Previous Endodontic Treatment Research Articles

The Outcome of Endodontic Retreatment: A 2-yr Follow-up

Retreatment is common in endodontics. The purpose of this article was to classify the different clinical situations encountered in retreatment cases and relate them to the outcome after an observation period of 24 months. A total of 425 patients (452 teeth) from 451 patients, consecutively admitted for root-canal retreatment, were monitored during a 24-month period. All teeth (254 molars, 107 premolars, and 91 single-root anterior teeth) were divided into two major categories: teeth with modified anatomy from previous endodontic treatment (root-canal-morphology altered) and teeth in which no significant anatomical changes were made by the former endodontic treatment (root-canal-morphology respected). Although the overall success was 69.03%, the success in the root-canal-morphology-respected group was 86.8% and in the root-canal-morphology-altered group 47% (Mann-Whitney U test p < 0.0001). The clinical success of an endodontic retreatment seems to depend on whether alterations in the natural course of the root canals were caused by previous root-canal treatment.

Periapical central giant cell granuloma: a potential endodontic misdiagnosis.

This retrospective study ascertained the incidence and clinicopathologic features of central giant cell granulomas (CGCGs) associated with teeth with necrotic pulps or teeth that had received previous endodontic treatment and determined whether periapical CGCGs can result in endodontic misdiagnosis. Clinical and histopathologic data of biopsy specimens diagnosed as CGCG were collected from the archives of the Oral Pathology Laboratory, Temple University, and were reviewed. Over the 9-year period, 16 of 79 cases (20%) of CGCG were associated with a tooth that had a history of pulp necrosis. Of those, 14 (88%) were associated with previous root canal treatment. The data from this series of 79 cases of CGCG also showed that CGCGs were less common in women, less common before age 30, and did not cross the midline of the jaw as often as previously reported. Clinical and histopathologic data were compared from (1) CGCGs associated with teeth with vital pulps or that occurred in edentulous areas; (2) CGCGs associated with teeth with necrotic pulps; and (3) 194 cases of periapical granulomas and radicular cysts. These data strongly suggest that CGCGs associated with teeth with necrotic pulps are not directly related to periapical inflammation and may be misdiagnosed as endodontic lesions. Posttreatment follow-up and routine submission of periapical surgical specimens are emphasized.

Endodontic-orthodontic relationships: a review of integrated treatment planning challenges.

Literature review There is a paucity of information on the concise relationship between endodontics and orthodontics during treatment planning decisions. This relationship ranges from effects on the pulp from orthodontic treatment and the potential for resorption during tooth movement, to the clinical management of teeth requiring integrated endodontic and orthodontic treatment. This paper reviews the literature based on the definition of endodontics and the scope of endodontic practice as they relate to common orthodontic-endodontic treatment planning challenges. Literature data bases were accessed with a focus on orthodontic tooth movement and its impact on the viability of the dental pulp; its impact on root resorption in teeth with vital pulps and teeth with previous root canal treatment; the ability to move orthodontically teeth that were endodontically treated versus nonendodontically treated; the role of previous tooth trauma; the ability to move teeth orthodontically that have been subjected to endodontic surgery; the role of orthodontic treatment in the provision for and prognosis of endodontic treatment; and, the integrated role of orthodontics and endodontics in treatment planning tooth retention. Orthodontic tooth movement can cause degenerative and/or inflammatory responses in the dental pulp of teeth with completed apical formation. The impact of the tooth movement on the pulp is focused primarily on the neurovascular system, in which the release of specific neurotransmitters (neuropeptides) can influence both blood flow and cellular metabolism. The responses induced in these pulps may impact on the initiation and perpetuation of apical root remodelling or resorption during tooth movement. The incidence and severity of these changes may be influenced by previous or ongoing insults to the dental pulp, such as trauma or caries. Pulps in teeth with incomplete apical foramen, whilst not immune to adverse sequelae during tooth movement, have a reduced risk for these responses. Teeth with previous root canal treatment exhibit less propensity for apical root resorption during orthodontic tooth movement. Minimal resorptive/remodelling changes occur apically in teeth that are being moved orthodontically and that are well cleaned, shaped, and three-dimensionally obturated. This outcome would depend on the absence of coronal leakage or other avenues for bacterial ingress. A traumatized tooth can be moved orthodontically with minimal risk of resorption, provided the pulp has not been severely compromised (infected or necrotic). If there is evidence of pulpal demise, appropriate endodontic management is necessary prior to orthodontic treatment. If a previously traumatized tooth exhibits resorption, there is a greater chance that orthodontic tooth movement will enhance the resorptive process. If a tooth has been severely traumatized (intrusive luxation/avulsion) there may be a greater incidence of resorption with tooth movement. This can occur with or without previous endodontic treatment. Very little is known about the ability to move successfully teeth that have undergone periradicular surgical procedures. Likewise, little is known about the potential risks or sequelae involved in moving teeth that have had previous surgical intervention. Especially absent is the long-term prognosis of this type of treatment. During orthodontic tooth movement, the provision of endodontic treatment may be influenced by a number of factors, including but not limited to radiographic interpretation, accuracy of pulp testing, patient signs and symptoms, tooth isolation, access to the root canal, working length determination, and apical position of the canal obturation. Adjunctive orthodontic root extrusion and root separation are essential clinical procedures that will enhance the integrated treatment planning process of tooth retention in endodontic-orthodontic related cases.

Factors affecting the negotiability of second mesiobuccal canals in maxillary molars

Factors affecting the negotiability of MB2 canals were evaluated by studying 87 extracted maxillary molars that had undergone previous endodontic treatment in the endodontic technique laboratory. The mesiobuccal roots were resected and radiographed, after which a #08 file was used in an attempt to negotiate those roots with the potential for a second mesiobuccal canal. The file was then intentionally separated in the MB2 canals that could be negotiated. The roots were decalcified, cleared, and observed under a stereomicroscope. Several factors that could interfere with the total or partial negotiation of MB2 canals were identified and included accumulation of debris and sealer that blocked access to these canals, dentinal debris produced with the pathfinding instrument, the presence of anatomical variations, diffuse calcifications, and pulp stones.

Prevalence of previous endodontic treatment, technical standard and occurrence of periapical lesions in a randomly selected adult, general population

A random sample of 967 subjects selected from the total population in a Swedish county were examined radiographically regarding prevalence and quality of endodontic treatment and occurrence of periapical lesions. The relationship between the technical standard of endodontic treatment and the occurrence of periapical lesions was also analyzed. Of the selected individuals, 95% attended examination (751 dentate and 169 edentulous individuals). Of the 17,430 teeth examined, 1,492 (8.6%) were endodontically treated. Approximately 70% of the treated root canals were inadequately obturated; 10% showed excess of root filling beyond the apex. The prevalence of periapical lesions was 2.9%, and 24.5% of the endodontically treated roots demonstrated periapical lesions. Root fillings ending more than 2 mm from apex had a significantly lower frequency of periapical lesions than root fillings ending within 2 mm of the apex. No difference in the frequency of periapical lesions was found between properly and improperly obturated root canals. Excess of root filling material beyond the apex was related to a significantly higher frequency of periapical lesions.

Relationship of intracanal medicaments to endodontic flare‐ups

The purpose of the study was to compare the effect of three intracanal medicaments on the incidence of post-instrumentation flare-ups. All teeth were instrumented to a predetermined minimum size using a 0.5% solution of sodium hypochlorite as the irrigant. Formocresol, Ledermix, and calcium hydroxide were placed in strict sequence irrespective of the presence or absence of symptoms or radiographic signs of apical periodontitis. The patients were given written post-operative instructions and a prescription for 600 mg ibuprofen to be taken if mild to moderate pain developed. If severe pain and/or swelling developed the patient was instructed to call the office immediately and was considered to have had a flare-up. Twelve flare-ups occurred in teeth with radiographic signs of apical periodontitis; none in teeth without periapical radiolucencies. Six of the twelve flare-ups occurred in retreatment cases and the other six occurred in teeth without previous endodontic treatment. No significant difference was found in the flare-up rate among the three intracanal medicaments.

Endodontic status and suggested treatment in a population requiring substantial dental care

The purpose of this study was to analyse endodontic status and treatment suggested for Swedish citizens requiring substantial dental care. According to the Swedish dental insurance system, treatment plans including radiographs have to be submitted for approval if the estimated cost of treatment exceeds a certain level (USD 500 in 1977). A sample of 1094 treatment plans received during 1977 and 1978 was randomly selected. In the radiographs the number of remaining teeth was recorded, periapical condition was evaluated and the quantity and quality of previous endodontic treatment were estimated. In addition, treatment plans concerning the teeth with periapical lesions were studied. The results indicated that patients analysed in this study that needed expensive treatment had more missing teeth, more root-filled teeth and more teeth with periapical lesions than what has been reported in previous studies of samples supposed to accurately represent the Swedish population. However, the technical quality of the root fillings and the frequency of periapical lesions in root-filled teeth were the same as in previous studies, with high frequencies of inadequate root fillings and related unfavourable responses. Thus the patients in this study retained a significant need for endodontic treatment despite having already received a great deal of endodontic care. Further, it was found that nearly half of the observed periapical lesions would not be treated based on the submitted plans.

Acute pulpal-alveolar cellulitis syndrome IV. Exacerbations during endodontic treatment: Part 3. A case report

An asymptomatic abscessed maxillary premolar, which had undergone previous endodontic treatment, was retreated. The initial attempt to remove the silver cone seal was unsuccessful. Early the next morning, the patient appeared with a severe cellulitis exacerbation. The silver cone was now loose: a literal “blowout.” Specific cultures of the silver cone and exudate revealed three aerobic microbes: a Streptococcus sp and two obligate Pseudomonas spp. Anaerobes were shown to be absent with anaerobic subcultures. This case would appear to substantiate the alteration of the tissue oxidation-reduction potential as the major factor in endodontic cellulitis exacerbations, as previously reported.

Endodontic retreatment—Case selection and technique. Part 1: Criteria for case selection

The question of retreating a tooth that has had previous endodontic treatment is a common occurrence in dental practice. However, the mention of endodontic retreatment as such in the literature is minimal. It might be due to the failure to recognize endodontic retreatment as varying in many respects from primary endodontic treatment. Considering retreatment of an endodontically treated tooth raises several questions: Is it worth damaging a successful restoration in order to gain access to the root canals (1)? Is it necessary to retreat a case just because it seems radiographically unsatisfactory and what are the chances of improving the filling by retreatment (2)? What are the chances of success in cases where previous treatments failed, especially when no apparent reason can be suggested for failure? How do you relate to the patients' increased awareness to these questions in cases of retreatment? These questions affect the subjective interpretation of information which is the basis for case selection in endodontics (3). The difficulty in decision making is coupled with the reduced rate of success in endodontic retreatment (2, 4). This complexity of case selection in endodontic retreatment was recently demonstrated by the marked variation of treatment plans of endodontic failure cases included in a survey among general dental practitioners and endodontists (5). In addition, modified techniques must be used in endodontic retreatment to overcome obstacles of a nature and incidence not encountered in primary endodontic treatment. It is the purpose of this article to discuss the criteria for case selection in endodontic retreatment, as well as the specific techniques existing for retreating endodontically treated teeth. 28 CRITERIA FOR CASE SELECTION IN ENDODONTIC RETREATMENT