Morphology of the Second Mesiobuccal Canal in the Maxillary Second Molar / Morfología del Segundo Canal Mesiovestibular en el Segundo Molar Maxilar

SUMMARY: Failure to locate a complete canal system affects the prognosis of root canal treatment. A missed root canal is one of the most common reasons for failed root canal treatment. The prevalence of the second mesiobuccal canal in the maxillary second molar is relatively high and has a variety of configurations. Therefore, knowledge of its morphology is required in clinical endodontics. This review presented the canal in terms of its prevalence, classification, anatomical features, and the method for locating the second mesiobuccal canal in the maxillary second molar. Root canal treatment requires knowledge of tooth morphology, appropriate access preparation, and a thorough examination of the tooth's interior. Thus, clinicians should carefully employ various methods for assessing the anatomy of the entire root canal system to prevent failure in locating the second mesiobuccal canal. This canal can be located by modifying the access cavity design and utilizing specific instruments to improve the second mesiobuccal canal system visualization.

La falta de localización de un sistema completo de canal afecta el pronóstico del tratamiento de éste. La omisión de un tratamiento de canal es uno de los motivos más frecuentes por las que el tratamiento de canal fracasa. La prevalencia del segundo canal mesiovestibular en el segundo molar superior es relativamente alta y tiene una variedad de configuraciones. Por tanto, el conocimiento de su morfología es necesario en endodoncia clínica. Esta revisión presentó el canal en términos de su prevalencia, clasificación, características anatómicas y el método para localizar el segundo canal mesiovestibular en el segundo molar superior. El tratamiento de canal requiere conocimiento de la morfología del diente, una preparación adecuada del acceso y un examen exhaustivo del interior del diente. Por lo tanto, los dentistas deben emplear cuidadosamente varios métodos para evaluar la anatomía de todo el sistema de canales radiculares para evitar fallas en la localización del segundo canal mesiovestibular. Este canal se puede localizar modificando el diseño de la cavidad de acceso y utilizando instrumentos específicos para mejorar la visualización del sistema del segundo canal mesiovestibular.

Clinical efficacy of pulpotomy in elderly patients / 中华老年医学杂志

Objective:To evaluate the clinical efficacy of pulpotomy in elderly patients with caries-related exposed pulp.Methods:A randomized controlled study was conducted at the Department of General Dentistry, Peking University Stomatology Hospital from October 2019 to March 2022.The study included 46 elderly patients with carious exposure, who were randomly divided into two groups: an experimental group with 22 cases and a control group with 24 cases.The teeth in the experimental group underwent pulpotomy, while the teeth in the control group underwent root canal treatment.The patients in both groups were followed up at 1 week, 6 months, and 12 months after the operation.Self-perceived pain symptoms were assessed using a visual analogue scale(VAS)before and 1 week after treatment in the experimental group, and before, at the second visit(visit 1), at the third visit(visit 2), and 1 week after treatment in the control group.Results:The mean preoperative pain score of the patients, as measured by the VAS scale, was(1.09±1.19)in the experimental group.There was no statistically significant difference when compared to the control group(1.13±1.23)( t=-0.096, P=0.924). The postoperative pain score of the experimental group was(0.27±0.77). On the other hand, the average overall pain score of the control group after treatment(visit 1, visit 2, and 1 week postoperatively)was(1.19±1.82). The postoperative pain score of the experimental group was significantly lower than that of the control group( t=-3.416, P=0.001). The effective rates were 95.24%(20/21)(experimental group)and 100%(22/22)(control group)respectively.There was no significant difference between the cure rates of the two groups( χ2=1.458, P=0.488). Conclusions:The findings suggest that pulpotomy can be an effective method for managing elderly patients with exposed pulp due to caries.

Efficacy of oral midazolam solution for preoperative sedation in pediatric outpatients undergoing root canal treatment under general anesthesia / 中华麻醉学杂志

Objective:To evaluate the efficacy of oral midazolam solution for preoperative sedation in the pediatric outpatients undergoing root canal treatment under general anesthesia.Methods:One hundred and forty-seven pediatric patients of either sex, aged 2-7 yr, weighing 10-30 kg, of American Society of Anesthesiologists Physical Status classificationⅠ or Ⅱ, were divided into 3 groups ( n=49 each) using a random number table method: oral midazolam solution group (OM group), midazolam injection group (M group), and dexmedetomidine group (D group). In OM group, patients received oral midazolam solution at a dose of 0.5 mg/kg along with a placebo (an equivalent amount of normal saline based on body weight) administered via nasal drops. In M group, patients were given oral midazolam injection at a dose of 0.5 mg/kg along with a placebo via nasal drops. In D group, patients were administered a placebo orally along with dexmedetomidine at a dose of 2 μg/kg via nasal drops. The Induction Compliance Checklist (ICC) scores upon entering the operating room, sedation success rates (ICC score ≤ 3), drug acceptance scores, mask acceptance scores, and separation anxiety scores were recorded. The emergence time, time of stay in postanesthesia care unit (PACU), and occurrence of adverse events such as bradycardia, hypotension, hypoxemia, and laryngospasm during surgery and in PACU were recorded. Results:A total of 143 pediatric patients were finally included in the study, with 48 cases in OM group, 48 cases in M group and 47 cases in D group. Compared with M and D groups, the ICC scores upon entry to the operating room were significantly decreased, the sedation success rates were increased, drug acceptance scores were increased, separation anxiety scores were decreased, and mask acceptance scores were decreased in OM group ( P<0.05). Compared with D group, the ICC scores upon entry to the operating room were significantly decreased, the sedation success rates were increased, and mask acceptance scores were decreased in M group ( P<0.05). There were no statistically significant differences in the emergence time, time of stay in PACU, and incidence of adverse events during surgery and in PACU among the three groups ( P>0.05). Conclusions:Oral midazolam solution provides good effect with less adverse reactions when used for preoperative sedation in the pediatric outpatients undergoing root canal treatment under general anesthesia.

Research progress on small biomolecule formulations for chemical disinfection of root canals / 口腔疾病防治

@#Successful treatment of endodontic and periapical diseases requires the elimination of bacteria and microbial biofilms from root canals. Currently, the most preferred irrigation method involves the delivery of sodium hypochlorite via the combination of a syringe and ultrasonic activation. Calcium hydroxide is the main choice for intracanal medicament between endodontic appointments and treatment. However, conventional chemical disinfection of root canals is controversial due to drug permeability and drug resistance. New small biomolecule formulations with high penetrability and bioremediatory capacity, including antimicrobial peptides such as M33D and LL-37, antisense RNA ASwalR/ASvicR and nanoparticles such as silver nanoparticles, mesoporous calcium-silicate nanoparticles and chitosan nanoparticles, have effective antibacterial and antibiofilm properties for use in root canal systems and dentinal tubules, thereby promoting the healing of apical lesions. However, the in vivo drug stability, biosafety, and clinical efficacy of small biomolecule formulations need further investigation. Future research will still focus on the improvement and combination of traditional drugs, as new small molecule formulations and ideal disinfectant drugs need to be developed. In the present paper, we reviewed the development of new antibacterial agents and application of small biomolecule formulations for chemical disinfection of infected root canals.

Root canal therapy of maxillary molars with atypical canals:A report of three cases / 北京大学学报(医学版)

Maxillary molar with three roots and 3 to 4 canals is a common occurrence.However,in addition to common root canal anatomy,there may be significant differences in the number,distribution,and morphological structure of root canals.The success of root canal treatment is dependent on ensuring that all the intricate details associated with it are meticulously followed.Failure to locate all canals could have a negative effect on the treatment as it may lead to initiation or continuation of periapical pathology.Missed canals were the main reason for patients reporting back for nonsurgical root canal retreatment.Moreover,the bacteria residing in such canals could also result in persistence of symptoms.Root canal anatomy is complex,and the recognition of anatomic variations could be a challenge for clinicians.This article presents three cases of endodontic management of maxillary molars with atypical canal morphology.In the three cases of this study,the patients underwent cone beam computed tomographic(CBCT)examination before root canal treatment.The CBCT images revealed that the maxillary molars in case 1 and case 2 had 5 canals.Case 1:2 mesiobuccal(MB,MB2),two distobuccal(DB and DB2),and one palatal canal.Case 2:2 mesiobuccal(MB,MB2),one distobuccal(DB),and two palatal canals(MP and DP).In case 3,CBCT scan slices showed that the maxillary first molar presented as a C-shaped root canal with a rare tooth anomaly of taurodontism.Although C-shaped root canals were most frequently seen in the mandibular second molar,they might also appear in maxillary molars.A literature search revealed only a few case reports of C-shaped root canal systems in maxillary molars.Case 3 described the fusion between mesiobuccal and palatal roots of the maxillary first molar,forming a C-shaped mesiopalatal root canal.The above cases suggest that endodontists should always be aware of aberrancies in root canal sys-tem apart from the knowledge of normal root canal anatomy.CBCT as a means of diagnosis can be helpful for identifying and managing these complex root canal systems.This case series also highlights the impor-tance of magnification and illumination.Through using an endodontic microscope,clinicians can identify root canals that are difficult to locate or overlooked with normal vision.A correct access opening is a most important step to locate and negotiate the orifices of root canals.The use of ultrasonic tips can refine the access cavity and allow controlled and delicate removal of calcifications and other interferences to the ca-nal orifices,thereby helping to locate the extra orifices.

Morphological assessment of the isthmus in mesial root canals of first mandibular molars / Avaliação morfológica do istmo nos canais radiculares mesiais dos primeiros molares inferiores

ABSTRACT Root canal morphology and its anatomical variations pose a great challenge to endodontists Aim The aim of this in silico study was to perform a qualitative and quantitative analysis of the threedimensional morphological characteristics of the isthmus in the mesial root canals of mandibular molars using microcomputed tomography (micro-CT) Material and Method Six hundred first mandibular molars were selected, including 317 with two mesial canals with isthmuses between the canals, and fully formed root. Isthmus morphology was determined in 3D longitudinal sections using Fan et al. (2010) classification. Root length, and the volume and area of apical and coronal level were measured. Additionally, the structural model index (SMI) of the canals were also assessed Results The prevalence of isthmuses in the mesial root canals was 32% type II, 29% type III, 22% type IV, and 17% type I. The root length was found to be 9.1±0.5 mm, the volume and area, of all root canal system, were 41.8±40.1 mm3 and 63.6±24.2 mm2 respectively. The isthmi volume and area alone were 11.06±9.03 mm3 and 30.02±11.02 mm2. The study confirmed that isthmuses are present in mesial canals of mandibular first molars, being more frequent in the apical third Conclusion The high prevalence of isthmuses with complex morphological features underscores the importance of using intracanal medications to disinfect areas unprepared by instruments.

RESUMO A morfologia do canal radicular e suas variações anatômicas representam um grande desafio para os endodontistas. O objetivo deste estudo ex vivo foi realizar uma análise qualitativa e quantitativa das características morfológicas tridimensionais do istmo nos canais mesiais de molares inferiores por meio de microtomografia computadorizada (micro-CT) Material e Método Foram selecionados 600 primeiros molares inferiores, incluindo 317 com dois canais mesiais com istmos e raiz totalmente formada. A morfologia do istmo foi determinada em cortes longitudinais 3D usando a classificação Fan et al. (2010). Foram mensurados o comprimento da raiz, o volume e a área apical e coronal e da cavidade pulpar. Adicionalmente, também foram avaliados o structure model index (SMI) dos canais Resultados A prevalência de istmos nos canais mesiais foi de 32% tipo II, 29% tipo III, 22% tipo IV e 17% tipo I. O comprimento da raiz foi de 9,1±0,5 mm, o volume e a área de todo o sistema de canais radiculares foram de 41.8±40.1 mm3 e 63.6±24.2 mm2, respectivamente. O volume e área do istmo isoladamente foram 11.06±9,03 mm3 e 30.02±11.02 mm2. O estudo confirmou que os istmos estão presentes em canais mesiais dos primeiros molares inferiores, sendo mais frequentes no terço apical Conclusão A alta prevalência de istmos com características morfológicas complexas ressalta a importância do uso de medicação intracanal para desinfecção de áreas não tocadas por instrumentos.

Effect of different disinfection protocols in bacterial viability of an intraradicular biofilm formed in situ

Abstract The present study aimed to evaluate bacterial viability after the use of different disinfection protocols in root canals infected with a multispecies biofilm (MB) formed in situ. Palatal roots with a single canal were obtained from extracted maxillary molars and sterilized before being inserted into the mouth. The roots were contaminated with a MB in an intraoral appliance worn by ten volunteers. All volunteers wore six roots simultaneously in two intraoral devices for 21 days. One root from each volunteer was assigned to each group (n=10): PUI - passive ultrasonic irrigation; EC - Easy Clean; XPF - XP-endo Finisher; aPDT - antimicrobial photodynamic therapy; CI - conventional irrigation; and NC - negative control. The samples were evaluated under confocal laser scanning microscopy. The percentage of viable cells (VC) was calculated over the total percentage of MB biovolume. Data were statistically analyzed (α=5%). The cell viability in the entire root canal or for each third was compared between groups (Kruskal-Wallis test, Dunn post-hoc test) and for the same group (Friedman test, Dunn post-hoc test). Disinfection protocols were not significantly different from each other (P>.05). Samples in EC, PUI, and aPDT had lower cell viability than in NC (P<.05). In the coronal third of samples in the EC, XPF, PUI and aPDT, the percentage of VC biovolume was lower than in the NC (P<.05). The percentage of VC in EC samples was lower in the coronal and middle thirds than in the apical third (P<.05). EC, PUI and aPDT had significant effects on cell viability in intraradicular multispecies biofilm formed in situ when compared with untreated samples.

Resumo O presente estudo teve como objetivo avaliar a viabilidade bacteriana após o uso de diferentes protocolos de desinfecção em canais radiculares infectados com um biofilme multiespécies (MB) formado in situ. Raízes palatinas com canal único foram obtidas de molares superiores extraídos e esterilizadas antes de serem inseridas na boca. As raízes foram contaminadas com MB em um aparelho intraoral usado por dez voluntários. Todos os voluntários usaram seis raízes simultaneamente em dois dispositivos intrabucais por 21 dias. Uma raiz de cada voluntário foi atribuída a cada grupo (n=10): PUI - irrigação ultrassônica passiva; EC - Easy clean; XPF - XP-endo Finisher; aPDT - terapia fotodinâmica antimicrobiana; IC - irrigação convencional; e, NC - controle negativo. As amostras foram avaliadas em microscopia confocal de varredura a laser. A porcentagem de células viáveis (VC) foi calculada sobre a porcentagem total do biovolume de MB. Os dados foram analisados estatisticamente (α=5%). A viabilidade celular em todo o canal radicular ou em cada terço foi comparada entre os grupos (teste de Kruskal-Wallis, teste post-hoc de Dunn) e no mesmo grupo (teste de Friedman, teste post-hoc de Dunn). Os protocolos de desinfecção não foram significativamente diferentes entre si (P>0,05). Amostras dos grupos EC, PUI e aPDT apresentaram menor viabilidade celular do as do NC (P<0,05). No terço cervical das amostras do EC, XPF, PUI e aPDT, a porcentagem de biovolume de VC foi menor do que no NC (P<0,05). A porcentagem de VC nas amostras do EC foi menor nos terços cervical e médio do que no terço apical (P<0,05). EC, PUI e aPDT tiveram efeitos significativos na viabilidade celular do biofilme multiespécies intrarradicular formado in situ quando comparado com amostras não tratadas. Estudos clínicos devem investigar o papel da redução de cargas bacterianas viáveis no sistema de canais radiculares para o sucesso do tratamento endodôntico.

Therapeutic Approach in Large Periapical Cyst: Clinical Case Report / Abordagem Terapêutica em Cisto Periapical de Grande Proporção: Relato de Caso Clínico

Periapical cysts of endodontic origin originate from an infection that affects the apical region, causing pulpal necrosis that stimulates an inflammatory response. Among many pathologies found on radiographs, one of them is the root cyst, considered to be a lesion frequently found in the maxilla and mandible, associated with the apex of a tooth with pulp necrosis. They present slow growth and are discovered in routine examinations because they are asymptomatic. Due to the chronic aggression, the lesion does not present painful symptoms in most cases, and grows slowly, thus being able to reach large extensions, with the presence of swelling and sensitivity, as well as slight mobility in the affected tooth and adjacent ones. The objective of this study was to report a clinical case of swelling in the anterior region of the mandible, which was diagnosed as a periapical cyst, in this way the treatments performed and the final result after 18 months of follow-up will be reported. However, to achieve good results during periapical cyst treatment, it is necessary to make a correct diagnosis, followed by adequate planning, always performing clinical and radiographic follow-up, in addition to the patient's cooperation, so that good results can be achieved during the treatment. It can be observed that a well-performed endodontic treatment, associated with a elaborated surgical technique, in addition to anatomopathological evidence and radiographic follow-up, make the therapeutic success to be obtained in cases of large periapical cysts.(AU)

Os cistos periapicais de origem endodôntica, originam-se a partir de uma infecção que acomete em região apical, ocasionando uma necrose pulpar que estimula uma resposta inflamatória. Das várias patologias encontradas radiograficamente, o cisto radicular tem sido o mais frequente encontrado, tanto em maxila, quanto em mandíbula, associado ao ápice de um dente com necrose pulpar. Apresentam crescimento lento e são descobertos nos exames de rotina, por serem assintomáticos. Devido a agressão crônica, a lesão não apresenta sintomatologia dolorosa, na maioria dos casos, tendo seu crescimento lento, desta maneira podendo atingir grandes extenções, com presença de tumefação e sensibilidade, além de leve mobilidade no dente acometido e nos adjacentes. O objetivo deste estudo foi relatar um caso clínico de tumefação na região anterior de mandíbula, o qual foi diagnosticado como cisto periapical, desta forma serão relatados os tratamentos realizados e o resultado final após 18 meses de acompanhamento. Contudo, para que sejam alcançados bons resultados durante o tratamento do cisto periapical é necessário realizar um correto diagnóstico, seguido por um planejamento adequado, realizando sempre o acompanhamento clínico e radiográfico, além da colaboração do paciente, para que possam ser atingidos bons resultados durante o tratamento. Pode-se observar que um tratamento endodôntico bem realizado, associado à uma técnica cirúrgica bem elaborada, além de comprovação anatomo-patológica e acompanhamento radiográfico, fazem com que o sucesso terapêutico seja obtido para os casos de cistos periapicais de grande proporção.(AU)

Classification of furcation involvement of endodontically treated mandibular first permanent molars based on cone beam CT / 口腔疾病防治

Objective @#To classify the furcation involvement (FI) of endodontically treated mandibular first permanent molars based on cone beam computed tomography (CBCT), provide reference for individualized treatment of FI. @*Methods@#CBCT images of the FI of 164 endodontically treated mandibular first permanent molars from 163 patients in Nanjing Stomatological Hospital, Medical School of Nanjing University were collected retrospectively. On the CBCT images, the shape and extent of periapical and periodontitis bone resorption, the thickness of residual dentin in the pulp floor and root canal wall, and the periodontal bone resorption of the complete dentition were evaluated. The FI was classified into periodontal, periapical, perforated and mixed types.@* Results@#Among the 164 FIs of endodontically treated mandibular first permanent molars, the periapical type was the most common (41.5%), followed by the mixed type (26.2%), perforated type (18.3%), and periodontal type (14.0%). Among the 68 periapical-type FIs of endodontically treated mandibular first permanent molars, 48.5% were proper root canal filling, 44.1% were insufficient filling and 7.4% were overfilling. Among the 43 mixed-type FIs, the periodontal mixed periapical type was the most common (72.1%).@*Conclusion @#Detailed evaluation and classification of furcation involvement could be performed using CBCT images; therefore, the study has guiding significance for clinical treatment.

Improvement of inflammatory cytokines level in peripheral blood, anxiety and depressive symptoms in patients with pulpitis by root canal therapy / 口腔疾病防治

Objective@# To investigate the effect of root canal therapy (RCT) on inflammatory cytokines level in peripheral blood, anxiety, and depression in patients with pulpitis.@*Methods @#A total of 155 patients with pulpitis admitted to the Stomatology Hospital of the Fourth Military Medical University from June 2021 to June 2022 were treated with root canal therapy. Another 155 persons who received health examinations during the same period were selected as the control group. The Generalized Anxiety Disorder-7 (GAD-7) scores and the Patient Health Questionnaire-9 (PHQ-9) scores of the two groups were compared. The GAD-7, PHQ-9 and pain scores of the test group before treatment and 3 and 6 weeks after treatment were compared. Pain was assessed with a visual analog scale (VAS). Inflammatory cytokine [interleukin-8 (IL-8), interleukin-1 β (IL-1β), tumor necrosis factor-α (TNF-α), c-reactive protein (CRP)] levels in the test group before treatment and 3 and 6 weeks after treatment were compared. @*Results @#The GAD-7 and PHQ-9 scores in the test group were higher than those in the control group before treatment (P<0.05). The GAD-7 and PHQ-9 scores in the test group at 3 and 6 weeks after treatment were lower than those before treatment (P<0.05); there was no significant difference between the GAD-7 and PHQ-9 scores at 3 and 6 weeks after treatment(P>0.05). The pain scores of the experimental group at 3 and 6 weeks after treatment were lower than those before treatment (P<0.05), and the pain scores 6 weeks after treatment were lower than those at 3 weeks after treatment (P<0.05). The levels of IL-8, IL-1β, TNF-α and CRP in the peripheral blood of the experimental group were lower 3 and 6 weeks after treatment than before (P<0.05), and the levels of IL-8 and IL-1β in the peripheral blood at 6 weeks after treatment were significantly lower than at 3 weeks after treatment (P<0.05). The levels of TNF-α and CRP in the peripheral blood at 6 weeks after treatment were not significantly different from those at 3 weeks after treatment (P>0.05).@*Conclusion @#The peripheral blood of patients with pulpitis has a high level of inflammatory cytokines, and the patients suffer from obvious anxiety and depression. Root canal therapy can relieve their anxiety and depression by reducing their level of inflammatory cytokines in peripheral blood.

Effect of Photobiomodulation on Pain Following Single Visit Non-surgical Root Canal Treatment of Molar Teeth with Symptomatic Irreversible Pulpitis

ABSTRACT Objective: To assess the effect of Photobiomodulation (PBM) on post-endodontic pain of mandibular molar teeth with symptomatic irreversible pulpitis. Material and Methods: In this clinical trial, mandibular molars with symptomatic irreversible pulpitis underwent primary endodontic treatment in 90 systemically healthy patients. After root canal treatment, the patients were randomly divided into two groups of PBM with diode laser at 940 nm wavelength and 200 mW output power and placebo (mock PBM therapy). Level of pain was recorded at 6, 12, 24, 48, and 72 hours postoperatively using a visual analog scale (VAS). The data were analyzed using the Mann-Whitney test and the Kruskal-Wallis test. Results: The results showed that post-endodontic pain at all time points was significantly lower in the PBM group compared with the placebo group. The pain score in the PBM group was significantly lower than the placebo group (p<0.05). However, this difference was not significant at 48 h (p=0.18) and 72 h (p=0.12) postoperatively. Also, the results showed that the mean pain score in males and females in the PBM group was significantly lower than in males and females in the placebo group. Conclusion: Photobiomodulation can effectively decrease post-endodontic pain in mandibular molar teeth with symptomatic irreversible pulpitis.

Morphological alterations of the apical foramen after foraminal enlargement: a systematic review of ex vivo studies / Alterações morfológicas do forame apical após ampliação foraminal: uma revisão sistemática de estudos ex vivo

Foraminal enlargement has been recommended to optimize the disinfection of infected root canals, although some authors still claim that the foramen should be kept in its original shape and position. This study aimed to evaluate morphological alterations of apical foramen after foraminal enlargement through a systematic review. An electronic search was conducted until April 2022. Ex vivo studies evaluating influence of foraminal enlargement in the morphologic changes of apical foramen were included. Studies without a control group or available full text were excluded. Foraminal deformation and area increase were considered as primary outcomes. Risk-of-bias assessment was performed according to a modified Joanna Briggs Institute's Checklist. From 702 studies retrieved, five were eligible. Most studies used single-rooted teeth, and rotary systems for instrumentation ranging from ­ 2 mm to + 1 mm to the apex. All studies found increased major foramen deformation after foraminal enlargement. Among four studies that evaluated foraminal area, all found increased area after foraminal enlargement. Insufficient data for touched/untouched walls by instruments and dentinal microcrack formation was observed. A low risk of bias was found. Foraminal enlargement during root canal preparation seems to increase deformation and major apical foramen area. Future investigations with standardized methodologies are encouraged (AU)

A ampliação foraminal tem sido recomendada para otimizar a desinfecção de canais radiculares infectados, embora alguns autores ainda afirmem que o forame deve ser mantido em sua forma e posição originais. Este estudo teve como objetivo avaliar alterações morfológicas do forame apical após ampliação foraminal por meio de uma revisão sistemática. Uma busca eletrônica foi realizada até abril de 2022. Foram incluídos estudos ex vivo que avaliaram a influência da ampliação foraminal nas alterações morfológicas do forame apical. Foram excluídos estudos sem grupo controle ou com texto completo indisponível. A deformação foraminal e o aumento da área foram considerados desfechos primários. A avaliação do risco de viés foi realizada de acordo com uma lista de verificação modificada do Instituto Joanna Briggs. Dos 702 registros recuperados, cinco foram elegíveis. A maioria dos estudos utilizou dentes unirradiculares e sistemas rotatórios para instrumentação, com comprimento de trabalho variando de ­ 2 mm a + 1 mm até o ápice. Todos os estudos encontraram aumento da deformação do forame maior após ampliação foraminal. Dos quatro estudos que avaliaram a área foraminal, todos encontraram aumento de área após alargamento foraminal. Foram observados dados insuficientes para paredes tocadas/intocadas pelos instrumentos e formação de microfissuras dentinárias. Um baixo risco de viés foi encontrado. A ampliação foraminal durante o preparo do canal radicular parece aumentar a deformação e a área do forame apical. Futuras investigações com metodologias padronizadas são incentivadas (AU)

Effect of Glycolic Acid, Maleic Acid, and EDTA in the Removal of Smear Layer from Root Canal Dentin

ABSTRACT Objective: To assess the efficacy of 5% Glycolic Acid (GA), 17% ethylenediaminetetraacetic acid (EDTA) and 7% maleic acid (MA), in removing the smear layer (SL). Material and Methods: For the experiment, forty single-rooted human teeth were selected. To perform the chemo‑mechanical preparation, the root canals were instrumented to an apical size of #30, along with simultaneous irrigation of 2.5% NaOCl. The samples were allotted to the experimental groups based on the final irrigating solution (n=10): (1) The GA group: 05%, (2) the EDTA group: 17%, (3) the MA group: 7%, and (4) the control group: Distilled water. The teeth were evaluated for the presence or absence of SL using SEM. Results: Comparing the 5% GA, 7% MA and 17% EDTA groups, no statistically significant differences were found at the coronal and middle thirds (p>0.05). However, in the apical third, MA had greater efficacy than EDTA (p=0.002) and GA (p=0.041), with a significant difference in the SL removal, while there was no significant difference between the latter (p=0.148). Conclusion: Thus, it was concluded that 7% maleic acid as a final irrigating solution is more efficacious than 17% EDTA and 5% glycolic acid in eliminating the smear layer from the apical portion of the root canal.

Influence of Apical Diameter on Filling Material Extrusion during Retreatment - A Micro-CT and CBCT evaluation

Abstract Aim: To investigate whether foraminal widening performed at primary treatment has an effect on the amount of apically extruded obturator material during retreatment and to evaluate the sensitivity of cone beam computed tomography (CBCT) in detecting extruded obturator material. Methods: Forty palatal roots of maxillary molars were selected based on micro-CT and divided into two groups (n=20): with foraminal widening (WE) and without foraminal widening (NE). To standardize the apical foramen, all specimens were instrumented to the foramen using the Protaper Next system, up to instrument X3. The WE group was instrumented to the foramen up to instrument X5, and the NE group was instrumented 1 mm lower. The canals were obturated 1 mm below the apical foramen with gutta-percha and AH Plus and stored for 7 days at 37 °C and 95% humidity. Roots were fixed in microtubes filled with 1.5% agar gel. The obturation material was removed with Reciproc R50. Scans of the teeth and agar were performed using micro-CT and CBCT. Comparison between groups and between methods was performed using Mann-Withney test (p ≤0.05). Results: No statistical difference was found when comparing the extruded material between groups using micro-CT (p = 0.589) or CBCT (p = 0.953). CBCT measured a greater volume of extruded material than micro- CT (p = 0.0004). Conclusion: Foraminal widening had no effect on the extrusion of filling material during retreatment. The CBCT favored the evaluation of apically extruded filling material.

Resumo Objetivo: Investigar se o alargamento do foramen realizado durante o tratamento primário tem um efeito na quantidade de material obturador apicalmente extruído durante oretratamento e verificar a sensibilidade da tomografia computorizada de feixe cônico (TCFC) na detecção de material obturador extruído. Métodos: Quarenta raízes palatinas de molares superiores foram selecionadas de acordo com a microtomografia computorizada, e foram divididas em dois grupos (n=20): com alargamento do foraminal (CA) e sem alargamento do foraminal (SA). Para padronizar o forame apical, todas as amostras foram instrumentadas com o sistema ProTaper Next até ao instrumento X3 até o forame. O grupo CA foi instrumentado até ao instrumento X5 até o forame, e o grupo SA foi instrumentado 1 mm aquém. Os canais foram obturados 1 mm abaixo do forame apical com gutta-percha e AH Plus e armazenados durante 7 dias a 37 °C e 95% de umidade. As raízes foram fixadas em microtubos preenchidos com gel de ágar a 1,5%. O material obturador foi removido com Reciproc R50. Os escaneamentos dos dentes e do ágar foram realizados com micro-CT e CBCT. A comparação entre grupos e entre métodos foi realizada utilizando o teste Mann-Withney (p ≤0.05). Resultados: Não foi encontrada diferença estatística ao comparar o material extruído entre grupos utilizando o Micro-CT (p = 0,589) ou TCFC (p = 0,953). Foi medido um volume maior de material extruído com a TCFC do que com a Micro- CT (p = 0,0004). Conclusão: O alargamento foraminal não teve qualquer efeito na extrusão do material obturador durante o retratamento. A TCFC favoreceu a avaliação do material de obturador apicalmente extruído.

Influence of working length and anatomical complexities on the apical root canal filling: a nano-CT study

Abstract The present study aimed to compare the filled volume by gutta-percha and sealer in the apical region of the main canal and ramifications, after instrumentation at two different working lengths using nano-computed tomography (nano-CT). Twenty-two premolars with apical ramifications were selected after micro-computed tomography evaluation and were randomly divided into groups for further endodontic instrumentation at two different working lengths: G1 - Root canals shaped 1 mm short of the apical foramen (n=11), and G2 - Root canals shaped at the apical foramen (n=11). After completing root treatment, nano-CT images were acquired, and the filled volume by gutta-percha and sealer in the main canal apical 0-4 mm and 0-1 mm ranges, and apical ramifications were objectively measured by an operator specialized in both radiology and endodontics, blinded for both groups. The Mann-Whitney test was applied to compare both groups regarding the filling of the main canal apical ranges and apical ramifications with a significance level of 5% (α ≤ 0.05). It was observed that root canals shaped at the apical foramen had a larger volume of the main canal filled than root canals shaped 1 mm short of the apical foramen, at both apical ranges (0-4 and 0-1 mm) (p<0.05). Regarding the filling of the apical ramifications, there was no significant difference between groups (p>0.05). In conclusion, the root canals shaped at apical foramen exhibited increased filling volume of the main canal in the apical region. However, neither of both working lengths influenced filling of the apical ramifications.

Resumo O presente estudo teve como objetivo comparar o volume preenchido por guta-percha e cimento na região apical do canal principal e ramificações, após instrumentação em dois comprimentos de trabalho diferentes, por meio de nano tomografia computadorizada (nano-TC). Vinte e dois pré-molares com ramificações apicais foram selecionados após avaliação por micro-tomografia computadorizada e foram divididos aleatoriamente em grupos para posterior instrumentação endodôntica em dois comprimentos de trabalho diferentes: G1 - Canais radiculares instrumentados 1 mm aquém do forame apical (n = 11) e G2 - Canais radiculares instrumentados até o forame apical (n = 11). Após a obturação dos canais radiculares, imagens de nano-CT foram adquiridas, e o volume preenchido por guta-percha e cimento nas faixas apicais de 0-4 mm e 0-1 mm do canal principal, e ramificações apicais, foram avaliadas objetivamente por um especialista em radiologia e endodontia, cego para ambos os grupos. O teste de Mann-Whitney foi aplicado para comparar os dois grupos quanto ao preenchimento das faixas apicais do canal principal e ramificações com nível de significância de 5% (α ≤ 0,05). Observou-se que canais radiculares instrumentados até o forame apical apresentaram maior volume do canal principal preenchido do que canais radiculares instrumentados 1 mm aquém do forame apical, em ambas as faixas apicais (0-4 e 0-1 mm) (p <0,05) Em relação ao preenchimento das ramificações apicais, não houve diferença significativa entre os grupos (p> 0,05). Em conclusão, os canais radiculares instrumentados até o forame apical mostraram um maior volume de preenchimento na região apical do canal principal. No entanto, os dois diferentes comprimentos de trabalho não influenciaram o preenchimento das ramificações apicais.

Odontometria eletrônica em dentes decíduos: revisão de literatura e relato de caso / Eletronic working length determination in primary tooth: review of literature and case report

Objetivo: Realizar uma revisão dos principais artigos encontra-dos na literatura acerca do uso dos Localizadores Eletrônicos Foraminais (LEF) em dentes decíduos e representar através de um relato de caso clínico, a importância do uso destes dispositivos durante o tratamento endodôntico em dentes decíduos. Revisão da literatura: Foi realizada uma busca nas principais bases de dados, e selecionados 13 artigos consi-derados mais relevantes. Todos os estudos mostraram que a determinação da odontometria em dentes decíduos utilizando o LEF é bastante segura e com boa acurácia, podendo ser utilizado o localizador para esta finalidade. Relato do caso:No caso clínico apresentado, o uso do LEF foi fundamental para a obtenção de uma odontometria precisa, além da diminuição do tempo de cadeira e identificar reabsorções não detectáveis radiograficamente. O caso foi conduzido em duas sessões, onde na primeira foi realizada a cirurgia de acesso, odontometria eletrônica, preparo manual dos canais e utilização de medicação intracanal de hidróxido de cálcio. Na segunda sessão foi removida a medicação intracanal e os canais foram obturados utilizando pasta iodoformada. Discussão: O uso do LEF no tratamento endodôntico de dentes decíduos tem se mostrado uma ferramenta segura e eficiente, tendo melhor performance na determinação do comprimento de trabalho quando comparado a outros métodos. Conclusão: De acordo com os estudos apresen-tados na revisão de literatura e o caso clínico apresentado, pudemos constatar que o uso do LEF contribui positivamente ao tratamento, principalmente quanto ao ganho de tempo e determinação confiável e segura do comprimento de trabalho.

Aim: To review the main articles found in the literature on the use of Electronic Apex Locators (EAL) in deci-duous teeth, and to represent, through a clinical case report, the importance of using these devices during endodontic treatment in deciduous teeth. Review of literature: A search was performed in the main data-bases, and 13 articles considered most relevant were selected. All studies showed that the determination of odontometry in deciduous teeth using LEF is quite safe and with good accuracy, and the localizer can be used for this purpose. Case report: In the clinical case presented, the use of EAL was fundamental to obtain an accurate odontometry, besides the reduction of chair time and exposure to ionizing radiation. The case was conducted in two sessions, where in the first one the access surgery was performed, electronic odontometry, manual preparation of the canals and use of intracanal medication of calcium hydroxide. In the second session the intracanal medication was removed and the canals were filled using iodoform paste. Discussion: The use of LEF in the endodontic treatment of primary teeth has been shown to be a safe and efficient tool, with better permormance in determining the working length when compared to other methods. Conclusion: According to the studies presented in the literature review and the clinical case presented, we could verify that the use of LEF contributes positively to treatment, especially in terms of time gain and acurate determination of working length.

Ability of two reciprocating Nickel-Titanium instruments for guttapercha/ sealer removal in simulated curved root canals / Análisis de la capacidad de dos instrumentos reciprocantes de Niquel-Titanio para la remoción de gutapercha/sellador en conductos curvos simulados

ABSTRACT The aim of this study was to compare the capacity of two reciprocating NiTi instruments in removing gutta-percha/sealer material from simulated curved root canals (SCRC). The time required for filling material removal was also recorded. Twenty SCRCs were divided into two groups of 10 (n=10) samples each. In Group 1, the SCRC were prepared to a R25 Reciproc Blue instrument (RCPB; VDW, Munich, Germany). In Group 2 the SCRC were prepared to a Primary WaveOne Gold instrument (PWOG; Dentsply, Ballaigues, Switzerland). In both groups, the canals were filled with matched-taper single gutta-percha cones and AH Plus sealer. Filling materials were removed with R25 RCPB (Group 1) and PWOG (Group 2). The amount of remaining gutta-percha/sealer was calculated at three predetermined levels of evaluation located at 2, 6 and 10 mm from the WL and expressed in percentages. Canals re-treated with RCPB contained significantly less remaining gutta-percha/sealer compared to canals prepared with PWOG (P=0.02). The RCPB instruments required significantly less time to complete the retreatment procedures (P<0.01). No unwinding or instrument separation was noted. RCPB instruments removed significantly more gutta-percha/sealer from simulated curved root canals than PWOG. However, neither of the tested instruments completely removed all filling materials.

RESUMEN El propósito del presente estudio fue comparar la capacidad de dos instrumentos de NiTi de movimiento reciproco para remover la obturación de gutapercha/sellador durante el retratamiento de conductos curvos simulados (SCRC). El tiempo requerido para la remoción del material fue también registrado. Se utilizaron veinte (n=20) SCRC divididos en dos grupos de diez especimenes (n=10) cada uno. En el Grupo 1 los SCRC se prepararon hasta un instrumento Reciproc Blue R25 (RCPB; VDW, Munich, Germany). En el Grupo 2, los SCRC se prepararon hasta un instrumento WaveOne Gold Primary (PWOG; Dentsply, Ballaigues, Switzerland). En ambos grupos los conductos se obturaron con cono único de gutapercha de conicidad creciente y el sellador AH Plus. La remoción de los materiales de obturación se realizó mediante los instrumentos RCPB R25 (Grupo 1) o PWOG (Grupo 2). La cantidad de gutapercha/sellador remanente se calculó en tres niveles de evaluación predeterminados ubicados a 2, 6 y 10 mm de la LT, y finalmente fue expresada en porcentajes. La cantidad de gutapercha/ sellador remanente en los SCRC retratados con RCPB fue significativamente menor en comparación con los que fueron retratados con PWOG (P=0.02). Los instrumentos RCPB requirieron un tiempo significativamente menor para completar el retratamiento (P<0.01). No se observaron deformaciones o separación de los instrumentos. Los instrumentos RCPB removieron una cantidad significativamente mayor de gutapercha/sellador que los instrumentos PWOG en conductos curvos simulados. Sin embargo, ninguno de los instrumentos ensayados removió completamente los materiales de obturación.

An unusual repair of perforating internal inflammatory root resorption; a case report of endodontic treatment

Internal inflammatory root resorption (IIRR) can occur as a serious complication of dental trauma which leads to progressive loss of the root structure. An early diagnosis could influence the therapeutic approach, but endodontic treatment becomes a challenge with a doubtful prognosis. The present report described an unusual clinical presentation of an IIRR with perforation resulting from a trauma four years previous. A 15-year-old female patient was presented to our service with pain in the maxillary incisor region. Intraoral radiography revealed a large radioloucent area compatible with IIRR, communicating with the periodontium in the middle third on the distal root face of the right central incisor. The root canal of the right central incisor was chemo-mechanically prepared. The calcium hydroxide (CH) intracanal medication was used and renewed periodically four times. The root canal was filled only in the cervical region to the level of resorption by the inverted gutta-percha cone technique. Clinically and radiographically, all follow-up examinations revealed an asymptomatic tooth, evidencing periapical tissue repair and new bone formation. The tooth remained asymptomatic 3 years afterwards. The present case report supports the idea of executing satisfactory intracanal decontamination by chemo-mechanical preparation, thus creating a favourable environment for tissue repair.

Nonsurgical management of an extensive periapical lesion combined with photodynamic therapy: a case report / Manejo não cirúrgico de lesão periapical extensa combinada com terapia fotodinâmica: relato de caso

Introduction: the major goal of endodontic treatment (ET) is the complete elimination and/or maximum possible reduction of bacteria and irritants in the root canal system (RCS). However, persistence of bacterial debris refractory to therapy may leading to ET failure, being necessary to realize conventional or surgical retreatment. Objective: this is a case report on the nonsurgical management of an extensive chronic periapical lesion in teeth 12 and 11 in an adult female patient with history of endodontic treatment failure. She presented with painless swelling and a fistula adjacent to tooth 11. Methodology: conventional ET combined with photodynamic therapy (PDT) was recommended, in addition to calcium hydroxide applications. Regular clinical and radiographic follow-up made over a 2-year period revealed progression of bone regeneration, without sign and symptoms, with a satisfactory outcome. Conclusion: this case report shows that the combination of conservative ET with PDT provided satisfactory results with the resolution of the chronic endodontic infection and bone repair of the extensive periapical lesion.

Introdução: o principal objetivo do tratamento endodôntico (TE) é a eliminação completa e/ou máxima redução possível de bactérias e irritantes no sistema de canais radiculares (SCR). Porém, a persistência de detritos bacterianos refratários à terapia pode levar ao insucesso do TE, sendo necessária a realização do retratamento convencional ou cirúrgico. Objetivo: este relato de caso descreve o manejo não cirúrgico de uma extensa lesão periapical crônica nos dentes 12 e 11 em paciente adulta do sexo feminino com histórico de fracasso endodôntico. A mesma queixava-se de inchaço indolor, com presença de fístula adjacente ao dente 11. Metodologia: preconizou-se a realização do TE convencional associado à terapia fotodinâmica (PDT), com três sessões de troca de hidróxido de cálcio, concluindo-se posteriormente o tratamento. Reavaliações clínicas e radiográficas periódicas ao longo de 2 anos revelaram a progressão da consolidação óssea, com um desfecho satisfatório. Conclusão: este relato de caso mostra que a combinação do TE conservador associado à PDT teve resultados satisfatórios na resolução de infecção endodôntica crônica e no reparo ósseo de lesão periapical extensa.

Application of a one-time filling root canal in root canal therapy in plateau areas / 中国基层医药

Objective:To investigate the application effects of a one-time filling root canal in root canal therapy in plateau areas and evaluate its feasibility in oral clinic in plateau areas.Methods:Sixty-eight patients who received root canal therapy for anterior teeth and premolars (75 teeth) from August to December 2018 in Shannan People's Hospital were included in this study. They were divided into control group ( n = 33; 36 teeth) and observation group ( n = 35; 39 teeth) according to odd and even numbers of admission date. Patients in the control group received conventional root canal therapy and those in the observation group underwent one-time root canal filling therapy. Efficacy was compared between the two groups. Results:After 1 week, 2 weeks and 1 month of treatment, the success rate in the control group was 88.9%, 94.4%, 100.0%, respectively, and it was 87.2%, 94.9% and 100.0%, respectively in the observation group. There was no significant difference in success rate between the two groups at three time points studied (all P > 0.05). Conclusion:One-time filling root canal therapy can achieve ideal therapeutic effects under strict control of surgical indications. This method is worthy of clinical promotion especially in plateau areas.