Cone-beam computed tomography scanning versus electronic apex locators to measure working length in teeth with large periapical lesions
Using cone-beam computed tomography (CBCT) to measure the root canal length of teeth with large periapical lesions is just as reliable as using electronic apex locators (EALs).
In an article published in the September issue of Journal of Endodontics, researchers based that finding on a study of patients that compared the 2 methods. They analyzed 73 teeth from 30 patients referred to the Erciyes University Faculty of Dentistry in Kayseri, Turkey.
CBCT scans were used as part of a treatment plan that included 1 tooth with a single canal and a root that could be seen in the scanned field of view. A single radiologist with 6 years’ experience evaluated all CBCT images.
Each image was evaluated twice, with a 1-week break between evaluations. Root canal length was measured in the CBCT images as the distance between the most incisal or caninal tooth edge in the projected midline of the pulp cavity and the major foramen.
An expert endodontist later completed all treatment procedures using Reciproc system (VDW) instruments and an endodontic motor. Root canals were irrigated, then filled with gutta-percha and a resin-based canal sealer. Radiographs of each case were obtained for final review.
The endodontist was masked to the CBCT measurement results. Clinical root canal length was measured twice using 2 separate EALs: Propex Pixi (Dentsply) and Raypex 6 (VDW). Each was used according to the manufacturer’s instructions.
Root canal length measurements were compared with measurements of preexisting CBCT scans. Statistical analysis showed no significant difference between CBCTs and EALs.
The authors noted that the cementodentinal junction and major foramen were acceptable reference points to evaluate the performance of EALs. Since it is not possible to see the cementodentinal junction in a CBCT scan, the authors used the major foramen as the apical reference point for working length (WL) measurements.
They found that EALs provided inconsistent results with metal-based restorations because of electrical short circuiting. CBCT scans, in these cases, could help practitioners obtain a more precise evaluation.
“The results of the present study showed that CBCT scans can be used as an alternative method for ascertaining the WL,” the authors concluded. “If a patient has a preexisting CBCT scan, the clinician should take advantage of this technique as an alternative, reliable method of determining the WL.”
Read the original article.
Consulting Editor: Susan Wood, DDS
Diplomate, American Board of Endodontics
Vertical root fractures in restored endodontically treated teeth
The presence of deep, narrow periodontal pockets and halo-shaped radiolucency strongly suggest vertical root fractures (VRFs) in crowned endodontically treated teeth. Posterior teeth, female patients, patients older than 40 years, and overfilled canals were all risk factors for VRFs within 5 years postoperatively.
Those two key findings are the results of new research published in the August issue of Journal of Endodontics.
The authors wanted to measure the postoperative period for the diagnosis of VRFs. They also wanted to examine clinical and diagnostic features of VRFs in crowned endodontically treated teeth restored with a crown and no post.
Researchers followed patients at the Dr. MGR Educational and Research Institute University in Chennai, India, who had 197 root-filled, crowned teeth with suspected VRF or no post.
Radiographs were obtained using a paralleling cone technique, with the assessment based on Tamse and colleagues’1 8-part classification. All teeth with VRFs were filled using the lateral compaction technique and gutta-percha points.
Among the recorded cases, researchers found that mandibular molars had the highest occurrence of VRFs (34%) followed by maxillary premolars (22.8%). The most common radiographic presentation was a “halo”-like radiolucency (48.7%) followed by thickened periodontal ligament space (23.4%). Most teeth (79.2%) had dense, overfilled root canals.
Further research showed that most mandibular molars (67.2%) and maxillary premolars (68.9%) were detected with a VRF 2 to 5 years after treatment. Women were more likely to seek treatment for a VRF 2 to 5 years later (63.9%) than were men (56.2%).
“These observations further emphasize that a VRF is likely a fatigue process,” the authors noted, “and the actual failure or crack resulting in a VRF would have been initiated much earlier than the date of extraction.”
The retrospective design and lack of information on preexisting cracks before root canal therapy were some of the study’s limitations, the authors noted.
Researchers also observed that patients 40 years and older had a 6 times greater chance to experience a VRF within 5 years of root canal treatment. They urged caution while performing endodontic procedures in patients over the age of 40, especially when the remaining dentin thickness is minimal.
1. Tamse A, Kaffe I, Lustig J, et al. Radiographic features of vertically fractured endodontically treated mesial roots of mandibular molars. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2006;101(6):797-802.
Read the original article.
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Postprocedure bacteremia in patients with heart disease
Endodontic therapy should be the treatment of choice for teeth in patients with a history of cardiac valve disease because the alternative of extraction is associated with a higher incidence of bacteremia.
Those findings, published in the August issue of Journal of Endodontics, were based on a study of blood samples from Brazilian patients. The study’s authors wanted to evaluate the incidence of bacteremia after endodontic procedures in patients with teeth with necrotic pulps and apical periodontitis. They performed their evaluation using blood samples and real-time quantitative polymerase chain reaction (qPCR).
A total of 32 teeth with necrotic pulps and apical periodontitis were included in the study. A total of 21 patients were at risk of developing infective endocarditis (IE), and 11 patients were considered not to be at risk of developing IE. Blood was collected in bottles containing aerobic and anaerobic media and incubated for 5 and 15 days, respectively.
Researchers found 1 blood sample taken after endodontic intervention that showed aerobic growth of a Micrococcus species. All remaining samples collected before and after root canal procedures were negative for bacterial growth.
The author’s qPCR analysis found that bacterial DNA occurred in all root canal samples. The Streptococcus species was detected in 6 of 34 canal samples (18%). No significant differences were observed in the total bacterial and streptococcal counts in root canal samples between the 2 groups.
Researchers noted that their study showed bacteremia only when using the molecular approach. The greater incidence may relate to the lower detection limits of the qPCR approach and its ability to detect hard-to-grow and as-yet uncultivated bacteria that may pass unnoticed in cultures.
Authors pointed to a key advantage of the qPCR approach: it helped them determine the scope of bacteremia, which had not been shown in previous studies related to endodontic procedures. “For the bacteremia to cause systemic effects,” the authors wrote, “factors other than the mere presence of bacterial cells in the bloodstream are of utmost importance.”
Limitations of the study include the fact that DNA-based molecular methods can detect bacteria that are no longer viable. So it is possible, they observed, that qPCR may have detected DNA from bacteria in the bloodstream that died shortly before analysis as a result of the antibiotic therapy or immune system response.
“These bacteria may have participated in the infectious process,” the authors wrote, “but their decision is not relevant from a clinical perspective because they do not need to be targeted by antibiotics.”
Because complications from IE and antibiotic overuse can be life threatening, the authors noted, further studies on the subject are needed to form a solid body of evidence for decision making about antibiotic prophylaxis for patients at risk of developing IE.
Read the original article.
Using mineral trioxide aggregate and super ethoxybenzoic acid as root-end filling materials in endodontic microsurgery
Long-term outcomes for endodontic microsurgery showed no significant difference between using mineral trioxide aggregate (MTA) or the super ethoxybenzoic acid (EBA). They also revealed no significant difference after 1 and 4 years.
Those are the findings of a randomized controlled study by South Korean researchers published in the July issue of Journal of Endodontics.
Researchers followed 260 teeth from people who underwent endodontic treatment at the Yonsei University Dental Hospital in Seoul, South Korea. They wanted to compare the long-term clinical outcomes of MTA with those of super EBA. They also wanted to compare the clinical outcomes at 1 and 4 years.
Researchers randomly assigned teeth to an MTA group or a super EBA group. Endodontic treatment consisted of flap elevation, osteotomy, apicoectomy, and homeostasis. Resected root-end surfaces were stained blue and inspected under a microscope. Root-end cavities were prepared by using ultrasonic tips driven by a piezoelectric ultrasonic unit and filled with MTA or super EBA.
Patients were recalled at 3, 6, 12 months, and yearly after treatment. Clinical examinations were conducted at every follow-up visit. Radiographs were obtained at 6 months, 1 year, and then annually.
Treated teeth were classified as successes or failures using Molven criteria.
Researchers reported no significant differences between the success rates of the 2 materials as root-end filling materials in endodontic microsurgery. They also found no significant difference between the 1- and 4-year follow-up data.
The 1-year success rate of MTA was 95.6%, and super EBA’s was 93.1%. The 4-year success rate of MTA was 91.6%, and super EBA’s was 89.9%.
The authors acknowledged that loss of follow-up in long-term studies can produce overestimates of treatment outcomes but observed that “success rate regression is inevitable in a long-term follow-up.”
Besides, they concluded, “these results correspond with several studies indicating that the most significant information regarding healing is obtain one year after surgery, with inadequately healed teeth one year after surgery transitioning to completely healed teeth after five years.”
Read the original article.
Endodontic courses to grow your practice
This hands-on demonstration for “Safe and Efficient Root Canal Treatment” is designed for the general practitioner. Root canal treatment is a great practice builder. However, many clinicians succumb to the anxiety of instrument breakage, long procedure time and high instrument costs. Dr. Scott Graham’s course will not only show you how to avoid those pitfalls while providing exceptional results, you can practice his techniques during this seminar and hands-on demonstration. More info. Additional courses.
ADA video explains endodontic treatment
For patients to understand and accept treatment, visual aids are essential. The ADA video “Root Canal” helps patients understand how endodontic treatment can save a tooth, as well as why it is needed. The video discusses causes of injured pulp, steps of root canal treatment, the need to return to the dentist to have the tooth restored with a restoration or a crown, and oral care after root canal treatment. An animation of infected pulp emphasizes the need for treatment.
The Root Canal video is available on the Toothflix 2.0 Dental Procedures DVD. To order, call 1-800-947-4746 or go to adacatalog.org. Readers who use the code 16405E before October 14 can save 15% on all ADA Catalog products.
Tango-Endo system receives awards
Tango-Endo, the new 2-step instrumentation system by Essential Dental System, has recently received multiple dentistry awards. For an updated list of awards and product reviews please CLICK HERE.
What is Specialty Scan?
This is one in a series of quarterly newsletters updating dentists on selected specialties in dentistry. Information presented is aggregated and summarized from previously published materials, each item attributed to its publication of origin. This issue of JADA Specialty Scan focuses on endodontics, the third in the series on this topic for 2016. Other specialty scan issues are devoted to oral pathology, oral and maxillofacial radiology, orthodontics, periodontics and prosthodontics. The ADA has engaged the specialty organizations in these areas as well as its own Science Institute and Division of Legal Affairs to assist with these newsletters. We welcome your feedback on this and all specialty scan issues.
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