Restauração em resina composta semidireta em dente posterior: relato de caso / Semi-direct composite restoration in posterior toth: a case report

A escolha da técnica restauradora desempenha papel fundamental na eficácia e duração de um tratamento reabilitador. O objetivo deste relato de caso foi descrever a utilização da técnica semidireta para a confecção de uma restauração em resina composta em um primeiro molar inferior. A paciente apresentava uma restauração insatisfatória no dente 36, que necessitava ser substituída devido à infiltração por cárie. Optou-se pela técnica semidireta devido à amplitude da cavidade, que envolvia estruturas de suporte, e pela combinação das vantagens das abordagens direta e indireta. O procedimento envolveu a remoção de tecido cariado, a aplicação de hidróxido de cálcio pasta, seguida da aplicação de uma fina camada de ionômero de vidro e, posteriormente, resina fluída para realizar o selamento dentinário. O preparo foi realizado seguindo os princípios necessários. O elemento em questão foi moldado com silicone de adição e o arco antagonista, com alginato. Ambos modelos foram vertidos com silicone para modelos semirrígidos e montados em oclusor de peças de brinquedo. A restauração semidireta foi confeccionada em resina composta Filtek Z350 XT, respeitando a anatomia do dente 36. Pigmentos foram utilizados para aprimorar detalhes estéticos. Após acabamento e polimento, a peça foi condicionada e cimentada com cimento dual Relyx Ultimate. Pode-se concluir que a abordagem restauradora por meio da técnica semidireta construída em modelo semirrígido é uma opção terapêutica conservadora e vantajosa para dentes com extensa destruição coronária. Essa técnica possibilita a restauração de forma eficaz, garantindo tanto a estética quanto a função adequada do dente afetado(AU)

The choice of restorative technique plays a fundamental role in the effectiveness and duration of rehabilitation treatment. The objective of this case report was to describe the use of the semi-direct technique to create a composite resin restoration in a lower first molar. The patient had an unsatisfactory restoration on tooth 36, which needed to be replaced due to cavity infiltration. The semi-direct technique was chosen due to the amplitude of the cavity, which involved support structures, and the combination of advantages of the direct and indirect approaches. The procedure involved the removal of carious tissue, and the application of calcium hydroxide paste, followed by the application of a thin layer of glass ionomer and, subsequently, fluid resin to seal the dentin. The preparation was carried out following the necessary principles. The element in question was molded with addition silicone and the antagonist arch was molded with alginate. Both models were poured with silicone for semi-rigid models and mounted on toy parts occluders. The semi-direct restoration was made in Filtek Z350 XT composite resin, respecting the anatomy of tooth 36. Pigments were used to improve aesthetic details. After finishing and polishing, the piece was conditioned and cemented with Relyx Ultimate dual cement. It can be concluded that the restorative approach using the semi-direct technique built on a semi-rigid model is a conservative and advantageous therapeutic option for teeth with extensive coronal destruction. This technique allows for effective restoration, ensuring both the aesthetics and adequate function of the affected tooth(AU)

Black male, 19: Brazilian "criminal commando" and the breach of human rights / Homem negro, 19 anos: o "comando criminoso" brasileiro e a violação dos direitos humanos

Dental age estimation is a technical procedure performed to support Court decisions in cases of legal liability, clandestine migration, sexual abuse, and several other applications. This study reports a case of an undocumented individuals that was originally identified by the criminal legal system (without a previous civil identity). In his identity records, a name was given: "Black male, 19" ­ indicating his population affinity (African), sex (male) and age (19 years). His body was found decapitated and referred to the medicolegal institute. The dental examination highlighted the presence of a third molar in the very early stage (») of root formation. Age was estimated using five methods based on dental development (the methods of Schour and Massler [1941], Moorrees et al. [1963], Anderson et al. [1976], London Atlas [2010], and Blenkin and Taylor [2012]). All the methods indicated that the individual was a minor, within the range between 14.5 and 15.5 years. This study highlights the importance of assigning adequate personnel to technical tasks in the police/forensic routine in order to safeguard human rights

A estimativa da idade dentária é um procedimento técnico realizado para apoiar decisões judiciais em casos de responsabilidade legal, migração clandestina, abuso sexual e diversas outras aplicações. Este estudo relata o caso de um indivíduo indocumentado que foi originalmente identificado pelo sistema penal (sem identidade civil prévia). Nos seus registos de identidade foi atribuído um nome: "Homem negro, 19 anos" ­ indicando a sua afinidade populacional (africana), sexo (masculino) e idade (19 anos). Seu corpo foi encontrado decapitado e encaminhado a um Instituto Médico-legal. O exame odontológico evidenciou a presença de um terceiro molar em fase muito inicial (») de formação radicular. A idade foi estimada usando cinco métodos baseados no desenvolvimento dentário (os métodos de Schour e Massler [1941], Moorrees et al. [1963], Anderson et al. [1976], London Atlas [2010] e Blenkin e Taylor [2012]). Todos os métodos indicaram que o indivíduo era menor de idade, na faixa entre 14,5 e 15,5 anos. Este estudo destaca a importância de designar pessoal adequado para tarefas técnicas na rotina policial/forense, a fim de salvaguardar os direitos humanos

Comparación de la microfiltración apical de cuatro tipos de cementos endodónticos: Endofill, mtaFillapex, Adseal y Roeko Seal / Comparison of the Apical Microleakage of Four Types Of Endodontic Cements: Endofill, mta Fillapex, Adseal and Roeko Seal / Comparação da microinfiltração apical de quatro tipos de cimentos endodônticos: Endofill, mta Fillapex, Adseal e Roeko seal

Introducción: La microfiltración apical es uno de los principales causantes de fracasos endodónticos donde hay invasión de bacterias y líquidos periapicales a la parte interna del conducto radicular y material de relleno. Materiales y Métodos: La muestra estuvo conformada por 60 dientes premolares unirradiculares que fueron seccionados en la unión amelocementaria, la instrumentación biomecánica se realizó con técnica rotatoria e irrigación con hipoclorito de sodio al 5.25% y EDTA 17%, se dividió aleatoriamente en 4 grupos (n=15) para cada tipo de cemento, la obturación se realizó con la técnica de condensación lateral, a nivel coronal se obturó con Ionómero vidrio base y resina, se colocaron en una incubadora a 37° sumergidos en NaCL 0.9% por 5 días hasta el fraguado de los cementos, para observar la microfiltración se utilizó el método filtración de tinta china y la diafanización con la técnica de Robertson. Las medidas de microfiltración apical se observaron utilizando el Estereomicroscopio. Resultados: El valor promedio fue menor para el cemento Adseal 0,33mm, seguido por los cementos Fillapex 0,87mm, Roeko seal 1,00mm y Endofill 1,30mm respectivamente. Hubo diferencias estadísticamente significativas en la microfiltración apical de los cuatro cementos endodónticos (p=0.00) Conclusiones: El cemento Adseal presentó menor microfiltración en comparación a los cementos Fillapex, Roeko seal y Endofill.

Introduction: Apical microleakage is one of the main causes of endodontic failure, either due to invasion of microorganisms or periapical fluids into the canal, and only the composition of the type of obturator cement favors its reduction. The objective of this research was to compare the apical microleakage of four types of endodontic cements Endofill, MTA Fillapex, Adseal and Roeko Seal. Materials and methods: The sample consisted of 60 single root premolar teeth that were sectioned at the cement- enamel junction, the biomechanical instrumentation was performed with a rotary technique and irrigation with sodium hypochlorite and edta, randomly divided into 4 groups (n = 15) for each type of cement, the obturation was performed with the lateral condensation technique, at the coronal level it was obturated with base glass ionomer and resin, they were placed in an incubator at 37° submerged in NaCL 0.9% for 5 days until setting. of the cements, to observe the microleakage the India ink filtration method was used and diaph-anization with the Robertson technique. Apical microleakage measurements were observed using the Stereomicroscope. Results: The average value was lower for the Adseal 0.33 mm cement, followed by the Fillapex 0.87 mm, Roeko Seal 1.00 mm and Endofill 1.30 mm cements respectively. There were sta-tistically significant differences in the apical microleakage of the four endodontic cements (p = 0.00) Conclusions: Adseal cement presented less microfiltration compared to Fillapex, Roeko Seal and Endofill cements

Introdução: a microinfiltração apical é uma das principais causas de falhas endodônticas onde há inva-são de microrganismos e líquidos periapicais ao interior do conducto e só a composição do tipo de cimento obturador favorece sua disminuição. O objetivo desta pesquisa foi comparar a microinfiltração apical de quatro tipos de cimentos endodônticos Endofill, MTA Fillapex, Adseal e Roeko Seal. Materiais e métodos: a amostra foi composta por 60 dentes pré-molares uniradiculares que foram seccionados na junção amelocementária. A instrumentação biomecânica foi realizada com técnica rotatória e irrigação com hipoclorito e edta, sendo dividida aleatoriamente em 4 grupos (n = 15) para cada tipo de cimento. A obturação foi realizada pela técnica de condensação lateral, no nível coronal foi obturado com base de ionômero de vidro e resina, foram colocados em incubadora a 37° submersos em NaCl 0,9% por 5 dias até a pega dos cimentos. Para observar a microfiltração utilizou-se o método de filtração em tinta nan-quim e diafanização pela técnica de Robertson. As medidas de microinfiltração apical foram observadas utilizando o estereomicroscópio. Resultados: o valor médio foi menor para o cimento Adseal (0,33 mm), seguido pelos cimentos Fillapex (0,87 mm), Roeko Seal (1,00 mm) e Endofill (1,30 mm), respectivamente. Houve diferenças estatisticamente significativas na microinfiltração apical dos quatro cimentos endo-dônticos (p = 0,00). Conclusões: o cimento Adseal apresentou menor microinfiltração comparado aos cimentos Fillapex, Roeko seal e Endofill.

Dental Loss in the Lower Socioeconomic Stratum of a Sample of the Chilean Population Born in the 19TH and 20TH Centuries

SUMMARY: Partial or total dental loss (edentulism) is associated with decreased quality of life. Chile has large socioeconomic gaps, which are also recognized in oral health, but it is not known how Edentulism has evolved throughout the country. The aim of this study was to determine the edentulism in people born during the 19th and 20th centuries in Chile, who died in the 20th century, and to compare it with current data from the Chilean Ministry of Health (MINSAL) to observe its evolution in the country. For this purpose, 60 3D models of skulls from the Subactual Osteological Collection of Santiago were analyzed (30 individuals per sex), in which the presence and absence of teeth in antemortem in the maxilla were analyzed. A high percentage of tooth loss was observed, with 65 % partial edentulism, a 30 % total edentulism, and only 5 % had complete dentition in this osteological collection. In addition, a significant decrease over time was found; in 2017, the percentage of complete dentition at the national level was 32.8 %. A higher frequency of edentulism was also found in females from the osteological collection, with a significant probability of twice as much edentulism as in males. However, this sex difference was smaller than those found in the current study. Our study is the first to compare edentulism in Chile in two different time periods, since, in addition to studying it in the 19th and 20th century, it is carried out with data from the present day and in line with previous research, reveals the importance of socioeconomic and sex variables for dental loss.

La pérdida parcial o total de dientes (edentulismo) se asocia a una disminución de la calidad de vida. Chile tiene grandes brechas socioeconómicas, que también se reconocen en la salud oral, pero se desconoce cómo ha evolucionado el edentulismo en el país. El objetivo de este estudio fue determinar el edentulismo en personas nacidas durante los siglos XIX y XX en Chile y fallecidas en el siglo XX, y compararlo con datos actuales del Ministerio de Salud de Chile (MINSAL) para observar su evolución en el país. Para ello, se analizaron 60 modelos 3D de cráneos de la Colección Osteológica Subactual de Santiago (30 individuos por sexo), en los que se analizó la presencia y ausencia de dientes en dentición antemortem en el maxilar. Se observó un alto porcentaje de pérdida dentaria, con un 65 % de edentulismo parcial y un 30 % de edentulismo total, y sólo un 5 % presentaba dentición completa en esta colección osteológica. Además, se encontró una disminución significativa a lo largo del tiempo; en 2017, la dentición completa a nivel país fue del 32,8 %. También se encontró una mayor frecuencia de edentulismo en las mujeres de la colección osteológica, con una probabilidad significativa del doble de edentulismo que en los hombres. Sin embargo, esta diferencia de sexo fue menor que la hallada en datos actuales. Este estudio es el primero que compara el edentulismo en Chile en dos épocas diferentes, ya que además de estudiarlo en los siglos XIX y XX, se realizó con datos de la actualidad y, en línea con investigaciones previas, revela la importancia de las variables socioeconómicas y de sexo en la pérdida dental.

Morphology of the Second Mesiobuccal Canal in the Maxillary Second Molar

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

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

Whitening toothpastes effect on enamel surface morphology, chemical profile and color: An In Vitro study / Efecto de las pastas dentales blanqueadoras sobre la morfología, el perfil químico y el color de la superficie del esmalte: un estudio In Vitro

Abstract To assess the effect of different whitening toothpastes on enamel surface morphology, chemical profile and their whitening efficiency. Sixty teeth were divided into 5 groups (12 teeth/group); Gp I: brushed with no toothpaste. Gp II: brushed with Pearl-based toothpaste. Gp III: brushed with Charcoal- based toothpaste. Gp IV: brushed with Alumina-based toothpaste. Gp V: brushed with salt and lemon- based toothpaste. Each tooth was brushed with a bean sized toothpaste wetted with distilled water twice daily by using standard electronic toothbrush for four weeks. Enamel surface morphology, chemical profile and color of each tooth were investigated. Chemical profile results and color measurements were analyzed statistically. Gp I revealed normal enamel surface morphology and chemical profile. Gp II and Gp III demonstrated surface morphology close to Gp I with insignificant reduction in mineral content. Gp IV showed obvious shallowing of perikymata ridges, exposure of fish-scale appearance, with pits and depressions, alongside to the significant reduction in mineral content. Gp V presented the most enamel surface alteration with widening of prism sheath and depressions all over the surface, besides the highest significant reduction in mineral content. Gp V, followed by Gp IV, demonstrated the highest color and whiteness changes, followed by Gp III, then Gp II, while the lowest value was in Gp I. Salt & lemon-based toothpaste, followed by Alumina-based, exerted the most considerable changes in the morphology and chemical profile of the enamel surface, beside to the higher whitening effects on teeth than the others.

Resumen El objetivo del presente estudio fue evaluar el efecto de diferentes pastas dentales blanqueadoras sobre la morfología y el perfil químico de la superficie del esmalte y su eficacia blanqueadora. Sesenta dientes se dividieron en 5 grupos (12 dientes/grupo); Grupo I: cepillado sin pasta de dientes. Grupo II: cepillado con pasta de dientes a base de perlas. Grupo III: cepillado con pasta de dientes a base de carbón. Grupo IV: cepillado con pasta de dientes a base de Alúmina. Grupo V: cepillado con sal y pasta de dientes a base de limón. Cada diente se cepilló con una pasta de dientes del tamaño de un frijol humedecida con agua destilada dos veces al día utilizando un cepillo de dientes electrónico estándar durante cuatro semanas. Se investigaron la morfología de la superficie del esmalte, el perfil químico y el color de cada diente. Los resultados del perfil químico y las mediciones de color se analizaron estadísticamente. El Grupo I reveló una morfología de la superficie del esmalte y un perfil químico normales. Los Grupos II y III demostraron una morfología de superficie cercana a la del Grupo I con una reducción insignificante en el contenido mineral. El grupo IV mostró una evidente reducción de las crestas perikymatas, exposición de apariencia de escamas de pez, con hoyos y depresiones, junto con una reducción significativa en el contenido mineral. El grupo V presentó la mayor alteración de la superficie del esmalte con ensanchamiento de la vaina del prisma y depresiones en toda la superficie, además de una significativa reducción en el contenido mineral. El grupo V, seguido del grupo IV, demostró los mayores cambios de color y blancura, seguido del grupo III, luego el grupo II, mientras que el valor más bajo se presentó en el grupo I. Las pastas dentales a base de sal y limón, seguidas de las de alúmina, ejercieron los cambios más considerables en la morfología y el perfil químico de la superficie del esmalte, además de tener mayores efectos blanqueadores sobre los dientes que las demás.

Quistes Dentígeros Asociados a Mesiodens. Revisión de la Literatura a Propósito de Dos Casos

El mesiodens es el diente supernumerario que se origina en la premaxila, siendo considerado el más prevalente o el más diagnosticado debido a las numerosas alteraciones que producen y que incluyen malposición de los dientes permanentes, formación de diastemas, retraso en la erupción de los incisivos anteriores superiores, y formación de quistes. La etiología de los mesiodens no está completamente comprendida, aunque se piensa que pueda deberse a la proliferación de la lámina dental u otros factores genéticos. El diagnóstico generalmente es tardío debido a que la mayoría permanece sin erupcionar, pudiendo generar complicaciones dentomaxilares que finalmente son el motivo de consulta de los pacientes. El quiste dentígero es un quiste odontogénico del desarrollo asociado a la corona de un diente incluido, numerario o supernumerario y su tratamiento es quirúrgico. El diagnóstico temprano y la planificación del tratamiento debe considerar una anamnesis minuciosa, un examen clínico e imágenes 3D. La cirugía debe consistir en la desinclusión del diente causal, la exéresis y legrado de la lesión, con o sin regeneración ósea inmediata del lecho quirúrgico con injerto. Se presentan dos casos de quiste dentígero asociado a un mesiodens que se diagnosticaron como hallazgo radiográfico. El plan de tratamiento consistió en evaluación y tratamiento endodóntico de los dientes desvitalizados, enucleción y legrado del quiste, junto a la desinclu sión del diente supernumerario, y seguimiento clínico y radiográfico en el largo plazo.

Mesiodens is the supernumerary tooth that originates in the premaxilla, considered the most prevalent or, the most diagnosed due to the multiple alterations that produce and that include malposition of the permanent teeth, formation of gaps, delayed eruption of the upper anterior incisors and cyst formation. The etiology of mesiodens is not fully established, although it is thought that it may be due dental lamina alteration or other genetic factors. Diagnosis is usually late because most remain unerupted, and can generate dentomaxillary complications that are ultimately the reason for patient consultation. The dentigerous cyst is a developmental odontogenic cyst associated with the crown of an included, numerary or supernumerary tooth and its treatment is surgery. Early diagnosis and treatment planning should consider a careful history, clinical examination, and 3D imaging. The surgery must consist of the disinclusion of the offending tooth, the exeresis and curettage of the lesion, with or without immediate bone regeneration of the surgical bed with a graft. Two cases of a dentigerous cyst associated with a mesiodens that were diagnosed as a radiographic finding are presented. The treatment plan consisted in evaluation and endodontic treatment of devitalized teeth, enucleation and curettage of the cyst, together with the disinclusion of the supernumerary tooth, and long-term clinical and radiographic follow-up.

Prevalência de anomalias dentárias e outros achados orais em radiografias panorâmicas de brasileiros com fissura labiopalatal: um estudo retrospectivo / Prevalence of dental anomalies and other oral findings on panoramic radiographs of Brazilian with cleft lip and palate: a retrospective study

Objetivo: avaliar a prevalência de anomalias dentárias (AD) e outros achados orais em radiografias panorâmicas de pacientes com fissuras labiopalatais (FLP) nascidos no Nordeste brasileiro. Métodos: a amostra foi composta por 69 pacientes com fissuras labiopalatais unilateral (FLPu) (n = 51) e bilateral (FLPb) (n = 18), não sindrômicos, de ambos os sexos, idade de 6 a 17 anos, nascidos no Nordeste brasileiro. Foram analisados prontuários e radiografias panorâmicas de pacientes atendidos de janeiro/2020 a julho/2022. Os dados categóricos foram expressos em forma de frequência absoluta e percentual e comparados por teste exato de Fisher ou qui-quadrado de Pearson (SPSS, p < 0,05). Resultados: entre os achados orais, destacaram-se as anomalias de número e as ausências dentárias por trauma, cárie ou doença periodontal. As AD foram identificadas em 34 pacientes (49,3%). As anomalias de número apresentaram maior prevalência, com diferença estatística significativa para pacientes FLPb do sexo masculino (p = 0,047). A agenesia foi a AD mais frequente (n = 24; 34,8%). As ausências dentárias por trauma, cárie ou doença periodontal foram observadas em 44 pacientes (n = 63,8%), com uma diferença estatística significativa entre os grupos FLPu e FLPb (p = 0,018). Conclusões: as AD e as ausências dentárias por trauma, cárie ou doença periodontal apresentaram uma alta prevalência entre pacientes brasileiros com FLP e devem ser consideradas durante o planejamento ortodôntico-cirúrgico desses indivíduos.

Aim: this study aimed to assess the prevalence of dental anomalies (DA) and other oral findings in panoramic radiographs of patients with cleft lip and palate (CLP) born in the Northeast region of Brazil. Methods: the sample consisted of 69 patients with unilateral cleft lip and palate (UCLP) (n = 51) and bilateral cleft lip and palate (BCLP) (n = 18), non-syndromic, of both genders, aged 6 to 17 years, born in the Brazilian Northeast. Patient records and panoramic radiographs from those treated between January 2020 and July 2022 were analyzed. Categorical data were expressed as absolute frequency and percentage and compared using Fisher's exact test or Pearson's chi-square test (SPSS, p < 0.05). Results: among oral findings, anomalies in number and tooth absences due to trauma, caries, or periodontal disease stood out. DAs were identified in 34 patients (49.3%). Anomalies in number showed higher prevalence, with a statistically significant difference for male BCLP patients (p = 0.047). Agenesis was the most frequent DA (n = 24; 34.8%). Tooth absences due to trauma, caries, or periodontal disease were observed in 44 patients (63.8%), with a statistically significant difference between the UCLP and BCLP groups (p = 0.018). Conclusions: DAs and tooth absences due to trauma, caries, or periodontal disease showed a high prevalence among Brazilian patients with CLP and should be considered during the orthodontic-surgical planning for these individuals.

Osteomielitis, perimplantitis y fractura vertical radicular mandibular en un paciente con fibromialgia: presentación de caso / Osteomyelitis, Peri-implantitis and Mandibular Root Vertical Fracture in a Patient with Fibromyalgia: Case Report / Osteomielite, peri-implantite e fratura vertical da raiz mandibular em um paciente com fibromialgia: relato de caso

Introducción: se considera la osteomielitis mandibular un proceso patológico poco frecuente. La mayor parte de los casos presentados involucran pacientes con osteorradionecrosis y aquellos pacientes con ingesta de algunos medicamentos antirresortivos. El objetivo es informar un caso inusual de una paciente con osteomielitis, perimplantitis y fractura vertical radicular con antecedentes de fibromialgia. Presentación del caso: mujer de 70 años de edad, no fumadora ni consumidora de alcohol, que acudió con un dolor posteroinferior izquierdo de un año de evolución. Presentaba una profundidad de son-deo mayor de 12 mm en el órgano dental (od) 37, sangrado a la palpación, dolor y movilidad grado ii. En el od 36 fue notoria la exposición clínica del tercio superior del implante dental, sin movilidad, con una profundidad de 4 mm. El tratamiento consistió en una exodoncia atraumática del od 37, donde se identificó una fractura radicular vertical. Discusión: actualmente, los implantes dentales permiten restablecer la salud bucodental. Sin embargo, ellos también pueden inducir una osteomielitis en los maxilares. La terapia instaurada redujo ostensiblemente la morbilidad del implante dental implicado y regeneró la zona intervenida.

Introduction: Mandibular osteomyelitis is considered a rare pathological process. Most of the cases pre-sented involve patients with osteoradionecrosis and those patients with intake of some antiresorptive drugs. The objective of this report is to report an unusual case of a patient with osteomyelitis, peri-im-plantitis and vertical root fracture with a history of fibromyalgia. Case presentation: A 70-year-old female patient, non-smoker or alcohol consumer, who presented with lower left postero-pain of one year's evolution. She presented a probing depth greater than 12 mm in dental organ (od) 37, bleeding on palpation, pain and grade II mobility. At the level of do 36, the clinical exposure of the upper third of the dental implant was notorious, without mobility, with a depth of 4 mm. The treatment consisted of an atraumatic extraction of do 37, where a vertical root fracture was identified. Discussion: Currently, dental implants make it possible to restore oral health. However, they can also induce osteomyelitis in the jaws. The established therapy ostensibly reduced the morbidity of the involved dental implant and regeneration of the intervened area

Introdução: a osteomielite mandibular é considerada um processo patológico raro. A maioria dos casos apresentados envolve pacientes com osteorradionecrose e aqueles pacientes com uso de alguns medi-camentos antirreabsortivos. O objetivo deste relato é relatar um caso incomum de um paciente com osteomielite, periimplantite e fratura radicular vertical com histórico de fibromialgia. Apresentação do caso: paciente do sexo feminino, 70 anos, não fumante ou etilista, que apresentou dor póstero-infe-rior esquerda com um ano de evolução. Apresentava profundidade de sondagem maior que 12 mm no órgão dentário (od) 37, sangramento à palpação, dor e mobilidade grau ii. Ao nível de do 36, foi notória a exposição clínica do terço superior do implante dentário, sem mobilidade, com profundidade de 4 mm. O tratamento consistiu em uma extração atraumática de do 37, onde foi identificada uma fratura vertical da raiz. Discussão: atualmente, os implantes dentários possibilitam o restabelecimento da saúde bucal. No entanto, eles também podem induzir osteomielite nos maxilares. A terapia instituída reduziu ostensivamente a morbidade do implante dentário envolvido e a regeneração da área intervencionada

Occlusion development after premature loss of deciduous anterior teeth: preliminary results of a 24-month prospective cohort study

ABSTRACT Objective: This study aimed to evaluate occlusion development after premature loss or extraction of deciduous anterior teeth, by means of a prospective cohort study. Methods: Fifteen infants and children aged 1 to 5 years old were longitudinally assessed (with loss or extraction of deciduous anterior teeth [n = 9], and without tooth losses [n = 6]). Photographs and dental casts at the baseline and after 24 months of follow-up were performed. Dental casts were scanned, and linear measurements were made on the digitalized models (missing tooth space, arch perimeter, arch length, arch width, intercanine length and intercanine width). The t-test was used for groups comparisons (α = 0.05). Results: Individuals' mean age at baseline was 2.93 (± 1.18) years. No statistically significant differences were observed in the missing tooth space in the group with tooth loss during the 24 months of follow-up (p > 0.05). Arch perimeter, arch length, arch width, intercanine length and intercanine width did not show differences between the groups (p > 0.05). Qualitative photographic evaluation revealed other changes in the dental arches and occlusion, such as exfoliation and eruption of deciduous teeth, eruption of permanent teeth, self-correction or establishment of malocclusion, among others. Conclusion: The results suggest that the premature loss of deciduous anterior teeth does not affect the perimeter, length and width of the dental arches; however, other alterations that lead to malocclusion could be established.

RESUMO Objetivo: Este estudo teve como objetivo avaliar o desenvolvimento da oclusão após perda prematura ou extração de dentes decíduos anteriores, por meio de um estudo de coorte prospectivo. Métodos: Quinze bebês e crianças de 1 a 5 anos foram avaliados longitudinalmente (com perda ou extração de dentes anteriores decíduos [n = 9] e sem perdas dentárias [n = 6]). Foram realizadas fotografias e modelos dentais no início e após 24 meses de acompanhamento. Os modelos dentários foram escaneados e medidas lineares foram feitas nos modelos digitalizados (espaço dentário perdido, perímetro da arcada, comprimento da arcada, largura da arcada, comprimento intercaninos e largura intercaninos). O teste t foi utilizado para comparações entre grupos (α = 0,05). Resultados: A média de idade dos indivíduos no início do estudo foi de 2,93 (± 1,18) anos. Não foram observadas diferenças estatisticamente significativas no espaço dentário perdido no grupo com perda dentária durante os 24 meses de acompanhamento (p > 0,05). O perímetro da arcada, comprimento da arcada, largura da arcada, comprimento intercaninos e largura intercaninos não apresentaram diferenças entre os grupos (p> 0,05). A avaliação fotográfica qualitativa revelou alterações nas arcadas dentárias e na oclusão, como: esfoliação e erupção de dentes decíduos, erupção de dentes permanentes, autocorreção ou estabelecimento de má oclusão, entre outras. Conclusão: Os resultados sugerem que a perda prematura de dentes anteriores decíduos não afeta o perímetro, comprimento e largura das arcadas dentárias; entretanto, outras alterações que levam à má oclusão poderiam ser estabelecidas.

At-home bleaching versus whitening toothpastes for treatment of tooth discoloration: a cost-effectiveness analysis

Abstract Objectives This study aimed to analyze the cost-effectiveness of whitening toothpastes and at-home bleaching for the treatment of tooth discoloration. Methodology A cost-effectiveness economic analysis was conducted, and eight randomized clinical trials were selected based on the whitening agent product used: blue covarine dentifrices (BCD), hydrogen peroxide dentifrices (HPD), dentifrices without bleaching agents (CD, negative control), and 10% carbamide peroxide (CP10, positive control) for at-home bleaching. The consumer/patient perspective was adopted, macro-costing techniques were used and a decision tree model was performed considering the costs in the American and Brazilian markets. The color change evaluation (ΔE*ab) was used to calculate the effectiveness of tooth bleaching. A probabilistic analysis was performed using a Monte Carlo simulation and incremental cost-effectiveness ratios were obtained. Results CP10 resulted in the highest cost-effectiveness compared to the use of dentifrices in both markets. In Brazil, HPD was more cost-effective than BCD and CD. In the US, the increased costs of HPD and BCD did not generate any whitening benefit compared to CD. Conclusions CP10 was more cost-effective than BCD and HPD for tooth bleaching from the perspectives of the Brazilian and American markets. Decision-making should consider the use of CP10 for treating tooth discoloration.

Knowledge of Brazilian Dentists about Dentoalveolar Trauma Care and their Experiences during the COVID-19 Pandemic

ABSTRACT Objective: To assess dentists' knowledge from Minas Gerais, Brazil, about dentoalveolar trauma (DT) and their experiences during the COVID-19 pandemic. Material and Methods: An online questionnaire with 34 questions was applied to collect personal data, professional training, self-assessment of experience/knowledge about DT, experience in care provided during the social distancing, and knowledge/conduct. The specific responses were evaluated based on the guidelines of the International Association of Dental Traumatology (IADT). Descriptive analysis and Pearson's chi-square test were performed. The level of significance was set at p≤0.05. Results: Most professionals (97.7%) had received information on DT, and only 4.6% of the participants considered their knowledge poor or very poor. However, 92.7% felt the need for more information on the subject. Regarding experiences during the pandemic, 55.7% provided trauma care during that period. Forty percent of the consultations were performed in person, and 33.3% of the professionals noted an increase in cases during the pandemic; 56.6% reported that the frequency did not change. The overall mean number of correct answers about DT was 5.29±2.11, indicating an acceptable level of knowledge. The mean percentage of hits for the specific questions was 44.1%. Conclusion: Although the level of knowledge of the dentists evaluated was acceptable, some aspects were deficient, with the need for more information about the IADT guidelines.

Can a dentin bonding agent prevent color change in regenerative endodontic procedures? An in vitro evaluation

Abstract This in vitro study aimed to determine the efficacy of dentin bonding agents in preventing color changes following Regenerative Endodontic Procedures. One hundred twenty bovine incisors were endodontically prepared and randomly assigned to a two main factors design: application of a dentin bonding agent (Scotchbond Adper, 3M ESPE, St Paul, MN, USA) in the pulp chamber (Group 1, n=60) versus no bonding intervention (Group 2, n=60), and five levels of intracanal medication (n=12/subgroup): Triple antibiotic paste (TAP), double antibiotic paste (DAB), calcium hydroxide (CH), modified triple antibiotic paste (TAPM), and Control (CTL). Color changes were measured over 28 days at multiple time points (1, 3, 7, 14, 21, and 28 days) using the CIEDE2000 formula to calculate the color difference (ΔE00) from baseline (T0). The ΔE00 quantifies the perceptible color difference between the initial and final tooth color, with lower values indicating less discoloration. The results were analyzed using repeated measures ANOVA-2 and post-hoc Holm-Sidak tests. The TAP subgroups, both with and without the bonding agent, exhibited the highest color variation. However, a pulp chamber seal with a bonding agent showed a protective effect against discoloration compared to no seal, even though complete prevention was not achieved. All groups demonstrated ΔE00 values beyond acceptable interpretation thresholds for clinical application, primarily driven by a reduction in lightness (L*) and a decrease in redness (a* value, shifting towards green). In conclusion, while the pulp chamber seal with a bonding agent mitigated TAP-induced discoloration, it did not eliminate it.

Resumo Este estudo in vitro avaliou adesivos dentinários na prevenção de alterações de cor após procedimentos endodônticos regenerativos. Cento e vinte incisivos bovinos foram preparados endodonticamente e aleatoriamente designados para um desenho com dois fatores principais: aplicação de agente adesivo (Scotchbond Adper, 3M ESPE, St Paul, MN, EUA) na câmara pulpar (Grupo 1, n=60) versus não intervenção adesiva (Grupo 2, n=60), e cinco níveis de medicação intracanal (n=12/subgrupo): pasta de triantibiótica (TAP), pasta diantibiótica (DAB), hidróxido de cálcio (CH), pasta triantibiótica modificada (TAPM) e Controle (CTL). Alterações cromáticas foram monitoradas por 28 dias em intervalos (1, 3, 7, 14, 21, e 28 dias), usando CIEDE2000 para calcular a diferença de cor (ΔE00) em relação a cor inicial. O ΔE00 quantifica a diferença entre a cor inicial e final do dente, com valores menores indicando menos descoloração. Os resultados foram analisados usando ANOVA-2 de medidas repetidas e teste posthoc de Holm-Sidak. Os grupos utilizando medicação TAP, com ou sem adesivo, possuíram as maiores variações cromática. Contudo, o uso do adesivo na câmara pulpar mostrou um efeito protetor contra descoloração, em comparação com a ausência do selamento adesivo, embora a prevenção completa não tenha sido alcançada. Todos os grupos demonstraram valores de ΔE00 além dos limiares aceitáveis para aplicação clínica, principalmente devido à redução na luminosidade (L*) e redução no vermelho (a*, deslocando-se em direção ao verde). Em conclusão, enquanto o selamento da câmara pulpar com um agente adesivo mitigou a descoloração induzida pelo TAP, mas não a eliminou completamente.

Inhibition of incipient caries lesion progression by different fluoridated varnishes

Abstract The aim of this in vitro study was to evaluate the potential of different fluoridated varnishes to inhibit the progression of incipient caries lesions after cariogenic challenge. Seventy-five enamel specimens of bovine teeth were prepared and selected based on the initial surface microhardness (SMH). The specimens were first subjected to artificial demineralization (in buffer solution) after which SMH was re-analyzed (SM1). They were then randomly assigned to five experimental groups: 1- CONTROL (pH cycling), 2 - MI VAR (MI Varnish with RECALDENTTM - CPP-ACP), 3 - PROFL (Profluorid®), 4 - CLIN (ClinproTM White Varnish with TCP), and 5 - DUR (Duraphat®) (n=15). The varnishes were applied in a thin layer and the specimens were then subjected to pH cycling for eight days. The SMH and cross-sectional microhardness (CSMH) were then analyzed (SM2). The fluoride and calcium ion concentrations in the solution were analyzed by the indirect method and atomic absorption spectrophotometry, respectively. Data were statistically analyzed by Student's t-test, ANOVA/Tukey-Kramer, or Kruskall-Wallis/Dunn tests for individual comparisons (p˂0.05). All varnishes led to significantly higher surface and subsurface remineralization compared with the control group but did not differ from each other. The varnishes with the highest fluoride release were: PROFL and CLIN, followed by MI VAR and DUR. The varnishes with significantly higher release of calcium were: DUR, CLIN, and PROFL. In conclusion, all commercial fluoridated varnishes tested have good potential to inhibit the progression of demineralization, regardless of the ion release mechanisms.

Resumo O objetivo deste estudo in vitro foi avaliar o potencial de diferentes vernizes fluoretados em inibir a progressão de lesões de cárie incipientes. Setenta e cinco espécimes de esmalte de dentes bovinos foram preparados e selecionados com base na microdureza superficial inicial (MDS/SM). Os espécimes foram submetidos à desmineralização artificial (em solução de Buskes), sendo então a MDS (SM1) reanalisada. Foram então distribuídos aleatoriamente em cinco grupos experimentais: 1- CONTROLE (pH cycling), 2 - MI VAR (MI Varnish with RECALDENTTM - CPP-ACP), 3 - PROFL (Profluorid®), 4 - CLIN (ClinproTM White Varnish with TCP), and 5 - DUR (Duraphat®). Os vernizes foram aplicados em camada fina e os espécimes foram então submetidos à ciclagem de pH por oito dias. A MDS final (SM2) e a microdureza transversal (CSMH) foram então analisadas. As concentrações de flúor e íons cálcio em solução foram analisadas pelo método indireto e espectrofotometria de absorção atômica, respectivamente. Os dados foram analisados estatisticamente pelo teste T de Student, ANOVA/Tukey-Kramer ou testes de Kruskall-Wallis/Dunn para comparações individuais (p˂0,05). Todos os vernizes levaram a uma remineralização superficial e subsuperficial significativamente maior em comparação com o grupo controle, não diferindo significativamente entre si. Os vernizes com maior liberação de flúor foram: PROFL e CLIN, seguidos de MI VAR e DUR. Os vernizes com liberação significativamente maior de cálcio foram: DUR, CLIN e PROFL. Pôde-se concluir que todos os vernizes fluoretados comerciais testados apresentam bom potencial de inibição da progressão da desmineralização, independentemente dos mecanismos de liberação de íons.

The effects of sodium alendronate on socket healing after tooth extraction: a systematic review of animal studies

Abstract The aim of this systematic review was to answer the following question: "Does alendronate, a nitrogen-containing bisphosphonate, improve or impair alveolar socket healing after tooth extraction in animal models"? To this end, a systematic review of the literature was carried out in PubMed, Scopus, LILACS, Web of Science, as well as in the gray literature up to May 2023. Preclinical studies that evaluated alveolar healing after tooth extraction and the intake of sodium alendronate compared with placebo were included. Two investigators were responsible for screening the articles independently, extracting the data, and assessing their quality through the SYRCLE's RoB tool for randomized trials in animal studies. The study selection process, study characteristics, risk of bias in studies, impact of alendronate on bone healing, and certainty of evidence were described in text and table formats. Methodological differences among the studies were restricted to the synthesis methods. The synthesis of qualitative results followed the Synthesis Without Meta-analysis (SWiM) reporting guideline. From the 19 included studies, five were considered to have low risk, three were of unclear risk, and eleven presented a high risk of bias. The studies were considered heterogeneous regarding alendronate posology, including its dosage and route of administration. Furthermore, a variety of animal species, different age ranges, diverse teeth extracted, and exposure or not to ovariectomy contributed to the lack of parity of the selected studies. Our results indicated that alendronate monotherapy negatively affects the early phase of wound healing after tooth extraction in preclinical studies, suggesting that the bone resorption process after tooth extraction in animals treated with alendronate might impair the bone healing process of the extraction socket. In conclusion, alendronate administration restrains bone resorption, thereby delaying alveolar socket healing . Future studies should be conducted to validate these findings and to better understand the effects of alendronate therapy on oral tissues.

Acid challenge exacerbates activation of matrix metalloproteinases in permanent teeth undergoing radiotherapy

Abstract The aim of this study was to investigate the effect of acid challenge on the activation of matrix metalloproteinases (MMPs) in the Dentinoenamel junction of primary and permanent teeth submitted to radiotherapy. For this purpose, a total of 178 dental fragments obtained from molars were used, and randomly divided into 2 groups (primary and permanent teeth) / 4 experimental subgroups (irradiated and non-irradiated, demineralized and non-demineralized). The fragments were exposed to radiation, with a dose fraction of 2 Gy, for 5 consecutive days, until a total dose of 60 Gy was reached, with a total of 30 cycles, for 6 weeks. To determine the activity of MMPs on the dentinoenamel junction (DEJ), in situ zymography assays on 0.6mm dental fragments were performed. To assess whether MMP activity would be impacted by an acidic environment, the fragments were placed in a demineralizing solution (pH of 4.8). The finding was that irradiation activated MMPs in DEJ and these effects were more evident in permanent when compared with primary teeth. When the effect of an acid challenge on MMPs activity was investigated, demineralization was observed not to increase MMPs activity in non-irradiated teeth, but it did increase MMPs activity in irradiated teeth. In conclusion, an acid challenge was found to exacerbate activation of MMPs in DEJ of permanent teeth submitted to irradiation, but not in primary teeth.

Accuracy of arch expansion with two thermoplastic materials in Invisalign® patients: EX30® and SmartTrack®

ABSTRACT Objective: The purpose of this retrospective study was to compare accuracy of arch expansion using two different thermoplastic materials in Invisalign aligners: EX30® (Polyethylene Terephthalate Glycol, or PETG) and SmartTrack® (polyurethane). Methods: The study sample comprised 65 adult patients consecutively treated with Invisalign from two private practices: group 1 - treated with EX30® (358 teeth) and group 2 - treated with SmartTrack® (888 teeth). Six hundred and twenty-three measurements were assessed in three digital models throughout treatment: model 1 - initial, model 2 - predicted tooth position, and model 3 - achieved position. Sixteen reference points per arch were marked and, after best alignment, 2 points per tooth were copied from one digital model to another. Linear values of both arches were measured for canines, premolars, and first molars: on lingual gingival margins and cusp tips of every tooth. Comparisons were performed by Wilcoxon and Mann-Whitney test. Results: Both termoplastic materials presented significant differences between predicted and achieved values for all measurements, except for the lower molar cusp tip in the SmartTrack® group. There is no statistical difference in the accuracy of transverse expansion between these two materials. Overall accuracy for EX30® aligners in maxilla and mandible were found to be 37 and 38%, respectively; and Smarttrack® presented an overall accuracy of 56.62% in the maxilla and 68.72% in the mandible. Conclusions: It is not possible to affirm one material expands better than the other. Further controlled clinical studies should be conducted comparing SmartTrack® and EX30® under similar conditions.

RESUMO Objetivo: O objetivo deste estudo retrospectivo foi comparar a acurácia na expansão da arcada utilizando alinhadores Invisalign com dois tipos de material termoplástico: EX30® (Polietileno Tereftalato Glicol, ou PETG) e SmartTrack® (poliuretano). Método: A amostra desse estudo incluiu 65 pacientes adultos tratados consecutivamente em dois consultórios particulares: grupo 1 - tratado com EX30® (358 dentes), e grupo 2 - tratado com SmartTrack® (888 dentes). Foram avaliadas 623 medidas em três pares de modelos digitais, ao longo do tratamento: modelo 1 - inicial, modelo 2 - posição dentária planejada, modelo 3 - posição alcançada. Foram marcados 16 pontos de referência por arcada e, após o bestfit, 2 pontos por arcada foram copiados de um modelo digital para o outro. Medidas lineares de ambas as arcadas foram aferidas para caninos, pré-molares e primeiros molares, localizadas na margem gengival lingual e ponta de cúspide de todos os dentes. Foram realizadas comparações usando os testes Wilcoxon e Mann-Whitney. Resultados: Ambos os materiais termoplásticos apresentaram diferenças significativas entre os valores planejados e alcançados em todas as medidas, exceto na ponta de cúspide dos primeiros molares inferiores do grupo SmartTrack®. Não houve diferença estatística entre esses dois materiais quanto à acurácia da expansão transversa. Em termos gerais, a acurácia dos alinhadores EX30® na maxila e mandíbula foi de 37% e 38%, respectivamente. O grupo SmartTrack® apresentou acurácia de 56,62% e 68,72% na maxila e mandíbula, respectivamente. Conclusões: Não foi possível afirmar que um material expande melhor que o outro. Estudos clínicos controlados futuros devem ser conduzidos comparando SmartTrack® e EX30® sob condições similares.

Accuracy of Invisalign® aligners in adult patients: a retrospective study of angular tooth movements

ABSTRACT Objective: This retrospective study aimed to assess the predictability of Invisalign® aligners regarding rotational, mesio-distal and buccal-lingual tip movements. Methods: Two materials were included in the analysis - EX30, used until 2013; and SmartTrack, in current use. The study comprised 56 adult patients treated with Invisalign Comprehensive. Data sample were assessed on three sets of digital models; model 1 - initial, model 2 - predicted, and model 3 - achieved. Sixty reference points were marked in each dental arch, and two reference planes assisted the superimposition. The degree of rotation, mesio-distal and buccal-lingual tip was obtained via trigonometric calculations, through a previously published validated method. The accuracy of outcomes was compared according to the types of tooth movement and teeth groups,and the influence of predetermined variables on movement accuracy was also investigated. Results: Rotation and mesio-distal tip did not present any significant difference when comparing EX30 and SmartTrack groups. Only buccal-lingual tip presented a significant difference, incisor and canine groups treated with EX30 aligners presented an increase in accuracy (p= 0.007 and p = 0.007, respectively). For each additional degree planned for rotation movements, there was an increase of 0.35° in the discrepancy, and an increase of 0.40° and 0.41° for mesio-distal and buccal-lingual tip, respectively. EX30 and SmartTrack discrepancies were compared by multilevel linear regression. Conclusion: EX30 aligners reached higher accuracy for buccal-lingual tip in anterior teeth. However, for rotation and mesio-distal tip, SmartTrack and EX30 are similarly accurate. The total amount of planned movement has a significant impact on accuracy rates, with a decrease in accuracy for every additional degree.

RESUMO Objetivo: Esse estudo retrospectivo teve como objetivo aferir a previsibilidade dos alinhadores Invisalign em relação aos movimentos de rotação e inclinações mesiodistal e vestibulolingual. Material e Métodos: Foram incluídos dois materiais nessa análise: EX30®, utilizado até 2013; e SmartTrack®, atualmente em uso. Esse estudo avaliou 56 pacientes tratados com Invisalign Comprehensive. Os dados foram avaliados em três pares de modelos digitais; modelo 1 - inicial, modelo 2 - planejado, e modelo 3 - alcançado. Foram marcados 60 pontos de referência em cada arcada, sendo a sobreposição realizada com auxílio de planos de referência. O grau de rotação e inclinações mesiodistal e vestibulolingual foi obtido por cálculos de trigonometria, usando um método validado publicado anteriormente. Os resultados foram comparados de acordo com os tipos de movimento dentário e grupos de dentes, também foi investigada a influência de variáveis predeterminadas na confiabilidade dos movimentos. Resultados: Os movimentos de rotação e inclinação mesiodistal não apresentaram diferença estatística, quando comparados os grupos EX30® e SmartTrack®. Somente a inclinação vestibulolingual apresentou diferença estatisticamente significativa, sendo que os grupos de incisivos e caninos tratados com alinhadores EX30® apresentaram um aumento na previsibilidade(p= 0,007 e p= 0,007, respectivamente). Para cada grau adicional planejado para movimento de rotação, ocorreu um aumento de 0,35° na discrepância, e aumentos de 0,40° e 0,41° para as inclinações mesiodistal e vestibulolingual, respectivamente. As discrepâncias entre EX30® e SmartTrack® foram comparadas por regressão linear multinível. Conclusão: Os alinhadores EX30® alcançaram maior previsibilidade para a inclinação vestibulolingual em dentes anteriores. No entanto, para rotação e inclinação mesiodistal, SmartTrack® e EX30® apresentaram previsibilidade similar. A quantidade total de movimento planejado apresenta influência significativa nas taxas de previsibilidade, com diminuição na acurácia para cada grau adicional.

Biomechanical impact of labiolingual diameter on endodontically treated anterior teeth with crown restoration under occlusal loading

Abstract Objective To evaluate the effect of the labiolingual diameter and construction of an endodontically treated (ET) anterior tooth with crown restoration on stress distribution and biomechanical safety under occlusal loading. Methodology Three-dimensional finite element models were generated for maxillary central incisors with all-ceramic crown restorations. The labiolingual diameters of the tooth, defined as the horizontal distance between the protrusion of the labial and lingual surfaces, were changed as follows: (D1) 6.85 mm, (D2) 6.35 mm, and (D3) 5.85 mm. The model was constructed as follows: (S0) vital pulp tooth; (S1) ET tooth; (S2) ET tooth with a 2 mm ferrule, restored with a fiber post and composite resin core; (S3) ET tooth without a ferrule, restored with a fiber post and composite resin core. A total of 12 models were developed. In total, two force loads (100 N) were applied to the crown's incisal edge and palatal surface at a 45° oblique angle to the longitudinal axis of the teeth. The Von Mises stress distribution and maximum stress of the models were analyzed. Results Regardless of the loading location, stress concentration and maximum stress (34.07~66.78MPa) in all models occurred in the labial cervical 1/3 of each root. Both labiolingual diameter and construction influenced the maximum stress of the residual tooth tissue, with the impact of the labiolingual diameter being greater. A reduction in labiolingual diameter led to increased maximum stress throughout the tooth. The ferrule reduced the maximum stress of the core of S2 models (7.15~10.69 MPa), which is lower compared with that of S3 models (19.45~43.67 MPa). Conclusion The labiolingual diameter exerts a greater impact on the biomechanical characteristics of ET anterior teeth with crown restoration, surpassing the influence of the construction. The ferrule can reduce the maximum stress of the core and maintain the uniformity of stress distribution.

Performance of obturation techniques in anatomical irregularities located at different thirds of the root canal system

Abstract This study aimed to compare the quality of root canal obturation (ratio of area occupied by gutta-percha (G), sealer (S), and presence of voids (V)) in different anatomical irregularities (intercanal communications, lateral irregularities, and accessory canals) located at different thirds of the root canal system of mandibular molar replicas. Sixty-seven 3D printed replicas of an accessed mandibular molar were prepared using ProGlider and ProTaper Gold rotatory systems. Three specimens were randomly selected to be used as controls and did not receive further treatment. The rest were randomly distributed in 4 experimental groups to be obturated using either cold lateral compaction (LC), continuous wave of condensation (CW), and core-carrier obturation (ThermafilPlus (TH) or GuttaCore (GC)) (n=16 per group). AHPlus® sealer was used in all groups. The three controls and a specimen from each experimental group were scanned using micro-computed tomography. The rest of the replicas were sectioned at the sites of anatomical irregularities and examined at 30× magnification. The G, S, and V ratios were calculated dividing the area occupied with each element by the total root canal area and then compared among groups using the Kruskal-Wallis test. Voids were present in all obturation techniques with ratios from 0.01 to 0.15. CW obtained a significantly higher G ratio in the irregularity located in the coronal third (0.882) than LC (0.681), TH (0.773), and GC (0.801) (p<0.05). TH and GC achieved significantly higher G ratios in those located in the apical third (p<0.05). The worst quality of obturation was observed in the loop accessory canal with all obturation techniques. Whitin the limitations of this study, it can be concluded that CW and core-carrier obturation are respectively the most effective techniques for obturating anatomical irregularities located in the coronal and the apical third.