Reasons For Failure Of Root Canal Therapy And Retreatment Strategies_News & Events

Pulp disease and periapical disease are common clinical infectious diseases, and root canal therapy is currently the most effective treatment method. However, there are still failed cases requiring root canal retreatment. When encountering treatment failure cases, it is necessary to carefully analyze the reasons for the failure of the initial root canal treatment, comprehensively consider the condition of the tooth, the overall condition of the patient, as well as the technical level of the clinician and the support of equipment and consumables, and choose the appropriate retreatment plan .

Reasons for failure of root canal treatment

There are many reasons for the failure of root canal treatment, including not fully understanding the complexity of the root canal system anatomy before the operation, improper mechanochemical preparation and filling of the root canal during the operation, and failure to perform a complete crown repair in time after the operation, etc. . Insufficient mechanochemical preparation of the root canal, insufficient root canal filling, and inadequate closure of the crown can lead to bacterial and microbial residues, causing continuous or secondary infections inside and outside the root canal, which are the main reasons for the failure of most cases.

Outcome of root canal therapy and diagnosis and treatment decision of retreatment

The outcome of root canal therapy includes cure, remission, and failure. It is generally evaluated through three aspects: medical history and patient's subjective feelings, clinical examination and imaging examination.

1. Cure: The patient complained of no discomfort, negative clinical signs, and no apical transmission in imaging examination. Such patients do not need to undergo root canal retreatment if they undergo repair treatment in time. However, if no crown restoration treatment is performed after root canal treatment, crown fracture occurs secondary, temporary or permanent fillings fall off, and root canal filling materials are exposed to the oral cavity for a long time, and infection will occur again. Root canal retreatment is required.

2. Relief: The patient complained of no discomfort, clinical signs were negative, and the apical transmission image of the radiological examination was reduced. Such patients are followed up for 6 to 12 months under the condition of perfect closure of the crown, pay close attention to the outcome of the disease, and choose the corresponding treatment plan.

3. Failure: The patient complained of discomfort or positive signs in clinical examination, and the apical transmission image did not decrease or increase in imaging examination. Such cases are considered clinically as a failure of root canal treatment.

For the disease after root canal treatment, it is necessary to make a clear diagnosis and determine the cause of the disease in order to provide a basis for decision-making on the timing and method of retreatment. This article analyzes from the following three aspects:

1. Evaluate the quality of the previous root canal treatment and determine the main cause of the disease after root canal treatment. For post-treatment lesions caused by residual infection in the root canal, non-surgical root canal retreatment can usually achieve a good prognosis.

2. Integrate and analyze the nature of the diseased tooth: For apical true cysts, periapical foreign body reactions, and extra-root infections, even if high-quality root canal treatment is completed, it is difficult to cure and usually requires microscopic root Tip surgical treatment.

3. Whether there are other concomitant diseases of the tooth: For example, root fracture, periodontal disease, etc., it is necessary to determine whether to choose a single tooth implant after extraction based on the patient's general condition and willingness.

Diagnosis and treatment methods of root canal retreatment and their difficulties and main points

The key points and difficulties of non-surgical root canal retreatment are as follows:

1. Remove the original filling

2. Mechanochemical preparation

3. Look for missing root canals

3. Repair perforations

5. Separation of equipment

6. Treatment of steps

7. Sealing medicine in the clinic

For refractory apical periodontitis, true cysts that cannot be effectively treated by non-surgical retreatment, and those whose symptoms still do not subside after non-surgical re-treatment, micro-apical surgery may be considered. If the root of the tooth is too short or partially fractured, after scientific analysis and evaluation of the poor prognosis of microsurgery, a single tooth implant after extraction can be selected. The diagnosis and treatment strategy of root canal retreatment requires the doctor's clinical experience and the patient's wishes to finally work out the most suitable treatment plan.