Bizarre anatomy
Exceptionally curved roots (Fig. 13), dilacerated teeth, and congenital palatal grooves may all present considerable difficulties if root canal treatment is attempted. In addition, any unusual anatomical features related to the roots of the teeth should be noted as these may affect prognosis.
Re-root treatment
One problem which confronts the general dental practitioner is to decide whether an inadequate root treatment requires replacement (Fig. 14). The questions the operator should consider are given below.
1 Is there any evidence that the old root filling has failed?• Symptoms from the tooth. Radiolucent area is still present or has
increased in size. Presence of sinus tract.
2 Does the crown of the tooth need restoring? 3 Is there any obvious fault with the present
root filling which could lead to failure? Practitioners should be particularly aware
of the prognosis of root canal re-treatments. As a rule of thumb, taking the average of the surveys reported in the endodontic literature (see Part 12) suggests a prognosis of 90–95% for an initial root canal treatment of a tooth with no radiographic evidence of a periradicular lesion. When such a lesion is present prognosis will fall to around 80–85%, and the longer the lesion has been present the more established will be the infection, treatment (ie removal of that infection from the entire root canal system) will be more difficult and the prognosis significantly lower. The average reported prognosis for re-treatment of a failed
British Dental Journal, January 1954 SSuubbssccrriippttiioonnss 11995544
Fig. 14 Tooth UL4 (24) has previously been root treated (and obturated with silver points) but is symptomless. However, the tooth now requires a full crown restoration. A decision must be made as to whether the tooth should be re-treated before fitting the advanced restoration.
root canal filling of a tooth with a periradicular lesion falls to about 65%. The final decision by the operator on the treatment plan for a patient should be governed by the level of his/her own skill and knowledge. General dental practitioners cannot become experts in all fields of dentistry and should learn to be aware of their own limitations. The treatment plan proposed should be one which the operator is confident he/she can carry out to a high standard.
1. Dental Practitioners’ Formulary 2000/2002. British Dental Association. BMA Books, London
2. Scully C, Cawson R A. Medical problems in dentistry. Oxford: Butterworth-Heinemann, p74, 1998.
3. National Radiographic Protection Board. Guidance Notes for Dental Practitioners on the safe use of x-ray equipment. 2001. Department of Health, London, UK.
4. Fox K, Gutteridge D L. An in vitro study of coronal microleakage in root-canal-treated teeth restored by the post and core technique. Int Endod J 1997; 30: 361–368.
5. Ørstavik D. Time-course and risk analysis of the development and healing of chronic apical periodontitis in man. Int Endod J 1996; 29: 150–155.
6. Andreasen J O, Andreasen F M. Chapter 9 in Textbook and colour atlas of traumatic injuries to the teeth. 3rd Ed, Denmark, Munksgard 1994.