Do endodontic retreatment techniques influence the fracture strength of endodontically treated teeth? A systematic review and meta-analysis.

One of the major concerns about endodontically retreated teeth (ERT) is undoubtedly its loss of remnant structure, which could lead to consequently greater fracture risk. Therefore, the objective of this systematic review is to assess the influence of endodontic retreatment on the fracture strength of the dental tooth remnant. In vitro studies assessing the influence of mechanical retreatment on the mechanical properties (static or under fatigue) of restored teeth were searched in PubMed and SCOPUS databases. Three independent reviewers screened titles/abstracts of articles and the full-text of potentially eligible studies. The risk of bias was independently assessed by one researcher and verified by another two. Comparison between the mean load to fracture of teeth after endodontic treatment and after endodontic retreatment were estimated using pairwise random effects meta-analysis to calculate pooled mean differences. Three studies were included for the systematic review and 2 for the meta-analysis. The pooled effect indicated a statistical difference (Mean difference: -121.03 95%CI: -183.02, -59.05) between conditions favoring the endodontically treated teeth. However, the low number of studies combined with their heterogeneity made it difficult to prove such phenomenon. ERT might present lower fracture strength than endodontically treated teeth. However, more coherent laboratory tests may provide better evidence and quantitative parameters on how much reliability can be attributed to an endodontic retreatment, in addition to which technique can provide more predictable results in this conservative approach.

Periapical Microsurgery: Do Root Canal-retreated Teeth Have More Dentinal Defects?

INTRODUCTION: This microsurgical clinical study evaluated if teeth that have undergone endodontic retreatment are associated with more dentinal defects than primary root canal-treated teeth. METHODS: One hundred fifty-five patients who underwent periapical microsurgery treatment in a private practice setting were evaluated. The root ends were resected, and the roots were inspected for the presence of dentinal defects through the surgical operating microscope with the help of a 0.8-mm-diameter light-emitting diode probe light and methylene blue dye. The root canal treatment history (primary vs retreatment) of the teeth was documented and related to the presence or absence of dentinal defects. Bivariate analysis was performed using the chi-square test, and a multivariate analysis was performed using logistic regression to evaluate possible confounding effects of patient age, sex, and tooth location on the association between treatment and the presence of dentinal defects. RESULTS: Of the 155 treated teeth, 33 were excluded (3 fractured and 30 missing treatment history). Of the remaining 122 included teeth, 73 (59.8%) had undergone primary root canal treatment and 49 (40.2%) retreatment. Sixteen teeth (22.5%) of the primary root canal group versus 33 (64.7%) of the retreatment group had dentinal defects. The proportion of retreated teeth with dentinal defects compared with primary treatment was statistically significant (P < .001) with a higher proportion of retreated teeth having dentinal defects. In the multivariate analysis, only the type of treatment was statistically significant (P < .001). CONCLUSIONS: This clinical study showed that root canal-retreated teeth are associated with more dentinal defects than primary root canal-treated teeth.

Retratamientos endodónticos: una realidad que preocupa / Endodontic retreatment: a worrying reality

Las evaluaciones radiográficas de tratamientos endodón- ticos realizadas por graduados muestran un alto porcentaje de procedimientos incorrectos. Esta circunstancia lleva a la rea- lización de un elevado número de retratamientos ortógrados y retrógrados, con los inconvenientes y desventajas que conlle- va recurrir a una reintervención endodóntica. Es responsabili- dad de los profesionales, docentes y autoridades universitarias y gubernamentales revertir esta situación que afecta a la salud bucal de la sociedad. En el presente editorial se proponen di- ferentes alternativas para intentar modificar este preocupante panorama (AU)

Radiographic evaluations of endodontic treatments per- formed by graduates show a high percentage of incorrect procedures. This circumstance leads to the performance of a high number of orthograde and retrograde retreatments, with the inconveniences and disadvantages that entails resorting to an endodontic reintervention. It is the responsibility of pro- fessionals, teachers, university and government authorities to reverse this situation that affects the oral health of society. In this editorial, different alternatives are proposed to try to modify this worrying outlook (AU)

Extraradicular infection as the cause of persistent symptoms: a case series.

INTRODUCTION: This article describes 3 cases that presented persistent symptoms after appropriate endodontic treatment. Histopathologic and histobacteriologic investigation were conducted for determination of the cause. METHODS: Three cases are reported that presented with persistent symptoms after endodontic retreatment (cases 1 and 2) or treatment (case 3). Periapical surgery was indicated and performed in these cases. The biopsy specimens, consisting of root apices and the apical periodontitis lesions, were subjected to histopathologic and histobacteriologic analyses. RESULTS: Case 1 was an apical cyst with necrotic debris, heavily colonized by ramifying bacteria, in the lumen. No bacteria were found in the apical root canal system. Case 2 was a granuloma displaying numerous bacterial aggregations through the inflammatory tissue. Infection was also present in the dentinal tubules at the apical root canal. Case 3 was a cyst with bacterial colonies floating in its lumen; bacterial biofilms were also seen on the external apical root surface, filling a large lateral canal and other apical ramifications, and between layers of cementum detached from the root surface. No bacteria were detected in the main root canal. CONCLUSIONS: Different forms of extraradicular infection were associated with symptoms in these cases, leading to short-term endodontic failure only solved by periapical surgery.

Seizures after Onyx embolization for the treatment of cerebral arteriovenous malformation.

Onyx embolization of cerebral arteriovenous malformations (AVM) has become increasingly common. We explored the risk of seizures after Onyx use.A retrospective review was conducted of 20 patients with supratentorial brain arteriovenous malformation (AVM) who received Onyx embolization between 2006 and 2009. Baseline demographics, clinical history, seizure history, AVM characteristics and treatment were compared between those who developed post-onyx seizure and those who did not. MRIs were reviewed for edema following Onyx treatment.Of 20 patients who underwent Onyx embolization, the initial AVM presentation was hemorrhage in 40% (N=8). The median number of embolizations was two (range 1-4) and the median final obliteration amount was 90% (range 50-100%). A history of seizure was present in 50% (N=10) of patients pre-embolization and 12 (60%) patients received seizure medications (treatment or prophylaxis) prior to embolization. Seizur post-Onyx embolization occurred in 45% (N=9). The median time to seizur post-Onyx was seven days (range 0.3-210). Four patients (20%) with seizures post-Onyx had no seizure history. Two of these patients (10%) had no other identifiable cause for seizure other than recent Onyx embolization. Seizures in these two patients occurred within 24 hours of Onyx administration. Among patients with post-Onyx seizures, there was a trend toward larger AVM size (P=0.091) and lower percent obliteration (P=0.062). Peri-AVM edema was present in 75% of MRIs performed within one month of Onyx treatment and may represent a possible etiology for seizures.New onset seizures post-Onyx embolization are not uncommon. Further study of seizure prevention is warranted.

Damage to root dentin during retreatment procedures.

INTRODUCTION: The aim of this study was to explore the influence of retreatment procedures on the appearance of defects on the root canal walls. METHODS: Two hundred mandibular premolars were divided into 4 groups. One group was left unprepared. The rest of the teeth were prepared with ProTaper files up to size F4 and filled with gutta-percha and AH26. One group was left filled and received no further treatments. The filling material was removed from the remaining teeth either with ProTaper retreatment files or with Hedström files. Roots were then sectioned and inspected under a microscope. Data were analyzed with the nominal regression test (α = 0.05). RESULTS: No defects were observed in the unprepared group. Retreatment groups showed significantly more defects than the initial treatment group (P < .05).There was no difference between the appearance of defects after retreatment with Hedström files and ProTaper retreatment files. The remaining dentin thickness and level of the root did not significantly influence the appearance of defects. CONCLUSIONS: Retreatment procedures result in more defects than initial treatment. When assessing the outcomes of endodontic retreatment, the substantial damage to the root canal walls should be considered.

Clinical investigation of patients who develop neuropathic tooth pain after endodontic procedures.

INTRODUCTION: This study aimed to determine the characteristics of patients with neuropathic tooth pain (NTP) who were selected from a group of patients who developed persistent pain after undergoing endodontic procedures. METHODS: Of 271 patients who had chronic persistent pain that did not respond to previous endodontic procedures and were referred to the Endodontic Team of the Nippon Dental University Hospital, 16 patients (5.9%; mean age, 46.8 years; 13 women) who fulfilled the diagnostic criteria for NTP were recruited. The inclusion criteria for the patients were the presence of chronic persistent pain and other pain-related symptoms, despite the absence of major pathology. RESULTS: Pain predominantly occurred in the maxilla (14 patients). In 10 patients (62.5%), NTP developed after retreatment. Daily application of tricyclic antidepressants produced pain relief in 11 patients (68.8%). CONCLUSIONS: These results indicated that NTP is a rare type of chronic intractable endodontic pain and that careful diagnosis of NTP is important.

Retratamento endodôntico em dens in dente com insertos ultrassônicos e iodofórmio: 2 anos de follow-up / Endodontic retreatment in dens in dente using ultrasonic tips and iodoform: a 2-year follow-up

Dens in dente (dens invaginatus) é uma anomalia de desenvolvimento que afeta a formados dentes. O órgão do esmalte é desorganizado e ocorre a invaginação da coroa do dente antes da fase de calcificação. O relato deste caso tem como objetivo apresentar o uso de inserto sultrassônicos e medicação intracanal com iodofórmio no retratamento endodôntico em dens indente tipo II com lesão periapical. O dente necessitou de retratamento endodôntico. O acesso coronário e a instrumentação dos canais radiculares foram realizados com auxílio de insetos ultrassônicos. Utilizou-se iodofórmio e hidróxido de cálcio como medicação intracanal em duas sessões. Na última sessão, a obturação foi realizada. Após dois anos de follow-up, observou-se sucesso no retratamento. O dente apresenta-se sem sintomatologia dolorosa e com redução da lesão periapical.

Dens in dente (dens invaginatus) is a developmental anomaly that affects the shape ofteeth. The enamel organ is disorganized and invagination of the tooth crown occurs before thecalcification stage. The aim of this case report is present the use of ultrasonic tips and intracanalmedication with iodoform in endodontic retreatment in dens in dente type II with periapicallesion. The tooth required endodontic retreatment. Coronal access and root canal instrumentationwere performed with the aid of ultrasonic tips. Iodoform and calcium hydroxide were usedas intracanal medication in two sessions. In the last session, filling was performed. After follow--up of 2 years, successful retreatment was observed. The tooth presented no painful symptomsand the periapical lesion was reduced.

Effect of repeated orthodontic treatment on the dental and periodontal tissues of the rat incisor.

This study evaluated the response of treated teeth to renewed orthodontic force. Thirty female rats (201 +/- 2.7 g) were divided into groups A and B. Linguointrusive loads (20.58 +/- 1.88 g) generated by springs were applied to the lower left incisor for 2 weeks and then removed to allow recovery during 27 weeks (group A). Identical loading was then repeated in group A and applied as primary treatment in group B. Five animals from each group were killed with the springs in situ (A-1 and B-1), while the remaining 20 animals were killed after a 3-month recovery (A-2, B-2). The decalcified incisors were cross-sectioned serially (2 microm), and the distance of each section from the apex was computed. Dental and periodontal injuries were evaluated by light microscopy and plotted according to their location on the tooth axis. The intrusion of the teeth in group A-1 was significantly greater, whereas recovery of the normal eruption rate in group A-2 was significantly slower compared with groups B-1 and B-2. The histopathologic lesions in groups A-1 and B-1 did not differ. However, group A-2 showed a higher frequency of injured enamel organ, tissue infiltration by inflammatory cells, necrotic areas, and dentin resorption than group B-2. Initial orthodontic loading had a detrimental effect on the ability of the periodontal and dental tissues to cope with, and to recover from, repeated stress, probably because of a decrease in the number of periodontal fibroblasts and damage to the dentin-protecting cementoblastic layer.

Postoperative discomfort associated with surgical and nonsurgical endodontic retreatment.

Endodontic retreatment decision-making must include an appraisal of the costs of the different strategies proposed. In addition to direct costs, postoperative discomfort may have other consequences in terms of time off work, unscheduled visits and suffering. To establish a foundation for the appraisal of such indirect and intangible costs the present study was set up in which patients' assessments of pain and swelling after surgical and nonsurgical retreatment procedures were recorded. Ninety-two patients with 95 root-filled incisors and canine teeth exhibiting apical periodontitis were included in the study. The mode of retreatment was randomly assigned. Each day during the first post-treatment week patients assessed their degree of swelling and pain on horizontal 100-mm visual analog scales (VAS). The scales ranged from "no swelling" to "very severe swelling" and "no pain" to "intolerable pain", respectively. Consumption of self-prescribed analgesics and time off work were also recorded. Significantly more patients reported discomfort after surgical retreatment than after nonsurgical procedures. High pain scores were most frequent on the operative day while swelling reached its maximum on the first postoperative day followed by progressive decrease both in frequency and magnitude. Postoperative symptoms associated with nonsurgical retreatment were less frequent but reached high VAS values in single cases. Analgesics were significantly more often consumed after periapical surgery. Patients reported absence from work mainly due to swelling and discoloration of the skin. This was found to occur only after surgical retreatment. Conclusively, surgical retreatment resulted in more discomfort and tended to bring about greater indirect costs than nonsurgical retreatment.