Removal of Thermafil Obturators Using 2 Different Techniques: A Comparative Ex Vivo Study.

INTRODUCTION: The aim of this ex vivo study was to compare 2 techniques for removal of Thermafil obturators from curved root canals in mandibular molars. METHODS: Sixty mesial root canals in extracted mandibular molars were distributed into matched pairs according to degree and radius of curvature and were prepared to size 35/.04 and obturated with Thermafil obturators size 35. Each tooth was embedded in resin, mounted in a mannequin head, and isolated with rubber dam to simulate clinical conditions. Removal of obturators was undertaken under a dental operating microscope by an experienced endodontist using either the FragRemover loop device, or reciprocating NiTi instruments. Pre- and postoperative micro-CT scans were taken to compare the amount of remaining filling material and of removed dentin. Eventual problems during removal attempts were recorded. RESULTS: Using Reciproc, 24 carriers (80%) were removed, 16 in one piece, 8 in small pieces, and in 6 cases removal failed. The FragRemover removed 12 carriers (40%), all of these completely, but in 18 cases removal failed (P < .05). Reciproc left less remaining filling material than the FragRemover (P < .05) but removed significantly more dentin in the apical part of the root canal (P < .01). There was no significant difference concerning the total amount of removed dentin (P > .05) between both groups. Seven complications occurred in the Reciproc group. In 5 teeth, working length could not be reached; in 2 teeth, a Reciproc file R25 fractured. With the FragRemover, 64 complications occurred, in 36 cases, including second removal attempts, the loop slipped over the carrier, in 24 cases the top of the carrier was sheared off. In 9 cases, separation of the core occurred too far apically, not allowing further use of the FragRemover. In 4 cases, the wire loop tore. CONCLUSIONS: Reciproc was more effective in removal of Thermafil carriers, whereas when using the FragRemover less dentin was removed in the apical part of the root canal and more obturation material was left.

Calcium Silicate-based Sealer Extrusion into the Mandibular Canal: 3 Different Recovery Outcomes-A Report of 3 Cases.

The use of calcium silicate-based sealers (CSSs) is increasing in dentistry as a result of their favorable properties. The inadvertent extrusion of these sealers into the mandibular canal (MC) can result in temporary or permanent neurosensory alterations. Three different recovery outcomes of CSS extrusion into the MC after endodontic treatment of mandibular molars confirmed by cone-beam computed tomographic imaging are described. In Case 1, CSS from the mesiolingual canal of tooth #31 was extruded into the MC during obturation. The patient reported paresthesia. The symptoms of paresthesia were completely resolved by 9 months. In Case 2, CSS from the mesial canals of tooth #30 was extruded into the MC during obturation. A "plasmalike spreading pattern" of the extruded sealer was observed on the radiographs. The patient reported paresthesia and dysesthesia. In addition, the patient complained of hyperalgesia with heat and mechanical allodynia. The symptoms continued to persist during follow-up. At 22 months, the patient still reported persistent paresthesia, hyperalgesia, and mechanical allodynia, affecting the ability to eat. In Case 3, CSS from the distal canal of tooth #31 was extruded into the MC during obturation. The patient did not report any paresthesia or dysesthesia. All 3 patients elected a follow-up approach and monitoring rather than surgical intervention. These cases illustrate the need for the development of guidelines for the management of iatrogenic CSS extrusion into the MC because such an occurrence may result in permanent, temporary, or no neurosensory alterations.

Root filled teeth in two parallel Danish cohorts: A repeated longitudinal cohort study.

AIM: The aim of the study was to compare the frequency of root filled teeth and quality of root fillings (RFs) in two parallel, Danish cohorts each examined over 10 years and to evaluate factors associated with apical periodontitis (AP) and extraction of root filled teeth. METHODOLOGY: Two randomly selected cohorts (C1, C2) from Aarhus (age: 20-64 years) were followed for approximately 10 years, with full-mouth radiographic surveys performed at 5-year intervals (C1: 1997-2003-2008; C2: 2009-2014-2019). Frequency of root filled teeth, quality of RFs and coronal restorations, periapical status and tooth extraction were registered. Logistic regression analyses compared C1 with C2 for baseline and follow-up periods and assessed variables associated with AP (PAI-based) and extraction of root filled teeth. RESULTS: C1 included 330 and C2, 170 individuals, mean age 42.9 and 47.3 years, respectively, who attended all three radiographic examinations. The relative frequency of root filled teeth was lower in C2 than C1 at baseline (C1: 4.7%, C2: 3.6%; p < .001) and after 10 years (C1: 5.7%, C2: 4.2%; p < .001). The relative frequency of new RFs was lower in C2 than in C1 (p = .02). C2 had fewer short/long RFs at baseline than C1; quality of new RFs or coronal restorations was similar in C1 and C2. The risk of tooth extraction (p = .93) and risk of AP (p = .37) at 10-year follow-up was similar between the two cohorts. For both C1 and C2, root filled teeth with AP at baseline had increased risk of having AP (p < .001) or having been extracted (p < .001) at follow-up. Risk of extraction was higher for root filled premolars (p = .01) and molars (p = .01) than anteriors. Risk of AP at follow-up was higher for root filled molars (p < .001). Furthermore, inadequate quality of RFs (p = .02) and coronal restorations (p = .04) increased the risk of AP at follow-up in C1 and C2. CONCLUSIONS: The frequency of root filled teeth and new RFs decreased and little to no change in new RFs' quality, AP, or tooth extraction was seen over time (1997-2019). Root filled molars and teeth with AP at baseline had increased risk of AP and extraction.

Effect of EDDY and manual dynamic activation techniques on postoperative pain in non-surgical retreatment: a randomized controlled trial.

BACKGROUND: During non-surgical retreatment process, the products such as dentin debris, root canal fillings, irrigation solutions, microorganisms and remaining pulp tissues can extrude to the apical area and can cause the postoperative pain and flare-up. Thus, the aim of this study was to evaluatethe effect of EDDY and manual dynamic activation (MDA) techniques on postoperative pain (PP) associated with retreatment. METHODS: Ninety patients scheduled for retreatment were treated at a single visit. Non-vital mandibular premolar teeth diagnosed with asymptomatic apical periodontitis were included in this study. The patients were divided into two groups (n = 45) on the basis of the need for additional irrigation activation procedures (EDDY and MDA). The patients' post-treatment pain levels were asked to rate the intensity of their pain on a 10-point numerical rating scale (NRS) at the 12th, 24th, 48th, and 72nd h and 7 days.The data were analyzed using the chi-square and Wilcoxon signed-rank test was used for within-group comparisons and Mann Whitney U test was used to compare the groups by time period. RESULTS: The difference in postoperative pain intensity between two groups was statistically significant at 12, 24, 48, and 72 h (p < 0.05). There was no significant difference at 7 days. Moreover, no statistically significant difference was found between the two groups in terms of gender and analgesic medication intake (p > 0.05). Pain intensity after the treatment was lesser in the MDA groupthanin the EDDY group at 12, 24, 48, and 72 h. CONCLUSION: This study could lead us to conclude that the two activation systems can be used during endodontic retreatment with no difference at PP 7 days later. However, a comparison of the groups indicated that the EDDY resulted in significantly more PP at 12, 24, 48, and 72 h. Trial registration ClinicalTrials.gov Identifier: NCT04726670.

Inferior alveolar nerve injury due to the extrusion of calcium hydroxide during endodontic treatment: A case report.

Although many materials are used for root canal fillings in endodontic treatment, calcium hydroxide has been preferred for many years due to its bactericidal effect and biocompatibility. Calcium hydroxide can be applied in more than one form. In this case study, calcium hydroxide in viscous form, applied into the root canal during endodontic treatment, overflowed from the apical part of the tooth to the inferior alveolar nerve canal. Postoperative paraesthesia was observed in the patient. Dental volumetric tomography was performed to study the extent of sealer in the inferior alveolar nerve canal. Considering the short resorption time of the calcium hydroxide paste, no surgical intervention was performed on the patient. After 6 months, the root canal material was completely resorbed, and paraesthesia decreased. At the 3-year follow-up, the patient's paraesthesia had completely disappeared.

Present status and future directions: vertical root fractures in root filled teeth.

Vertical root fracture (VRF) is a common reason for the extraction of root filled teeth. The accurate diagnosis of VRF may be challenging due to the absence of clinical signs, whilst conventional radiographic assessment is often inconclusive. However, an understanding of the aetiology of VRFs, and more importantly, the key predisposing factors, is crucial in identifying teeth that may be susceptible. Thorough clinical examination with magnification and co-axial lighting is essential in identifying VRFs, and although CBCT is unable to reliably detect VRFs per se, the pattern of bone loss typically associated with VRF can be fully appreciated, and therefore, increases the probability of correct diagnosis and management. The prevalence of VRFs in root filled teeth is significantly greater than in teeth with vital pulps, demonstrating that the combination of loss of structural integrity, presence of pre-existing fractures and biochemical effects of loss of vitality is highly relevant. Careful assessment of the occlusal scheme, presence of deflective contacts and identification of parafunctional habits are imperative in both preventing and managing VRFs. Furthermore, anatomical factors such as root canal morphology may predispose certain teeth to VRF. The influence of access cavity design and root canal instrumentation protocols should be considered although the impact of these on the fracture resistance of root filled teeth is not clearly validated. The post-endodontic restoration of root filled teeth should be expedient and considerate to the residual tooth structure. Posts should be placed 'passively' and excessive 'post-space' preparation should be avoided. This narrative review aims to present the aetiology, potential predisposing factors, histopathology, diagnosis and management of VRF and present perspectives for future research. Currently, there are limited options other than extraction for the management of VRF, although root resection may be considered in multi-rooted teeth. Innovative techniques to 'repair' VRFs using both orthograde and surgical approaches require further research and validation. The prevention of VRFs is critical; identifying susceptible teeth, utilizing conservative endodontic procedures, together with expedient and appropriate post-endodontic restorative procedures is paramount to reducing the incidence of terminal VRFs.

Influence of occlusal reduction on pain after endodontic treatment: a systematic review and meta-analysis.

The purpose of this systematic review was to analyze the influence of occlusal reduction on the postoperative pain levels after endodontic treatment (instrumentation and obturation of the root canal system). This review followed the PRISMA statement and was registered at PROSPERO (CRD42018107918). Two independent reviewers searched the Lilacs, Cochrane Library, PubMed (Medline), Web of Science, Scopus, Scielo, and ScienceDirect for articles published until April 2021. The research question was, "Does occlusal reduction decrease postoperative pain in endodontically treated teeth?". Only randomized clinical trials were included. The RevMan 5 program was used for meta-analysis, calculating the relative risk (RR) and 95% confidence interval (CI) of the dichotomous outcome (presence or absence of pain). The search strategies retrieved 4114 studies. Twelve studies were included for qualitative analysis and nine for quantitative analysis. The meta-analysis results did not reveal a significant difference in the reduction of postoperative pain levels for endodontic instrumentation at 6, 12, 24, 48 h and for endodontic obturation at 6 or 12 h after occlusal reduction. According to the GRADE tool, the analyzed outcome was classified as having a moderate level of certainty. It is concluded that occlusal reduction does not interfere with postoperative pain levels after endodontic treatment.

Postobturation Pain Associated with Tricalcium Silicate and Resin-based Sealer Techniques: A Randomized Clinical Trial.

INTRODUCTION: The incidence of immediate postobturation pain associated with 2 sealer techniques was compared and potential prognostic factors identified. METHODS: Patients referred for endodontic treatment were recruited with informed consent. Root canals were debrided and teeth rendered asymptomatic before random allocation to receive TotalFill BC (FKG Dentaire SA, La Chaux-de-Fonds, Switzerland) or AH Plus sealer (Dentsply Maillefer, Ballaigues, Switzerland). Patients blinded to the sealer reported their postobturation pain experience 1, 3, and 7 days after treatment. Blinded and calibrated assessors independently reviewed treatment quality, sealer extrusion, and radiographic data under standardized conditions. RESULTS: One hundred sixty eligible patients (163 teeth, 95.3%) returned their pain diary. No postobturation pain difference was found between the 2 sealers (P > .05), although the AH Plus sealer technique was significantly associated with extrusion beyond the apex (P < .05; odds ratio [OR] = 3.02; 95% confidence interval [CI], 1.39-6.57). Thirty-three (20.6%) patients reported pain on day 1 (median 1 = very mild pain), 16 (10.0%) on day 3 (median 1 = very mild pain), and 9 (5.6%) on day 7 (median 2 = mild pain). The prognostic factors were as follows: (1) moderate/severe preoperative pain (OR = 4.41; 95% CI, 1.42-13.76 on day 3 and OR = 5.16; 95% CI, 1.17-22.78 on day 7), (2) provoked preoperative pain (OR = 4.24; 95% CI, 1.40-12.78 on day 3 and OR = 5.35; 95% CI, 1.27-22.51 on day 7), (3) pulpless tooth (OR = 0.11; 95% CI, 0.02-0.57 on day 3), and (4) sonic activation during treatment (OR = 3.02; 95% CI, 1.39-6.57 on day 1 and OR = 3.01; 95% CI, 1.05-8.59 on day 3). CONCLUSIONS: There was no significant difference in pain experience between teeth filled using AH Plus or TotalFill BC Sealer 1, 3, and 7 days after obturation. Patient- and treatment-related factors could influence postobturation pain.

Evaluación del éxito de tratamientos endodónticos realizados por estudiantes de pregrado en una universidad chilena / Evaluation of success rate of root canal treatment performed by undergraduate dental students in a Chilean university

El tratamiento endodóntico tiene como finalidad prevenir o lograr la ausencia de periodontitis apical post-tratamiento, logrando la mantención del diente en la boca de manera funcional. La realización de tratamientos endodónticos de baja complejidad en la formación de pregrado es transversal a todas las universidades chilenas. El objetivo del presente estudio es evaluar la frecuencia de éxito de tratamientos endodónticos realizados por estudiantes de pregrado entre los años 2014-2017 de la Escuela de Odontología, Universidad Austral de Chile (UACh), Valdivia, Chile. Se realizó un estudio observacional descriptivo donde fueron evaluados 74 tratamientos endodónticos en dientes uniradiculares de 63 pacientes seleccionados a través de un muestreo aleatorio simple, que cumplieran con los criterios de selección. Los parámetros usados para la evaluación clínica fueron: ausencia de dolor a la palpación y percusión, ausencia de fístula y diente en función. En la evaluación radiográfica se utilizaron los siguientes parámetros: longitud de obturación en relación al ápice dentario, conicidad, densidad del material obturador y reducción de la lesión periapical. De los tratamientos evaluados se reportó un 78 % de éxito clínico y un 41 % de éxito radiográfico. Finalmente, se concluye que los resultados obtenidos a nivel clínico y radiográfico son similares a los reportados en la literatura.

The objective of endodontic treatment is to prevent or achieve the absence of post-treatment apical periodontitis, thereby maintaining functionality of the tooth in the mouth. In Chilean universities undergraduate programs, training in endodontics is limited to low level complexity cases and is transversal throughout the universities. The objective of this study is to evaluate the frequency of success of endodontic treatments performed by undergraduate students between the years 2014-2017 of the School of Dentistry, Universidad Austral de Chile (UACh), Valdivia, Chile. A descriptive observational study was conducted where 74 endodontic treatments were evaluated in uniradicular teeth of 63 patients, selected through a simple random sampling, that met selection criteria. The criteria used for the clinical evaluation were: absence of pain on palpation and percussion, absence of fistula and function tooth. In the radiographic evaluation the following criteria were used: length of obturation in relation to the dental apex, taper, density of the obturator material and reduction of the periapical lesion. Of the treatments evaluated, 78 % clinical success and 41 % radiographic success were reported. Finally, it is concluded that the results obtained at clinical and radiographic level are similar to those reported in the literature.

Effect of Root Canal Disinfection with a Diode Laser on Postoperative Pain After Endodontic Retreatment.

Objective: The aim of this randomized clinical trial was to evaluate the influence of root canal disinfection with a 940-nm diode laser on the intensity of pain after endodontic retreatment. Background data: Microorganisms are the most common causes of tooth pain. Therefore, clinical studies are needed to explore the effect of disinfection techniques on postoperative pain. Methods: Eighty-four patients scheduled for endodontic retreatment were allocated to two groups in a 1:1 ratio (n = 42 each). After root canal filling removal and chemomechanical procedures, the root canals were disinfected with a 940-nm diode laser in one group [laser disinfection (LD) group]. In the other group, a mock application of laser was made with the power off [pseudo-laser disinfection (PLD) group]. All retreatment procedures were completed in a single visit. The patients assessed their pain levels at 24, 48, and 72 h after retreatment using a numeric rating scale. The number of analgesic pills used during this period was also recorded. The collected data were statistically analyzed using Mann-Whitney U and Wilcoxon tests. Results: Postoperative pain on the first 2 days was significantly lesser in the LD group than in the PLD group (p < 0.05), and the difference became insignificant on the third day (p > 0.05). Moreover, analgesic intake over 3 days and pain on percussion on the fourth day were significantly lesser in the LD group than in the PLD group (p < 0.05). Conclusions: Elimination of microorganisms from root canals is important for preventing postoperative complications. Our findings suggest that diode LD can reduce postoperative pain and provide comfort after endodontic retreatment. This study is registered in www.ClinicalTrials.gov database with the identifier number NCT03584880.

The association between clinical diagnostic factors and the prevalence of vertical root fracture in endodontic surgery.

BACKGROUND/PURPOSE: Diagnosis of vertical root fractures (VRFs) can often be challenging due to the similarity of signs and symptoms with other common dental infectious diseases. This study was aimed at evaluating the potential relationship between VRFs and commonly used clinical diagnostic factors. METHODS: 330 root-filled teeth with endodontic failures were subjected to endodontic microsurgery over a six-year period. VRFs were identified in 61 teeth. A randomly age- and sex-matched retrospective case-control study was conducted on a subset of 59 root-filled teeth with VRFs (cases) and 177 root-filled teeth without VRFs (controls). The strength of association between preoperative signs and radiographic findings and VRFs was evaluated using logistic regression model. RESULTS: Sinus tract, periodontal pocket depth ≥5 mm, periodontal swelling or abscess, and radiological image of J-shaped or "halo" radiolucency were significantly more frequent in cases than in controls (p < 0.05). With regard to logistic regression analysis, J-shaped or "halo" radiolucency demonstrated the greatest association with VRF, followed by periodontal pocket depth ≥5 mm, sinus tract, and periodontal swelling or abscess. Approximately 70% of cases manifested themselves as combinations of at least two of these factors. Teeth having two and three or four of these factors had 3.14 times and 11.64 times higher risks for the presentations of VRFs, respectively (p < 0.001). CONCLUSION: The major risk for VRFs was represented by those presenting radiological image of J-shaped or "halo" radiolucency, periodontal pocket depth ≥5 mm, sinus tract, and periodontal swelling or abscess simultaneously.

Coronal Microleakage of Teeth Restored with Cast Posts and Cores Cemented with Four Different Luting Agents after Thermocycling.

PURPOSE: The apical seal provided by a root canal filling may be breached via coronal leakage. This study aimed to compare the teeth restored with custom-made cast metal posts and cores cemented with different luting agents in terms of coronal microleakage after thermocycling. MATERIALS AND METHODS: This in vitro study was conducted on 32 extracted single-canal teeth. Root canals were prepared by step-back technique and filled with gutta percha and sealer. The coronal 7 mm of gutta percha was removed, and post space was prepared using peeso reamers #2 and #3 consecutively. After fabricating the acrylic resin patterns of the posts and cores, they were cast using Ni-Cr metal alloy. The specimens were divided into 4 groups in which the castings were cemented using one of the following luting agents: zinc phosphate (ZP), glass ionomer (GI), Panavia F 2.0, and Speed CEM. After cementation, the teeth were immersed in distilled water and incubated for 7 days. Then, the teeth were subjected to thermocycling, immersed in silver nitrate for 6 hours, and finally sectioned. The degree of dye penetration into the coronal part of the specimens was measured using a stereomicroscope. Data were analyzed using Kruskal-Wallis and Mann-Whitey U tests with significance level of 0.05. RESULTS: The median microleakage in ZP, Speed CEM, GI, and Panavia were 171.89, 114.76, 26.51, and 20.02 µm, respectively. Pairwise comparisons among GI and ZP, GI, and Speed CEM, ZP and Panavia, ZP and Speed CEM, and Panavia and Speed CEM groups yielded significant differences (p < 0.05). CONCLUSION: Complete coronal seal was not achieved with any of the luting agents. The highest and the lowest degree of microleakage was yielded by ZP and Panavia luting agents, respectively.

Evaluation of Crack Formation and Propagation with Ultrasonic Root-End Preparation and Obturation Using a Digital Microscope and Optical Coherence Tomography.

OBJECTIVE: This study is aimed at determining (1) the effect of root-end resection, ultrasonic root-end preparation, and root-end filling on the incidence of crack formation and propagation by using a digital microscope (DM) and optical coherence tomography (OCT) and (2) the performance of OCT on the detection of cracks by comparing with microcomputed tomography (micro-CT) as a reference standard. METHODOLOGY: Thirty extracted lower incisors were endodontically treated and subjected to root-end resection and ultrasonic root-end cavity preparation. Then, the teeth were divided into three groups (n = 10, each), and the root-end cavity was either left unfilled or filled with mineral trioxide aggregate (MTA) or super-EBA. The resected surface was observed with OCT and DM after the root-end resection, ultrasonic root-end preparation, and root-end filling, and the frequency of incomplete and complete cracks were recorded. The observation was repeated after two weeks, one month, and two months, and micro-CT scans after two months were taken as the gold standard. RESULTS: The DM results show dentinal crack formation in 47% of the samples following root-end resection and in 87% following ultrasonic preparation. After the ultrasonic preparation, no existing crack propagated to a complete crack, but new cracks were formed. MTA and super-EBA had no effect on crack formation. The Spearman correlation coefficient between OCT and DM was 0.186 (very weak correlation; p = 0.015). Sensitivity and specificity in comparison to micro-CT were 0.50 and 0.55 in OCT and 1.00 and 0.35 in DM, respectively. McNemar's test showed a significant difference between OCT and DM (p < 0.05). CONCLUSION: Apical resection and ultrasonic preparation could form dentinal cracks. OCT and DM showed different detection frequencies of cracks with very weak correlation. DM showed superior sensitivity compared with OCT.

Factors associated to apical overfilling after a thermoplastic obturation technique - Calamus® or Guttacore®: a randomized clinical experiment.

The aims of this study were to analyze whether age, tooth type and sex are related to radiographically visible extrusion of filling material as an unintended outcome in teeth undergoing endodontic treatment with a thermoplastic obturation technique (Calamus® or GuttaCore®) and to determine whether the presence of such overfilling is associated to postoperative pain. We selected 120 teeth with diagnoses involving vital pulp and indication for endodontic treatment. Biomechanical preparation was performed using the Protaper Next® system with X2 or X3 master apical file. Teeth were randomly divided into 2 groups (n=60). Teeth in Group 1 were filled with the Guttacore® system and teeth in Group 2 were filled with single cone technique and Calamus® obturation system. Thermoplastic obturation techniques were found to cause overfilling in 53. 33% of the total cases (64 teeth) (56. 66% in Guttacore® group and 50% in the Calamus® group). Anterior teeth were found to be associated to presence of overfilling (p= 0. 024) (OR = 4. 35). Of the 120 teeth treated, 10 (8. 33%) presented postoperative pain and radiographically visible overfilling. The association between presence of extruded filling material and mild/moderate pain was statistically significant withp = 0. 002. To conclude, endodontic thermoplastic obturation with Guttacore® and Calamus® systems are significantly associated with the probability of filling material extrusion, and overfilling is associated to postoperative pain. Anterior teeth are 4 times more likely to be overfilled with the obturation techniques tested.

Los objetivos de esta investigación fueron: Analizar si factores como la edad, el tipo de diente y el género están asociados con la extrusión de material obturador radiográficamente visible como desenlace imprevisto en dientes sometidos a tratamiento endodóntico con una técnica de obturación termoplástica (Calamus® o GuttaCore®) y determinar si la presencia de esta sobreobturación está asociada con dolor posoperatorio. Se seleccionaron 120 dientes con diagnósticos que implicaban pulpa vital y con indicación de tratamiento de endodoncia. La preparación biomecánica se llevó a cabo con el sistema ProtaperNext® con lima apical principal X2 o X3. Los dientes se dividieron aleatoriamente de la siguiente forma (n=60): El grupo 1 se obturó con el sistema Guttacore® y el grupo 2 se obturó con una técnica de obturación de cono único y el sistema de obturación Calamus®. Se observó quelas técnicas de obturación termoplástica generaron sobreobturación en 53. 33% del total (64 dientes), 56. 66% se presentaron en el grupo de obturación con Guttacore® y 50% en el grupo de la técnica con el sistema Calamus®. Se encontró que los dientes anteriores presentaron asociación con la presencia de sobreobturación (p= 0. 024) (OR=4. 35). De los 120 dientes tratados, 10 (8. 33 %) presentaron dolor posoperatorio y sobreobturación radiográficamente visible. La asociación entre la presencia de extrusión de material de obturación y dolor leve-moderado fue estadísticamente significativa con un valorp= 0. 002. Como conclusión las técnicas de obturación termoplástica en endodoncia Guttacore® y el sistema Calamus® están asociadas significativamente con la probabilidad de extrusión de material obturador y dicha sobreobturación está asociada con dolor posoperatorio, los dientes anteriores presentan 4 veces más riesgo de sobreobturación con las técnicas de obturación utilizadas.

Effect of root canal obturation with calcium silicate materials on pH change in simulated root resorption defects.

This study evaluated the effect of 3 commercially available calcium silicate materials (CSMs) on pH changes in simulated root resorption defects. Simulated root resorption defects were prepared on the facial root surface of 40 mandibular premolars. The depth of each defect was individually calculated to standardize the remaining dentin thickness to 1 mm. Prepared canals were obturated with the 3 CSMs. Ten specimens were kept as controls, filled with unbuffered normal saline. The pH measurements were taken at 1 hour, 6 hours, 1 day, 1 week, 2 weeks, 3 weeks, 1 month, and 2 months. All CSM groups exhibited an initial alkaline pH of 9.0-9.7. The pH decreased to 8.0-8.5 after 2 months of storage. There were no significant differences between pH measurements at other time intervals. The CSM groups exhibited higher pH levels than the control group. The results showed that intracanal placement of the CSMs maintained initial pH levels of 9.0-9.7 inside the simulated resorption defects; these measurements gradually decreased to 8.0-8.5 over the span of 2 months.

Efficacy of the ProTaper retreatment system in removing Thermafil, GuttaCore or vertically compacted gutta-percha from curved root canals assessed by micro-CT.

AIM: To evaluate ex vivo the efficacy of ProTaper Universal Retreatment files (Dentsply Sirona, Ballaigues, Switzerland) in removing Thermafil, GuttaCore (both Dentsply Sirona) or vertically compacted gutta-percha from curved root canals using micro-CT. METHODOLOGY: Sixty curved molar roots with the same mean canal curvatures and radii in two directions were prepared using ProFile instruments (Dentsply Sirona) to size 30 with .04 taper and obturated with either Thermafil, GuttaCore or vertically compacted gutta-percha and AH Plus (n = 20). Specimens were retreated using the ProTaper Universal Retreatment files D1, D2 and D3 to working length, and root canal preparation was completed with ProTaper Next (Dentsply Sirona) to size ×4. Percentages of residual filling material and dentine removal were assessed using micro-CT imaging. Working time and procedural errors were recorded. Statistical analysis was performed using Kruskal-Wallis and Wilcoxon tests. RESULTS: No significant differences between carrier-based and warm vertical compaction regarding residual filling material (14.2-19.3%) and dentine removal (2.7-3.2 mm3 ) were detected (P > 0.05). Time to reach working length was significantly faster for canals filled with GuttaCore than that observed for Thermafil and warm vertical compaction (P < 0.05). Five lateral perforations with the D3 file occurred during retreatment, one in the Thermafil and four in the vertical compaction group. CONCLUSIONS: Remaining filling material and dentine removal were similar for all canal filling techniques. Regaining working length was significantly faster for GuttaCore compared with Thermafil and vertically compacted gutta-percha. Procedural errors occurred during retreatment of severely curved root canals with the ProTaper Universal Retreatment files in 5 of 60 canals (8%).

Clinical studies on core-carrier obturation: a systematic review and meta-analysis.

BACKGROUND: This systematic review aimed to evaluate the clinical performance of core-carrier obturation in endodontic treatment. METHODS: Keywords of "(core carrier OR Thermafil) OR (cold lateral condensation OR lateral condensation) OR (warm vertical condensation OR vertical condensation) AND (obturation OR root canal filling) AND clinical study" were searched for all obtainable publications up to year 2017 in the databases of PubMed, ScienceDirect, EMBASE, Scopus and Web of Science. The success rate, short-term postoperative pain, overfilling and adaptation of core-carrier obturation from clinical studies were selected. Reviews, laboratory studies, animal studies and irrelevant reports were excluded. RESULTS: 1349 relevant articles were identified with 149 duplicated articles removed and 1173 irrelevant articles were excluded after screening. The titles and abstracts of the 19 identified articles were screened in the systematic review. The full texts of remaining articles were retrieved with data extracted for meta-analysis on the success rate, postoperative pain, overfilling and adaptation of obturation. The pooled success rate of core-carrier obturation was 83% (95% CI: 69%-91%). The pooled incidence of 1-day and 7-day short-term postoperative pain were 35% (95% CI: 15%-62%) and 6% (95% CI: 1-35%). The pooled proportion of teeth with overfilling and adequate adaptation of the obturation material were 31% (95% CI: 18%-50%) and 85% (95% CI: 75%-91%), respectively. CONCLUSIONS: The success rate of endodontic treatment using core-carrier obturation was 83%. Short-term postoperative pain was not uncommon (24%). Most teeth (85%) had adequate adaptation using core-carrier obturation material, but a considerable amount of teeth (31%) had overfilling.

Retrospective evaluation of healing of periapical lesions after unintentional extrusion of mineral trioxide aggregate.

BACKGROUND: During the apexification procedure for teeth with open apices, mineral trioxide aggregate (MTA) may be unintentionally extruded. The aim of the present study was the retrospective evaluation of the healing of periapical lesions in permanent incisor teeth with open apices after the unintentional extrusion of MTA. METHODS: The clinical and radiographic records of 55 maxillary permanent central teeth treated by MTA apexification were evaluated. Filled teeth with unintentionally extruded MTA were selected as group 1 (n = 21), whereas the teeth with no MTA extrusion were selected as group 2 (n = 34). For each tooth, the clinical and radiographic records from a 3-year follow-up were investigated. RESULTS: Complete healing (CH) was observed in 19 teeth (90.4%) in group 1, whereas the same type of healing was observed in all 34 teeth (100%) in group 2 (p>0.05). At the 6-month follow-up appointment, 25 teeth (73.5%) showed CH in group 2, whereas 15 teeth (71.4%) showed CH at the 1-year follow-up in group 1 (p<0.001). At the end of the 3-year follow-up period, the amount of MTA extrusion was reduced in 17 teeth (85%) (p<0.05), whereas it was almost absent in 2 teeth (10%). CONCLUSIONS: The unintentional extrusion of MTA does not prevent the healing of periapical lesions, but may be a delaying factor for periapical healing.

Presence of Voids after Continuous Wave of Condensation and Single-cone Obturation in Mandibular Molars: A Micro-computed Tomography Analysis.

INTRODUCTION: The objective of this study was to assess the presence of voids in mesial root canals of mandibular molar teeth obturated by using the single-cone (SC) and continuous wave of condensation (CWC) obturation techniques, and results were analyzed by using micro-computed tomography. METHODS: Twenty-four mandibular molars with fully developed roots and mesial root curvature ranging from 25° to 35° were instrumented by using Reciproc R25 files, and then they were obturated by using the SC and CWC techniques. Specimens were scanned before and after obturation for micro-computed tomography analysis (voxel size, 17.42 µm). After volumetric analysis and tridimensional reconstruction of the root canals, data were analyzed by using analysis of variance and the Tukey test. RESULTS: No significant differences were observed between the 2 techniques in terms of total percentage volume of voids: CWC = 3.91% ± 0.72%; SC = 6.52% ± 1.16% (P > .05). Only in the cervical third, CWC showed a significantly lower percentage of voids when compared with SC, namely 2.86% ± 0.94% vs 8.00% ± 1.86%, respectively (P < .05). CONCLUSIONS: The percentage volume of voids was similar in the 2 groups and was influenced by the obturation technique only in the cervical third.

Influence of glass fibre post length and remaining dentine thickness on the fracture resistance of root filled teeth.

AIM: To evaluate, ex vivo, the influence of glass fibre post length and remaining thickness of dentine on the fracture resistance of bovine roots, after thermomechanical ageing. METHODOLOGY: Ninety bovine roots of the same size were root filled and randomly distributed into nine groups (n = 10), according to the root weakening protocol (NW - nonweakened; MW - medium weakened; HW - highly weakened) and post length (7 mm; 9 mm and 12 mm). The weakening of roots was performed using diamond burs, resulting in different thicknesses of remaining dentine. The post spaces were prepared, and in the weakened roots, the glass fibre posts were customized with composite resin, to create posts matching the canal size. Chemically activated resin cement was used to lute the posts. After luting, full crowns made of composite resin were attached to a silicon matrix. To reproduce physiological mobility, the roots were covered with polyether and embedded in polyurethane. The thermomechanical cycling was performed (1 200 000 cycles; 88N; 3,8 Hz; 5 ± 1 °C to 55 ± 1 °C). Then, the specimens were subjected to compressive force in a universal testing machine (1 mm min-1 ; 100 kgf) to analyse the fracture resistance. The specimens were analysed through a stereomicroscope to classify the failure mode (repairable/catastrophic). The values were subjected to statistical analysis (two-way anova and Tukey's test at 5%). The frequencies of failure mode were compared using chi-square test. RESULTS: The association between length and dentine thickness was significant (P > 0.05). The difference was between NW and HW roots for posts of 12 mm in length. There was an association between failure mode and the length and remaining dentine thickness. CONCLUSIONS: Reduced dentine thickness in roots with longer posts had lower fracture resistance values, as catastrophic failure was more predominant.