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Background: This study evaluates the fracture resistance of apical plugs created from Biodentine and mineral trioxide aggregate (MTA) in thicknesses of 3 and 5 mm within simulated open apex tooth models., Methods: Fifty human maxillary central incisors were obtained from a pool of freshly extracted teeth. In order to replicate open apices without cavity preparation, ten teeth in the control group received apical-to-coronal preparation with Peeso reamers. The remaining 40 teeth were randomly assigned to four experimental groups and received either 3 or 5 mm Biodentine or MTA apical plugs., Results: The mean fracture loads observed in this study were as follows: control group, 431.48 N (±34.55); 3 mm MTA, 774.88 N (±62.74); 5 mm MTA, 752.65 N (±73.79); 3 mm Biodentine, 918.25 N (±59.09); and 5 mm Biodentine, 903.42 N (±24.48). Specifically, teeth in the Biodentine group demonstrated considerably stronger fracture resistance compared to those in the MTA group ( p < 0.001). However, no significant differences were observed between the 3 and 5 mm thicknesses (MTA: p = 0.98, Biodentine: p = 0.99), suggesting that plug thickness did not affect fracture resistance within both groups., Conclusion: Biodentine apical plugs provided the highest fracture resistance among the materials, regardless of thickness., Competing Interests: Ajinkya M. Pawar is an Academic Editor for PeerJ., (© 2024 Panjwani et al.)

Aims: The aim of this prospective study was to assess the potential benefits of minimally-invasive non-surgical therapy (MINST) in the healing of intrabony defects reaching the apex., Methods: Twenty systemically healthy patients with stage III-IV periodontitis and with at least one tooth with an intrabony defect reaching the apex were included in the study. Step 1 and 2 periodontal therapy including MINST were provided to all patients and patients were then followed up to 12 months post-treatment. Clinical parameters, standardised periapical radiographs and gingival crevicular fluid (GCF) samples were collected at test and control sites. 31 biomarkers were analysed., Results: Three cases did not have the 12-months review (2 drop-outs and 1 tooth lost due to fracture). Despite significant improvements in clinical and radiographic parameters, the majority of defects still had PPD>5mm at the 12-months reassessment, therefore needing further treatment, including endodontic treatment in some cases. A pattern of increase in GCF biomarkers associated with a senescent secretory phenotype was detected immediately after treatment in test sites, with a decrease up to 12 months. An increase in IL-1β and MMP-3 in particular seems to be associated with increased risk to need endodontic treatment post-MINST., Conclusions: The treatment of teeth with unfavourable prognosis and bone loss to the apex with MINST leads to PPD reduction, CAL gain and reduction in radiographic defect depth 12 months after treatment. However, MINST alone may not be sufficient in terms of defects resolution in most of these cases., Clinical Significance: The treatment of teeth with unfavorable prognosis and bone loss to the apex (hopeless) using MINST may lead to consistent PPD reduction, CAL gain and radiographic defect depth reduction after 12 months. However, adjunctive therapies may be necessary to achieve endpoints of therapy in these defects. GCF biomarkers may clarify healing patterns., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

Background: Root canal retreatment is necessary when initial treatment fails. Nickel-titanium systems help remove filling materials; however, some methods can cause canal content extrusion, resulting in inflammation and delayed healing. This study aimed to examine the impact of different preparation techniques and endodontic file systems on apical debris volume to limit material dispersion to periradicular tissues., Methods: Ninety extracted maxillary incisors were evaluated. Simulated apical root resorption was created by removing the apical 2 mm of the root. The teeth were divided into two groups: one filled with a single cone and the other with cold lateral compaction (CLC). Each group was further divided into three subgroups (n = 15 each): Subgroup 1 used Reciproc R25 for removal and R50 for final preparation; Subgroup 2 used ProTaper Universal Retreatment (PTUR) files D1, D2, and D3 for removal and ProTaper Next X5 for finalization; and Subgroup 3 used VDW.Rotate Retreatment (VDW.RotateR) for removal and VDW.Rotate 50.04 for completion. Debris from retreatment was collected in pre-weighed tubes to determine the amount. The apical extrusion data underwent a two-way analysis of variance., Results: The Reciproc group had a mean extruded debris weight of 0.54 ± 0.24 mg, higher than the PTUR (0.28 ± 0.15 mg) and VDW.RotateR (0.39 ± 0.29 mg) groups (p < 0.05). The single-cone technique (SCT) resulted in a mean debris weight of 0.34 ± 0.23 mg, lower than the CLC technique, which had a mean of 0.46 ± 0.27 mg (p < 0.05). SCT had a shorter retreatment duration (111.12 ± 33.46 s) compared to CLC (176.26 ± 52.26 s) (p < 0.05)., Conclusion: The Reciproc file system and the CLC obturation technique resulted in greater apical debris extrusion than the other methods. SCT was quicker than CLC. The Reciproc groups are more susceptible to apex extrusion during retreatment., (© 2024. The Author(s).)

Information regarding the influence of resorption and glide paths on debris extrusion in primary teeth is lacking. Therefore, we evaluated debris extrusion with and without resorption and with and without the use of a path file in primary molar teeth prepared with ProTaper Ultimate (PTU) Prime and TruNatomy (TRN) Prime rotary file systems. Forty resorbed and forty non-resorbed primary molar teeth were collected. Both groups were divided into four subgroups (n = 10). The Eppendorf tubes were weighed pre-debris. The distal canals of the teeth were prepared with PTU Prime and TRN Prime file systems, with and without the use of path files. The debris-filled tubes were weighed, and the weight of only the extruded debris was calculated by subtraction. The data were analyzed using a three-way analysis of variance (ANOVA) test. The presence of tooth resorption significantly increased debris extrusion, and the use of a path file significantly decreased debris extrusion ( p < 0.001). The binary and ternary interactions of the three evaluated parameters among the groups showed no significant differences in terms of the amount of debris extruded ( p > 0.05). While debris extrusion was observed in all groups, the use of a glide path file in primary teeth before the preparation process resulted in less debris extrusion., Competing Interests: The authors declare no conflict of interest., (©2024 The Author(s). Published by MRE Press.)

Objective: The aim of the present pilot study was to assess the effectiveness of the platelet-rich fibrin (PRF) apical barrier for the placement of MTA for the treatment of teeth with periapical lesions and open apices., Methods: A total of thirty teeth on twenty-eight patients with open apices and periapical periodontitis were enrolled and divided into two groups in the present pilot study. In the PRF group (fourteen teeth in thirteen patients), nonsurgical endodontic treatment was performed using PRF as an apical matrix, after which the apical plug of the MTA was created. For the non-PRF group (fourteen teeth in fourteen patients), nonsurgical endodontic therapy was performed using only the MTA for an apical plug with no further periapical intervention. Clinical findings and periapical digital radiographs were used for evaluating the healing progress after periodic follow-ups of 1, 3, 6, and 9 months. The horizontal dimension of the periapical lesion was gauged, and the changes in the dimensions were recorded each time. The Friedman test, Dunn-Bonferroni post hoc correction, and Mann-Whitney U test were used for statistical analysis, with P < 0.05 serving as the threshold for determining statistical significance., Results: All patients in both groups in the present pilot study had no clinical symptoms after 1 month, with a significant reduction in the periapical lesion after periodic appointments. The lesion width of the PRF group was significantly smaller than that of the non-PRF group in the sixth and ninth month after treatment., Conclusions: PRF is a promising apical barrier matrix when combined with MTA for the treatment of teeth with open apices and periapical periodontitis. Small number of study subjects and the short time of follow-up period limit the generalizability of these results., Trial Registration: TCTR, TCTR20221109006. Registered 09 November 2022 - Retrospectively registered, https://www.thaiclinicaltrials.org/show/TCTR20221109006 ., (© 2024. The Author(s).)

Background: External apical root resorption (EARR) is a frequently observed adverse event in patients undergoing fixed appliance therapy. Assessing the patients' risk during treatment is important, as certain factors are assumed to be associated with an increased likelihood of occurrence. However, their predictive value remains limited, making evidence-based clinical decision-making challenging for orthodontists. To address this issue, the Dutch Association of Orthodontists (NvVO) developed a clinical practice guideline (CPG) for EARR in accordance with the AGREE II instrument (Appraisal of Guidelines for Research and Evaluation II) in 2018. The aim of this study is to get insight into the actual utilization and the practical implementation of the guideline among orthodontists. The hypothesis to be tested was that after its introduction, clinical practice for EARR has changed towards the recommendations in the CPG., Objective: To investigate the use of the 2018 clinical practice guidelines for EARR among orthodontists 3 years after its introduction., Methods: A questionnaire using a 7-point Likert scale was developed concerning four domains of EARR described in the guideline. The questionnaire was piloted, finalised, and then distributed digitally among Dutch orthodontists. REDCap was used for data collection, starting with an invitation email in June 2021, followed by two reminders. Effect was tested by the Mann-Whitney U test, and the influence of demographic variables was analysed., Results: Questionnaires were sent out to all 275 and completed by 133 (response rate 48%); N = 59 females and N = 73 males were included; 81% had their training in the Netherlands, 89% had ≥ 6 years of work experience, and 89% worked in private orthodontic practice. One hundred thirty orthodontists (98.5%) reported changes in clinical practice. The biggest positive change in clinical behaviour regarding EARR occurred if EARR was diagnosed during treatment. Sex, clinical experience, country of specialist training, and working environment of the respondents did not affect clinical practices regarding EARR., Conclusions: This questionnaire demonstrated that, 3 years after introduction of the guideline, orthodontists improved their self-reported clinical practices to a more standardised management of root resorption. None of the demographic predictors had a significant effect on the results., (© 2024. The Author(s).)

Introduction: Dental pulp regeneration is challenging in endodontics. Cellular therapy is an alternative approach to induce dental pulp regeneration. Mesenchymal stromal cells (MSCs) have the capacity to induce dental pulp-like tissue formation. In this study, we evaluated the capacity of allogeneic bone marrow MSCs (BM-MSCs) to regenerate pulp following necrosis and apical periodontitis in children's permanent immature apex teeth., Methods: Patients aged 8 to 12 years with pulp necrosis and apical periodontitis were evaluated. The study included 15 teeth (13 incisors and 2 molars) from 14 patients (8 boys and 6 girls). Radiographic evaluation showed periapical radiolucency and immature apex teeth. There was no response to cold or electric pulp testing. The root canal of each tooth was cleaned, shaped, and Ca(OH) 2 used as an interappointment medication. Cryopreserved allogeneic BM-MSCs were thawed, expanded, incorporated into preclotted platelet-rich plasma, and implanted into the tooth's pulp cavity. They were sealed with bioceramic cement and composite. Sensibility, apical foramen, calcium deposits within the root canal, and resolution of periapical lesions were evaluated in each tooth over the following 12 months., Results: Based on 9 variables established for dental pulp-like tissue regeneration, all MSC-treated teeth showed evidence of successful regeneration. Clinical and radiographic evaluation of the treated teeth showed periapical lesion healing, sensitivity to cold and electricity, decreased width of the apical foramen, and mineralization within the canal space., Conclusions: Transplantation of allogeneic MSCs induces the formation of dental pulp-like tissue in permanent immature apex teeth with pulp necrosis and apical periodontitis. Implant of MSCs constitutes a potential therapy in regenerative endodontics in pediatric dentistry. Future studies incorporating a larger sample size may confirm these results., (Copyright © 2024 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

This canine in vivo study assessed the effect of recombinant human platelet-derived growth factor (rhPDGF) on the healing of periapical tissues following apical surgery. From a total of 96 premolar teeth, 64 teeth from six beagle dogs (2 years old) were classified as experimental and were randomly assigned to four experimental groups (16 teeth per group). After having the pulp extirpated, leaving teeth open to the oral cavity for 1 week, and sealing with an immediate restorative material for 8 weeks, nonsurgical endodontic treatment was performed. A split-mouth design was used, and intra-animal randomization of treatment sides was applied to the groups as follows: apical curettage + 1.5-mm root-end resection (Group 1); apicoectomy + mineral trioxide aggregate (MTA) root-end filling (Group 2); apicoectomy + MTA root-end filling + rhPDGF (Group 3); and apical curettage + rhPDGF (Group 4). The animals were sacrificed 24 months after apical surgery, and histologic and μCT analyses were performed for bone volume loss (BVL). Group 1 showed partial resolution of the periapical lesions without signs of tissue regeneration (BVL: 49.09 ± 10.97 mm3). Group 2 had minimal bone regeneration and showed cementum reformation in 9 teeth, with no direct attachment to the MTA (BVL: 35.34 ± 10.97 mm3). Group 3 showed regeneration of all damaged apical tissues without direct contact between the cementum and MTA (BLV: 4.51 ± 1.55 mm3). Group 4 showed regeneration of PDL, bone, and cementum and attachment of functional cementum fibers (BVL: 2.82 ± 2.3 mm3). The difference in BVL was statistically significant only for Groups 1 and 2 (P < .05). rhPDGF may help regenerate apical tissue structures following apical surgery.

Background: The present study aimed to evaluate the effectiveness of using platelet-rich fibrin (PRF) as the apical matrix for the placement of MTA in nonsurgical endodontic therapy for teeth with periapical lesions and open apices., Methods: Twelve teeth from eleven patients with periapical periodontitis and open apices were enrolled in the study. Nonsurgical endodontic therapy was performed with the PRF used as an apical barrier and the MTA manipulated as an apical plug for further thermoplasticized gutta percha in the remaining part of the root canal. Clinical signs and periapical digital radiographs were recorded and analyzed to evaluate the curing progress after periodical follow-ups of 1, 3, and 6 months. The horizontal dimension of the periapical lesion was determined, and the changes in the dimensions were recorded each time. The Friedman test was used for statistical analysis, with P < .05 serving as the threshold for determining statistical significance., Results: All patients had no clinical symptoms after the first month of treatment, with a significant reduction in the periapical lesion after periodical appointments., Conclusions: PRF is an effective barrier when combined with MTA for the treatment of teeth with periapical periodontitis and open apices., (© 2024. The Author(s).)

Aim: This report addresses the management of a large persistent discharging lesion in an 11-year-old boy. The report describes the use of aspiration-irrigation technique for the management of immature necrotic tooth with persistent discharge after a failed regenerative procedure., Background: Regenerative endodontics aim to provide an increase in root canal width, length, and in apical closure. Alternative procedures, such as apexification, should be attempted when regeneration fails. If the canal cannot be dried to persistent discharge, the aspiration-irrigation technique can be used. The technique relies on using aspiration along with irrigation to remove pus from the periapical area., Case Description: This is a case for an 11-year-old patient who had trauma to tooth #11, which resulted in the complicated crown fracture. He had an emergency management that included pulpectomy and intracanal medication at another clinic. Two years later, the patient was presented to our clinic. Upon examination, the diagnosis was previously initiated therapy with asymptomatic apical periodontitis in immature tooth #11. Regeneration was attempted first but failed. The mineral trioxide aggregate (MTA) plug was removed, and the canal had persistent pus discharge. The canal was filled with intracanal medication, and then 2 weeks later, the canal was filled with triple antibiotic paste (TAP). Next visit, and due to continuous discharge, tooth #11 was treated conservatively with an intracanal aspiration-irrigation technique. An IrriFlex needle attached to a high-volume suction was used to aspirate the cystic fluid. Mineral trioxide aggregate plug apexification was performed in a later visit and the tooth was restored., Conclusion: During the 3-month and 16-month follow-up, there was resolution of the symptoms, a decrease in the periapical lesion size, and soft tissues appeared within normal limits., Clinical Significance: Regenerative procedures are a good option for immature necrotic teeth. These procedures may fail due to persistent pus discharge from the root canals. The aspiration-irrigation technique is a good treatment option in cases of consciously discharging canals. How to cite this article: Alsofi L, Almarzouki S. Failed Regenerative Endodontic Case Treated by Modified Aspiration-irrigation Technique and Apexification. J Contemp Dent Pract 2024;25(1):92-97.

Background : Endodontic success depends on the complete cleaning and shaping of the root canal. In order to achieve this goal, debris removal is essential. Even with improvements in instrument design, apical debris extrusion continues to be a cause of periradicular inflammation. The current study aimed to compare the amount of apically extruded debris throughout the canal instrumentation with TruNatomy, ProTaper Next, 2Shape rotary systems. Methods : A total of 60 freshly extracted single‑rooted mandibular premolars were used. An access opening was made, and a working length was estimated. The samples were arbitrarily allocated into three groups i.e. Group I: TruNatomy (n = 20), Group II: ProTaper Next (n = 20), Group III: 2Shape (n = 20). During the canal instrumentation, the extruded debris were collected in preweighed Eppendorf tubes. Post-instrumentation, the tubes were placed in a hot air oven at 140°C for five hours. For calculating the dry debris weight, the tube's pre-instrumentation weight was deducted from the post-instrumentation weight. The data was analysed using one‑way analysis of variance and post hoc Tukey's test. Results : Extrusion of debris was noted in all the specimens. TruNatomy rotary system showed least debris extrusion in comparison to ProTaper Next and 2Shape (P < 0.05). However, the results were statistically non-significant between ProTaper Next and 2Shape (P > 0.05). Conclusions : It was noted that all instruments apically extruded debris, with TruNatomy system being related to minimum extrusion., Competing Interests: No competing interests were disclosed., (Copyright: © 2023 Rajnekar R et al.)

Aim: To determine the efficacy of endodontic microsurgery for teeth with an undeveloped root apex and periapical periodontitis caused by an abnormal central cusp fracture after failed nonsurgical treatment., Methodology: Eighty teeth in 78 patients were subjected to endodontic microsurgery. All patients were clinically and radiologically examined 1 year postoperatively. The data were statistically analyzed using SPSS 27.0 software., Results: Of the 80 teeth in 78 patients, periapical lesions had disappeared in 77 teeth at 1-year postoperative follow-up, with a success rate of approximately 96.3% (77/80). The efficacy of endodontic microsurgery was not affected by sex, age, extent of periapical lesions, and presence of the sinus tract. Between-group differences were not statistically significant (P > 0.05)., Conclusions: Endodontic microsurgery can be an effective alternative treatment option for teeth with an undeveloped root apex and periapical periodontitis caused by an abnormal central cusp fracture after nonsurgical treatment failure., (© 2023. The Author(s).)

Pre-Eruptive Intracoronal Resorption (PEIR) is a rare yet significant phenomenon in which an abnormal, well-circumscribed, radiolucent area develops in the tooth prior to eruption. This case report outlines the treatment of a 12 year old Hispanic female who was referred for endodontic evaluation of tooth #31 and subsequently diagnosed with PEIR. The patient's chief complaint was recorded as "spontaneous pain" in the lower right quadrant of her jaw. Clinical examination revealed a partially erupted tooth #31 with no visible decay. Radiographic examination, including a cone beam computed tomography scan, led to the detection of a radiolucent area surrounding the pulp chamber on the mesial aspect of tooth #31. Radiographically, the enamel appeared intact with no signs of perforation. Based on the clinical and radiographic evaluation, tooth #31 was determined to have PEIR, with the pulpal and periapical diagnosis of "Symptomatic Irreversible Pulpitis" and "Normal Apical Tissue," respectively. The Orthodontic consultation obtained for this patient recommended that tooth #31 be maintained at least until tooth #32 appeared in the oral cavity and could be used as a replacement. Therefore, a treatment plan involving vital pulp therapy and gingivectomy was selected. During the procedure, granulation tissue was excavated and sent for histological evaluation, which concluded the presence of "granulation tissue with acute and chronic inflammation". No caries were detected. Following the procedure, the tooth was found to be asymptomatic with continued root development. A positive response to Electric Pulp Test was achieved after 3.5 years of follow up., (Copyright © 2022 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Purpose: To evaluate the effectiveness of apexification versus revascularization in the treatment of necrotic immature teeth and determine which strategy affords the greatest radiological success rate., Methods: An analysis was made of 18 teeth subjected to mineral trioxide aggregate (MTA) apical plugging and regenerative endodontic treatment, assessing healing of the apical lesions and the changes in root dimensions., Results: Significantly greater root growth was observed with revascularization in terms of the percentage change in length (12.75% at 6 months) and dentin thickness (34.57% at 6 months) (p < 0.05). There were no significant differences between the two treatments in terms of the apical healing scores after 6 months of follow-up (p > 0.05)., Conclusion: Apexification with an MTA apical plug and pulp regeneration are reliable treatments for non-vital immature teeth. The radiographic outcomes are comparable between the immature teeth subjected to MTA apexification versus those subjected to revascularization. The results of the present study indicate a greater increase in root length and width with regenerative endodontic treatment., (© 2022. The Author(s).)

Background: Dens invaginatus (DI) is a developmental anomaly, Oehlers Type III DI is the most complex type and early diagnosis and treatment is complicated and challenging. This report presents a rare case of a type IIIb DI associated with a periapical lesion in bilateral immature permanent mandibular central incisors., Case Presentation: An eight-year-old boy referred to our clinic manifesting with pain along with swelling in the mandibular incisors for the past one month. Radiographic examination showed periapical radiolucency exhibiting a scantly defined border, as well as an invagination which had a central invaginated canal extending from the pulp chamber throughout the apical foramen in both mandibular central incisors. We performed two different treatment procedures on the basis of the condition of the main pulp of the mandibular central incisors. in which only the invagination root canal was treated in the right mandibular central incisor, while the invagination and main root canals were treated in the left mandibular central incisor. During the 18-month follow-up period, the teeth were clinically asymptomatic. Imaging examinations indicated complete healing of the periapical lesion and revealed that the wall of the root canal was thickened and the open apex was closed., Conclusion: For young permanent teeth with type III Dens invaginatus, it is particularly important to keep pulp vitality, which could maintain root development and allow a good long-term prognosis., (© 2022. The Author(s).)

Introduction: Malignant nonendodontic periapical lesions represent a rare diagnosis, in which few case have been reported about this condition. Due to the low occurrence and little exploration of this subject, serious errors of diagnosis are observed in the oral medicine services. In this sense, the purpose of the present review was to integrate the information on the record published on malignant lesions that mimic endodontic pathoses into a comprehensive analysis of their clinical, radiologic, and histopathologic features., Methods: An online search was made in March 2020 in the following databases: Pubmed, Web of Science, and Scopus. Eligibility criteria included publications having enough clinical, radiologic, and histopathologic information to confirm the diagnosis. Data were assessed descriptively., Results: Forty-nine publications from 16 countries comprising 60 cases were included. There is a nearly equal occurrence rate between males and females (male/female ratio is 49.15%/50.84%) with a mean age of 46.56 years. The lesions were more prevalent in the posterior mandibles (40.69%), and, radiographically, they were unilocular radiolucent. Histopathologic analysis showed metastasis (26.67%) as the most prevalent lesion followed by salivary gland malignant disease (25%)., Conclusions: The present systematic review revealed several histologic types of malignant periapical lesions that could be mimicking endodontic pathoses. Because these lesions usually do not show clinical or radiologic features of malignant alteration, clinicians should consider these hypotheses in their routine., (Copyright © 2020 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Purpose/Aim : The aim of this study was to explore whether dentinogenesis imperfecta (DGI)-related aberrations are detectable in odontogenic tissues. Materials and Methods : Morphological and histological analyses were carried out on 3 teeth (two maxillary 1 st molars, one maxillary central incisor) extracted from a patient with DGI Type II. A maxillary 2 nd molar teeth extracted from a healthy patient was used as control. A micro-computed tomographic (μCT) data-acquisition system was used to scan and reconstruct samples. Pentachrome and picrosirius red histologic stains were used to analyze odontogenic tissues and their collagenous matrices. Results : Our findings corroborate DGI effects on molar and incisor root elongation, and the hypo-mineralized state of DGI dentin. In addition to these findings, we discovered changes to the DGI pulp cavity: Reactionary dentin formation, which we theorize is exacerbated by the early loss of enamel, nearly obliterated an acellular but still-vascularized DGI pulp cavity. We also discovered an accumulation of lamellated cellular cementum at the root apices, which we hypothesize compensates for the severe and rapid attrition of the DGI tooth. Conclusions : Based on imaging and histological data, we propose a novel hypothesis to explain the complex dental phenotypes observed in patients with DGI Type II.

This study evaluated the long-term clinical outcomes of single-visit root canal treatments with apical enlargement on patients with necrotic pulp tissue retrospectively. A total of 137 teeth with necrotic pulp tissue which underwent single-visit root canal treatments were included. The root canals were shaped up until the apical constriction, which was determined by an apex locator. The outcomes were evaluated by two independent and calibrated endodontists clinically and radiographically. Teeth were dichotomized into healed (PAI ≤ 2, no signs or symptoms) and nonhealed (PAI > 2, with/without signs or symptoms) groups. Each patients' preoperative PAI and lesion size were recorded to evaluate the preoperative periapical status as well as several other prognostic factors. Statistical analyses were performed ( p = 0.05) on ninety teeth. The mean observation time was 60 months. Out of ninety teeth, 87 (96.7%) were healed and 3 (3.3%) were nonhealed. No correlations were found between the prognostic factors and the outcomes ( p > 0.05). Cohen's kappa and Gwet's agreement coefficient scores between the preoperative PAI scores and preoperative lesion sizes showed good agreements, with values of 0.834 and 0.898, respectively. Apical enlargement is a viable treatment option for single-visit root canal treatments., Competing Interests: The authors declare no conflict of interest regarding any of the materials used in this study., (Copyright © 2020 Tan F. Eyüboğlu et al.)

Objective: The aim of this study was to compare apical debris extrusion when neodymium-doped yttrium aluminium garnet (Nd:YAG) lasers, erbium-doped yttrium aluminium garnet (Er:YAG) or photon-induced photoacoustic streaming (PIPS) are used for irrigation activation. Materials and methods: A total of 60 extracted human mandibular premolar teeth have similar dimensions were included and the samples were split into four groups according to the irrigation technique ( n  = 15): conventional needle irrigation, PIPS, Er:YAG and Nd:YAG. ProTaper Universal system up to F4 was used for root canal instrumentation. Bidistilled water was used as an irrigation solution during instrumentation and irrigation activation. Apically extruded debris was collected into preweighed Eppendorf tubes during instrumentation and irrigation activation procedures. The tubes were then kept in an incubator at 70 °C for 5 days. The initial weight of the tube was subtracted from the final weight and the result was recorded as the weight of dry extruded debris. The data were evaluated statistically using a one-way ANOVA test followed by least significant difference post hoc test ( p  < .05). Results: Conventional needle irrigation caused significantly less debris extrusion than laser-assisted irrigation activation groups ( p  < .05). Laser-assisted irrigation activation groups caused statistically similar debris extrusion ( p  > .05). Conclusion: Laser-assisted irrigation activation techniques caused more debris extrusion when compared to conventional needle irrigation.

Introduction: The aim of this report is to present a case of an apically involved tooth with successful regeneration by only applying enamel matrix derivative. The root of the tooth was planed and the defect area was well debrided using various instruments, including curettes and an ultrasonic scaler, and the root surface of the tooth and the defect area were loaded with enamel matrix derivative., Patient Concerns: A 32-year-old man visited the clinic due to a referral for the evaluation of his mandibular left first molar., Diagnosis: The clinical and radiographic assessment displayed the loss of the periodontium around the tested tooth with apical involvement of the mesial root. Bleeding upon probing was noted at the mandibular first molar, with the deepest periodontal probing depth of 15 mm., Interventions: A nonsurgical approach was firstly performed on the tooth, and the deepest probing depth was reduced to 12 mm. After re-evaluation, elevation of a full-thickness flap was done, the root of the tooth was planed, and the defect area was well debrided using various instruments, including curettes and an ultrasonic scaler. The defect area on the mandibular left first molar was grafted with enamel matrix derivative., Outcomes: The 7-month postoperative clinical and radiographic evaluation showed healthy gingiva and an increase in radiopacity. The final 1-year and 9-month postoperative evaluation showed that regeneration of bony defect was well maintained up to the final evaluation with reduction of probing depth., Conclusion: In conclusion, a case of apically involved tooth can be treated only with enamel matrix derivative after meticulous debridement with curettes and an ultrasonic scaler.

This study aimed to evaluate the role of photobiomodulation (PBM) in apexification and apexogenesis of necrotic rat molars with an open apex. Rat molars were exposed to the oral environment for 3 weeks. Canals were rinsed with 2.5% NaOCl and 17% EDTA, filled with antibiotic paste and sealed. After 7 days, canals were rinsed and divided into six groups (n=6): mineral trioxide aggregate (MTA); blood clot (BC); human dental pulp stem cells (hDPSC); MTA+PBM; BC+PBM; and hDPSC+PBM. In hDPSC groups, a 1% agarose gel scaffold was used. Two groups were not exposed: healthy tooth+PBM (n = 6), healthy tooth (n = 3); and one was exposed throughout the experiment: necrotic tooth (n = 3). In PBM groups, irradiation was performed with aluminum gallium indium phosphide (InGaAlP) diode laser for 30 days within 24-h intervals. After that, the specimens were processed for histological and immunohistochemical analyses. Necrotic tooth showed greater neutrophil infiltrate (p < 0.05). Necrotic tooth, healthy tooth, and healthy tooth+PBM groups showed absence of a thin layer of fibrous condensation in the periapical area. All the other groups stimulated the formation of a thicker layer of fibers (p < 0.05). All groups formed more mineralized tissue than necrotic tooth (p < 0.05). PBM associated with MTA, BC, or hDPSC formed more mineralized tissue (p < 0.05). MTA+PBM induced apexification (p < 0.05). Rabbit polyclonal anti-bone sialoprotein (BSP) antibody confirmed the histological findings of mineralized tissue formation, and hDPSC groups exhibited higher percentage of BSP-positive cells. It can be concluded that PBM improved apexification and favored apexogenesis in necrotic rat molars with an open apex.

Background: This study evaluated the antibacterial efficiency and ability of propolis to promote regeneration of immature permanent non-vital dogs' teeth., Methods: Ninety six immature permanent premolars teeth in 6 mongrel dogs were divided randomly into: experimental teeth (N = 72) and control teeth (N = 24). Periapical pathosis was induced in all experimental and positive control teeth. Experimental teeth were classified according to the used intra-canal medication into: group I (N = 36), propolis paste was used and group II (N = 36), triple antibiotic paste (TAP) was used. Bacteriologic samplings were collected before and after exposure to intra-canal medicaments. After the disinfection period (3 weeks), revascularization was induced in all experimental teeth. Each group was subdivided according to the root canal orifice plug into: subgroup A (N = 18), propolis paste was used and subgroup B (N = 18), mineral trioxide aggregates (MTA) was used. Each subgroup was further subdivided according to the evaluation period into 3 subdivisions (6 teeth each): subdivision 1; after 2 weeks, subdivision 2; after one month and subdivision 3; after 2 months. Positive control group had 12 teeth with induced untreated periapical pathosis. Negative control group had 12 untouched sound teeth. All teeth were evaluated with radiography and histology. The bacteriologic and radiographic data were analyzed using repeated measures ANOVA and post-hoc Tukey tests. The histologic data were analyzed using Kruskal-Wallis test, Mann-Whitney U test with Bonferroni's adjustment and Chi-square test. The significance level was set at P ≤ .05., Results: There was no significant difference in the antibacterial effectiveness between TAP and propolis groups (P > .05). In all subdivisions, there was no significant difference between the experimental groups in terms of increase in root length and dentin thickness, decrease in apical closure, new hard tissue formation, vital tissue formation inside the pulp canal and apical closure scores (P > .05)., Conclusion: Propolis can be comparable with TAP as a disinfection treatment option in regenerative endodontic. As a root canal orifice plug after revascularization of necrotic immature permanent teeth in dogs, propolis induces a progressive increase in root length and dentin thickness and a decrease in apical diameter similar to those of MTA.

Background: This study was performed to evaluate the amount of apically extruded debris removed from a root canal filled with cold lateral condensation (CLC), and warm vertical compaction (WVC) techniques, using b or a phase gutta-percha with AH-Plus (Dentsply DeTrey, Konstanz, Germany) or Resilon (Resilon Research LLC, Madison, WI) with RealSeal SE (SybronEndo, Amersfoort, The Netherlands)., Materials and Methods: About 100 human incisor teeth were prepared with a #25.06 NiTi rotary system and divided into five groups according to the filling material used: Group 1: CLC (gutta-percha, AH-Plus); Group 2: WVC (b phase gutta-percha, AH-Plus); Group 3: WVC (a phase gutta-percha, AH-Plus); Group 4: CLC (Resilon, RealSeal SE); and Group 5: WVC (Resilon, RealSeal SE). Extruded debris during the retreatment procedure was collected in preweighed Eppendorf tubes. The times required for retreatment were recorded., Results: The amount of debris extrusion was significantly greater with WVC than CLC in the gutta-percha and Resilon groups (P < 0.001). Using a phase gutta-percha resulted in significantly more debris extrusion than b phase gutta-percha (P < 0.001). In the WVC groups, Resilon caused significantly more debris extrusion than gutta-percha (P < 0.05). Retreatment was faster for CLC than WVC (P < 0.05)., Conclusions: In the retreatment procedure, the amount of apically extruded debris and retreatment duration were dependent on the type of obturation material and technique used., Competing Interests: None

Objective: The aim of this study was to evaluate the relationship between length of root canal obturation (RCO) and the presence of apical periodontitis (AP) in different dental groups using cone-beam computed tomography (CBCT) analysis., Materials and Methods: A total of 392 roots with canal treatment performed for more than 4 years were evaluated using CBCT. Distances from the apex to the tip of filling material were measured and classified as more than 2 mm short of the apex, approximately 1-2 mm short of the apex, at the apex, and beyond the apex. Odds ratio, confidence interval, and the χ 2 test were used for statistical analyses., Results: The frequency of AP was significantly greater in molars than in the other tooth groups (p < 0.05). Moreover, RCO that ended 1-2 mm short of the apex was associated with a lower prevalence of AP in molars and premolars (p < 0.05) and in anterior teeth (p < 0.1) when compared with RCO at the apex, more than 2 mm short of the apex, or beyond the apex. When the RCO reached the apex, there was no difference in the presence of AP among dental groups (p > 0.05)., Conclusion: The length of RCOs can influence the presence of AP, with molars showing a higher prevalence. RCOs ending 1-2 mm short of the apex are associated with an absence of AP., Clinical Relevance: The length of obturation is related to the presence of apical peridontitis and consequently to the success of endodontic treatment.

Objectives: The aim of this study was to evaluate the influence of foraminal enlargement on the healing of induced apical periodontitis in a rat model., Material and Methods: Periapical lesions were bilaterally induced in mandibular first molars of 24 Wistar rats, through root canals exposure to the oral environment during 3 weeks. Endodontic treatment was performed in the mesial canal of right molars, which were separated into two experimental groups (n = 12/group). The foraminal enlargement group (FEG) received instrumentation in the entire root canal length, including the cemental canal, while in the non-foraminal enlargement group (NFEG), instrumentation was carried out 1 mm short of the apical foramen. Root canals were filled with gutta-percha and AH Plus sealer, in the same visit, 1 mm short of the apical foramen in both experimental groups. Left molars were not treated and served as a baseline control group. The animals were killed after 4 weeks, and their hemi-mandibles were prepared for radiographic and histological analysis. Data were analyzed by Student's t test and ANOVA., Results: Only FEG presented lower areas of periapical radiolucency compared to the control (p < .05). Both FEG and NFEG allowed decreased inflammation intensity (p < .0001 and p < .01) and higher scores of cementum neoformation when compared to non-treated samples (p < .0001). FEG was more effective than NFEG in promoting biological seal, i.e., apical closure with cementum (p < .01). FEG, but not NFEG, showed lower scores of root resorption than the control., Conclusions: Foraminal enlargement during root canal preparation improved periapical healing in rat molars., Clinical Significance: Foraminal enlargement has been suggested to improve disinfection at the apical portion of root canals. This procedure may favor the healing of chronic periapical lesions.

Despite the fact that external cervical resorption (ECR) is a well-known and rather frequently met condition, the driving force of this phenomenon still remains unclear. Recently, hypoxia has been linked to ECR. Thus, the aim of this work was to investigate the existence of hypoxia in ECR and hypothesize on its role at the time of extraction. This work is a case study of a tooth with ECR. ECR diagnosis was based on clinical and radiographic examination with cone-beam computed tomographic imaging. The extracted tooth was further analyzed by using nanofocus computed tomographic imaging and immunohistology. To investigate the 3-dimensional extent and pattern of ECR, in vivo cone-beam computed tomographic imaging and ex vivo nanofocus computed tomographic imaging were used. Different histologic stains were used to investigate the presence of a hypoxic environment and to gain a better insight into the involved cells, neuronal structures, and remodeling process during ECR. A higher distribution of hypoxia-inducible factor 1a-positive cells was found in the apical part of the resorption area when compared with the coronal area of the resorption. In addition, a similar distribution of hypoxia-inducible factor 1a-positive odontoblasts was observed in the pulp. Three-dimensional analysis of the calcification of the pulp revealed the formation of pulp stones in areas with higher hypoxia. Histology showed that remodeling during ECR can occur according to a layered pattern. This investigation confirms the presence of hypoxia in ECR and shows that there is a gradient of hypoxia within the ECR lesion and surrounding tooth structure. The hypoxic environment within the pulp is also indicated by the formation of pulp stones., (Copyright © 2018 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Background: Accurate working length (WL) determination is necessary in achieving optimal healing by non-surgical root canal therapy in teeth with inflammatory apical root resorption. Electronic apex locators (EALs) are one of the mainstays in determination of WL of teeth., Aim: This study evaluated the accuracy of three EALs [RootZX (third generation), iPex (fourth generation) and Raypex 6 (modification of a fifth generation)] in determining the WL of teeth with simulated apical root resorption in permanent teeth., Materials and Methods: Forty freshly extracted maxillary anterior teeth were collected and a 45° oblique cut was made at the root apex with a disc to simulate apical root resorption. Actual working length (AWL) was determined by direct visual method and was used as a control. Electronic working length (EWL) values were measured by three different apex locators that are RootZX (Group I), iPex (Group II) and Raypex 6 (Group III) at apex, 0.5 mm and 1 mm from apex. All values obtained were tabulated and statistical evaluation was carried out., Results: At apex, EWL obtained using iPex (p=0.05) showed a statistically significant difference from AWL. At 0.5 mm and 1.0 mm tolerance, iPex showed non-acceptability for WL measurement in 67.5% and 17.5% of samples compared to Root ZX (12.5% and 2.5%) and Raypex (7.5% and none) respectively., Conclusion: Within the limitation of this study, it can be concluded that Raypex 6 and RootZX show statistically significant accuracy in WL measurement compared with iPex in teeth with apical root resorption.

Aim: The aim of this in vivo study was to evaluate the revascularization procedure both in immature and mature teeth with necrotic pulp and open apices, disinfected with triple antibiotic paste followed by inducing blood clot in the root canal., Materials and Methods: Fifteen patients were selected who presented with immature and mature permanent teeth with pulpal necrosis and open apices. In the first visit, the root canal was accessed with LA and rubber dam isolation; then the canal was disinfected using triple antibiotic paste containing ciprofloxacin, metronidazole, and clindamycin in the ratio of 1:1:1 and closed with IRM. In the second visit, after administering local anesthesia and isolating with a rubber dam, the triple antibiotic paste was washed out by saline irrigation, and apical papilla beyond the confines of the root canal was stimulated with sterile H file to produce a blood clot. Finally, the access was closed using a double seal with mineral trioxide aggregate (MTA) placed apical to cementoenamel junction and resin bonded cement over the MTA. Radiographic examination and pulp sensibility test was done during the follow-up period of 2,4,6,8 and 10 months., Result: After 10 months follow-up, 10 out of 13 patients showed root development and apical closure. The eight patients out of 13 showed root development, apical closure and lateral thickening of radicular dentin and 2 out of 13 patients showed a positive response to electric sensibility test., Conclusion: Within the limitation of this study, it can be concluded that there is evidence of root development, increase in lateral wall thickness, apical closure and positive response to pulp sensibility test in both mature and immature teeth with necrotic pulp., Clinical Significance: The conventional approach for management of teeth with necrotic pulp and the open apex is altered with the possibility of tissue regeneration within the pulp space and continued root development through revascularization procedures. It also re-establishes the vitality in a previously nonvital and necrosed tooth.

Aim: To evaluate the influence of different apical enlargement protocols on the radiographic and histological healing of apical periodontitis in rats., Methodology: Apical periodontitis was induced bilaterally in the mandibular right and left first molars of 24 Wistar rats by pulp exposure to the oral cavity for 3 weeks. A standard serial root canal preparation technique was performed in the molar of one side, whilst the opposite side was the control group. Rats were randomly divided into three experimental groups (n = 8), according to the diameter of apical enlargement during root canal preparation: K-files size 20 (EG1), size 25 (EG2) and size 30 (EG3). Each animal was its own positive control, because the opposite arch remained untreated. Root canals were filled with a standard technique. After 3 weeks, the animals were euthanized. The main outcome of apical periodontitis healing was evaluated radiographically (mm 2 ) and histologically (ordinal scores of inflammation) using a HE staining technique. The measurement of effect was obtained between the three experimental groups by carrying out generalized estimating equations, with Poisson regression with robust variance, pairing each experimental group with its respective control group within animals, adjusted for the mean within animal differences, with α = 5%., Results: The mean and standard deviations of radiographic apical periodontitis size (mm 2 ) and intensity of histological inflammatory scores were, respectively: EG1 (0.44 ± 0.27; 2.25 ± 0.46), EG2 (0.33 ± 0.10; 2.50 ± 0.53) and EG3 (0.22 ± 0.08; 2.63 ± 0.74). After 3 weeks, a significantly more favourable radiographic repair was observed when larger apical enlargement was performed (EG3), compared to EG1 and EG2 (P = 0.001). All experimental groups were associated with a significant difference on the radiographic and histological healing of apical periodontitis compared with its respective control group., Conclusion: Under the experimental conditions of this study, a larger apical enlargement protocol favoured a more rapid radiographic repair of apical periodontitis in rats after a 3-week follow-up., (© 2018 International Endodontic Journal. Published by John Wiley & Sons Ltd.)

This article describes 2 unusual cases of mucosal fenestration associated with necrotic infected teeth, resulting in exposure of the root apex to the oral cavity. Both cases consisted of maxillary incisors with pulp necrosis and radiographic/tomographic evidence of apical periodontitis. Clinically, the root apex was exposed to the oral cavity through a fenestration in both bone and mucosa and covered with bacterial plaque and calculus. These teeth were treated by a combination of nonsurgical and surgical endodontic treatment. During surgery, the root apices were resected to within the alveolus and the fenestrated area covered by the flap. Specimens consisting of the root apex and surrounding soft tissues were subjected to histopathological and histobacteriological analyses. Histobacteriological analysis revealed extensive resorptive defects on the root apices filled with thick bacterial biofilm, irregular detachment of the cementum layers with consequent infection of the underlying spaces, and heavy infection in the apical foramina. The soft tissue specimens exhibited no or minimal inflammation. The 2 cases showed satisfactory postsurgical healing of the hard and soft tissues. Both cases of mucosal fenestration showed root apices covered with dense bacterial biofilms and associated with a bone crypt with no significant inflammatory tissue therein. The 2 cases were successfully treated by conservative approaches involving a combination of nonsurgical and surgical endodontic treatment with root-end resection., (Copyright © 2018 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: The purpose of this study was to evaluate the short-term impact of rapid maxillary expansion (RME) on the eruption paths of ectopically and normally erupting maxillary canines in the mixed dentition., Methods: Thirty-two patients with 49 ectopically erupting canines (EEC group; age, 9.53 ± 1.10 years) and 18 patients with 27 normally erupting canines (NEC group; age, 9.25 ± 1.06 years) underwent RME. Thirty-six subjects with 54 normally erupting canines composed the untreated control group (UC group; age, 9.03 ± 0.72 years). Horizontal, vertical, and angular positions of canines and adjacent teeth were evaluated in the expanded (EEC and NEC groups) and unexpanded (UC group) patients using panoramic radiographs taken at 2 times with a 1-year interval. The radiographic evaluation methods included score ranking and proportional measurements to minimize panoramic radiograph limitations. Statistical comparisons were performed among the groups (P <0.05)., Results: Before expansion, the EEC group's canines were significantly closer to the midline, more distant from the occlusal plane, and more mesially angulated than those in the UC group. After expansion, the canine positions in the EEC and UC groups were similar, whereas the NEC group had a more favorable canine position for eruption. The EEC and NEC groups showed similar canine positional changes, whereas the UC group had the smallest changes. The positions of teeth adjacent to the canine were also significantly affected by RME, and these changes may be associated with improvement of the ectopic canine position., Conclusions: The changes produced by RME reduced the percentage of ectopic eruption paths and maintained the nonectopic eruption percentage., (Copyright © 2018 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: NeoMTA Plus (Avalon Biomed Inc, Bradenton, FL) is a tricalcium silicate material similar to the first mineral trioxide aggregate product, ProRoot MTA (Dentsply Sirona, York, PA), but with improvements such as decreased setting time, increased ion release, increased water sorption, and nonstaining radiopacifiers. Quick-Set2 (Avalon Biomed Inc) is a newly formulated calcium aluminosilicate material that has a faster setting time and increased acid resistance and is nonstaining. The purpose of this study was to compare the healing of pulpal and periapical tissues in dogs after exposure to NeoMTA Plus and Quick-Set2 after pulpotomy and root-end surgery procedures., Methods: Seventy-two teeth (36 for each procedure) in 6 beagle dogs received pulpotomy or root-end surgery using either NeoMTA Plus or Quick-Set2. The dogs were sacrificed at 90 days, and the teeth and surrounding tissues were prepared for histologic evaluation. Sixty teeth were evaluated and scored histologically (29 with pulpotomies and 31 with root-end resections). Specimens were scored for inflammation, quality and thickness of dentin bridging, pulp tissue response, cementum and periodontal ligament formation, and apical bone healing., Results: Both materials displayed favorable healing at 90 days. The only significant difference was the quality of dentin bridge formation in pulpotomies using NeoMTA Plus compared with Quick-Set2., Conclusions: Quick-Set2 and NeoMTA Plus had similar effects on inflammation, pulp response, periodontal ligament and cementum formation, and apical tissue healing in dogs. NeoMTA Plus had superior dentin bridge quality compared with Quick-Set2., (Copyright © 2018 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: The purpose of this study was to evaluate apical debris extrusion associated with different kinematics in curved root canals., Methods: Forty-five extracted mandibular molars with root curvature angles ranging between 20° and 40° and curvature radii <10 mm were randomly assigned to 3 groups (n = 15) according to the kinematics used for root canal preparation: reciprocating motion with the WaveOne Gold system (Dentsply Tulsa Dental, Tulsa, OK), rotary/reciprocating motion with the Twisted File Adaptive system (SybronEndo, Orange, CA), and the manual technique. The debris apically extruded during preparation was collected into preweighed Eppendorf tubes. The tubes were then stored in an incubator at 70°C for 5 days. The extruded debris was quantified by subtracting the preinstrumentation from the postinstrumentation weight of the Eppendorf tubes. The time required for each instrumentation procedure was recorded. Data were analyzed using 1-way analysis of variance Tukey post hoc tests (∝ = 0.05)., Results: The WaveOne Gold reciprocating single-file system was associated with less extrusion of debris compared with hand files (P < .05) and the Twisted File Adaptive system (P > .05). The preparation time required by hand files was significantly longer than that required by the other techniques (P < .05)., Conclusions: Under the conditions of this study, all of the instrumentation systems caused apical debris extrusion to some degree. The WaveOne Gold reciprocating system was associated with less debris extrusion in curved root canals compared with the manual technique and the Twisted File Adaptive system although the difference between the WaveOne Gold and Twisted File Adaptive systems was not significant., (Copyright © 2018 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

This article reports an innovative technique in the treatment of a central incisor with a wide open apex and parallel dentinal walls. Root canal treatment was initiated, and calcium hydroxide intracanal medicament was placed in the canal for a month. The intracanal medicament was removed by instrumentation and irrigation with 3% sodium hypochlorite and 17% ethylenediaminetetraacetic acid. A light body impression of the root canal space was made and replicated the three-dimensional root canal space in a putty impression. Mineral trioxide aggregate (MTA) was condensed into the impression and allowed to set for 24 h in the presence of moisture to obtain a BioRoot inlay. This BioRoot inlay was cemented into the canal. Follow-up of every 6 months for 4 years revealed clinically asymptomatic and satisfactory healing of periapical lesion., Competing Interests: There are no conflicts of interest

Background: There is insufficient information available in the literature about the efficacy of laser-activated irrigation (LAI) in removing dentine debris at different coronal-apical levels of the root canal system (RCS)., Objectives: To evaluate the efficacy of erbium (LAI) in removing dentine debris from different coronal-apical levels of the RCS when compared to passive ultrasonic irrigation (PUI) and conventional irrigation (CI)., Material and Methods: Forty-five single-rooted human teeth were split longitudinally into halves. In each sample, a standardized groove was cut 2-6 mm from the apex along the canal wall of the 1st half, and another standardized groove was cut 10-14 mm from the apex along the canal wall of the 2nd half. Each groove was filled with dentine debris mixed with sodium hypochlorite (NaOCl) 5.25%. The samples were assigned to 3 experimental groups according to the irrigant activation techniques (n = 15); (a) CI group, (b) PUI group and (c) LAI group. The amount of the remaining dentine debris was identified and scored using a stereomicroscope., Results: Laser-activated irrigation removed significantly more debris than PUI and CI systems. The efficacy of dentine debris removal was not affected by the root canal third within all groups., Conclusions: Erbium LAI enhances dentine debris removal from the artificial irregularities in the RCS.

Aim: To achieve a better understanding of a calcified extraradicular deposit on the apical root surfaces of a mandibular first molar associated with a radicular cyst and a sinus tract. A multimodular approach was applied using a combination of multiple investigation methods., Summary: This case report presents a mandibular first molar with a calcified extraradicular deposit on the apical root surfaces of both roots. An apical periodontitis lesion was present and a sinus tract served as the only communication with the oral cavity. Diagnosis and treatment planning were based on clinical, radiographic (two- and three-dimensional) and ultrasound examination. The tooth was further analysed after extraction using microscopic imaging, nano-computed tomography (nano-CT), hard- and soft tissue histology and electron probe microanalysis. This multimodular approach revealed the calculus-like appearance and mineral composition of the extraradicular deposit. Multiple hypotheses about its aetiology are discussed., Key Learning Points: Calcified extraradicular deposits can develop on the apical root surfaces of teeth with apical periodontitis in association with a radicular cyst and sinus tract. A sinus tract can serve as the only communication between the apical lesion and the oral cavity whilst no periodontal defects are present. The interplay of intra-oral radiography, high resolution CBCT, nano-CT, hard tissue histology and EPMA can reveal the calculus-like appearance and composition of the extraradicular deposit. Calcified extraradicular deposits appear hyperechoic on ultrasound imaging and can lead to the occurrence of twinkling artefacts due to their rough mineralized surface., (© 2017 International Endodontic Journal. Published by John Wiley & Sons Ltd.)

Aim and Background: Debriding and disinfecting complex anatomies within the root canal system pose a major challenge during root canal therapy. Even with current chemomechanical techniques, debris and bacterial remnants are commonly left behind, which are generally believed to increase the risk of endodontic failure. This case details the use of a new technique to debride complex apical anatomy in a maxillary molar., Case Report: A 48-year-old female presented to the clinic with a chief complaint of increasing pain in her tooth. Clinical examination of the right first maxillary molar (#3) revealed moderate sensitivity to percussion and mild sensitivity to palpation. A pulpal diagnosis of symptomatic irreversible pulpitis and a periapi-cal diagnosis of symptomatic apical periodontitis were made. Mechanical instrumentation was performed using rotary file size #25/.04 for the mesiobuccal and distobuccal canals and size #25/.06 for the palatal canal to create a fluid path and enable obturation of the root canal system following the GentleWave® Procedure. The GentleWave Procedure was completed using Multisonic Ultracleaning™ for complete debridement and disinfection of the root canal system. The tooth was obturated using a warm vertical continuous wave obturation technique. Postoperative radiographs revealed complex anatomy within the apical third that was undetected both during pre-operative radiography and mechanical instrumentation. The palatal canal exhibited a complex apical delta with multiple points of exit, and the mesiobuccal canal revealed an undetected lateral canal within the apical third that had a separate and distinct egress. Conclusion and clinical significance: It is important for the clinician to debride and disinfect complex anatomy within the root canal system to reduce the risk of endodontic failure. This case report highlights the clinical significance of utilizing the GentleWave Procedure for detecting complex apical anatomy during endodontic therapy.

Aim: The aim of the present study was to evaluate the effect of large instrument use on the shaping ability and apical debris extrusion of rotary and reciprocating systems in oval-shaped root canals., Methods: Forty-five mandibular premolars, with an 18-mm long, oval-shaped single canal, and apical diameter ranging from 300 to 350 μm, were separated into three groups (n=15), according to the system used: ProTaper Universal group, F5 (0.50/0.05); ProTaper Next (PTN group), X5 (0.50/0.06); and Reciproc (RC group), R50 (0.50/0.05). Cone-beam computed tomography was performed before and after preparation to analyze apical transportation (AT), centering ability (CA), and change in root canal diameter (CRCD). For evaluating apical debris extrusion, the roots were coupled to pre-weighed glass receptacles to collect the extruded debris during preparation., Results: All systems promoted AT and apical debris extrusion; the latter was higher for the PTN group (P<.05). No system presented perfect CA. The RC group demonstrated the largest CRCD (P<.05)., Conclusions: As consequences of their use, the large instruments promoted undesirable AT and debris extrusion, irrespective of the system used to perform root canal preparation. Moreover, no system was able to remain perfectly centralized within the root canal., (© 2017 John Wiley & Sons Australia, Ltd.)

Introduction: Acute apical abscess is caused by bacteria that leave the infected dental root canal to invade the periodontal tissues. Most species occurring in abscesses are also found in asymptomatic infections; therefore, the possibility exists that not only the presence of certain species but also their specific counts influence the appearance of symptoms. This molecular study compared the frequency and levels of several candidate endodontic pathogens in teeth with acute apical abscesses and asymptomatic apical periodontitis., Methods: Samples were taken from the root canals of teeth with asymptomatic apical periodontitis (n = 73) and by aspiration of purulent exudate from acute abscesses (n = 55). DNA was extracted from samples and bacterial identifications were performed by a closed-ended semi-quantitative reverse-capture checkerboard approach targeting 40 bacterial species/phylotypes., Results: Bacterial DNA was detected in all cases. In abscesses, the most prevalent taxa were Fusobacterium nucleatum (60%), Porphyromonas endodontalis (53%), Parvimonas micra (51%), and Streptococcus species (45%). The most frequently detected taxa in asymptomatic teeth were P. endodontalis (63%), Dialister invisus (58%), Olsenella uli (56%), and F. nucleatum (51%). None of the targeted taxa were significantly associated with abscesses when only mere presence was evaluated (p>0.05). However, semi-quantitative data demonstrated that P. endodontalis, Prevotella baroniae, Treponema denticola and Streptococcus species were significantly more frequent at levels >105 in abscesses than in asymptomatic cases (p<0.05)., Conclusion: None of the target species/phylotypes were associated with abscesses in terms of frequency. However, some taxa were significantly found in higher levels in abscesses. Presence of a potentially virulent pathogen in high counts may increase the collective pathogenicity of the bacterial community and give rise to symptoms.

Objective: The aim of this study was to evaluate the amount of apically extruded debris and irrigant during cleaning and shaping with different file systems., Materials and Methods: Seventy-five extracted mandibular premolar and canine teeth were randomly divided into five groups (n = 15). The root canals were instrumented by using Mtwo (VDW, Munich, Germany), Twisted File (TF; Sybron Endo, Orange, California, USA), Reciproc (VDW), Self-Adjusting File (SAF; Re Dent-Nova, Ra'anana, Israel) systems, and K-type stainless steel hand file (Mani Inc., Tochigi, Japan). Apically extruded debris was collected and dried in preweighed Eppendorf tubes. Extruded irrigant was collected from the cannula by using a plastic insulin syringe. After drying, the amount of apically extruded debris was established by subtracting the initial weight from the final weight of the tubes. After performing the Kolmogorov-Smirnov test, data were analyzed by Kruskall-Wallis test at a significance level of P value less than 0.05., Results: There were no statistically significant differences between the file systems in terms of debris and irrigant extrusion. Mtwo group produced the highest mean debris extrusion value and the TF group produced the less compared with the other files. The least mean irrigant extrusion value was associated with the SAF group, whereas the highest mean irrigant extrusion value was associated with the Reciproc group., Conclusion: Under the conditions of the study, all file systems were associated with apical debris and irrigant extrusion.

Background and Objective: Tissue engineering by using recombinant human (rh) growth factor technology may offer a promising therapeutic approach for treatment of gingival recession. Fibroblast growth factor-2 (FGF-2) has shown the ability to promote periodontal regeneration. Gelatin/beta-tricalcium phosphate (gelatin/β-TCP) sponges have been developed to control the release of growth factors. The present study evaluated the periodontal regenerative efficacy of rhFGF-2 by comparing gelatin/β-TCP sponges incorporated with rhFGF-2 to the scaffolds alone in artificially created recession-type defects in dogs., Material and Methods: Critically sized buccal gingival recession defects were surgically created on maxillary canine teeth of five dogs. In each animal, defects were randomized to receive either a gelatin/β-TCP sponge soaked with rhFGF-2 (gelatin/β-TCP/rhFGF-2) or phosphate-buffered saline (gelatin/β-TCP). Eight weeks after surgery, biopsy specimens were obtained and subjected to microcomputed tomography and histological analyses., Results: Complete root coverage was achieved in both groups. Microcomputed tomography revealed significantly greater new bone volume in the gelatin/β-TCP/rhFGF-2 group. Histologically, both groups achieved periodontal regeneration; however, gelatin/β-TCP/rhFGF-2 sites exhibited more tissue regeneration, characterized by significantly larger amounts of new cementum and new bone. Gelatin/β-TCP sites featured increased long junctional epithelium and connective tissue attachment. In the gelatin/β-TCP/rhFGF-2 sites, new bone exhibited many haversian canals and circumferential lamellae as well as remarkably thick periosteum with blood vascularization and hypercellularity., Conclusion: Within the limitations of this study, rhFGF-2 in gelatin/β-TCP sponges exhibits an increased potential to support periodontal wound healing/regeneration in canine recession-type defects., (© 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Introduction: The effect of rheumatoid arthritis (RA) on the healing and pathophyisiology of apical periodontitis is unknown because there is no study in the literature evaluating the association of RA with the prevalence of periapical rarefying osteitis (PAR) and endodontic treatment. Therefore, the goal of this cross-sectional study was to evaluate the prevalence of PAR and root canal treatment in RA patients when compared with controlled individuals., Methods: Full-mouth radiographs of 131 individuals with RA were examined and compared with 131 controls that were sex and age matched exactly with the diseased group. The total number of teeth, presence or absence of root canal filling, quality of root canal filling, quality of restoration, and periapical status were recorded., Results: Overall, the prevalence of teeth with PAR was 4.0% in the diseased group and 3.5% in the control group (P > .05). The prevalence of root canal-treated teeth was 6.2% in the RA group and 5.6% in the control group (P > .05). Controls have significantly more teeth than those with RA (P = .027)., Conclusions: The prevalence of PAR and endodontic treatment was not significantly different in individuals with RA compared with control patients., (Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: The apical portion of the root canal is very complex and challenging during endodontic treatment. Root canal preparation and obturation to the apical constriction may provide the best prognosis. Incomplete debridement, foramen transportation, and inadequate seal in the apical portion are considered to be responsible for treatment failure. The technique "apical patency" is considered as a way for maintaining the apical part the free of the debris by recapitulation, using a small K-file through the area of the apical foramen. This term was firstly proposed by Buchanan. In this technique, the smallest diameter file is set 1 mm longer than working length and recapitulated after each instrument to prevent packing of debris in the apical part. Apical patency has been found to be effective in achieving an apical seal with gutta-percha. Teeth prepared with a step back method and with maintained apical patency may show less leakage when obturated with cold lateral condensation technique. Data regarding the effect of apical patency on the healing of periapical tissue are very scarce, and it has been shown that the patency file has detrimental effect on the healing of periapical tissues in animal studies. However, using patency file in endodontic treatment is controversial and further studies are needed. The purpose of this article is to review the effect of using a patency file on the extrusion of root canal contents, the apical seal, postoperative pain, and healing of periapical tissues. Furthermore, the effect of establishing patency on reaching irrigation solutions to the apical portion of the canal and prognosis of root canal treatment are discussed., Clinical Significance: Keywords: Apical patency, Apical seal, Apical transportation, Postoperative pain, Prognosis.

Introduction: Apical papilla represents a source of an enriched mesenchymal stem cell (MSC) population (stem cells of the apical papilla [SCAPs]) that modulates root development and may participate in regenerative endodontic procedures in immature teeth with pulp necrosis. The characteristics and phenotype of this tissue in the presence of inflammation are largely unknown. The purpose of this study was to characterize a human apical papilla sample that was isolated from an immature tooth with pulp necrosis and apical periodontitis., Methods: Inflamed periapical tissue that included part of the apical papilla (apical papilla clinical sample [CS]) was collected from an immature mandibular premolar previously diagnosed with pulp necrosis and apical periodontitis during an apexification procedure. Harvested cells from this tissue (SCAP CS) were compared with inflamed periapical progenitor cells (IPAPCs) and normal SCAP (SCAP-RP89) in flow cytometry and quantitative osteogenesis experiments. Part of the issue was further processed for immunohistochemistry and compared with apical papilla and coronal pulp sections from normal immature teeth as well as inflamed periapical tissues from mature teeth., Results: Similar to SCAP-RP89, 96.6% of the SCAP CS coexpressed the MSC markers CD73, CD90, and CD105, whereas only 66.3% of IPAPCs coexpressed all markers. The SCAP CS showed a significantly greater mineralization potential than both SCAP-RP89 and IPAPCs. Finally, immunohistochemical analysis revealed moderate infiltration of cells expressing the inflammatory markers CD45/68 in the apical papilla CS and prominent CD24, CD105, and von Willebrand factor expression., Conclusions: Under inflammatory conditions, human apical papilla was found moderately inflamed with retained SCAP vitality and stemness and increased osteogenic and angiogenesis potential., (Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Background: Osseo-gingival pathology (OGP) may be observed in traumatized primary teeth, and its knowledge is essential for treatment decision., Aim: To describe the occurrence and treatment of OGP in traumatized primary upper incisors., Design: One examiner collected data from patients' charts of the Clinic of Trauma in Primary Teeth of the University of Sao Paulo. OGP was divided into apical fenestration (AF), total gingival recession (TGR), and partial gingival recession (PGR)., Results: From 2516 charts, 61 patients (2.4%) presented 73 teeth with OGP (9.6% AF, 19.2% TGR and 71.2% PGR). OGP was observed in 63% of male and 43.8% of children aged 4-5 years old. Mean time between trauma and diagnosis was 15 months AF, 23.5 months TGR, and 7.5 months PGR. Periodontal trauma occurred in 86.3% of teeth with OGP. Pulp necrosis was observed in all cases of AF and 92.9% of TGR; however, 76.9% of PGR were vital. All teeth with AF and 85.7% of TGR were extracted, and 44.2% of PGR were monitored., Conclusions: Osseo-gingival pathology has low occurrence in traumatized primary upper incisors. The treatment for AF and TGR is tooth extraction, and for PGR is tooth monitoring or extraction depending on the case severity., (© 2016 BSPD, IAPD and John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

The aim of this study was to analyze alveolar bone morphology following periodontally accelerated osteogenic orthodontics. Treated patients were called for a full periodontal examination and a cone beam computed tomography scan. Mean treatment time was 6.08 months. Mean probing pocket depth was 2.7 mm. No gingival recessions were noted. In the maxilla, buccal plate thickness was 0.48 to 2.14 mm. In the mandible, bone thickness was 0.2 to 1.82 mm. Root fenestrations and dehiscences were present in up to 40% of the anterior teeth. Although clinical outcomes were favorable, due to the presence of multiple posttreatment bone fenestrations and dehiscences, a revision of the treatment protocol might be considered.

Introduction: The aim of this in vitro study was to identify the formation of dentinal defects on the external apical root surface of teeth instrumented at different working lengths by using WaveOne reciprocating files., Methods: Sixty human single-rooted mandibular premolars were divided into 3 groups (n = 20) according to the file used for instrumentation: WaveOne Small (WOS), premolars presenting mechanical resistance to the penetration of #10 K-file 1 mm short of the apical foramen; WaveOne Primary (WOP), this limit easily reached with #10 K-file; and WaveOne Large (WOL), this limit easily reached with #20 K-file or higher. A closed system and a muffle were created to allow alternating sessions of root canal instrumentation and image acquisition. The teeth were further divided according to 3 different working lengths: 1 mm short of the apical foramen, flush with the apical foramen, and 1 mm beyond the apical foramen. Micrographs of the external apical root surface of each specimen at baseline and after instrumentation up to each working length were examined for the presence of dentinal defects. Inter-examiner agreement was evaluated by using Pearson correlation test, and the Kruskal-Wallis test was used to analyze intragroup and intergroup differences (P < .05)., Results: Inter-examiner agreement was high in all experimental groups (r = 1.0000, r = 0.8885, and r = 0.7867 for WOS, WOP, and WOL, respectively). There was no significant difference in the number of teeth with dentinal defects in the intergroup (P = .8119) or intragroup analyses (P = .9309, .8648, and .4772 for WOS, WOP, and WOL, respectively)., Conclusions: Instrumentation with different WaveOne files up to different working lengths was not associated with the formation of dentinal defects., (Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: The purpose of this study was to determine the arch form of the root apices of normally erupting teeth and then determine the differences in the location of the apex of impacted canines relative to normally erupting canines. In addition, we sought to determine whether the labiopalatal position of the impacted canines influences the position of the apices., Methods: The study included 21 patients with unerupted canines that subsequently had a normal eruption, 21 patients with palatally impacted canines, 27 patients with labially impacted canines, and 17 patients with midalveolus impacted canines. Images were obtained using cone beam computed tomography, and the x, y, and z coordinates of the root apices were determined using Ondemand3D software (Cybermed Co., Seoul, Korea). Two-dimensional coordinates were converted from acquired 3-dimensional coordinates via projection on a palatal plane, and the Procrustes method was used to process the converted 2-dimensional coordinates and to draw the arch forms of the root apices. Finally, we measured the extent of root apex deviation from the arch forms of the root apices., Results: Normally erupting canines showed that even though calcifications may be immature, their positions were aligned with a normal arch form. The root apices of the impacted canines were an average of 6.572 mm away from the root apices' arch form, whereas those of the contralateral nonimpacted canines were an average distance of 2.221 mm away, a statistically significant difference. The palatally impacted canines' root apices distribution tended toward the first premolar root apices., Conclusions: Incompletely calcified, unerupted teeth with a subsequent normal eruption showed a normal arch form of the root apices. The root apices of impacted canines were farther from the arch forms than were the nonimpacted canines. Also, the root apices of impacted canines in the palatal area showed distributions different from those of the other impacted canine groups., (Copyright © 2017 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)

Background: A fracture of root canal instruments, with a fractured piece protruding beyond the apex, is a troublesome incident during an endodontic treatment. Locating and retrieving them represents a challenge to maxillofacial surgeons because it is difficult to access due to the proximity between the foreign body and vital structures. Although safe and accurate for surgery, radiographs and electromagnetic devices do not provide a precise three-dimensional position. In contrast, computer-aided navigation provides a correlation between preoperatively collected data and intraoperatively encountered anatomy. However, using a navigation system for mandible treatment is difficult as the mobile nature of the mandible complicates its synchronization with the preoperative imaging data during surgery., Case Presentation: This report describes a case of a dental instrument breakage in the mandible during an endodontic treatment for a restorative dental procedure in a 65-year-old Japanese woman. The broken dental instrument was removed using a minimally invasive approach with a surgical navigation system and an interocclusal splint for a stable, identically repeatable positioning of the mandible. Using the three-dimensional position of the navigation probe, a location that best approximated the most anterior extent of the fragment was selected. A minimally invasive vestibular incision was made at this location, a subperiosteal reflection was performed, and the foreign body location was confirmed using a careful navigation system. The instrument was carefully visualized and extruded from the apical to the tooth crown side and was then removed using mosquito forceps through the medullary cavity of the crown side of the tooth. Follow-up was uneventful; her clinical course was good., Conclusions: The use of a surgical navigation system together with an interocclusal splint enabled the retrieval of a broken dental instrument in a safe and minimally invasive manner without damaging the surrounding vital structures.