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)

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 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.

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.

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.

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.

Avaliação da dor pós-operatória e efetividade antimicrobiana no tratamento endodôntico com uso de irrigação ultrassônica versus irrigação convencional: revisões sistemáticas e meta-análises de ensaios clínicos randomizados / Evaluation of postoperative pain and antimicrobial effectiveness in endodontic treatment using ultrasonic irrigation versus conventional irrigation: systematic reviews and meta-analyses of randomized clinical trials

O objetivo deste estudo foi avaliar a efetividade antimicrobiana e a dor pós-operatória (PP) da irrigação ultrassônica (IU) em comparação com a irrigação convencional (CI), por meio de duas revisões sistemática e meta-análises de ensaios clínicos randomizados, para isto foram produzidos dois artigos, um para dor pós operatória e outro para avaliação antimicrobiana, desta forma a dissertação a seguir contará com dois capítulos. Essa revisão foi elaborada seguindo o guia PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analyses). Após elaborada a pergunta clínica e a estratégia PICO de cada estudo, uma pesquisa bibliográfica foi realizada nas principais bases de dados científicas por meio de uma estratégia de busca elaborada com termos MeSH e termos livres adaptados para as bases de dados. As meta-análise foram conduzidas usando o software R com o pacote "META", o efeito de medida de diferença média (MD) e odds ratio (OR) foi calculada e o modelo de efeito fixo foi aplicado com um intervalo de confiança (IC) de 95%. A escala da colaboração Cochrane foi usada para avaliar o risco de viés e a ferramenta GRADE para avaliar a qualidade das evidências. Os resultados mostraram vantagem favorecendo o grupo irrigação ultrassônica em ambas as variáveis de interesse (dor pós-operatória e efetividade antimicrobiana), na dor pós-operatória, 6 ensaios clínicos randomizados (RCTs) foram incluídos para revisão sistemática e quatro para meta-análise. IU resultou em menor PP em 3 dos 5 períodos, 6 horas (MD -1,40 [CI -2,38 a - 0,42] p = 0,0052), 24 horas (MD -0,73 [CI -1,07 a -0,39] p = 0,0001), e 48 horas (MD -0,36 [CI -0,59 a -0,13] p = 0,022). No entanto, a PP não apresentou diferenças significativas entre os grupos em 72 horas e 7 dias (p> 0,05). Um baixo risco de viés foi observado para a maioria dos domínios, exceto a alocação que foi considerada pouco clara. A certeza da evidência foi classificada em moderada (24 horas, 48 horas e 7 dias) e baixa (6 e 72 horas). Já na efetividade antimicrobiana, 12 RCTs foram incluídos para a revisão sistemática e oito para as meta-análises onde 4 foram utilizadas para (MD) e 4 para (OR). Em ambas análises a IU resultou em melhor efeito antimicrobiano em comparação com a CI MD -1,42 [-1,60; -1,23] p < 0,0001, I2 = 80% e OR 3.86 [1.98; 7.53] p< 0.0001, I2 = 28.7%. Um baixo risco de viés foi observado para a maioria dos domínios, exceto a alocação que foi considerada pouco clara. A certeza das evidências foi considerada moderada na meta-análise utilizando OR, devido aos achados de imprecisão, e baixa na meta-análise utilizando MD devido a presença de inconsistência e imprecisão. Desta forma é possível concluir que dentro das limitações das presentes revisões sistemáticas a IU apresentou resultados favoráveis tanto para dor pós-operatória quanto para o aumento da efetividade antimicrobiana. Contudo ensaios clínicos randomizados mais robustos são necessários para corroborar com esses achados(AU)

The aim of this study was to evaluate the antimicrobial effectiveness and postoperative pain (PP) of ultrasonic irrigation (UI) compared to conventional irrigation (CI), through two systematic reviews and meta-analyses of randomized clinical trials for this, two articles were produced, one for postoperative pain and another for antimicrobial evaluation, so the dissertation below will have two chapters. This review was prepared following the PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analyses). After preparing the clinical question and the PICO strategy for each study, a literature search was carried out in the main eletronic databases through a search strategy elaborated with MeSH terms and free terms adapted to the databases. Meta-analyses were conducted using the R software with the "META" package, the mean difference (MD) and odds ratios (OR) was the measure effect necessary and the fixed-effect model was applied with a 95% confidence interval (CI). The Cochrane Collaboration Scale was used to assess the risk of bias and the GRADE tool to assess the quality of evidence. The results showed an advantage favoring the ultrasonic irrigation group in both variables of interest (postoperative pain and antimicrobial effectiveness), in postoperative pain, 6 RCTs were included for systematic review and four for metaanalysis. UI resulted in lower PP in 3 of the 5 periods, 6 hours (MD -1.40 [CI -2.38 to -0.42] p = 0.0052), 24 hours (MD -0.73 [CI -1 .07 to -0.39] p = 0.0001), and 48 hours (MD -0.36 [CI -0.59 to -0.13] p = 0.022). However, PP did not show significant differences between groups at 72 hours and 7 days (p> 0.05). A low risk of bias was observed for most domains, except the allocation was considered unclear. The certainty of the evidence was classified as moderate (24 hours, 48 hours and 7 days) and low (6 and 72 hours). In the study of antimicrobial effectiveness, 12 RCTs were included for the systematic review and 8 for the meta-analyses where 4 were used for (MD) and 4 for (OR). In both analyses, UI resulted in better antimicrobial effect compared to CI MD -1.42 [- 1.60; -1.23] p< 0.0001, I2 = 80% and OR 3.86 [1.98; 7.53] p< 0.0001, I2 = 28.7%. A low risk of bias was observed for most domains, except the allocation was considered unclear. The certainty of evidence was considered moderate in the meta-analysis using OR, due to the imprecision findings, and low in the meta-analysis using MD due to the presence of inconsistency and imprecision. Thus, it is possible to conclude that, within the limitations of the present systematic reviews, UI presented favorable results both for postoperative pain and for the increase in antimicrobial effectiveness. However, more robust randomized controlled trials are needed to corroborate these findings(AU)

Post-obturation pain and its relationship with reference time and other risk factors / Dor pós-obturação e sua relação com o tempo de referência e outros fatores de risco

Objective: To evaluate incidence and intensity of postoperative pain in patients treated in the Residency Program in Endodontics at the State University of Maringá. The influence of factors inherent to the patient and treatment on preoperative pain was also the focus of our study. Material and Methods: 99 patients participated in this study and underwent non-surgical endodontic treatment. Initially, palpation, vertical and horizontal percussion were performed on the tooth to be treated. After the root canals filling, patients received a printed Numerical Rating Scale and were instructed to record the level of pain in the postoperative periods of 24, 48 and 72 hours. For each postoperative period, the patient recorded the values. A descriptive analysis of the data and a model of generalized estimation equations were performed to verify the relationship between the variables and postoperative pain, at a significance level of 5%. Results: During the follow-up period, the pain rates found were low represented by 16%, 11% and 7% in the periods of 24, 48, and 72h, respectively. In addition, the rates significantly decreased after 72h. Only one case of flare-up was recorded. Presence of pain on palpation, use of reciprocating file and use of 2.5% sodium hypochlorite influenced the results (p<0.05), increasing the changes of post-operative pain by 3.36, 0.4 and 0.2 times, respectively. Conclusion: Incidence and intensity of postoperative pain monitored in the residency program reduced significantly after 72 hours. Postoperative pain was associated with pain on palpation, use of reciprocating files and irrigation with 2.5% hypochlorite.(AU)

Objetivo: Avaliar a incidência e intensidade da dor pós-operatória em pacientes atendidos no Programa de Residência em Endodontia da Universidade Estadual de Maringá. A dor do paciente foi monitorada após 24, 48 e 72 horas após a obturação do canal radicular. A influência de fatores inerentes ao paciente e ao tratamento na dor pré-operatória também foi foco de nosso estudo. Material e Métodos: 99 pacientes participaram deste estudo e foram submetidos a tratamento endodôntico não cirúrgico. Inicialmente, foram realizadas palpação, percussão vertical e horizontal no dente a ser tratado. A presença de dor foi classificada em uma Escala Numérica de Avaliação (NRS). Após a obturação dos canais radiculares, os pacientes receberam a NRS impressa e foram orientados a registrar o nível de dor nos pós-operatórios de 24, 48 e 72 horas. A cada pós-operatório, um pesquisador entrava em contato com o paciente e registrava os valores. Foi realizada uma análise descritiva dos dados e um modelo de equações de estimativa generalizada (GEE) para verificar a relação entre as variáveis e a dor pós-operatória, ao nível de significância de 5%. Resultados: Durante o período de acompanhamento, os índices de dor encontrados foram baixos representados por 16%, 11% e 7% nos períodos de 24, 48 e 72h, respectivamente. Além disso, as taxas diminuíram significativamente após 72h. Apenas um caso de reagudecimento foi registrado. Presença de dor à palpação, uso de lima reciprocante e uso de hipoclorito de sódio 2,5% influenciaram os resultados (p<0,05) aumentando as alterações da dor pós-operatória em 3,36, 0,4 e 0,2 vezes, respectivamente. O tempo médio de encaminhamento foi de 6,28 meses, o que não influenciou nos resultados. Conclusão: A incidência e intensidade da dor pós-operatória monitorada no programa de residência reduziram significativamente após 72 horas. A dor pós-operatória foi associada à dor à palpação, uso de limas reciprocantes e irrigação com hipoclorito a 2,5%. (AU)

Success of a tooth auto-transplant despite delayed endodontic treatment due to COVID-19 pandemic lock-down: a case report / Sucesso de um autotransplante dentário apesar do atraso no tratamento endodôntico devido ao confinamento da pandemia de COVID-19: relato de caso

Auto-transplantation has been suggested to be a favourable treatment option in comparison to prosthodontic replacements. Studies have shown an average survival rate of 89.1% for auto-transplanted teeth. This article aims to report a successful third molar auto-transplantation, despite delayed endodontic treatment because of movement control order (MCO) imposition following COVID-19 out-break in Malaysia. A 22-year-old female patient's impacted lower left third molar (38) was used as a donor to replace her lower left second molar (37), which was deemed non-restorable due to caries and root resorption as a result of impinging pressure from the impacted adjacent third molar. Successful outcome and uneventful healing were achieved over a period of one year, despite delayed endodontic treatment following auto-transplantation. A favourable auto-transplant can be achieved despite delayed endodontic treatment post-transplantation, if the procedure is performed in a good aseptic environment and bacterial load is controlled at the site (AU)

O autotransplante tem sido sugerido como uma opção de tratamento favorável em comparação com as substituições protéticas. Estudos mostraram uma taxa de sobrevivência média de 89,1% para dentes autotransplantados. Este artigo tem como objetivo relatar um autotransplante de terceiro molar bem-sucedido, apesar do atraso no tratamento endodôntico devido à imposição da ordem de controle de movimento (MCO) após o surto de COVID-19 na Malásia. O terceiro molar inferior esquerdo impactado de uma paciente de 22 anos (38) foi usado como doador para substituir seu segundo molar inferior esquerdo (37), que foi considerado não restaurável devido à cárie e reabsorção radicular como resultado da pressão de impacto do terceiro molar adjacente impactado. Resultado bem sucedido e cicatrização sem intercorrências foram alcançados ao longo de um período de um ano, apesar do atraso no tratamento endodôntico após o autotransplante. Um autotransplante favorável pode ser alcançado apesar do atraso no tratamento endodôntico pós-transplante, se o procedimento for realizado em um ambiente asséptico e com carga bacteriana controlada no local.(AU)

XP Endo Finisher-R and PUI as supplementary methods to remove root filling materials from curved canals

Abstract: This study assessed the ability of XP-endo Finisher R (FKG, La Chaux-de-Fonds, Switzerland) to remove filling remnants from curved mesiobuccal canals of maxillary molars, using the passive ultrasonic irrigation (PUI) technique as a comparison. Twenty-four curved main mesiobuccal canals (MB1) of maxillary molars were instrumented with Wave One (#25/07) and filled with gutta-percha points and AH Plus Sealer. Samples were then re-treated with a standardized protocol with Wave One (#35/06) as the master apical file. Micro-CT scans measured baseline volume of remaining filling material (in mm3). Samples were divided into two groups (n = 12) according to the supplementary cleaning approach: (PUI) or XP-endo Finisher R. Statistics compared baseline and final volume of filling material (within-group); and the percentage of filling material reduction (between-group). Mean baseline volumes, final volumes, and percentages of reduction (%) of filling material for XP-endo Finisher R and PUI were respectively: 0.060 mm3, 0.042 mm3, and 31.28%; and 0.064 mm3, 0.054 mm3, and 16.57%. Both tested protocols reduced the amount of filling material (p < 0.05). XP-endo Finisher R had higher percentage of reduction as compared to PUI (p < 0.05). XP-endo Finisher R and PUI used as supplementary cleaning protocols during re-treatment improved the removal of root filling material in curved canals; but XP-endo Finisher R was approximately twice more efficient. The complete filling material removal during re-treatment procedures is still a challenge. Supplementary cleaning protocols may help to remove the remaining material after the complete mechanical preparation of curved canals. XP-endo Finisher R was approximately twice more efficient than PUI.

Evaluation in the danger zone of mandibular molars after root canal preparation using novel CBCT software

Abstract: This study measured the thickness of cementum/dentin in the danger zone of the mandibular molars after root canal preparation using novel cone-beam computed tomography (CBCT) software. Eighty-four teeth were distributed into four groups: ProTaper Next, BioRace, Reciproc Blue, and WaveOne Gold. E-Vol DX® CBCT software was used to measure initial and final remaining cementum-dentin thicknesses after root canal preparation of the mesial root of mandibular molars at 1 and 3 mm from the furcation. The Kolmogorov-Smirnov test was used to test variable symmetry. The variables were described as mean and standard deviations, compared among the groups using analysis of variance (ANOVA), and within the groups using the Student t test. A generalized estimating equation model was used to compare the variation before and after root canal preparation. The level of significance was set at 5%. Differences between mean initial and final thicknesses of the mesiobuccal (MB) and mesiolingual (ML) canals were not statistically significant. The mean initial thickness was 3 mm (0.900 mm ± 0.191), considering that a mean lower than 1 mm (1.035 mm ± 0.184) indicates the danger zone. Although cementum/dentin is thinner at 3 mm from the furcation (0.715±0.186) after root canal preparation, the greatest amount of dentin removed was found at 1 mm (0.734 ± 0.191). The cementum-dentin remaining after preparation was thicker than 0.715 mm in root canals prepared using #35 (WaveOne Gold®) and #40 (ProTaper Next®, BioRace® and Reciproc Blue®) instruments. This confirms the safety of canal preparation in the danger zone using these systems.

Influence of anatomical features in the endodontic treatment planning of maxillary anterior teeth

Abstract This study evaluate the maxillary anterior teeth anatomy by micro-computed tomography (μCT), about relevant characteristic for endodontic treatment planning. Fifty maxillary central incisors (MCI), lateral incisors (MLI) and maxillary canines (MC) were scanned using a μCT device. Two and three-dimensional parameters at 1 to 5mm distance to the apical foramen, external anatomic characteristics of the teeth and qualitative analysis of the internal anatomy was performed. The roundness and form factor values revealed a circular canal in the apical third in the MCI and MC, whereas MLI showed flattening in the apical third. The linear regression test indicated a progressive increase in the major/minor diameters in the five mm assessed (p < 0.001). The 3D analysis revealed the greatest volume and surface area in MC. The SMI showed a cylindrical geometry of root canals. All teeth presented Vertucci's type I root canal configuration. A mild curvature was prevalent in the MCI (45%) and a moderate one in the MLI (50%) and MC (50%). Palatal shoulder volume was smaller in the MLI (11.46 ± 3.09) than in the MCI (14.15 ± 3.85) and MC (13.95 ± 2.55). The most common exit of main apical foramen was in a central (22%), distolingual (30%) and mesiobuccal position (28%) for MCI, MLI and MC, respectively. Radicular grooves were observed in 2% of MCI and 4% of MLI. Two and three-dimensional data obtained by μCT allowed to observe morphological characteristics of internal/external anatomy of the maxillary anterior teeth. These characteristics may affect the endodontic treatment planning.