Root Canal Treatment of Mandibular First Premolar with 3 Canals: A Case Report / Tratamiento Endodóntico de Primer Premolar Mandibular con 3 Canales: Reporte de un Caso

SUMMARY: The mandibular first premolar is commonly a single-rooted tooth with occasional presentation of radicular variations. This tooth usually has one root with only one canal (97.9 %). Presence of three canals is very rare. Anomalies may appear during odontogenesis which can lead to anatomical variations in teeth. Similarly, these variations may be associated with characteristics that can be attributed to specific population groups. Due to their low frequency, these additional canals can easily be missed. For this reason, a meticulous knowledge of tooth morphology and their possible anatomical variations are necessary, and the presence of extra roots and canals should be always considered before initiation of root canal treatment. Additionally, different radiographs and appropriated access cavity preparation is needed to ensure a success endodontic treatment. This article reports a diagnosis and endodontic treatment of a mandibular first premolar with three canals.

El primer premolar mandibular suele ser un diente unirradicular con presentación ocasional de variaciones radiculares. Este diente suele tener una raíz con un solo conducto (97,9 %). La presencia de tres canales es muy rara. Durante la odontogénesis pueden aparecer anomalías que pueden provocar variaciones anatómicas en los dientes. De manera similar, estas variaciones pueden estar asociadas con características que pueden atribuirse a grupos de población específicos. Debido a su baja frecuencia, estos canales adicionales pueden pasar desapercibidos fácilmente. Por esta razón, es necesario un conocimiento meticuloso de la morfología dental y sus posibles variaciones anatómicas, y siempre se debe considerar la presencia de raíces y conductos adicionales antes de iniciar el tratamiento de conducto. Además, se necesitan diferentes radiografías y una preparación adecuada de la cavidad de acceso para garantizar un tratamiento de endodoncia exitoso. Este artículo reporta un diagnóstico y tratamiento endodóntico de un primer premolar mandibular con tres canales.

Resistencia a la Fractura de Premolares Según el Diseño de Cavidad de Acceso Endodóntico. Estudio in vitro

La preparación de la cavidad de acceso es el primer paso y un requisito esencial, para la instrumentación y obturación de los conductos radiculares durante el tratamiento endodóntico. El objetivo del presente estudio fue comparar la resistencia a la fractura in vitro de premolares con cavidad de acceso tradicional (CAT), cavidad de acceso conservador (CAC) y cavidad de acceso ultraconservador (CAU). Esta fue una investigación transversal, prospectiva y experimental pura. Se realizó con 40 segundos premolares superiores, divididos en 4 grupos. Todas las muestras fueron desinfectadas y almacenadas en recipientes con suero fisiológico al 0,9 %. Al primer grupo se designó como el control, al segundo grupo CAT, al tercer grupo CAC y al cuarto grupo CAU. Se realizaron todos los accesos endodónticos con una pieza de mano de alta velocidad con refrigeración respetando el protocolo de cada uno de los diseños, posterior a ello se realizó el tratamiento endodóntico y restauración de los especímenes. Una vez preparadas todas las muestras, estas fueron sometidas a una prueba de fatiga en una máquina de ensayo universal y los resultados se registraron en Newtons. La prueba estadística usada fue ANOVA con un nivel de significancia de 5 %. Las CAT obtuvieron el menor valor de resistencia a la fractura en comparación con el grupo control. Sin embargo, no se observaron diferencias estadísticamente significativas entre los grupos CAT, CAC Y CAU. Entre los grupos CAC y CAU, no se encontraron diferencias estadísticamente significativas en comparación con el grupo control.

The preparation of the access cavity is the first step and an essential requirement for the instrumentation and obturation of the root canals during endodontic treatment. The objective of the present study was to compare the in vitro fracture resistance of premolars with traditional access cavity (CAT), conservative access cavity (CAC) and ultraconservative access cavity (CAU). This was a cross-sectional, prospective and pure experimental research. It was carried out with 40 upper second premolars, divided into 4 groups. All samples were disinfected and stored in containers with 0.9 % physiological saline. The first group was designated as the control, the second group CAT, the third group CAC and the fourth group CAU. All endodontic accesses were carried out with a high-speed handpiece with refrigeration, respecting the protocol of each of the designs, after which the endodontic treatment and restoration of the specimens was carried out. Once all the samples were prepared, they were subjected to a fatigue test in a universal testing machine and the results were recorded in Newtons. The statistical test used was ANOVA with a significance level of 5 %. The CAT obtained the lowest fracture resistance value, presenting statistically significant differences with the control group. However, no statistically significant differences were observed between the CAT, CAC, and CAU groups. Furthermore, between the CAC and CAU groups, no statistically significant differences were found compared to the control group.

Amputação radicular para preservação de elemento dentário / Root amputation for tooth preservation

A periodontite é uma doença inflamatória crônica dos tecidos de sustentação e proteção dos dentes. Em dentes posteriores, a perda de inserção pode resultar em vários graus de dano à furca, que se refere à destruição dos tecidos de suporte de dentes multirradiculares caracterizada por reabsorção óssea e perda de inserção no espaço interarradicular. Independente do grau de envolvimento da furca, o tratamento periodontal básico (RAR) é a primeira opção para estabilizar a periodontite, contudo, em algumas situações é utilizada uma terapia cirúrgica periodontal bastante conhecida: a rizectomia ou amputação radicular. O objetivo do trabalho é relatar o caso de uma amputação radicular de um dente comprometido periodontalmente, a fim de se preservar o elemento dentário. O dente 27 foi diagnosticado com periodontite, o que ocasionou a lesão de furca grau III. O tratamento endodôntico foi realizado prévio ao procedimento cirúrgico, viabilizando a amputação da raiz disto-vestibular deste elemento. A partir do relato deste caso, se pode concluir que a amputação radicular é considerada um procedimento conservador, capaz de manter em função molares com histórico de periodontite associado ao envolvimento de lesões de furca(AU)

Periodontitis is a chronic inflammatory disease of the supporting and protective tissues of the teeth. In posterior teeth, attachment loss can result in varying degrees of damage to the furcation, which refers to the destruction of the supporting tissues of multirooted teeth characterized by bone resorption and attachment loss in the interarticular space. Regardless of the degree of furcation involvement, basic periodontal treatment (RAR) is the first option to stabilize periodontitis; however, in some situations, a well-known periodontal surgical therapy is used: rhizectomy or root amputation. Rhizectomy is a treatment option for multirooted teeth. The technique preserves the crown and requires endodontic treatment of the affected tooth, preferably done before surgery(AU)

Comparación de la actividad antimicrobiana de cementos selladores en endodoncia / Comparison of the antimicrobial activity of sealing cements in endodontics

Introducción: la persistencia de microorganismos en los conductos radiculares es uno de los principales factores del fracaso endodóncico. Por ello la importancia de conocer las propiedades antimicrobianas de los distintos tipos de selladores. Objetivo: realizar una comparación con base en la evidencia disponible sobre la actividad antimicrobiana de los diferentes cementos selladores en endodoncia. Material y métodos: la información fue recopilada de las bases de datos PubMed y Google Académico en el idioma inglés y español, publicados en el periodo 2014-2023. Resultados: un gran número de microorganismos se encuentran presentes en los diferentes tipos de infecciones de origen endodóncico, se han identificado más de 500 especies microbianas, entre ellas bacterias, hongos, arqueas y virus. Los cementos selladores se pueden clasificar según su composición química, en cementos a base de óxido de zinc-eugenol, hidróxido de calcio, a base de ionómero de vidrio, silicona, resina y biocerámicos. Conclusión: los cementos selladores que mostraron mayor actividad antimicrobiana contra los microorganismos persistentes fueron los cementos a base de óxido de zinc-eugenol, resina y biocerámicos. Sin embargo, se identificó que cada autor utilizó diferentes métodos y tiempos, por lo tanto, no es posible lograr definir con exactitud qué cemento sellador posee la mejor capacidad antimicrobiana (AU)

Introduction: the persistence of microorganisms in root canals is one of the main factors of endodontic failure. Therefore, the importance of knowing the antimicrobial properties of the different types of sealants. Objective: to make a comparison based on the available evidence on the antimicrobial activity of the different endodontics sealers. Material and methods: the information was collected from PubMed and Google Academic databases in English and Spanish, published in the period 2014-2023. Results: a large number of microorganisms are present in the different types of infections of endodontic origin, more than 500 microbiological species have been identified, including bacteria, fungi, archaea and viruses. Sealer cements can be classified according to their chemical composition, into cements based on zinc oxide-eugenol, calcium hydroxide, based on glass ionomer, silicone, resin and bioceramics. Conclusion: sealer cements that showed the highest antimicrobial activity against persistent microorganisms were zinc oxide-eugenol, resin, and bioceramic-based cements. However, it was identified that each author used different methods and times, therefore, it is not possible to accurately define which sealer cement has the best antimicrobial capacity (AU)

Research progress on cemental tears in terms of clinical diagnosis and treatment / 口腔疾病防治

@#A cemental tear is defined as an incomplete or complete detachment of the cementum along the dentino-cemental junction (CDJ) or the incremental line within the body of the cementum, which can also involve part of the root dentine adjacent to the cementum. The pathogenesis of cemental tears is not fully elucidated. From the literature review, possible predisposing factors were identified, including tooth type, sex, age, periodontitis, previous periodontal treatment or root canal treatment, history of dental trauma, and occlusal trauma or excessive occlusal force. The morphology of cemental tears can be either piece-shaped or U-shaped, which usually contributes to periodontal and periapical breakdown. Clinically, cemental tears have a unitary periodontal pocket and present with symptoms mimicking localized periodontitis, apical periodontitis, and vertical root fractures. Imaging examination is of great significance for the clinical diagnosis of cemental tears, which often manifest as thin ‘prickle-like’ radiopaque masses located longitudinally adjacent to the affected root surface. Exploratory surgery is needed in some cases. Although intraoperative cemental fragments and cemental lines on the root surface can assist in the diagnostic process, histopathology examination is the gold standard for the diagnosis of cemental tears. The treatment methods vary depending on the timing of the correct diagnosis and the clinical or radiological manifestations. With the development of regenerative biomaterials and the development of intentional replantation, an increasing number of affected teeth can survive for a long time. The aim of this review is to systematically describe the biological basis and predisposing factors, clinical features, radiographic and histological characteristics, diagnosis and clinical management of cemental tears, and treatment outcomes to help make a clear diagnosis and develop a personalized treatment plan.

Regenerative endodontic therapy based on tissue engineering mediating by inflammatory microenvironment / 中国组织工程研究

BACKGROUND:Recently,regenerative endodontic therapy is a promising alternative to the maturation of tissue engineering.Inflammatory microenvironment plays a key role in regulating pulp regeneration. OBJECTIVE:To focus on the change in the inflammatory pulp microenvironment,the balance between inflammation and regeneration,and the research advances in tissue-engineered regenerative endodontic therapy within the context of the inflammatory microenvironment to provide a reference for future investigations into regenerative endodontic therapy. METHODS:We conducted a literature search on PubMed and CNKI using search terms"pulp regeneration,inflammation,regenerative endodontic therapy,tissue engineering"in Chinese and English for articles published between 2013 and 2023.The review finally included 61 relevant articles. RESULTS AND CONCLUSION:(1)The changes in the microenvironment of pulpitis involve a complex interplay of cellular and molecular reactions,which,as inflammation progresses,ultimately the microenvironment hinders tissue repair more than facilitates it.(2)Inflammation can promote dental pulp regeneration through stem cell recruitment and activate the complement system,but it can also hinder the regenerative process through immunosuppression and fibrosis.(3)Tissue engineering's three components(stem cells,growth factors,scaffold materials)collaborate to balance inflammation and regeneration,for example,by using interleukin-6 to regulate dental pulp stem cells and foster a regenerative environment.(4)Current research has been largely silent on infection and inflammation issues.The mechanisms underlying changes in the microenvironment of pulpitis are still not fully understood.One promising avenue for improving the clinical applicability of regenerative dental pulp therapy is to achieve precise regulation of the inflammatory-regeneration balance and create a regenerative microenvironment by synergistically leveraging the three elements of tissue engineering.However,this field of investigation still exhibits significant gaps in understanding,necessitating further exploration into innovative strategies for facilitating dental pulp regeneration under inflammation.As such,additional animal experimentation and randomized clinical trials are required to establish a robust foundation for the clinical practice of tissue engineering-based regenerative dental pulp therapy.

Characteristics analysis of clinical trial registration for endodontic diseases based on the ClinicalTrials.gov and ChiCTR databases / 口腔疾病防治

Objective@#To summarize the clinical registration data of endodontic diseases registered in ClinicalTrials.gov in the United States and Chinese Clinical Trial Registry (ChiCTR), and analyze the registration characteristics at home and abroad@*Methods@#We searched the clinical studies related to endodontic disease registered in the two databases from January 1, 2000, to August 20, 2023. We extracted and analyzed the information from clinical studies related to endodontic diseases. The extracted content included information on the registration region, registration year, trial title, research direction, sample size, trial progress, study type, trial design, blinding method, clinical trial phase, and participating institutions.@*Results@#The two databases contained a total of 536 191 registered items, of which 634 were endodontic diseases. Clinical trials in the registry of endodontic diseases involved 43 countries, of which the top three were Egypt (188 items), China (130 items), and the America (46 items). In addition, the number of registrations of clinical trials on endodontic diseases has significantly increased since 2015. The research directions were mainly pulposis (434 items), caries (106 items), and periapical diseases (77 items), which mostly involved etiology, drug intervention, surgical intervention, new technology, and new materials. Moreover, there were 430 clinical trials (67.82%) with a sample size < 100 and 185 (29.18%) with a sample size of 100-999. The progress status at the time of registration showed the largest number of completed trials, accounting for 286 items (45.11%), followed by unknown (125 items), recruiting (110 items), and not yet recruiting (81 items). The main research types were intervention studies (546 items, 86.12%), and the main design model was randomized parallel controlled trials (473 items, 74.61%). Additionally, 423 items (66.72%) were marked using the blind method, mainly double-blind trials (195 items), followed by other/unmarked (123 items, 19.40%) and open study (88 items, 13.88%). Furthermore, the largest number of items in the study phase were marked other/unlabeled (388 items), followed by phaseⅡ study (69 items) and preliminary study (62 items). Additionally, 611 items (96.37%) were clinical trials with a number of participating institutions < 3, and 23 items (3.63%) had a number of participating institutions ≥ 3@*Conclusion@#The number of clinical trials registered for endodontic diseases is generally on the rise, but it is still relatively small. The quality of the study design needs to be enhanced, and the registration information in the study phase needs to be improved. Moreover, the number of multicenter trials is small. In the future, we should fully mobilize the talent advantages of well-known stomatology majors in China, take the lead in conducting high-quality, multi-center clinical research, and realize the transformation of results.

Intentional replantation for the treatment of a double-rooted maxillary lateral incisor with periodontal-endodontic lesions: a case report and literature review / 口腔疾病防治

Objective@#To investigate the clinical characteristics, diagnosis and treatment of severe combined periodontal-endodontic lesions in a double-rooted maxillary lateral incisor with a palatal radicular groove and to provide a reference for clinical diagnosis and treatment.@*Methods@#A patient with a double-rooted left maxillary lateral incisor with a palatal radicular groove and severe combined periodontal-endodontic lesions underwent complete root canal therapy and intentional replantation, and a retrospective analysis of the management of this type of patient was performed based on the literature.@*Results@#The 3-year follow-up examination revealed no discomfort, good healing of the upper left lateral incisor, no pathological loosening, and a palatal gingival sulcus was found at a depth of approximately 1 mm. Review of the literature showed that the prognosis of the affected tooth and the choice of treatment plan were correlated with the length and depth of extension of the lingual groove toward the root, the periodontal condition and the pulpal status of the affected tooth. For minor PRGs or for affected teeth with no loss of pulpal viability, flap surgery and odontoplasty can be used to avoid endodontic treatment or retreatment. For deep or long lingual grooves that result in significant loss of periodontal tissue, endodontic treatment, odontoplasty, or closure of the grooves and guided tissue regeneration are needed. In the case of PRGs with double root formation, the affected tooth can be preserved via root canal therapy, removal of the small root and filling with apical restorative material, and intentional replantation.@*Conclusion@#In cases of severe combined periodontal-endodontic lesions due to palatal radicular grooves occurring in double-rooted maxillary lateral incisors, clinical presentation and imaging can prevent missed diagnoses, and appropriate treatment should be based on the length and depth of lingual grooves extending toward the roots, periodontal conditions, and pulpal status of the affected teeth.

Root canal curvature influences uncontrolled removal of dentin and cleaning efficacy after ultrasonic activation

Abstract This study evaluated the correlation between root canal curvature and the effects of ultrasonic irrigation in the following parameters: volume of uncontrolled dentin removal (UDRVol), maximum depth of dentin defects, removal of accumulated hard tissue debris (AHTD), and canal transportation in prepared curved root canals. Twenty-four human permanent mandibular molars were divided into two groups according to root canal curvature: moderate curvature (MC: mean 25°); and severe curvature (SC: mean 48°). The specimens were scanned using an X-ray microcomputed scanner (Skyscan 1172) before and after cleaning and shaping and after the final irrigation protocol with ultrasonic irrigation. There was a moderate correlation between the degree of root canal curvature and the volume of remaining AHTD (p<0.05) and between the degree of root canal curvature and maximum depth of defects due to uncontrolled removal of dentin (p<0.05). The teeth in the SC group had a greater maximum depth of defects on the dentin wall in the apical third than the teeth in the MC group (p <0.05). Both groups had a significant reduction of AHTD in all canal thirds, but the amount of remaining AHTD in the middle and apical thirds and the whole canal was significantly greater in the SC than in the MC group (p <0.05). Canal transportation was not influenced by the canal curvature in all thirds (p >0.05). This study concluded that root canal curvature affects significantly the uncontrolled removal of dentin and remaining AHTD volume after the final irrigation protocol with ultrasonic irrigation.

Resumo Este estudo avaliou a correlação entre a curvatura do canal radicular e os efeitos da irrigação ultrassônica nos seguintes parâmetros: volume de remoção não controlada de dentina (UDRVol), profundidade máxima do desgaste de dentina, remoção de debris de tecido duro acumulado (AHTD) e transporte em canais radiculares curvos. Vinte e quatro molares inferiores humanos permanentes foram divididos em dois grupos de acordo com a curvatura do canal radicular: curvatura moderada (MC: média de 25°); e curvatura acentuada (SC: média de 48°). Os espécimes foram digitalizados usando um scanner microcomputador de raios X (Skyscan 1172) antes e depois da limpeza e modelagem e após a irrigação ultrassônica. Houve uma correlação moderada entre o grau de curvatura do canal radicular e o volume de AHTD remanescente (p<0,05) e entre o grau de curvatura do canal radicular e a profundidade máxima de defeitos devido à remoção descontrolada de dentina (p<0,05). Os dentes do grupo SC apresentaram maior profundidade máxima de defeitos na parede dentinária no terço apical do que os dentes do grupo MC (p<0,05). Ambos os grupos tiveram uma redução significativa de AHTD em todos os terços do canal, mas a quantidade de AHTD remanescente nos terços médio e apical e em todo o canal foi significativamente maior no grupo SC do que no grupo MC (p <0,05). O transporte do canal não foi influenciado pela curvatura do canal em todos os terços (p > 0,05). Este estudo concluiu que a curvatura do canal radicular afeta significativamente a remoção descontrolada de dentina e o volume remanescente de AHTD após a irrigação ultrassônica.

Aplicação de líquidos ativados com plasma frio na endodontia / Application of plasma-activated liquids in endodontics

O insucesso do tratamento endodôntico é decorrente principalmente da presença de microrganismos remanescentes no canal radicular decorrente da dificuldade de remoção de biofilmes e das limitações dos irrigantes convencionais. Por este motivo, há necessidade de novas alternativas para a desinfecção intracanal. O objetivo deste estudo foi avaliar a atividade inibitória de líquidos ativados por plasma frio sobre biofilmes de interesse endodôntico, além de caracterizar as condições para obtenção do líquido ativado e analisar a citotoxicidade dos líquidos. Biofilmes mono e dual espécies de 24 horas foram obtidos a partir de suspensões padronizadas de Candida albicans (ATCC 18804) e Enterococcus faecalis (ATCC 29212). Os biofilmes foram expostos aos líquidos ativados, sendo estes água destilada, solução fisiológica e água mineral. Foram incluídos grupos de líquidos não ativados (controles negativos) e grupo controle de crescimento. Após 24 horas, os biofilmes foram expostos ao tratamento por 2 períodos, 1 minuto e 1,5 minutos. O número de células remanescentes foi determinado após semeadura da suspensão microbiana resultante em meios de cultura seletivos. A citotoxicidade dos líquidos ativados frente às células 3T3 foi avaliada. O teste ex vivo foi realizado em canais radiculares de dentes humanos, no qual totalizou 54 dentes humanos unirradiculares que foram preparados, instrumentados e esterilizados para receberem tratamentos com água destilada ativada. Os dados foram analisados pelo software GraphPad Prism, versão 6.01. As comparações foram feitas utilizando testes de análise de variância (ANOVA One-way), seguidas do post-hoc de Tukey, adotando-se o nível de significância de 5%. A exposição dos líquidos ativados por plasma frio levou a reduções significativas (p<0.0001) em todos os grupos quando comparados ao grupo controle de crescimento e com os grupos dos líquidos não ativados, tanto para biofilmes mono e dual espécies. A Água destilada ativada levou à maior redução em relação aos demais líquidos e o tempo de tratamento mais efetivo foi de 1,5 minutos. Os líquidos ativados não foram citotóxicos para células 3T3. No teste ex vivo, a água destilada ativada levou à redução da viabilidade dos biofilmes em 80% a 91%. Conclui-se os líquidos ativadas com plasma frio apresentaram ação inibitória sobre biofilmes mono e dual espécies formados por C. albicans e E. faecalis, tanto em modelo in vitro quanto ex vivo, com ausência de toxicidade para células 3T3.(AU)

The failure of endodontic treatment is mainly due to the presence of remaining microorganisms in the root canal due to the difficulty in removing biofilms and the limitations of conventional irrigants. For this reason, there is a need for new alternatives for intracanal disinfection. The objective of this study was to evaluate the inhibitory effect of by cold plasma activated liquids on biofilms of endodontic interest, in addition to characterizing the conditions for obtaining the activated liquid and analyzing the cytotoxicity of the liquids. 24-hours mono- and dual-species biofilms were obtained from standardized suspensions of Candida albicans (ATCC 18804) and Enterococcus faecalis (ATCC 29212). The biofilms were exposed to the activated liquids, which were distilled water, saline solution and mineral water. Non-activated liquid groups (negative controls) and growth control group were included. After 24 hours, the biofilms were exposed to treatment for 2 periods, 1 minute and 1.5 minutes. The number of remaining cells was determined by plating method using selective culture media. The cytotoxicity of activated liquids on 3T3 cells was evaluated. The ex vivo assays were carried out in root canals of human teeth. A total of 54 single-rooted human teeth were prepared, instrumented and sterilized to receive treatments with activated distilled water. Data were analyzed using GraphPad Prism software, version 6.01. Comparisons were made using analysis of variance tests (One-way ANOVA), followed by Tukey's posthoc test, adopting a significance level of 5%. Significant reduction of cell viabilities (p<0.0001) in all groups were observed after exposure to plasma activated liquids when compared to the growth control group and the non-activated liquid groups, both for mono and dual species biofilms. Activated distilled water led to the greatest reduction compared to other liquids and the most effective treatment time was 1.5 minutes. The activated liquids were not cytotoxic to 3T3 cells. In the ex vivo assay, activated distilled water led to a reduction in biofilm viability from 80% to 91%. It is concluded that plasma activated liquids showed inhibitory action on mono and dual species biofilms formed by C. albicans and E. faecalis, both in in vitro and ex vivo models, with no toxicity for 3T3 cells (AU)

Shaping ability of a pediatric motor-driven instrumentation system in primary molar root canal prototypes

Abstract Evaluate the shaping ability and preparation time using a pediatric motor-driven rotary instrumentation compared to other systems in resin prototypes of primary molars. Methods: Thirty specimens were scanned in micro-CT and divided into three groups according to the instrumentation type: pediatric motor-driven Sequence baby File (SBF); conventional motor-driven (Sequence Rotary File - SRF); manual K file. Instrumentation time was timed. After preparation, the specimens were scanned again. The pre- and post-instrumentation images were superimposed to measure the amount of root canal deviation and the resin remnant thickness. ANOVA followed by the Tukey test analyzed the comparisons between groups (p<0.05). Results: No statistically significant differences occurred in root canal deviation among groups (p>0.05). There were statistically significant differences in the comparison among root thirds (p<0.001) but without significant differences in the interaction group vs. root third (p>0.05). Both motor-driven instrumentations showed statistically greater weariness than manual instrumentation (p<0.001), without significant significant differences between SBF and SRF. Motor-driven instrumentation had a shorter working time than manual instrumentation (p<0.001). Conclusion: Pediatric motor-driven instrumentation demonstrated good outcomes in relation to root canal deviation and amount of remnant structure, with shorter instrumentation time. SBF can be a suitable alternative for endodontic instrumentation in primary molars.

Resumo Objetivo: Avaliar os resultados da instrumentação endodôntica e o tempo de preparo de lima odontopediátrica ativada por motor (Sequence Baby File- SBF) em canais de molares decíduos prototipados. Métodos: Trinta espécimes foram escaneados em micro-CT e divididos em três grupos de acordo com o tipo de instrumentação: mecanizada odontopediátrica (SBF); mecanizada convencional; lima K manual. O tempo de instrumentação foi cronometrado. Após o preparo, os espécimes foram escaneados novamente. As imagens pré e pós-instrumentação foram sobrepostas e a quantidade de desvio do canal radicular e a espessura de resina remanescente foram mensurados. Para as análises de comparações entre os grupos foram realizados teste ANOVA seguido do teste de Tukey (p<0,05). Resultados: Não ocorreram diferenças estatisticamente significativas entre os grupos no desvio do canal radicular (p>0,05). Houve diferenças estatisticamente significativas na comparação entre terços radiculares (p<0,001), mas sem diferenças significativas na interação grupo vs. terço radicular (p>0,05). A instrumentação mecanizada apresentou desgaste estatisticamente maior do que a instrumentação manual (p<0,001), sem diferenças estatísticas entre a SBF e a lima mecanizada convencional. A instrumentação mecanizada teve menor tempo de trabalho quando comparado a instrumentação manual (p<0,001). Conclusão: A instrumentação mecanizada odontopediátrica demonstrou bons resultados em relação ao desvio do canal radicular e quantidade de estrutura remanescente, com menor tempo de instrumentação. A SBF pode ser uma alternativa adequada para a instrumentação endodôntica em molares decíduos.

Bypass de instrumento endodôntico fraturado: relato de caso / Bypass of a fractured endodontic instrument: case report

Introdução: Mesmo com toda evolução tecnológica desses instrumentos, com o desenvolvimento das limas de liga de níquel-titanio (NiTi) e sistemas mecanizados, as fraturas podem ocorrer durante o preparo químico/mecânico. Existem três abordagens mais regulamente aplicadas para solucionar essa intercorrencia: tentativa de remoção do instrumento com ultrassom, tentativa de ultrapassálo (bypass) ou a obturação do segmento. Objetivo: Relatar um caso da técnica de bypass em instrumento fraturado no canal radicular. Descrição do caso: Paciente, sexo feminino, 47 anos, brasileira, sem condições sistêmicas associadas, foi encaminhada à clínica do Curso de Odontologia da UNIFENAS, Divinópolis, Minas Gerais, Brasil, para resolução de fratura de instrumento no canal mésio- vestibular do primeiro molar superior direito (16). Optou-se pelo tratamento pela técnica de bypass, que envolveu as seguintes etapas: anestesia, abertura, utilização de lima C-Pilot #08 para ultrapassar o instrumento fraturado, odontometria, escalonamento regressivo a partir da lima k#20, desinfecção com hipoclorito de sódio 5%, medicação com hidróxido de cálcio por 21 dias, agitação da substância irrigadora e obturação dos canais radiculares. Conclusão: O bypass ao instrumento é uma técnica conservadora, eficaz e uma solução adequada em casos de fratura de limas endodônticas dentro dos canais radiculares. Essa técnica visa preservar o máximo possível da estrutura dental original, evitando procedimentos mais invasivos.(AU)

Introduction: Even with all technological evolution of these instruments, with the development of nickel-titanium alloy (NiTi) files and mechanized systems, fractures can occur during chemical/mechanical preparation. There are three most commonly applie to resolve this complication: attempting to remove the instrument with ultrasound, attempting to bypass it, or obturating the segment. Objective: To report a case of bypass technique in fractured instrument in the root canal. Case description: A 47-year-old female patient from Brazil, with no associated systemic conditions, was referred to the clinic of the Dentistry Course at UNIFENAS, Divinópolis, Minas Gerais, Brazil, for resolution of an instrument fracture in the mesio-vestibular canal of the right upper first molar (16). Treatment was performed using the bypass technique, which involved the following steps: anesthesia, opening, use of a C-Pilot #08 file to bypass the fractured instrument, odontometry, regressive scaling from the k#20 file, disinfection with 5% sodium hypochlorite, medication with calcium hydroxide for 21 days, agitation of the irrigating substance and root canal filling. Conclusion: Instrument bypass is a conservative, effective technique and an adequate solution in cases of endodontic file fracture within root canals. This technique aims to preserve as much of the original tooth structure as possible, avoiding more invasive procedures.(AU)

Tratamento de lesão periradicular, de origem endodôntica, com auxílio de laserterapia: uma revisão sistemática da literatura e apresentação se caso clínico / Treatment of periradicular injury, of endodontic origin, with the aid of laser therapy: a systematic review of the literature and presentation if clinical case

É sabido que a cavidade oral é a porta de entrada para muitos microrganismos e que possui alguns gêneros de bactérias que quando se associam ou proliferam em excesso, com a falta de higienização correta, fatores ambientais e imunológicos podem causar danos em algumas partes dos dentes como no tecido pulpar e canais radiculares. Neste sentido, a endodontia tem sido capaz de tratar pessoas com problemas dentários em fases muito precoces como as medidas profiláticas até casos infeciosos que afetam a polpa dos dentes causando as lesões perirradiculares que são infecções causadas por microrganismos, Para tanto, é necessário que a odontologia ofereça transformações positivas por meio de técnicas que sejam mais previsíveis para os tratamentos. A literatura tem indicado o uso da laserterapia como técnica auxiliar para o tratamento endodôntico pelo seu potencial mínimo invasivo, preciso e eficaz em menor tempo de cura de patologias orais como as lesões perirradiculares. Este estudo pretendeu abordar a importância da laserterapia sobre as variáveis patológicas de pacientes com lesão perirradiculares. Para realiza-lo foi necessário buscar na literatura estudos que associem este tipo de tratamento e sua eficiência no tratamento desta patologia. Para realizar esta pesquisa foi necessário buscar dados na literatura que tratam sobre o tema para investigar o tempo indicado ao tratamento com a laserterapia bem como o estágio em que as lesões podem ser tratadas com auxílio deste método. Corroborando com o estudo apresentamos um caso clínico(AU)

It is known that the oral cavity is the gateway to many microorganisms and that it has some genera of bacteria that when they associate or proliferate in excess, with the lack of correct hygiene, environmental and immunological factors can cause damage in some parts of the teeth such as in pulp tissue and root canals. In this sense, endodontics has been able to treat people with dental problems at very early stages such as prophylactic measures to infectious cases that affect the pulp of teeth causing perirradicular lesions that are infections caused by microorganisms, therefore, it is necessary that dentistry offer positive transformations through techniques that are more predictable for treatments. The literature has indicated the use of laser therapy as an auxiliary technique for endodontic treatment for its minimal invasive, precise and effective potential in shorter time of cure of oral pathologies such as perirradicular lesions. This study aimed to address the importance of laser therapy on the pathological variables of patients with perirradicular lesions. To accomplish this, it was necessary to seek studies in the literature that associate this type of treatment and its efficiency in the treatment of this pathology. To carry out this research it was necessary to seek data in the literature that deal with the subject to investigate the time indicated for treatment with laser therapy as well as the stage at which lesions can be treated with the aid of this method. Corroborating the study, we present a clinical case(AU)

ASSESSMENT OF TORSION RESISTANCE OF GLIDE PATH ROTARY INSTRUMENTS

NiTi endodontic instruments for glide path are the most susceptible to fractures inside the root canal, mainly as a result of high torsional stress. Objective: The present study investigated the resistance to torsion and angular deflection of instruments destined for the glide path: ProGlider #16.02; T-File #17.02 and the MK Life #16.02. Materials and methods: Thirty rotating NiTi glide path instruments (n=10) with 25mm lengths were selected. The torsion test was performed based on ISO 3630-01 (1992). Three millimeters from the tip of the instruments, it was attached to a small load cell by a lever arm connected to the torsion shaft. Torsional strength and angular deflection were evaluated. Fracture surfaces were examined by scanning electron microscopy with magnifications of 1000x and 5000x in the cross section, and 50x in the lateral section. Statistical analysis was performed using the Kruskal-Wallis H test, followed by the Down's post hoc test. Results: The ProGlider instrument showed greater torsional strength (p<0.05) compared to the T-File (p<0.05) and MK Life (p<0.05), respectively. However, the T-File showed greater angular deflection (p<0.05) than the other groups tested. Conclusion: It can be concluded that the ProGlider instrument presented greater torque for the fracture, while the T-File instrument presented greater angular deflection.

Infecções odontogênicas - patogênese e repercussões sistêmicas: revisão de literatura / Odontogenic infections pathogenesis and systemic repercussions

A região de cabeça e pescoço pode ser acometida por doenças infecciosas de origem não odontogênica ou odontogênica - sendo essa geralmente de causa endodôntica. A saúde bucal faz parte do sistema corporal de um indivíduo, desse modo, a negligência com seus cuidados gera um impacto sistêmico. Sendo assim, o objetivo do presente trabalho é analisar o desenvolvimento das infecções odontogênicas desde a necrose pulpar às possíveis repercussões sistêmicas, como: Angina de Ludwing, Mediastinite Necrosante, Fasceíte Necrosante, Endocardite Bacteriana, Sinusite do Seio Maxilar e Osteomielite. É de suma importância que o profissional cirurgião dentista conheça a patogênese dessas infecções, para que este seja capaz de elaborar um diagnóstico precoce e preciso, bem como saiba utilizar os protocolos de prevenção e condutas, a fim de evitar graves complicações sistêmicas. A partir dessa elucidação, será possível evitar o adoecimento do corpo gerado por uma doença da cavidade oral.

The head and neck region can be affected by infectious diseases of non-odontogenic or odontogenic origin - the latter usually having an endodontic cause. Oral health is part of an individual's body system, thus, neglecting its care generates a systemic impact. Therefore, the aim of this study is to analyze the development of odontogenic infections from pulpal necrosis to possible systemic repercussions, such as: Ludwing's Angina, Necrotizing Mediastinitis, Necrotizing Fasciitis, Bacterial Endocarditis, Maxillary Sinusitis and Osteomyelitis. It is extremely important that the dental surgeon knows the pathogenesis of these infections, so that he is able to make an early and accurate diagnosis, as well as know how to use prevention protocols and conducts, in order to avoid serious systemic complications. From this elucidation, it will be possible to avoid the illness of the body generated by a disease of the oral cavity.

Comparison of two obturation techniques on adhesion and proliferation of human periodontal ligament fibroblasts / Comparación de la adhesión y proliferación de fibroblastos periodontales humanos en dos técnicas de obturación endodóntica

The present study aimed to compare the adhesion and proliferation of human periodontal ligament fibroblasts (hPDL) in transverse sections of the teeth sealed with two different obturation techniques, BioRoot RCS/hydraulic obturation (HO) and AH-Plus/continuous-wave condensation (CWC). The techniques were tested using an in vitro model to simulate the interaction between periodontal tissues and the materials. The root canals were instrumented and sterilized. A total of 15 samples were obturated with BioRoot RCS/HO and 15 samples with AH-Plus/CWC. Then, roots were sectioned to obtain obturated teeth slices, and hPDL cells were seeded onto the root slices. The results were obtained at intervals of 4 and 24h for cell adhesion; and at 3,7,14, and 21 days for cell proliferation. Empty cell culture plates were use as controls. The cell adhesion was increased at 4 and 24h for both groups, with an increased response observed in the BioRoot RCS/HO group (p<0.05). The difference in cell proliferation was also found between experimental groups. After 14 days of culture, BioRoot RCS/HO group showed an increase response than control and AH-Plus/CWC groups (p<0.05), and after 21 days both groups behaved better than control group, with an increased response observed in the BioRoot RCS/HO group. This study demonstrated that both root canal sealers allow the attach and growth of periodontal ligament fibroblasts, with an increased biological response in the BioRoot RCS/HO group.

El presente estudio se enfocó en comparar la adhesión y proliferación de fibroblastos de ligamento periodontal humano (hPDL) en secciones transversales de raíces previamente obturadas con dos técnicas de obturación diferentes: obturación hidráulica empleando cono único de gutapercha y BioRoot RCS como sellador (HO), y obturación de condensación de onda continua y AH-Plus como sellador (CWC). Los selladores se usaron en un modelo in vitro que simula la interacción entre los tejidos periodontales y los materiales de obturación. Los conductos radiculares fueron instrumentados, esterilizados y obturados. La muestra se compuso de un total de 15 raíces con la técnica BioRoot RCS/HO y 15 raíces con la técnica AH-Plus/CWC. Las células de hPDL fueron sembradas en condiciones estándar de cultivo sobre las raíces seccionadas. Los resultados fueron obtenidos a intervalos de 4 y 24h para adhesión celular, y a los 3,5,7,14 y 21 días de cultivo para proliferación celular. La adhesión celular a las 4 y 24 horas mostró ser diferente para ambas técnicas en comparación con el grupo control, siendo más importante en el grupo BioRoot RCS/HO. La diferencia en la proliferación entre grupos se observó a los 14 días de cultivo, únicamente para el grupo BioRoot RCS/HO; Sin embargo para el día 21 ambas técnicas mostraron mayor proliferación celular que el grupo control, con mejor respuesta para el grupo BioRoot RCS/HO. Este estudio ha demostrado que ambos selladores de conductos permiten la adhesión y crecimiento de fibroblastos de ligamento periodontal, siendo el grupo BioRoot RCS/HO el que mostró mayor biocompatibilidad.

Correlation between bacterial type/bacterial quantity and bone loss detected by cone beam computed tomography (CBCT) in primary endodontic infections / Correlación entre el tipo y cantidad de bacterias y la pérdida ósea detectada por Tomografía Computarizada de Haz Cónico (CBCT) en infecciones endodóncicas primarias

Abstract Periapical lesions (PL) of endodontic origin are one of the most common pathological conditions that affect peri-radicular tissues. The main objective of this study was to evaluate the amount and species of microorganisms isolated from necrotic pulps, establish a correlation between these and the size of periapical lesions, and how the amount and species of microorganisms decreased with non-surgical root canal treatment. Twenty-seven patients with a clinical diagnosis of dental pulp necrosis and chronic periapical lesions were selected; a Cone Beam Computed Tomography (CBCT) and microbial samples of the root canal system were taken previous to a disinfection protocol, a post-instrumentation/ disinfection protocol, and a post-medication placement. Samples were processed for colony-forming unit (CFU) counting, Gram staining technique, and bacterial identification by the API-20 Strep/API-20A system. The API system identified 21 species of microorganisms in the pre-instrumentation samples, 11 species in the post-instrumentation samples, and 11 in the post-medication samples. There was a correlation coefficient of 0.598% between the initial size of the lesion and the number of bacteria, with a coefficient of determination up to 35.7%, a correlation coefficient of 0.486% and a determination coefficient of 23.6% between the size of the periapical lesion and the number of CFUs. This study contributes to the knowledge of the amount and species of microorganisms isolated and identified from necrotic pulps, establishes a correlation between the amount and species of microorganisms and the size of the periapical lesions, and shows how the decrease of microorganisms contributes to the healing of PL, corroborating the importance of an adequate disinfection protocol.

Resumen Las lesiones periapicales (LP) de origen endodóncico son la condición patológica más común que afectan los tejidos perirradiculares. El objetivo principal de este estudio es evaluar la cantidad y especie de bacterias aisladas de pulpas necróticas, correlacionar la cantidad y especies bacterianas con el tamaño de la lesión, y cómo disminuyen la cantidad y especies de microorganismos con el tratamiento de conductos. A 27 pacientes con diagnóstico de necrosis pulpar y lesión periapical crónica detectada con CBCT se les tomaron muestras microbianas del sistema de conductos antes y después del protocolo de desinfección y de la medicación intraconducto. Las muestras se procesaron para el recuento de unidades de formación de colonias (UFC), tinción de Gram e identificación mediante el sistema API-20 Strep/API-20A. Se identificaron 21 especies en las muestras pre-instrumentación, 11 en las muestras post-instrumentación y 11 en las muestras post-medicación; se observó un coeficiente de correlación del 0,598% entre el tamaño inicial de la lesión y la cantidad de bacterias, con un coeficiente de determinación hasta el 35,7%, un coeficiente de correlación del 0,486% y un coeficiente de determinación del 23,6% entre el tamaño de la lesión periapical y el número de UFCs. Este estudio contribuye al conocimiento sobre la cantidad y especies de microorganismos aislados e identificados a partir de pulpas necróticas, establece una correlación entre la cantidad y especies de microorganismos y el tamaño de las lesiones periapicales y exhibe cómo la disminución de microorganismos contribuye a la curación de LP, corroborando la importancia de un adecuado protocolo de desinfección.

Efficacy of Chlorine Dioxide as an Endodontic Irrigant for Pulp Dissolution in vitro

Determine the efficacy of 5 % chlorine dioxide as an endodontic irrigant for pulp dissolution. Thirty five samples of human dental pulp were obtained, previously weighed and immersed in three solutions= 5 % ClO 2, 5.25 % NaOCl and saline (control group), for 10 minutes at 32 ºC; they were dried and reweighed. Then the weight loss was compared to the original weight and analyzed statistically. 5.25 % NaOCl and 5 % ClO 2 dissolved the dental pulp samples more effectively than saline (p> 0.001). No statistically significant difference was found between the tissue dissolving proper ties of 5.25 % NaOCl and 5 % ClO2 (p=0.893). 5 % ClO2 is effective in dissolving human dental pulp tissue.

El objetivo de este estudio fue determinar la eficacia del dióxido de cloro al 5 % como irrigante endodóntico para la disolución pulpar. Se obtuvieron 35 muestras de pulpa dental humana, se pesaron previamente y se sumergieron en tres soluciones= 5 % ClO2, 5.25 % NaOCl y suero fisiológico (grupo control), durante 10 minutos a 32ºC; se secaron y se pesaron de nuevo. Luego se comparó la pérdida de peso del peso original y se analizó estadísticamente. NaOCl al 5.25 % y ClO2 al 5 % disolvieron las muestras de pulpa dental con más eficacia que el suero fisiológico (p> 0.001). No se encontró diferencias estadísticamente significativas entre las propiedades de disolución de tejido de NaOCl al 5.25 % y ClO2 al 5 % (p=0.893) ClO2 al 5 % es eficaz para disolver tejido de pulpa dental humana.

Efectividad de las Técnicas de Retratamiento Endodóntico en la Remoción de ementos Biocerámicos como Material de Obturación Radicular: Revisión Sistemática

El retratamiento no quirúrgico es la primera opción ante el fracaso del tratamiento endodóntico, por lo que se vuelve importante asegurar el completo retiro del material de relleno del conducto radicular, para mejorar el pronóstico del procedimiento. Los cementos biocerámicos en base a silicatos cálcicos han aparecido en los últimos años, caracterizados principalmente por su bioactividad, lo que adicionalmente se puede traducir en una mayor dificultad para su retiro del conducto radicular. El objetivo de esta revisión es determinar qué técnica de retratamiento es más efectiva en la eliminación de cementos selladores biocerámicos, en base al volumen de material remanente en el conducto radicular, evaluado a través del análisis de imágenes con micro-CT. Se realizó una revisión sistemática mediante la búsqueda de publicaciones en las bases de datos Pubmed, ScienceDirect y SciELO, de los últimos 10 años, en idioma español e inglés. Se incluyeron sólo estudios in vitro de dientes obturados con cemento biocerámico y diferentes técnicas de retratamiento endodóntico, en los que se evalúe la limpieza del conducto post eliminación del relleno mediante micro-CT. De un total de 174 artículos encontrados, 7 fueron seleccionados, analizados y se incluyeron en esta revisión sistemática. Los resultados de los estudios seleccionados no encuentran diferencias significativas en la eliminación de material entre las diferentes técnicas de retratamiento evaluadas. A pesar de la heterogeneidad presente en las metodologías de los artículos analizados, ninguna técnica de retratamiento ni técnicas complementarias lograron dejar completamente limpios los conductos radiculares, por lo que se sugiere realizar nuevos estudios en el futuro que evalúen nuevas técnicas de desobturación radicular.

Non-surgical retreatment is the first option in the case of endodontic treatment failure, so it becomes important to ensure complete removal of the root canal filling material, to improve the prognosis of the procedure. Bioceramic cements based on calcium silicate have appeared in recent years, characterized mainly for their bioactivity, which can additionally translate into greater difficulty in their removal from the root canal. The aim of this review is to determine which retreatment technique is most effective in the removal of bioceramic sealer cements, evaluated through micro-CT image analysis. A systematic review was performed by searching for publications in Pubmed, ScienceDirect and SciELO databases, of the last 10 years in Spanish and English. Only in vitro studies of teeth filled with bioceramic cement and different endodontic retreatment techniques were included, in which the cleaning of the canal after removal of the filling was evaluated by micro- CT. From a total of 174 articles found, 7 were selected, analyzed and included in this systemic review. The results of the included studies did not find significant differences in the removal of material between the different retreatment techniques evaluated. Despite the heterogeneity in the methodologies of the studies, no retreatment technique or complementary techniques were able to completely clean the root canals, it is therefore suggested that new studies be carried out in the future to evaluate new techniques.

Desmineralización de la Dentina Humana Producida por Irrigantes Endodónticos Combinados

El objetivo de este trabajo fue evaluar el efecto de soluciones de irrigación endodónticas solas y combinadas sobre iones calcio y fosfato de la dentina radicular ex vivo. Se emplearon 56 discos de dentina obtenidos del tercio medio radicular de premolares inferiores unirradiculares extraídos por razones ortodóncicas. Los discos se dividieron al azar en 8 grupos (n=7). Grupo I: agua destilada (AD), Grupo II: hipoclorito de sodio (NaClO) 1 %, Grupo III: EDTA 17 %, Grupo IV: ácido maleico (AM) 5 %, Grupo V: ácido acético (AA) 5 %, Grupo VI: EDTA 17 % + NaClO 1 %, Grupo VII: AM 5 % + NaClO 1 %, Grupo VIII: AA 5 % + NaClO 1 %. Los segmentos de dentina permanecieron en contacto a 37° C durante 5 min y 2,5 minutos en cada solución cuando se usaron en forma sucesiva. Se determinó la concentración de iones calcio de las soluciones mediante espectrometría de absorción atómica y la concentración de iones fosfatos mediante colorimetría (Wienner Lab.). Los resultados se expresaron en mg/ml/gr de tejido. Para el análisis estadístico se utilizó ANOVA y Test de Tukey. AA 5 % y EDTA 17 % se comportaron de manera similar utilizados solos durante 5 minutos, NaClO 1 % no mostró diferencias con el AD. AM 5 % eliminó significativamente más calcio y fosfato que todos los grupos. Todas las soluciones desmineralizaron la dentina, pero AM 5 % durante 5 min fue la solución que más afectó el componente inorgánico de la dentina.

The aim of the present study was to evaluate ex vivo irrigating solutions effect under calcium and phosphates dentin ions, using them alone and combined. In this study 56 dentin discs where used. They were obtained from middle third of mandibular single-root premolars extracted for orthodontics reasons. Discs were randomly divided into 8 groups (n:7). Group I: Distilled water (DW), Group II: 1 % sodium hypochlorite (NaOCl), Group III: 17 % EDTA, Group IV: 5 % maleic acid (MA), Group V: 5 % acetic acid (AA), Group VI: 17 % EDTA + 1 % NaOCl, Group VII: 5 % MA + 1 % NaOCl, Group VIII: 5 % AA + 1 % NaOCl. Dentin segments were kept in contact with irrigating solutions at 37°C for 5 minutes, when used alone, or for 2.5 minutes when used combined. After that, calcium ions (using absorption atomic spectrometry) and phosphorus ions (by colorimetry Wienner Lab.) were determined. Results were expressed in mg/ml/g tissue. Statistical analysis was performed by ANOVA and Tukey test. 5 % AA and 17 % EDTA eliminated similar concentrations of calcium and phosphates ions from dentin at 5 minutes exposure time, while 1 % NaOCl did not present statistical differences with control. 5 % MA eliminated significantly more calcium and phosphates ions than the rest of analyzed groups. Every tested solutions demineralized human dentin, but 5 % MA used for 5 minutes did it the most.