OBJECTIVE: Commissioned by the German Institute of Medical Documentation and Information (DIMDI) the Austrian Health Institute (ÖBIG) prepared a HTA report on the long-term effectiveness of endodontic treatment (root canal treatment, RCT) of molars. The focus is to examine factors influencing the outcome of endodontic treatment and showing their impact on long-term results. Additionally, economic aspects of root canal treatment in Germany are discussed. METHODOLOGY: By performing a systematic literature search in 29 databases (e.g. MEDLINE), the Cochrane Library and by hand searching two peer-reviewed endodontic journals the authors could identify 750 relevant articles, of which finally 18 qualified for assessment. RESULTS: The findings show that the most relevant factor influencing the long-term outcome of endodontic treatment is the preoperative status of a tooth. The lowest success rates are reported for molars with a preoperative devital or necrotic pulp and persisting periapical lesions (so called periapical disease). DISCUSSION: Even if there is no positive selection of patients and the RCT is performed by a normal dentist rather than an endodontist - a fact which is very common - long-term success rates of more then 90% are possible. The overall success rates for endodontic treatment of molars therefore seem to be similar to those of other tooth-types. CONCLUSIONS: Especially primary, conventional (i.e. non-surgical) root canal treatment is an effective and efficient therapy for endodontically ill molars, especially if no large periapical lesion persists. Nonetheless, a long term successful endodontic therapy requires a thorough assessment of the pre-operative status of the molar and treatment according to established guidelines.
OBJECTIVE: Commissioned by the German Institute of Medical Documentation and Information (DIMDI) the Austrian Health Institute (ÖBIG) prepared a HTA report on the long-term effectiveness of endodontic treatment (root canal treatment, RCT) of molars. The focus is to examine factors influencing the outcome of endodontic treatment and showing their impact on long-term results. Additionally, economic aspects of root canal treatment in Germany are discussed. METHODOLOGY: By performing a systematic literature search in 29 databases (e.g. MEDLINE), the Cochrane Library and by hand searching two peer-reviewed endodontic journals the authors could identify 750 relevant articles, of which finally 18 qualified for assessment. RESULTS: The findings show that the most relevant factor influencing the long-term outcome of endodontic treatment is the preoperative status of a tooth. The lowest success rates are reported for molars with a preoperative devital or necrotic pulp and persisting periapical lesions (so called periapical disease). DISCUSSION: Even if there is no positive selection of patients and the RCT is performed by a normal dentist rather than an endodontist - a fact which is very common - long-term success rates of more then 90% are possible. The overall success rates for endodontic treatment of molars therefore seem to be similar to those of other tooth-types. CONCLUSIONS: Especially primary, conventional (i.e. non-surgical) root canal treatment is an effective and efficient therapy for endodontically ill molars, especially if no large periapical lesion persists. Nonetheless, a long term successful endodontic therapy requires a thorough assessment of the pre-operative status of the molar and treatment according to established guidelines.
Endodontic therapy (root canal treatment, RCT) is a medicinal treatment method to maintain teeth with an irreversible impairment of the pulpa, i.e. acute pulpitis. Basically it is distinguished between conservative, conventional and surgical root canal treatment. In conservative RCT the dentist removes the pulpa from above, prepares the remaining root canal system in a sterile way and seals it thoroughly to keep out bacteria. Via endodontic surgery (e.g. apicoectomy) the damaged nerve of the tooth is prepared in a retrograde way, i.e. from the root tip).Under which conditions a tooth may be considered as "compatible and maintainworthy" is defined in Dental Therapy Guidelines set up in 2004 by the German Joint Federal Committee of Dentists and Health Insurance Institutions. Following this guideline endodontic treatment is under all circumstances recommendable, if a closed row of teeth may be conserved, if an one-sided free end situation can be avoided or functional dental implants can be sustained.
2. Aim
It is assumed that endodontic treatment of molars is more likely to fail than those of other tooth types, because of the physiological constitutions of molars, which have several, often ramified roots. The current HTA-report performed by the Austrian Institute of Health (ÖBIG) on behalf of the German Institute of Medical Documentation and Information (DIMDI) intends to assess the long-term effectiveness of endodontic treatment of molars from a German perspective.The focus is to examine factors influencing the outcome of endodontic treatment and showing their impact on long-term results, i.e. lasting more than ten years. Furthermore the medical effectiveness of the root canal treatment under normal conditions is analysed thoroughly. Additionally factors contributing to a successful long-term endodontic treatment are assessed.Moreover, a discussion of the economical and ethical aspects of a root canal treatment is included.
3. Medicinal Assessment
3.1 Methodology
By performing a systematic literature research in 29 databases (MEDLINE, EMBASE, Cochrane Library etc.) and by hand searching two peer-reviewed endodontic journals, the authors could identify 750 relevant articles. Two of the identified articles were endodontic therapy guidelines. However, it has to be stated that the overall quality of the retrieved studies was poor, i.e. only very few randomised clinical trials could be found and in many studies the observation period was very short, just up to six months. After careful consideration of the selection criteria (e.g. defining that only studies with an explicit analysis of molars rather than other tooth-types will qualify for further analysis) by two independent experts, 26 articles, thereof three systematic reviews qualified for further assessment.After an in-depth analysis of these articles, 18 reports were chosen for final assessment (thereof eleven on conventional root canal treatment and seven on endodontic surgery). Besides the type of treatment the authors also considered if it was an initial endodontic treatment or re-treatment of a failure.
3.2 Results
The findings show that the most relevant factor influencing the long-term outcome of endodontic treatment is the preoperative status of a tooth. The lowest success rates are reported for molars with a preoperative devital or necrotic pulp and persisting periapical lesions (so called periapical disease).Further factors that have significant influence the success rates of RCT in the long run, arethe quantity and the quality of the root canal preparation and filling (e.g. root canal filling ending 0 to 2 mm before the apex)the final restoration of the treated tooth (type of filling, coronal restoration) andthe tooth type (front tooth, premolar, molar)Moreover, the quality of the treatment process has essential impact on the outcome (sterile working conditions, use of modern techniques and filling materials).Factors that certainly do not influence the outcome of endodontic therapy are gender and age of the patient. However, cooperative behaviour of the patient, for example in regard to the oral hygiene constitutes a crucial prerequisite for the long term success of surgical root canal treatment.Contradicting results for the prognosis of the endodontic treatment were found in respect to the localisation of molars (maxilla, mandible) and the impact of the treating person (student/graduate, dentist, endodontist).The most often reported undesirable adverse effects are tooth loss or extractions. The main reasons for extractions were, amongst others, fractures, periodontal diseases and profound caries. In the analysed studies the issue of potential technical and human biases was not expressly raised. To reduce the risk of complications especially for planned surgical interventions extensive oral hygiene before and after the treatment is recommended.
3.3 Discussion
According to the assessed literature the retention period of the treated molars is, in regard to the treatment procedure as well as to the healing process, a particular challenge for the dentist.Nonetheless, under ideal circumstances (state-of-the-art treatment, aseptic and sterile surrounding, etc.) root canal treatment of molars may lead to the same outcome as those of other tooth types: Even if there is no positive selection of patients and the RCT is performed by a normal dentist rather than an endodontist - which in fact is very common - long-term success rates of more than 90% are possible also for molars. In addition, all studies analysing the pre-operative status of the tooth (like existing periapical disease or a necrotic pulpa) showed that it had significantly more influence on the likelihood of survival than the tooth type or its location. The overall success rates for endodontic treatment of molars therefore tend to be similar to those of other tooth-types.However it seems that molars are somewhat more often extracted than other teeth, the reason being obviously that the danger of failures increases with the number of roots. Molars have sometimes more than four roots.
4. Economical Assessment
4.1 Methodology
Despite of the described extensive and systematic research for articles, no studies could be identified that explicitly analysed economical aspects of root canal treatment, especially with regard to Germany. Only one article referring to economic consequences of differences in success rates in specialized endodontic and general dentist practices could be retrieved via hand searching.Alternatively the authors tried to estimate the direct costs of different treatment options of molars with acute pulpitis from the perspective of German Health Insurance. The estimation was based on publicly available economic data (e.g. reimbursement fees for dental treatment) and information obtained from German experts.
4.2 Results
In Germany root canal treatment is reimbursed in kind, via fee-for-service with variable fees, depending on the type of service performed. Therefore treatment expenditure may differ considerably depending on the individual situation. The reimbursement rate for conventional endodontic treatment including tooth sensitivity examination, local anaesthesia, so-called rubber dam isolation, root canal preparation and filling, intracanal medication and dressing, and finally radiographic examination granted by German Statutory Health Insurance (Gesetzliche Krankenversicherung, GKV) amounts to € 220. In addition reimbursement is granted for definite filling and coronal restoration of the endodontically treated tooth. The remuneration rate for endodontic surgery is lower than for conventional root canal treatment.
4.3 Discussion
When comparing the efficacy of treatment options, besides direct costs, also the cost of non-treatment or of potential follow-up treatment have to be considered. Follow-up cost might occur due to a necessary revision of the endodontic treatment, (re-)surgery (e.g. apicoectomy) or an unavoidable extraction. Especially an extracted tooth that is not replaced by retention post and crown or an implant could cause relocation and/or loss of other teeth and finally lead to aesthetic damage.In several German studies it is postulated that the remuneration of root canal treatment in the context of the GKV might be to low. Literature research could only show that remuneration of endodontic treatment as regulated in the fee-for-dental service codex in the private health care sector (Gebührenordnung für Zahnärzte, GOZ [1]) is higher than in GKV. However, sufficient time for preparation and filling of the root canal as well as a accurate, state-of-the-art treatment are crucial pre-requisites for long term survival rates of endodontic treatment.No literature at all could be identified in terms of the "standard time" necessary to duly perform conventional or surgical endodontic treatment, especially not for specific treatment types, i.e. primary conventional RCT or complex re-surgery. Therefore the authors suggest - before continuing the discussion on over- or under funding of RCT - to fill this information gap by further investigating the topic in a German setting.
5. Ethical Assessment
5.1 Methodology
No relevant literature dealing explicitly with ethical aspects of root canal treatment could be identified.
5.2 Results
Due to the lack of literature and data the research team at ÖBIG was not able to draw conclusions. But it has to be added that according to the current dentist "doctrine" every lost tooth leads to a limitation of the quality of life. Consequently the primary goal of oral medicine is to maintain as many teeth as possible. From this point of view and in the accordance with WHO oral health goals the first treatment option for molars with acute pulpitis should be RCT rather than extraction.
6. Concluding discussion of all results
Due to the explained methodological weaknesses of the retrieved studies/articles and the lack of economical evaluations (see above) no definitive hard results could be found, but the authors succeeded in proving some assumptions.Systematic literature synthesis shows that endodontic treatment of molars, due to its larger number of roots, is more difficult than those of teeth with one root. However, some observational studies showed that even without positive selection of patients and the RCT being performed by a normal dentist rather than an endodontist - which in fact is very common - long-term success rates of more than 90% are possible even for molars. In particular, conventional root canal treatment of molars constitutes an effective method for the treatment of acute pulpitis. A limiting factor for the success, though, is a preoperative devital or necrotic pulp and persisting periapical lesions (periapical disease). The likelihood of survival decreases significantly with the growing size of a periapical lesion. Important pre-requisites for success in the long run are an accurate assessment of the preoperative status by the dentist under careful consideration of alternatives and treatment in line with endodontic therapy guidelines like those of the European Association for Endodontology.Several authors suspect the quality of endodontic therapy in Germany to be comparatively low, a possible explanation being the remuneration, which is considered as not sufficient for the time needed to perform a state-of-the-art RCT. However, the medicinal assessment showed no significant difference between the prognosis of RCT performed in Germany and in other Western countries. Moreover it could be demonstrated that the overall quality of endodontic therapy has improved in the last years mainly due to enhanced treatment techniques.No evidence could be found to limit the performance of RCT only to endodontists. In fact the treating person seems to have almost no influence on the outcome, provided that the RCT is undertaken carefully and in line with the established standards. An especially important factor is the time spent for the treatment, because endodontic therapy is rather time-consuming. However, no literature on the "standard time" necessary to duly perform conventional or surgical endodontic treatment could be identified.
7. Conclusions
Especially primary, conventional (i.e. non-surgical) root canal treatment is an effective and efficient therapy for endodontically ill molars, especially if no large periapical lesion persists. Nonetheless, a long term successful endodontic therapy requires a thorough assessment of the pre-operative status of the molar and treatment according to established guidelines like those of the European Association for Endodontology (like e.g., use of rubber dam, root canal filling ending 1 to 2 mm before the apex, etc.)Even in case of a revision due to a failed first conventional or surgical RCT, sustainable success rates can be achieved in most circumstances. When considering treatment alternatives, in most occasions extraction of the tooth, it should be kept in mind that revised molars with a necrotic, devital pulp and associated periapical lesions - in particular if the root canal had been overfilled - have the least prognosis.An estimation of the cost of conventional RCT on behalf of the GKV in accordance with certain guidelines like normal filling using rubber dam isolation and definite coronal restoration accounted for € 260. So from GKV perspective only, tooth extraction is always less costly than root canal treatment. However, considering possible consequences of extraction or loss of a tooth - like the need of a dental implant - the authors recommend RCT of molars, especially when taking ethical reasons (parodontal consequences, aesthetic damage) into account.Due to the lack of comparable and valid studies no definitive findings could be obtained for the long term prognosis of primary surgical-endodontic treatment as well as for the adequacy of the current remuneration of RCT in Germany. Consequently we suggest to set up a prospective endodontic trial in Germany with a representative sample of the population (age, gender, social status) by using a comparable, standardised assessment tool for outcome measure at identical measuring points and including economical parameter (e.g. time needed for thorough and state-of-the-art treatment).