Quiste radicular residual / A residual radicular cyst

En la región cervicofacial los quistes de los maxilares de origen odontogénico constituyen una afección relativamente importante, los más frecuentes son los quistes radiculares. Se presentó un paciente masculino de 23 años de edad con un quiste radicular residual extenso que ocupaba la zona mandibular posterior izquierda, y acude a consulta estomatológica de la Clínica «Celia Sánchez Manduley» por un aumento de volumen que causa asimetría facial notable de la hemicara izquierda, de tres centímetros de diámetro, indoloro, asintomático, con 6 meses de evolución y consistencia dura; además refiere tratamiento de exodoncia de molar inferior en la zona (37) hace 2 años. Se indicó radiografía periapical y panorámica donde se observó zona radiolúcida bien definida de 35 a 38 con reabsorción de raíz mesial de 38, distal de 36 y movilidad dentaria grado II en ambos dientes. Se realizó exéresis de la lesión cuyo estudio histológico informó un quiste radicular residual.

Jaw cysts of odontogenic origin constitute a relatively important condition in the cervicofacial region, where radicular cysts are the most frequent. We present a 23-year-old male patient who come to "Celia Sánchez Manduley" Dental Clinic with an extensive residual radicular cyst that occupied his left posterior mandibular area and an increase in volume that caused him a notable facial asymmetry in the left side of his face, of three centimeters in diameter, painless, asymptomatic, with 6 months of evolution and hard consistency; he also mentions a lower molar extraction treatment in area (37) 2 years ago. Periapical and panoramic X-rays were indicated where a well-defined radiolucent zone of 35 to 38 was observed with mesial root resorption of 38, distal of 36 and grade II dental mobility in both teeth. Exeresis of the lesion was performed, whose histological study reported a residual radicular cyst.

Success and survival rates of immediate anatomic zirconia implants: a prospective clinical and radiographic evaluation

Modern immediate titanium implants have two major drawbacks which are the black metal appearance that might be seen through the mucosa and the gap between implant and extraction socket. Immediate anatomical zirconia implants were introduced to match the shape of the extracted root and fill the socket without gaps while still providing better metal-free appearance. Aim: This study aims to investigate success and survival rates of immediate anatomical zirconia implants. Methods: This prospective interventional study was held between 2017 and 2020 in the faculty of dental medicine, Damascus University, Syria. The sample consisted of 27 immediate anatomical zirconia implants in 21 patients from both genders. Implants were designed and manufactured starting from CBCT image and prior to extraction. Specialized software applications were used to modify implant design. Implants went through different processing procedures to make them ready for insertion immediately after tooth extraction. Restorations were made after a minimum period of 3 months, clinical and radiographic follow ups were performed after 10 - 13.5 months from restoring the implants in order to evaluate their success/ survival. Repeated measures ANOVA was used to assess marginal bone loss, t test for probing depth assessment. Results: Immediate anatomical zirconia implants showed success in (n=17) 63% of total cases, satisfactory survival (n=3) 11.1%, compromised survival (n=2) 7.4% and they failed in (n=5) 18.5%. Conclusions: Immediate anatomical zirconia implants had low success/survival rates when compared to conventional immediate implants. Therefore, they cannot be considered as a predictable alternative in their current form

Comparação de duas técnicas cirúrgicas para recobrimento radicular de recessões unitárias: ensaio clínico paralelo, randomizado e duplo cego / Comparison of two surgical techniques for root coverage of single-unit recessions: parallel, randomized, double-blind clinical trial

As crescentes demandas dos pacientes pelo tratamento das recessões gengivais trazem à tona questões terapêuticas clinicamente significativas, exigindo dos profissionais constante aperfeiçoamento em técnicas cirúrgicas cada vez menos invasivas e mais previsíveis. OBJETIVO: Comparar duas técnicas para recobrimento radicular em recessões gengivais unitárias, unilaterais, do tipo 1. METODOLOGIA: Este estudo clínico, paralelo, randomizado e duplo cego avaliou indivíduos com recessões gengivais unitárias, unilaterais, do tipo 1 (RT1), submetidos à cirurgia para recobrimento radicular, através da associação do enxerto de tecido conjuntivo subepitelial ao retalho posicionado coronalmente (grupo controle) e técnica de túnel (grupo teste). Os principais parâmetros avaliados foram profundidade de sondagem (PS), sangramento à sondagem (SS), nível clínico de inserção (NCI), recessão gengival (RG), faixa e espessura da mucosa ceratinizada (MC e EG), percentual de recobrimento radicular (RR) e fenótipo gengival (FG), além de fatores centrados no paciente (FCP), como dor pós-operatória, hipersensibilidade dentinária cervical (HSDC), estética, grau de satisfação e a qualidade de vida, intra e intergrupo, ao longo de 06 meses de acompanhamento. Os dados foram analisados estatisticamente através dos testes t emparelhado de Student, teste t para amostras independentes, Qui-quadrado, McNemar, Análise de Variância Split-Plot com pós-teste t de Student (α = 5%). RESULTADOS: 46 indivíduos finalizaram este estudo (controle: 23; teste: 23). O tempo de cirurgia foi maior para o grupo teste (controle: 40min ± 5,6; teste: 51min ± 5,9; p = 0,041). Foram observadas reduções estatisticamente significativas para a RG e ganho significativo do NCI, de MC e de EG na análise intragrupo, em ambos os grupos de tratamento, porém, sem diferenças entre as técnicas. O RR aumentou significativamente nos períodos avaliados, mas não foram observadas diferenças intergrupo (controle: 89,2%; teste: 86,5%; p = 0,069). A análise intragrupo revelou mudança de FG (controle: 95,65%; teste: 91,3%; p < 0,001). Ambos os protocolos de tratamento reduziram dor pós-operatória e HSDC, e proporcionaram melhora na estética, satisfação e na qualidade de vida (p < 0,001), sem diferenças entre as técnicas ao longo do tempo. CONCLUSÃO: Ambos os tratamentos apresentaram eficácia clínica semelhante em termos de recobrimento radicular e melhora dos FCP (AU).

The increasing demands of patients for the treatment of gingival recessions bring up clinically significant therapeutic issues, requiring professionals to constantly improve in less invasive and more predictable surgical techniques. AIM: To compare two root coverage techniques to treat single, unilateral, type 1 gingival recessions. METHOD: This parallel, randomized, doubleblind clinical trial evaluated individuals with single, unilateral, type 1 gingival recessions 1 (RT1), who underwent root coverage procedure with subepithelial connective tissue graft associated to a coronally advanced flap (control group) or a tunnel technique (test group). The main parameters evaluated were probing depth (PD), bleeding on probing (BoP), clinical attachment level (CAL), gingival recession (GR), heigth of keratinized tissue (KTH), gingival thickness (GT), percentage of root coverage (RC) and gingival phenotype (GP), in addition to patient-reported outcome measures (PROMs), such as postoperative pain, cervical dentin hypersensitivity (CDH), esthetics, degree of satisfaction and quality of life, intra and intergroup, throughout 06 months follow-up. Data were statistically analyzed using paired Student t-test, t-test for independent samples, Chi-square, McNemar, Split-Plot Analysis of Variance with post hoc t-test (α = 5%). RESULTS: 46 subjects completed this study (control: 23; test: 23). Surgery time was longer for the test group (control: 40min ± 5.6; test: 51min ± 5.9; p = 0.041). Statistically significant reductions for GR and significant gain for CAL, KTH and GT were observed in the intragroup analysis, in both treatment groups, however, without differences between techniques. The CR increased significantly, but no intergroup differences were observed (control: 89.2%; test: 86.5%; p = 0.069). Intragroup analysis revealed a change in GP (control: 95.65%; test: 91.3%; p < 0.001). Both treatment protocols reduced postoperative pain and CDH and improved esthetics, satisfaction and quality of life (p < 0.001), with no differences between the techniques over time. CONCLUSION: Both treatments showed similar clinical efficacy in terms of root coverage and improvement in PROMs (AU).

Tratamento endodôntico de incisivo central inferior permanente com dilaceração radicular incomum, após trauma no predecessor decíduo: relato de caso / Endodontic treatment of mandibular central incisor with unusual root dilaceration, following trauma to the deciduous predecessor: case report

Introdução: Alterações morfológicas na cavidade pulpar e na anatomia radicular podem constituir um desafio ao tratamento endodôntico. A dilaceração pode ser resultado de trauma na dentição decídua, na época da formação das raízes, provocando acentuada curvatura da raiz ou da coroa em um dente permanente. Objetivo: O presente relato de caso teve por objetivo descrever o tratamento endodôntico de um dente #41 com acentuada dilaceração radicular. Radiograficamente, a região periapical do dente #41 mostrou extensa área radiolúcida, sugestiva de osteólise periapical em decorrência de necrose pulpar, que foi confirmada pela ausência de resposta aos testes pulpares. O tratamento endodôntico foi realizado. Conclusão: Após 90 meses de acompanhamento, constatou-se ausência de sinais ou sintomas, e o exame radiográfico forneceu evidências de cicatrização óssea periapical (AU).

Introduction: The morphological changes in the pulp cavity and root anatomy can lead to difficulties in carrying out endodontic treatment. Dilaceration can be the result of trauma in primary dentition, in the root formation phase, provoking accentuated root or crown curvature in a permanent tooth. Objective: The present case report aimed to describe the endodontic treatment of tooth 41 with accentuated root laceration. Radiographically, the periapical region of tooth #41 showed an extensive radiolucent area, suggestive of periapical osteolysis due to pulp necrosis, which was confirmed by the lack of response and pulp tests. Endodontic treatment was realized. Conclusion: The follow-up at 90 months showed no signs or symptoms, and the radiographic examination provided evidence of periapical bone healing.

Prevalence of three-rooted primary mandibular first and second molars / Prevalencia de primeros y segundos molares primarios mandibulares con tres raíces

ABSTRACT The aim of this study was to determine prevalence and describe the clinical and radiographic findings of three-rooted primary mandibular first and second molars in a Mexican population. Intraoral periapical radiograph, orthopantomogram or cone beam computed tomography (CBCT) were obtained. A total 2284 children from the state of Puebla, Mexico were examined, of whom 20 presented an anatomic variant in tooth crown shape. Of the total teeth with crown alterations, 10 first and 5 second primary mandibular molars were found to have supernumerary roots. In one case, it was possible to obtain micro-CT images. The study recorded prevalence, unilateral or bilateral occurrence, and ratio between sexes. Data were analyzed using descriptive statistics. Clinical findings were presence of an anatomical variation (tuberculum paramolare / right and/or left cervical convexity) in primary mandibular first molars. Second molars presented conventional crown morphology. Prevalence of three-rooted primary mandibular first and second molars was 0.44% and 0.22%, respectively. Male: female ratio for presence of threerooted primary mandibular first molars was 4:1, showing genetic predisposition in males, and for second molars it was 1.5:1, with no predisposition according to sex. The clinical and radiographic anatomical variants in primary molars should be considered by pediatric dentists during routine care because they may cause difficulties in restorations.

RESUMEN El objetivo de este estudio fue determinar la prevalencia, así como los hallazgos clínicos y radiográficos de los primeros y segundos molares primarios mandibulares con tres raíces en una población mexicana. Se obtuvieron radiografías periapicales intraorales, ortopantomografía o tomografía computarizada de haz cónico (TCHC). Fueron revisados en total 2284 niños originarios del estado de Puebla, México, de los cuales 20 sujetos presentaron una variante anatómica en la forma de la corona dental. En el total de dientes con alteraciones coronarias, se encontraron 10 primeros y 5 segundos molares primarios mandibulares con raíces supernumerarias. En un caso fue posible la obtención de imágenes de micro tomografía computarizada (micro-CT). Fueron registradas la prevalencia, la ocurrencia uni o bilateral y la relación entre sexos. Los datos se analizaron mediante estadística descriptiva. Los hallazgos clínicos fueron: presencia de una variación anatómica (tuberculum paramolare / convexidad cervical derecha y/o izquierda) en los primeros molares primarios mandibulares. Los segundos molares presentaron una morfología coronal convencional. Entre los hallazgos radiográficos, fue común encontrar un conducto en cada raíz. La prevalencia fue de 0,44% y 0,22% para los primeros y segundos molares primarios mandibulares con tres raíces, respectivamente. La relación por sexo en los primeros molares primarios mandibulares con tres raíces fue de 4:1, indicando una predisposición genética para el sexo masculino, mientras que, en los segundos molares, la razón fue de 1,5:1 sin predisposición por sexo. Las variantes anatómicas clínicas y radiográficas presentes en los molares primarios deben ser tomadas en cuenta por los odontopediatras durante su rutina de atención, ya que pueden ocasionar dificultades para la restauración.

Uso de Soluções Irrigadoras na Pulpectomia de Dentes Decíduos: Revisão de Literatura / Use of Irrigating Solutions in Pulpectomy of Deciduous Teeth: Literature Review

A limpeza dos canais radiculares se apresenta como uma etapa crucial para o sucesso do tratamento endodôntico. Por essa razão, a busca por soluções irrigadoras eficazes na terapia endodôntica de dentes decíduos é frequente nas pesquisas e demonstra a necessidade de encontrar substâncias com menor toxicidade e maior eficiência. Sendo assim, o objetivo do presente estudo é analisar as diferentes soluções e protocolos de irrigação no tratamento endodôntico de dentes decíduos, a fim de construir uma conduta clínica. Para isso, foi realizada uma busca na literatura nas bases de dados PubMed/MEDLINE, Cochrane Library, SCIELO, Portal de Periódicos CAPES e BVS utilizando a combinação dos termos "deciduous tooth", "root canal irrigants", "pulpectomy" e seus derivados, associados entre si pelo operador booleano "AND" e adaptados para cada base de dados. As buscas foram realizadas no período de Julho à Agosto de 2020. Foi encontrado o total de 192 resultados. Após uma leitura crítica, foram selecionados 8 estudos. A revisão incluiu estudos que abordassem as soluções irrigantes mais usuais: hipoclorito de sódio, digluconato de clorexidina, ácido cítrico e ácido etilenodiaminotetracético (EDTA) na terapia endodôntica de dentes decíduos. O EDTA e digluconato de clorexidina apresentam baixa toxicidade e o hipoclorito de sódio 1% combinado com ácido cítrico 6% apresentam a combinação mais próspera. A associação das duas substâncias mostrou ser mais eficiente na limpeza dos canais radiculares e na remoção da smear layer. Porém, mais estudos são necessários, principalmente clínicos, para confirmação do melhor protocolo de irrigação para o tratamento endodôntico de dentes decíduos.

Cleaning of root canals is a crucial step for a successful endodontic treatment. For this reason, the search for effective irrigating solutions in endodontic therapy of deciduous teeth is frequent in research and it demonstrates the need to find substances with lower toxicity and greater efficiency. Thus, this study aims to analyze the different irrigating solutions and protocols in the endodontic treatment of deciduous teeth, in order to build a clinical approach. For this, a literature search was performed in the Databases PubMed/ MEDLINE, Cochrane Library, SCIELO, Portal de Periódicos CAPES and VHL using the combination of the terms "deciduous tooth," "root canal irrigants," "pulpectomy" and their derivatives, associated with each other by the Boolean operator "AND" and adapted for each database. The searches were carried out from July to August 2020. In total, 192 results were found. After a critical reading, eight studies were selected. The review included studies addressing the most common irrigating solutions: sodium hypochlorite, chlorhexidine digluconate, citric acid, and ethylenediaminetetraacetic acid (EDTA) in endodontic therapy of deciduous teeth. EDTA and chlorhexidine digluconate have low toxicity and the 1% sodium hypochlorite combined with 6% citric acid have the most prosperous combination. The association of these two substances proved to be more efficient in cleaning root canals and removing the smear layer. However, more studies are necessary, mainly clinical ones, to confirm the best irrigating protocol for the endodontic treatment of deciduous teeth.

Rethinking the decision-making process to treat gingival recession associated with non-carious cervical lesions

Abstract The presence of a tooth-surface defect, such as a non-carious cervical lesion (NCCL), associated with sites of gingival recession (GR) defects creates a combined soft tissue/tooth defect (CD) that requires a different treatment plan. This study aimed to critically review the literature regarding the available treatment protocols for CDs and suggest a new decision-making process. NCCLs were classified as Class A-: the cementoenamel junction (CEJ) was visible and the root surface discrepancy was < 0.5 mm (no step); Class A+: CEJ was visible and the root surface discrepancy was > 0.5 mm (with a step); Class B-: unidentifiable CEJ without a step; Class B+: unidentifiable CEJ with a step. NCCLs affecting both root and crown surfaces (Class B) lead to CEJ destruction and consequently eliminate an important landmark used before and after root coverage procedures. The depth of the root surface discrepancy is vital owing to its possible impact on soft tissue adaptation after healing, which, in turn, may influence the treatment options, namely the use of graft and/or composites to compensate for the discrepancy. Clinically, a step with horizontal depth greater than 0.5 mm should be recognized as the minimum threshold value to define this condition. Extremely deep defects tend to assume a V-shaped topography. Therefore, extremely deep V-shaped defects were classified into subclasses A+V, a V-shaped defect, and B+V, a V-shaped defect with loss of CEJ, for management considerations. The treatment options, supported by the literature, and a decision-making process to deal with each condition are presented.

Comparação do alargamento apical do canal radicular através dos sistemas de instrumentação SAF e Reciproc / Comparison of apical enlargement of the root canal through SAF and Reciproc instrumentation systems

Objetivo: Comparar o aumento percentual da área da secção reta transversal de canais radiculares, no nível de 3 mm aquém do ápice radicular, após instrumentação com dois sistemas de instrumento único. Métodos: Dezenove primeiros molares inferiores extraídos tiveram as raízes mesiais seccionadas no nível de 3 mm aquém do ápice radicular, sendo os 2 milímetros finais de cada raiz removidos e descartados, para proceder a mensuração da área pré-operatória, através de estereomicroscopia. As raízes foram instrumentadas com os sistemas SAF e Reciproc R25.08 e procedeu-se nova mensuração para comparação do aumento percentual da área. O aumento percentual da área da secção reta transversal foi comparado e analisado estatisticamente pelo teste t de Student. O nível de significância foi estabelecido em 5% (p < 0,05). Resultados: O aumento percentual da área dos canais foi significativamente maior para o grupo Reciproc (p = 0,001) em comparação com o grupo SAF. Os canais instrumentados com o sistema SAF tiveram sua área aumentada em média 53,5%, enquanto que nos instrumentados com o sistema Reciproc a média foi 154,5%. Conclusão: O sistema Reciproc proporcionou um aumento percentual da área da secção reta transversal dos canais radiculares, no nível dos 3 mm apicais, 3 vezes maior que o sistema SAF.

Aim: To compare the percentage increase in the cross-sectional area of root canals, at the level of 3 mm from the root apex after instrumentation with two single instrument systems. Methods: The roots of 19 extracted mandibular first molars were sectioned 3 mm short of the apex level, with the final 2 millimeters of each root removed and discarded in order to enable the preoperative area to be measured by stereomicroscopy. Subsequently, the roots were instrumented with the SAF and Reciproc 25/.08 systems, alternating the technique used per canal from root to root, and a new measurement was performed. After, the percentage increase in area was calculated considering the values of the original and the final area. The Student'st-test was applied to the results, with a level of significance set at 5%. Results: The percentage increase in area of the root canals was significantly higher for the Reciproc (p = 0.001) when compared to the SAF group. In the canals instrumented with the SAF system, the mean increase in area was 53.5%, while in those using the Reciproc system, it was 154.5%. Conclusion:The Reciproc system produced a 3-fold higher percentage increase in the cross-sectional area of the root canals at the level of 3 mm from the root apex than did the SAF system.

Micro-computed tomographic assessment of the variability and morphological features of root canal system and their ramifications

Abstract Objectives This study assessed the incidence and variability features of root canals system (RCS) and their ramifications according to Pucci & Reig (PR) (1944) and the American Association of Endodontists (AAE) (2017) by micro-computed tomography (μCT). Methodology 500 representative extracted human teeth of each tooth group (n=50) (maxillary/mandibular central and lateral incisors, canines, first and second premolars and molars) were scanned by μCT with a resolution of 26.70 μm. The reconstructed cross-sections images and the visualization of the continuous slices in the transversal axis were performed using DataViewer software. RCS were classified according to Pucci & Reig (main canal, collateral canal, lateral canal, secondary canal, accessory canal, intercanal, recurrent canal) and AAE (main canal, accessory canal, lateral canal). The apical deltas were assessed for both classifications. The prevalence of apical deltas was evaluated using the Chi-squared test (p<0.05). Results According to PR, a higher incidence of lateral canals was observed in maxillary canines (10%), central incisors (8%) and first premolars (6%). Using AAE, the highest incidence of lateral canals was observed in the mandibular first premolars (85%), first and second molars (84%), lateral incisors (67%), canines (59%), and in maxillary first premolars (52%). Regarding accessory canals, the PR showed a frequency in 2% of the maxillary lateral incisors and maxillary and mandibular first premolars and 3% of mandibular first and second molars. On the other hand, the AAE showed the highest incidence of accessory canals in 86% of the maxillary first premolars, 71% in mandibular lateral incisors, 69% in mandibular first premolars, 65% in mandibular canines, and 56% in maxillary canines. The PR showed the lowest incidence of apical deltas for all dental groups when compared with AAE (p=0.004). Interestingly, distal canals in maxillary molars showed a significant discrepancy between classifications (p=0.027). Conclusions μCT enabled accurately describing the RC system and related ramifications, adding to the PR and AAE classifications, with some discrepancies reported for maxillary molars. Clinical Relevance This μCT study enabled a thorough description of the variability among root canals and their ramifications, including clinically relevant details on the presence and location of lateral canals and accessories in all human tooth groups, beyond the currently existing classification systems.

Clinical utility of cone beam computed tomography to define treatment in cases of medium and high endodontic complexity / Utilidad clínica de la tomografía computarizada cone beam para definir conducta terapéutica en casos de mediana y alta complejidad endodóntica

The aim of this study was to evaluate the clinical utility of Cone Beam Computed Tomography (CBCT) in cases of medium and high endodontic complexity. The relevance of CBCT to define treatment was evaluated through the Wittenberg questionnaire and the variation in treatment plans after CBCT exam analysis. The sample (n=40) was chosen for convenience over a period of 4 months. It considered the current recommendations to request CBCT exams before performing root canal treatments. Data collection was carried out through a survey applied to the treating clinicians, after examining the information obtained by the CBCT system. Data were analyzed with the Stata version 13 software, and the Chi-square test was used for inferential analysis. A 95% confidence interval was considered. The most frequent dental groups corresponded to upper posterior and upper anterior teeth (47.5% and 30.0%); the cases were equally distributed according to complexity (50% and 50%). The main reason for requesting CBCT exams corresponded to complex anatomy and/or atypical canal system (37.5%). The use of CBCT increased confidence in the initial treatment chosen by clinicians in 50% of cases according to the Wittenberg questionnaire, and a 45% variation in treatment plans was observed. There was no statistical relationship between complexity and the variables studied. CBCT contributed greatly to the therapeutic management of cases regardless of their complexity.

El objetivo de este estudio fue evaluar la utilidad clínica de la Tomografía Computarizada Cone Beam (CBCT) en casos de mediana y alta complejidad endodóntica. Se midió la relevancia del CBCT para definir conducta terapéutica a través del cuestionario de Wittenberg y en la variación de los planes de tratamientos posterior al análisis del examen. La muestra (n=40) se eligió por conveniencia en un período de 4 meses, considerando las recomendaciones actuales para solicitar este examen en Endodoncia. La recolección de datos se realizó por medio de una encuesta aplicada a los clínicos tratantes, después de examinar la información obtenida por el CBCT. Los datos se analizaron a través del software Stata version 13 y para el análisis inferencial se utilizó la prueba de chi cuadrado. Se utilizó un intervalo de confianza de 95%. Los grupos dentarios más frecuentes correspondieron a posteriores y anteriores superiores (47,5% y 30,0%), los casos se distribuyeron igualitariamente según complejidad (50% y 50%), el motivo principal para solicitar el CBCT, correspondió a anatomía del sistema de conductos de carácter complejo y/o atípico (37,5%), el CBCT aumentó la confianza en el tratamiento inicial escogido por los clínicos en el 50% de los casos según el cuestionario de Wittenberg y se obtuvo un 45% de variación en los planes de tratamientos. No se apreció relación estadística entre la complejidad con las variables estudiadas. El CBCT aportó en gran medida el manejo terapéutico de los casos independiente de su complejidad.

Accuracy of Four Electronic Apex Locators During Root Canal Length Determination / Precisión de Cuatro Localizadores de Ápice en la Determinación de la Longitud de Trabajo

ABSTRACT: The apical limit of tooth roots for instrumentation and obturation is a controversial subject due to the high morphological complexity presented by the apical zone of the root. The development of electronic apex locators (EALs) has made working length (WL) determination more predictable, producing more accurate results; however, the interpretation mechanisms of different devices may affect measurements taken under different clinical conditions. One hundred premolars were used to compare the effectiveness of Propex II, Raypex 6, Propex Pixi and Root ZX II in locating the apical foramen (AF). No statistically significant differences were observed when the accuracy of measurement was compared between the different groups of EALs, however Root ZX II and Raypex 6 presented the best overall performance.

RESUMEN: El límite apical radicular para la instrumentación y obturación es un tema controversial, debido a la alta complejidad morfológica que presenta la zona apical de la raíz. El desarrollo de localizadores de ápice electrónicos (EALs) ha hecho la determinación de la longitud de trabajo (WL) más predecible y con resultados más precisos. Sin embargo, el mecanismo de interpretación de cada dispositivo puede afectar la determinación de las mediciones en diferentes condiciones clínicas. Cien premolares fueron utilizados para comparar la efectividad de Propex II, Raypex 6, Propex Pixi y Root ZX II en localizar el foramen apical (AF). No se observaron diferencias estadísticamente significativas cuando se comparó la precisión de medición entre los diferentes grupos de EALs, sin embargo, Root ZX II y Raypex 6 mostraron un mejor desempeño global.

Influence of the anterior arch shape and root position on root angulation in the maxillary esthetic area

PURPOSE: This study was conducted to characterize the relationship of the angulation between the tooth root axis and alveolar bone axis with anterior alveolar (AA) arch forms and sagittal root position (SRP) in the anterior esthetic region using cone-beam computed tomography (CBCT) images. MATERIALS AND METHODS: CBCT images that met the inclusion and exclusion criteria were categorized using a recent classification of AA arch forms and a SRP classification. Then, the angulation of the root axis and the alveolar bone axis was measured using mid-sagittal CBCT images of each tooth. The relationships of the angulation with each AA arch form and SRP classification were evaluated using 1-way analysis of variance and a linear regression model. RESULTS: Ninety-eight CBCT images were included in this study. SRP had a greater influence than the AA arch form on the angulation of the root axis and the alveolar bone axis (P<0.05). However, the combination of AA arch form and SRP was more predictive of the angulation of the root axis and the alveolar bone axis than either parameter individually. CONCLUSION: The angulation of the root axis and alveolar bone axis demonstrated a relationship with the AA arch form and SRP in teeth in the anterior esthetic region. The influence of SRP was greater, but the combination of both parameters was more predictive of root-to-bone angulation than either parameter individually, implying that clinicians should account for both the AA arch form and SRP when planning implant placement procedures in this region.

The effect of individualization of fiberglass posts using bulk-fill resin-based composites on cementation: an in vitro study

OBJECTIVES: This study evaluated the bond strength of various fiberglass post cementation techniques using different resin-based composites. MATERIALS AND METHODS: The roots from a total of 100 bovine incisors were randomly assigned to 5 treatment groups: G1, post + Scotchbond Multi-Purpose (SBMP) + RelyX ARC luting agent; G2, relined post (Filtek Z250) + SBMP + RelyX ARC; G3, individualized post (Filtek Z250) + SBMP; G4, individualized post (Filtek Bulk-Fill) + SBMP; G5, individualized post (Filtek Bulk-Fill Flow) + SBMP. The samples were subjected to the push-out (n = 10) and pull-out (n = 10) bond strength tests. Data from the push-out bond strength test were analyzed using 2-way analysis of variance (ANOVA) with the Bonferroni post hoc test, and data from the pull-out bond strength test were analyzed using 1-way ANOVA. RESULTS: The data for push-out bond strength presented higher values for G2 and G5, mainly in the cervical and middle thirds, and the data from the apical third showed a lower mean push-out bond strength in all groups. No significant difference was noted for pull-out bond strength among all groups. The most frequent failure modes observed were adhesive failure between dentine and resin and mixed failure. CONCLUSIONS: Fiberglass post cementation using restorative and flowable bulk-fill composites with the individualization technique may be a promising alternative to existing methods of post cementation.

Root dysplasias of human teeth: a review / 中华口腔医学杂志

Tooth development is a complex physiological process, which goes through bud stage, cap stage, bell stage and root development stage. The aim of this review article is to report the clinical manifestations of root malformations and the mechanisms of root dysplasias of human teeth. The effects of epithelial root sheath on the development of tooth roots were also elaborated.

Efeito da idade nos aspectos morfológicos, químicos e físicos das dentinas radiculares humana e bovina / The effect of age on morphological, chemical and physical aspects of human and bovine root dentin

Dentes bovinos têm sido utilizados como substitutos aos humanos em pesquisas odontológicas. Entretanto, faltam dados que suportem o uso da dentina radicular bovina, sobretudo, que analisem o efeito da idade nas propriedades do substrato. Assim, analisou-se o efeito da idade nos aspectos morfológicos, químicos e físicos das dentinas radiculares humana e bovina, em função dos terços da raiz. Trata-se de um estudo experimental, in vitro, aprovado pelo Comitê de Ética em Pesquisa (COEP-UFMG 1.803.933) e pela Comissão de Ética no Uso de Animais (CEUAUFMG 372/2016). A amostra foi composta por dentes unirradiculares, cujas dentinas radiculares foram categorizadas em: humana jovem (HJ, 20-30 anos); humana madura (HM, acima de 60 anos); bovina jovem (BJ, 24-36 meses); e bovina adulta (BA, acima de 48 meses). Os dentes foram seccionados abaixo da junção amelocementária e ao longo eixo da raiz, para a obtenção de hemisecções. Uma hemisecção foi escolhida e cortes foram feitos para a obtenção dos espécimes, conforme cada método de análise. Para as análises dos aspectos morfológicos ­ número, diâmetro e área dos túbulos dentinários ­ os espécimes foram analisados em Microscópio Eletrônico de Varredura. A composição química foi analisada por Espectroscopia de Raios X por Dispersão em Energia, Espectroscopia por Comprimento de Onda Dispersivo e Espectroscopia Raman por Transformada de Fourier. Na análise das propriedades mecânicas, os espécimes foram submetidos aos testes de nanoindentação, resistência à flexão em três pontos e compressão. Para a análise da resistência ao cisalhamento por extrusão, as raízes receberam tratamento endodôntico e foram fixados pinos de fibra de vidro com cimentos resinosos (dual convencional e autoadesivo). As raízes foram seccionadas nos terços radiculares e os espécimes testados em máquina universal de ensaios. Adicionalmente, avaliou-se o grau de conversão dos cimentos resinosos. Os dados foram analisados em software estatístico, nível de significância de 5%. A HM apresentou os menores valores para número, diâmetro e área de túbulos dentinários (p<0,05). A HM apresentou maiores valores de cálcio, razão Ca/P e concentração mineral relativa, com diminuição na organização e qualidade do colágeno (p<0,05). A HM apresentou os maiores valores de nanodureza, módulo de elasticidade e resistência à compressão, mas os menores valores de resistência à flexão e módulo de elasticidade à flexão (p<0,05). A HM apresentou os menores valores de resistência de união, com diferenças entre os terços radiculares (p<0,05). O grau de conversão dos cimentos apresentou uma diminuição ao longo dos terços radiculares (p<0,05). Concluiu-se que a idade possui um efeito nos aspectos morfológicos, químicos e físicos da dentina radicular humana, sem efeito na dentina bovina. Assim, quando da necessidade de substituição da dentina radicular humana pela bovina em pesquisas, é necessário considerar o efeito da idade nos desfechos analisados.

Bovine teeth have been used as a substitute for human teeth in dental research. However, there is a lack of data that support the use of bovine root dentin, mainly, that analyze the effect of age on the properties of the substrate. Thus, the effect of age on the morphological, chemical and physical aspects of human and bovine root dentin was analyzed, in function of the root thirds. This is an in vitro experimental study, approved by the Research Ethics Committee (protocol number: 1.803.933) and the Ethics Committee on the Use of Animals (protocol number: 372/2016). The sample was composed of single-rooted teeth and root dentin was categorized into: young human (YH, 20-30 years); old human (OH, above 60 years); young bovine (YB, 24-36 months); and adult bovine (AB, over 48 months). The roots were sectioned below the cement-enamel and longitudinally to produce two hemi-sections. One hemi-section was chosen and sections were made to obtain the specimens, according to each method of analysis. For the analyzes of the morphological aspects - number, diameter and area of the dentinal tubules - the specimens were analyzed in Scanning Electron Microscope. The chemical composition was analysed by Energy Dispersive Spectroscopy, Wavelength Dispersive Spectroscopy and Fourier Transformed Raman Spectroscopy. In the analysis of the mechanical properties, the specimens were submitted to nano-indentation, three-point flexural and compression tests. For the analysis of the push-out bond strength test, the roots received endodontic treatment and fiber post with resin cements (conventional and selfadhesive dual) were fixed. The roots were sectioned in the root thirds and the specimens tested in a universal testing machine. Additionally, the degree of conversion of the resin cements was evaluated. The data were analyzed in statistical software, level of significance of 5%. The OH presented the lowest values for number, diameter and area of dentinal tubules (p<0.05). OH showed higher values of calcium, Ca/P ratio and relative mineral concentration, with decrease in the organization and quality of the collagen (p<0.05). The OH showed the highest values of nano-hardness, elastic modulus and compressive strength, but the lowest values of flexural strength and flexural modulus (p<0.05). The OH presented the lowest values of bond strength, with differences among the root thirds (p<0.05). The degree of conversion of the cements showed a decrease along the root thirds (p<0.05). It was concluded that age has an effect on the morphological, chemical and physical aspects of human root dentin, with no effect on bovine dentin. Thus, when it is necessary to replace the human root dentin by the bovine in research, it is necessary to consider the effect of age on the analysed outcomes.

Efeito da idade nos aspectos morfológicos, químicos e físicos das dentinas radiculares humana e bovina / The effect of age on morphological, chemical and physical aspects of human and bovine root dentin

Dentes bovinos têm sido utilizados como substitutos aos humanos em pesquisas odontológicas. Entretanto, faltam dados que suportem o uso da dentina radicular bovina, sobretudo, que analisem o efeito da idade nas propriedades do substrato. Assim, analisou-se o efeito da idade nos aspectos morfológicos, químicos e físicos das dentinas radiculares humana e bovina, em função dos terços da raiz. Trata-se de um estudo experimental, in vitro, aprovado pelo Comitê de Ética em Pesquisa (COEP-UFMG 1.803.933) e pela Comissão de Ética no Uso de Animais (CEUAUFMG 372/2016). A amostra foi composta por dentes unirradiculares, cujas dentinas radiculares foram categorizadas em: humana jovem (HJ, 20-30 anos); humana madura (HM, acima de 60 anos); bovina jovem (BJ, 24-36 meses); e bovina adulta (BA, acima de 48 meses). Os dentes foram seccionados abaixo da junção amelocementária e ao longo eixo da raiz, para a obtenção de hemisecções. Uma hemisecção foi escolhida e cortes foram feitos para a obtenção dos espécimes, conforme cada método de análise. Para as análises dos aspectos morfológicos ­ número, diâmetro e área dos túbulos dentinários ­ os espécimes foram analisados em Microscópio Eletrônico de Varredura. A composição química foi analisada por Espectroscopia de Raios X por Dispersão em Energia, Espectroscopia por Comprimento de Onda Dispersivo e Espectroscopia Raman por Transformada de Fourier. Na análise das propriedades mecânicas, os espécimes foram submetidos aos testes de nanoindentação, resistência à flexão em três pontos e compressão. Para a análise da resistência ao cisalhamento por extrusão, as raízes receberam tratamento endodôntico e foram fixados pinos de fibra de vidro com cimentos resinosos (dual convencional e autoadesivo). As raízes foram seccionadas nos terços radiculares e os espécimes testados em máquina universal de ensaios. Adicionalmente, avaliou-se o grau de conversão dos cimentos resinosos. Os dados foram analisados em software estatístico, nível de significância de 5%. A HM apresentou os menores valores para número, diâmetro e área de túbulos dentinários (p<0,05). A HM apresentou maiores valores de cálcio, razão Ca/P e concentração mineral relativa, com diminuição na organização e qualidade do colágeno (p<0,05). A HM apresentou os maiores valores de nanodureza, módulo de elasticidade e resistência à compressão, mas os menores valores de resistência à flexão e módulo de elasticidade à flexão (p<0,05). A HM apresentou os menores valores de resistência de união, com diferenças entre os terços radiculares (p<0,05). O grau de conversão dos cimentos apresentou uma diminuição ao longo dos terços radiculares (p<0,05). Concluiu-se que a idade possui um efeito nos aspectos morfológicos, químicos e físicos da dentina radicular humana, sem efeito na dentina bovina. Assim, quando da necessidade de substituição da dentina radicular humana pela bovina em pesquisas, é necessário considerar o efeito da idade nos desfechos analisados.

Bovine teeth have been used as a substitute for human teeth in dental research. However, there is a lack of data that support the use of bovine root dentin, mainly, that analyze the effect of age on the properties of the substrate. Thus, the effect of age on the morphological, chemical and physical aspects of human and bovine root dentin was analyzed, in function of the root thirds. This is an in vitro experimental study, approved by the Research Ethics Committee (protocol number: 1.803.933) and the Ethics Committee on the Use of Animals (protocol number: 372/2016). The sample was composed of single-rooted teeth and root dentin was categorized into: young human (YH, 20-30 years); old human (OH, above 60 years); young bovine (YB, 24-36 months); and adult bovine (AB, over 48 months). The roots were sectioned below the cement-enamel and longitudinally to produce two hemi-sections. One hemi-section was chosen and sections were made to obtain the specimens, according to each method of analysis. For the analyzes of the morphological aspects - number, diameter and area of the dentinal tubules - the specimens were analyzed in Scanning Electron Microscope. The chemical composition was analysed by Energy Dispersive Spectroscopy, Wavelength Dispersive Spectroscopy and Fourier Transformed Raman Spectroscopy. In the analysis of the mechanical properties, the specimens were submitted to nano-indentation, three-point flexural and compression tests. For the analysis of the push-out bond strength test, the roots received endodontic treatment and fiber post with resin cements (conventional and selfadhesive dual) were fixed. The roots were sectioned in the root thirds and the specimens tested in a universal testing machine. Additionally, the degree of conversion of the resin cements was evaluated. The data were analyzed in statistical software, level of significance of 5%. The OH presented the lowest values for number, diameter and area of dentinal tubules (p<0.05). OH showed higher values of calcium, Ca/P ratio and relative mineral concentration, with decrease in the organization and quality of the collagen (p<0.05). The OH showed the highest values of nano-hardness, elastic modulus and compressive strength, but the lowest values of flexural strength and flexural modulus (p<0.05). The OH presented the lowest values of bond strength, with differences among the root thirds (p<0.05). The degree of conversion of the cements showed a decrease along the root thirds (p<0.05). It was concluded that age has an effect on the morphological, chemical and physical aspects of human root dentin, with no effect on bovine dentin. Thus, when it is necessary to replace the human root dentin by the bovine in research, it is necessary to consider the effect of age on the analysed outcomes.

Calidad del sellado apical del conducto radicular comparando dos cementos endodónticos mediante microscopio electrónico de barrido / Apical sealing quality of the root canal by comparing two endodontic sealers evaluated by scanning electron microscope / Qualidade do selamento apical do canal radicular comparando dois cimentos endodônticos avaliados por microscopia eletrônica de varredura

El desarrollo de nuevos cementos de obturación radicular tiene como finalidad conseguir un sellado hermético y obturación tridimensional, siendo fundamental para evitar la microfiltración bacteriana y posibles fracasos del tratamiento endodónti-co. Objetivo: Comparar la calidad de sellado de obturación entre dos tipos de cementos: resinoso y biocerámico a 1mm y 4mm del ápice radicular. Materiales y métodos: Se utilizó una muestra de 40 primeros premolares uniradiculares, donados por una clínica particular de la ciudad de Quito- Ecuador. Se dividieron en dos grupos de 20 dientes cada uno, se estanda-rizó la porción radicular a 16 mm y se conformó endodónticamente con el sistema rotatorio MTwo (VDW), la obturación fue por la técnica de cono único con diferentes cementos siendo: G1: Cemento biocerámico Total Fill BC Sealer (FKG) y G2: Cemento resinoso Top seal (Dentsply). Se seccionó transversalmente las raíces con un micrótomo a 1 y 4 mm del ápice, la calidad del sellado de los cortes se evaluó con Microscopio Electrónico de Barrido (MEB). Los datos se analizaron mediante la prueba estadística ANOVA, con un nivel de significancia de 5%. Resultados: La calidad del sellado del tercio apical radicular a 1 mm del ápice fue de 4,70 ± 1,54 µm y 6,95 ± 2,69 µm para G1 y G2 respectivamente (p=0.003), en la distancia de 4 mm del ápice radicular fue de 8,50 ± 4,54 µm y 9,70 ± 3,24 µm para G1 y G2 respectivamente (p=0.383). Conclusión: La calidad del sellado fue mejor a 1 mm de apical en el cemento biocerámico; sin embargo, a 4 mm no se observó diferencia estadísticamente significativa entre los cementos.

The purpose of the development of new root filling sealers is to achieve a hermetic sealing and three-dimensional obtu-ration, which is essential to avoid bacterial microfiltration and possible failures of endodontic treatment. Objective: To compare the sealing quality of obturation root canal between two sealers: resinous and bioceramic at 1mm and 4mm at the root apex. Materials and methods: Forty first mandibular premolars, donated by a clinic in the city of Quito, Ecuador, was used. The samples were divided into two groups of 20 teeth each, the root canal was standardized to 16 mm and shaped using MTwo rotary system (VDW), the obturation was by the single cone technique with different endodontic sealers: G1: Bioceramic Total Fill BC Sealer (FKG) and G2: resinous Top seal sealer (Dentsply). The roots were cut transversally at 1 and 4 mm from the apex using a microtome, and the sealing quality of the sections was evaluated with a Scanning Elec-tronic Microscope (SEM). The data were analyzed using the ANOVA statistical test at significance level of 5%. Results:The apical sealing quality at 1 mm from the apex was 4.70 ± 1.54 µm and 6.95 ± 2.69 µm for G1 and G2 respectively (p = 0.003), and 8.50 ± 4.54 µm and 9.70 ± 3.24 µm at 4 mm for G1 and G2 respectively (p = 0.383). Conclusion: The apical sealing quality of the bioceramic sealer was better than resinous sealer at 1 mm from apex; however, both bioceramic and resinous sealers was similar at 4 mm from apex.

O desenvolvimento de novos cimentos para obturação do radicular tem como finalidade obter selamento hermético e ob-turação tridimensional, o que é essencial para evitar a microfiltração bacteriana e possíveis falhas do tratamento endodôn-tico. Objetivo: Comparar a qualidade do selamento entre dois tipos de cimentos: resinoso e biocerâmico a 1mm e 4mm no ápice radicular. Materiais e métodos: Quarenta primeiros pré-molares unirradiculares, doados por uma clínica particular na cidade de Quito, Equador, foram utilizados. As amostras Foram divididas em dois grupos de 20 dentes , o canal radicular foi padronizado em 16 milímetros e preparados utilizando sistema rotatório Mtwo (VDW), a obturação foi realizada pela técnica de cone único com diferentes cimentos endodônticos: G1: Cimento biocerâmico Total Fill BC Sealer (FKG) e G2: cimento resinoso Top Seal (Dentsply). As raízes foram seccionadas transversalmente com um micrótomo a 1 e 4 mm do ápice, e a qualidade de selamento das seções foi avaliada com um Microscópio Eletrônico de Varredura (MEV). Os dados foram analisados pelo teste estatístico ANOVA, com nível de significância de 5%. Resultados: A qualidade do selamento apical a 1 mm do vértice radiográfico foi de 4,70 ± 1,54 µm e de 6,95 ± 2,69 µm para G1 e G2, respectivamente (p = 0.003), e de 8,50 ± 4,54 µm e 9,70 ± 3,24 µm a 4 mm para G1 e G2, respectivamente (p = 0.383). Conclusão: A qualidade de apical selamento do cimento biocerâmico foi melhor que o resinoso a 1 mm de ápice; porém, eles foram semelhantes a 4 mm do ápice.

Study on the application of cone-beam CT in root canal morphology of first deciduous molars / 口腔疾病防治

Objective@#To analyze the number, distribution of root canals in children's first deciduous teeth through a retrospective study of cone-beam computed tomography (CBCT). @* Methods@#A total of 185 first deciduous molars were selected from 91 children aged 4 to 8 years old in the Stomatology Department of Mianyang Hospital of Traditional Chinese Medicine. The number, distribution of root canals were analyzed.@* Results @#All 46 maxillary first deciduous molars had three roots; 139 mandibular first deciduous molars had two roots (77.70%) and three roots (22.30%). The root canals of all maxillary first deciduous molars are type Ⅰ, while the main root canal type of mandibular first deciduous molars is type Ⅳ. Of 51 children with bilateral mandibular first deciduous molars, 48 (94.12%) had symmetrical root and canal distributions.@*Conclusion @#The first deciduous molars usually have 2 to 3 roots. Root canals are mainly type I and IV. The distribution of root canals is symmetrical.

CBCT study on root and root canal morphology of maxillary second permanent molars in the Guangfu population in the Lingnan area / 口腔疾病防治

Objective @#To research the root and root canal morphology of maxillary second permanent molars in the Guangfu population of the Lingnan area.@*Methods@#A total of 1220 maxillary second permanent molars were collected from the 723 CBCT images of the Guangfu population. The root and root canal configurations were observed and counted, and the morphological characteristics and changes were compared and analyzed.@*Results@# The maxillary second permanent molars included 709 three-root molars, 417 double root molars, 68 single root molars and 26 four-root molars. The difference in the detection rate of each root type in different sex and age groups was not statistically significant (P > 0.05). Root canal morphdogy of maxillary second permanent molars: type Ⅷ (3-3) was the most common type of root canals in single root molars, accounting for 63.25%. Significant differences in the detection rates of canal configurations were noted among the three subtypes of fused root canals in double root molars (P < 0.01). Root canal morphology of the mesiobuccal root of the three-root molars was mainly typeⅠ (1-1), significantly accounting for 78.84%. Significant sex and age differences were noted in the detection rate of type Ⅰ and Ⅳ root canals (P < 0.01). In addition, 75.86% of maxillary second permanent molars had symmetrical roots, and 73.64% of the bilateral teeth had symmetrical roots and canals.@*Conclusion@#The root and root canal morphology of maxillary second permanent molars in the Guangfu population in the Lingnan area are different compared with other areas at home and abroad.

Evaluation of Frontal Teeth Stabilization after Root Apex Resection among the Ukrainian Young People

Objective: To develop a protocol of improved stabilization of teeth after root apex resection among young people using endodonto-endoossal implants and assessing its effectiveness. Material and Methods: Thirty-six patients were previously selected and divided into Group 1 (without additional stabilization) and Group 2 (with additional stabilization). The efficacy of treatment in both clinical groups was estimated at 90, 180 and 360 days, respectively. The results were evaluated on the Miller scale in the Flesrar modification. Density of bone tissue was expressed in Hounsfield units. Results: The average mobility indices over 90 days indicate a significant lower mobility of teeth in patients in Group 2, where as an advanced method, the RTR with an additional filling of the bone marrow defect with an osteoplastic material was chosen as the method of treatment (+ 18.0 ± 0.21 U.M. 10.0 ± 0.8 µm, p<0.05). In Group 1, 90 and 180 days after surgery, the density of bone tissue in the defect area was 756.3 ± 2.45 HU and 880.1 ± 4.34 HU. In Group 2, these indices were insignificantly higher and amounted to 834.3 ± 4.35 HU and 880.4 ± 2.56 HU. After 360 days after treatment in the first clinical group the bone density index was 957.4 ± 2.45 HU, while in the second group - 1003.3 ± 4.38 HU. Conclusion: The mobility of teeth among patients on 90-th day corresponded to level 1, and on 360-th day corresponded to level 0, indicating the effectiveness of the proposed method. The biomechanical stabilization of the teeth was confirmed by the results of densitometry among patients of both groups, in particular, the recovery of bone density in the affected site was observed after 360 days.