrent inflamation of the tooth and absence of radiographic healing of leshion.
The success of root canal is determined by factors that the induvidual should be able to to chew normally, exhibit lack of pathosis, and radiographic evidence of absence of a pathosis, and if there was an existing previous leshion and which is eventually replaced by normally healed peri-radicular osseous structre The cause of endodontic failure is often multivariant, causes of failure can be due to incomplete obturation, overfilled canals, missed canals, developing leshion in adjacent tooth and even the inproper post-endontic restoration by crown which has open margin. Eventually resulting in failure of root canals due to devloping leshion or caries below the crown margins and even fracture of tooth. Careful case slection and treatment planning is the key to sucess root canal treatment. Thus the effectiveness of single vist or multiple visit endodontics can vary form tooth to tooth with presence or absence of leshion,the frequency of post operative pain is comparitively more in single visit endodonntics, than in multiple vist endodontics. Clinical application of through knowledge of canal anatomy and proper attention to to treatment detial are essential to minimize failure rates and thus the need for subsequent re-root canals.
Endodontics has so advanced that re-root canals became more sucessful, provided the case slection has an important role. Tooth which are groosly decayed or furcally involved or fracture of instruments in apical third is not a tooth with good prognosis, such tooth can be saved by hemisection. With the advent of ultrasonics into dentistry it has become easier to perform post removal from root canal and perform re-root canal.