Células tronco e endodontia regenerativa / Stem cells and regenerative endodontics

Desde o incremento das pesquisas das células-tronco em 1961, por cientistas canadenses, os avanços em estudos, pesquisas e o desenvolvimento de novos tratamentos com esse tipo de recurso se mostram promissores. O uso de células-tronco é uma grande aposta tanto para a medicina quanto para a odontologia regenerativa. Os tratamentos com essa terapia podem oferecer mais qualidade de vida para as pessoas. O potencial dessas células tão especiais se encontra em duas características peculiares: elas são capazes de se multiplicarem e de se diferenciarem em outros tipos de células, como de tecidos, cartilagens e neurônios. É dessa maneira que elas têm um papel fundamental para estudos e tratamentos relacionados à regeneração. O uso de células-tronco na Odontologia torna possível diferentes processos odontológicos que oferecem mais qualidade de vida ao paciente. Isso porque fatores como defeitos genéticos, hábitos nocivos, cáries dentárias e perdas precoces dos dentes contribuem com a perda de dentes ao longo da vida. No início do século XXI, por volta dos anos de 2005, 2006, pesquisadores começaram a publicar em revistas internacionais da área uma nova técnica baseada no uso de célulastronco existentes no osso de sustentação dos dentes e na articulação dento alveolar. Esta técnica, chamada de Revascularização, promove o aparecimento de um novo tecido pulpar sadio, devolvendo ao dente sua vitalidade e higidez(AU)

Since the increase in stem cell research in 1961 by Canadian scientists, advances in studies, research and the development of new treatments with this type of resource have shown promise. The use of stem cells is a big bet for both medicine and regenerative dentistry. Treatments with this therapy can offer more quality of life for people. The potential of these very special cells lies in two peculiar characteristics: they are able to multiply and differentiate into other types of cells, such as tissues, cartilage and neurons. It is in this way that they play a key role for studies and treatments related to regeneration. The use of stem cells in dentistry makes possible different dental processes that offer more quality of life to the patient. That's because factors such as genetic defects, harmful habits, tooth decay, and early tooth loss all contribute to lifelong tooth loss. At the beginning of the twenty-first century, around the years 2005, 2006, researchers began to publish in international journals of the area a new technique based on the use of existing stem cells in the supporting bone of the teeth and in the alveolar tooth joint. This technique, called Revascularization, promotes the appearance of a new healthy pulp tissue, returning to the tooth its vitality and hygiene(AU)

Dental age estimation by assessing the pulp volume of five teeth in a peruvian population using cone beam computed tomography images / Estimación de la edad dental evaluando el volumen pulpar de cinco dientes utilizando imágenes de tomografías computarizadas de haz cónico en una población peruana

Abstract Dental age estimation is very important for individual identification in criminal and civil forensic investigations. One of the methods for age estimation is studying age related changes in pulp volume of teeth. The objective of the current study was to estimate dental age from the pulp volume of five different categories of teeth of a Peruvian sample using cone beam computed tomography (CBCT). Retrospective CBCT records of 231 patients (females (134), males (97), age: 12-60 years) were included in the study, categorized into five different age groups (12-19, 20-29, 30-39, 40-49, 50-59, 60 years and older). Dental pulp volume of five categories of teeth(upper canines, left upper central incisors, left upper first molars, lower left first premolars, first molars) were analyzed using Romexis® 5.3.3.5 software for each patient. There was a reduction in the pulp volume of upper right and left canine with age. The Pulp volume was lowest in people aged 60 years and over. Linear regression analysis of the pulp volume and chronological age showed a coefficient of determination of 30%, suggesting a weak correlation. A weak correlation between dental pulp and age is derived. But, a robust large homogenous sample of teeth in future for different age groups may establish a reliable regression equation.

Resumen La estimación de la edad dental en personas vivas y cadáveres es muy importante para la Odontología Forense, sobre todo en casos de identificación en investigaciones legales y sociales. El objetivo del estudio fue estimación de la edad dental mediante la medición del volumen pulpar de imágenes dentales en tomografía computarizada de haz cónico (TCHC) de pacientes peruanos. Fueron analizadas 231 TCHC de pacientes entre 12 a 60 años a más. (Mujeres (134), hombres (97)) se dividieron en seis grupos de edad (12-19, 20-29, 30-39, 40-49, 50-59, 60 años a más). El análisis volumétrico de la pulpa dental se realizó en un total de 1155 dientes (caninos superiores, incisivos centrales superiores izquierdos, primeros molares superiores izquierdos y primeros premolares inferiores izquierdos), mediante el software Romexis® 5.3.3.5. El análisis de regresión lineal mostró un coeficiente de determinación del 30% que sugiere una correlación débil entre la relación del volumen pulpar de los dientes y la edad. El volumen pulpar de los caninos superiores derecho e izquierdo disminuyó a medida que aumentaba la edad y el volumen pulpar en dientes de personas de 60 años a más fue el más bajo. Sin embargo, se pueden proponer estudios futuros para incluir una gran muestra homogénea de dientes en diferentes categorías y grupos de edad para confirmar la correlación y establecer una ecuación de regresión confiable.

Continuous Wave of Condensation Improves the Filling of Curved Canals: a Micro-CT Study / La condensación de onda contínua mejora el selle de canales curvos: un estudio de micro-CT

Abstract The aim of this study was to compare the filling capacity in curved root canal using a new continuous wave of condensation technique (Termo Pack II, Easy Dental Equipments, Brazil) or lateral compaction. The percentage of voids in the filling of mesial root canals of mandibular molars was assessed by micro-computed tomography (micro-CT). Mesial root canals (n=24) of mandibular molars with a degree of curvature between 20° and 40° were prepared using rotary system (ProDesign Logic, Easy, Brazil) up to #35, .05 taper. The root canals were filled by using the continuous wave of condensation system or lateral compaction and AH Plus sealer (n=12). Scanning at 9 µm was performed after preparation and after filling by using micro-CT SkyScan 1176. The volumetric percentage of filling material and voids (total length and in each root canal third) were calculated. Data were analyzed using ANOVA/ Tukey and Student's t tests (α=0.05). Before the filling techniques, the root canals volume after preparation was similar (p>0.05). The root canals filled by the continuous wave of condensation technique presented the lowest percentage of voids, and the greatest percentage of filling material in total length and thirds (cervical, middle and apical) (p<0.05). Both techniques were not able of completely filling the root canals. The continuous wave of condensation technique Termo Pack II promoted better root canal filling in curved root canals, when compared with lateral compaction.

Resumen El objetivo de este estudio fue comparar la capacidad de obturación en conductos radiculares curvos utilizando una nueva técnica de condensación de onda continua (Termo Pack II, Easy Dental Equipments, Brasil) vs compactación lateral. El porcentaje de brechas en la obturación de los conductos radiculares mesiales de los molares mandibulares se evaluó mediante microtomografía computarizada (micro-CT). Se prepararon conductos radiculares mesiales (n=24) de molares mandibulares con un grado de curvatura entre 20° y 40° utilizando un sistema rotatorio (ProDesign Logic, Easy, Brasil) al #35, conicidad 0,05. Los conductos radiculares se obturaron utilizando un sistema de condensación de onda contínua o compactación lateral y cemento AH Plus (n=12). Se realizó un escaneo de 9 µm después de la preparación y después de la obturación usando el micro-CT SkyScan 1176. Se calculó el porcentaje volumétrico de material de obturación y vacíos (longitud total y en cada tercio del conducto radicular). Los datos se analizaron utilizando las pruebas ANOVA/Tukey y t de Student (α=0,05). Antes de las técnicas de obturación, el volumen de los conductos radiculares después de la preparación fue similar (p>0,05). Los conductos radiculares obturados con la técnica de condensación por onda contínua presentaron el menor porcentaje de vacíos y el mayor porcentaje de material de obturación en longitud total y en tercios (cervical, medio y apical) (p<0,05). Ambas técnicas no fueron capaces de llenar completamente los conductos radiculares. La técnica de condensación de onda contínua Termo Pack II promovió un mejor relleno del conducto radicular en conductos radiculares curvos en comparación con la compactación lateral.

Tratamento de perfuração iatrogênica de furca com técnica de inserção modificada do mta: relato de caso / Iatrogenic furca perforation treatment with modified mta insertion technique: case report

As perfurações endodônticas podem ocorrer patologicamente por lesão cariosa profunda, bem como durante o acesso ou na instrumentação dos canais radiculares, que em sua grande maioria estão relacionadas com a negligência ou desconhecimento das variações anatômicas internas do dente. O presente trabalho descreve um caso clínico de perfuração de furca, onde o tratamento inicial foi baseado na descontaminação e selamento da comunicação com uma técnica de inserção modificada do MTA. Após a anestesia, foi realizado o isolamento absoluto e remoção de tecido infectado presente na câmara pulpar. Feita a limpeza da perfuração utilizando soro fisiológico e modelagem do canal com o instrumento reciprocante, a obturação foi concebida com cone de guta percha e cimento biocerâmico. Em seguida, o MTA foi manipulado, de acordo com recomendações do fabricante usando água destilada na proporção 1:1 e inserido na canaleta de uma régua endodôntica com a espátula de inserção nº1. O material foi removido da canaleta e inserido na perfuração, finalizando o vedamento da mesma. Portanto, concluiu-se que o selamento da perfuração apresentou um resultado satisfatório, tanto clínico como radiográfico, destacado pela proservação de 5 meses, evidenciando discreta formação de trabeculado ósseo na região de furca(AU)

Endodontic perforations can occur pathologically due to a deep carious lesion, as well as during access or instrumentation of root canals, which are mostly related to negligence or ignorance of the internal anatomical variations of the tooth. The present work describes a clinical case of furcation perforation, where the initial treatment was based on decontamination and sealing of the communication with a modified MTA insertion technique. After anesthesia, absolute isolation and removal of infected tissue present in the pulp chamber was performed. After cleaning the perforation using saline solution and modeling the canal with the reciprocating instrument, the filling was designed with a gutta-percha cone and bioceramic cement. Then, the MTA was manipulated, according to the manufacturer's recommendations, using distilled water in a 1:1 ratio and inserted into the groove of an endodontic ruler with the #1 insertion spatula. The material was removed from the channel and inserted into the perforation, finishing its sealing. Therefore, it was concluded that the sealing of the perforation presented a satisfactory result, both clinical and radiographic, highlighted by the 5-month followup, evidencing a slight formation of bone trabeculate in the furcation region(AU)

Insights on the role of cytokines in carious lesions / Insights sobre o papel das citocinas em lesões cariosas

Objetivo: A resposta imune da dentina-polpa à patogênese da cárie ainda é pouco compreendida devido à complexa interação dos processos envolvidos. O objetivo desta revisão foi explorar o papel das citocinas e sua relevância na patogênese da cárie dental. Resultados: A cárie dentária pode resultar em uma resposta inflamatória do hospedeiro na polpa dental, caracterizada pelo acúmulo de células inflamatórias levando à liberação de citocinas inflamatórias como, Interleucina-4 (IL-4), Interleucina (IL-6), Interleucina-8 (IL-8) e fator de necrose tumoral­α(TNF-α). IL-4 parece estar correlacionada com a profundidade das lesões cariosas; IL-6 está fortemente correlacionada com a doença cárie e é considerada um potente biomarcador; IL-8 pode ser um potente biomarcador tanto para cárie quanto para outras alterações presentes na polpa e sua liberação está correlacionada com TNF-α e IL-6; TNF-α desempenha um papel importante não apenas na progressão da cárie, mas também em outros processos patológicos. Conclusao: Mediadores específicos têm um grande potencial para servir como biomarcadores quanto à presença e progressão da doença cárie, o que incita a necessidade de mais investigações nesse campo (AU).

Objectives: The dentin-pulp immune response to caries pathogenesis is still poorly understood due to the complex interplay of the involving processes. The aim of this review was to explore the role of cytokines and its relevance in the pathogenesis of dental caries. Results: Dental caries can result in a host inflammatory response in the dental pulp, characterized by the accumulation of inflammatory cells leading to the release of inflammatory cytokines such as Interleukin-4 (IL-4), Interleukin (IL-6), Interleukin-8 (IL-8) and Tumor necrosis factor­ α (TNF- α ). IL-4 seems to be correlated to the depth of carious lesions; IL-6 is strongly correlated to caries disease and is considered a potent biomarker; IL-8 can be a potent biomarker for both caries and other changes present in the pulp and, its release is correlated to TNF- α and IL-6; TNF-α plays an important role not only in caries progression, but also in other pathological processes. Conclusion: Specific mediators have a great potential to serve as biomarkers alluding to the presence and progress of caries disease, urging further investigations in the field (AU)

Combined micro-apical surgery and vital pulp therapy in mandibular second molars with external root resorption caused by impacted teeth / 华西口腔医学杂志

OBJECTIVES@#This study aimed to establish a new treatment of the mandibular second molars with external root resorption caused by impacted teeth to preserve the affected teeth and their vital pulps.@*METHODS@#For mandibular second molars clinically diagnosed as external root resorption caused by impacted teeth, debridement and removal of the root at the resorption site via micro-apical surgery and direct capping of the pulp with bioactive material on the surface of the root amputation via vital pulp therapy were performed immediately after the impacted teeth were extracted.@*RESULTS@#The external root resorption of the affected tooth was ceased. It was asymptomatic with intact crown, normal pulp, periapical alveolar bone reconstruction, normal periodontal ligament, continuous bone sclerosis, and no periapical translucency in radiographic examination at the 1-year postoperative follow-up, thus showing good prognosis.@*CONCLUSIONS@#Simultaneous combination of micro-apical surgery and vital pulp therapy after extraction of impacted teeth could successfully preserve mandibular second molars with ERR caused by impacted teeth and their vital pulps.

Wnt pathway inhibitors are upregulated in XLH dental pulp cells in response to odontogenic differentiation / 国际口腔科学杂志·英文版

X-linked hypophosphatemia (XLH) represents the most common form of familial hypophosphatemia. Although significant advances have been made in the treatment of bone pathology, patients undergoing therapy continue to experience significantly decreased oral health-related quality of life. The following study addresses this persistent oral disease by further investigating the effect of DMP1 expression on the differentiation of XLH dental pulp cells. Dental pulp cells were isolated from the third molars of XLH and healthy controls and stable transduction of full-length human DMP1 were achieved. RNA sequencing was performed to evaluate the genetic changes following the induction of odontogenic differentiation. RNAseq data shows the upregulation of inhibitors of the canonical Wnt pathway in XLH cells, while constitutive expression of full-length DMP1 in XLH cells reversed this effect during odontogenic differentiation. These results imply that inhibition of the canonical Wnt pathway may contribute to the pathophysiology of XLH and suggest a new therapeutic strategy for the management of oral disease.

Prognóstico pulpar após lesões por luxação em dentes permanentes: uma análise de riscos competitivos / A retrospective cohort study of pulp prognosis in luxated permanent teeth: a competing risk analysis

As lesões por luxação representam o grupo de lesões traumáticas dento-alveolares (LTDA) caracterizadas pelo dano simultâneo ao feixe vásculo-nervoso periapical e estruturas de sustentação dentária, em diferentes graus de complexidade, dependendo da força e direção do impacto. A patogenia das alterações pulpares decorrentes das luxações é resultado da extensão da lesão do feixe vásculo-nervoso apical e de sua capacidade de reparo, que determinam os seguintes desfechos para a polpa: manutenção da vitalidade pulpar, manutenção da vitalidade pulpar com obliteração da cavidade pulpar (OCP) ou a necrose pulpar. Entretanto, o processo de reparo pulpar pode envolver fenômenos intermediários cujos sinais e sintomas se modificam ao longo do período de acompanhamento até um diagnóstico definitivo. Sendo assim, do ponto de vista clinico, o tempo até a observação destas respostas, bem como seus fatores determinantes, representa uma informação tão importante quanto o próprio desfecho, pois tem influência direta na tomada de decisão sobre as condutas clinicas mais adequadas. A presente pesquisa consistiu num estudo clínico longitudinal retrospectivo com o objetivo de avaliar o prognóstico pulpar de dentes permanentes portadores de lesões por luxação, seu padrão cronológico e fatores determinantes, entre os pacientes atendidos na Clínica de Traumatismos Dentários da Faculdade de Odontologia da Universidade Federal de Minas Gerais no período de 2014 a 2022. Foram analisados prontuários de 224 pacientes com 427 dentes permanentes portadores de luxações, acompanhados por um período mediano de 1,4 anos (variação de 11 dias a 6,9 anos). O padrão de resposta pulpar foi classificado como manutenção da vitalidade pulpar, OCP e necrose pulpar através da avaliação clínica e radiográfica. Uma análise de sobrevivência utilizando-se o modelo de riscos competitivos foi realizada e curvas de função de incidência acumulada (FIA) foram construídas para se avaliar as taxas de cada um dos desfechos pulpares utilizando-se o estimador de Aalen-Johansen. O efeito de variáveis independentes, incluindo sexo, idade do paciente no momento do trauma, estágio de desenvolvimento radicular, grupo dentário, tipo de luxação, presença de fratura coronária concomitante e prescrição de antibioticoterapia sistêmica (ATS), foi avaliado utilizando-se um modelo multivariado de Cox causa-específico. Os dados foram analisados no programa estatístico R (versão 4.0.4, Viena, Áustria, 2021). Os resultados demonstraram manutenção da vitalidade pulpar em 38,2% da amostra (163 dentes), necrose pulpar em 28,1% (120 dentes) e OCP em 12,9% da amostra (55 dentes). O tempo mediano para o diagnóstico de necrose pulpar foi de 3 meses, enquanto o tempo para vitalidade pulpar foi de 8 meses e para OCP foi de 16 meses A probabilidade de manutenção de vitalidade pulpar diminuiu significativamente com a ocorrência de fraturas coronárias de esmalte e dentina concomitantes (HR 0,38 IC 95% [0,2 ­ 0,8] p = 0,006). A taxa de necrose pulpar foi significativamente menor em dentes com forame apical amplo (HR 0,62 IC 95% [0,4 ­ 0,96] p = 0,03) mas aumentou significativamente em dentes com luxações associadas às fraturas coronárias (HR 4,0 IC 95% [2,6 - 6,1] p = 0,001) e em dentes portadores de luxações intrusivas (HR 2,3 IC 95% [1,2 - 4,1] p = 0,007). Dentes portadores de luxações laterais ou extrusivas (HR 3,0 IC 95% [1,3 ­ 6,9] p = 0,001) ou com forame amplo (HR 2,4 IC 95% [1,2 ­ 4,7] p=0.01) apresentaram as maiores taxas de OCP.

Luxation injuries are a group of traumatic dental injuries (TDI) that involve damage to both the pulp and periodontium, with different degrees of complexity. Pulp damage results from injury to the apical neuro-vascular bundle and, depending on the repair potential, may result in the following outcomes: maintenance of pulp vitality, maintenance of pulp vitality with pulp canal obliteration (PCO) or pulp necrosis. However, the pulp healing process may involve intermediate and reversible phenomena whose signs and symptoms mimic pulp necrosis, rendering the timing of these events critical for decision-making during the follow-up period. The present study consisted in a retrospective cohort to evaluate the pulpal prognosis of luxated permanent teeth, its chronological pattern and predictive factors, among patients treated at the Dental Trauma Clinic of the Federal University of Minas Gerais, from 2014 to 2021. Records of 224 patients with 427 permanent teeth with luxations, followed up for a median period of 1.4 years (ranging from 11 days to 6.9 years) were analysed. Pulp outcomes - maintenance of pulp vitality, PCO and pulp necrosis were defined trough clinical and radiographic evaluation. A competing risk survival analysis was performed and cumulative incidence function (CIF) curves were build using the Aalen-Johansen estimator to assess the rates of each of the pulp outcomes during the follow-up period. The effect of independent variables including patient's gender and age at the time of trauma, tooth group and stage of root development, type of luxation, concomitant injuries, systemic antibiotic therapy (SAT) prescription, was evaluated using a cause-specific Cox regression model. Data were analysed in the R statistical program (version 4.0.4, Vienna, Austria, 2021). The results showed maintenance of pulp vitality in 38.2% of the sample (163 teeth), pulp necrosis in 28.1% (120 teeth) and OCP in 12.9% of the sample (55 teeth). The median time for the diagnosis of pulp necrosis was 3 months, while the time for pulp vitality was 8 months and for PCO was 16 months. The hazards of pulp vitality significantly decreased with the occurrence of concomitant coronal fractures (HR 0 .38 95% CI [0.2 ­ 0.8] p = 0.006). The hazards of pulp necrosis was significantly lower in teeth with a wide apical foramen (HR 0.62 95% CI [0.4 ­ 0.96] p = 0.03) but increased significantly in teeth with luxations associated with crown fractures (HR 4.0 CI 95% [2.6 - 6.1] p = 0.001) and in teeth with intrusive displacement (HR 2.3 CI 95% [1.2 - 4.1] p = 0.007). Teeth with lateral or extrusive luxations (HR 3.0 CI 95% [1.3 ­ 6.9] p = 0.001) or with a wide foramen (HR 2.4 CI 95% [1.2 ­ 4.7] p =0.01) showed the highest rates of PCO.

Accelerating Wound Healing of Traumatic Ulcer with Topical Application of Dental Pulp Mesenchymal Stem Cell Secretome and Robusta Green Coffee Bean Extract Combination in vivo

ABSTRACT Objective: To investigate the ability of a combination dental pulp mesenchymal stem cell secretome (DPMSCS), robusta green coffee bean extract (RGCBE), and Carboxymethylcellulose-Natrium (CMC-Na) in a Wistar rats model of traumatic ulcers. Material and Methods: Twenty-eight young, male, healthy Wistar rats (Rattus norvegicus) were divided into seven groups randomly: Group K0, group K1-3 (traumatic ulcer rats that received CMC-Na gel for three days), group K1-7 (traumatic ulcer rats that received CMC-Na gel for seven days), group K2-3 (traumatic ulcer rats that received RGCBE for three days), group K2-7 (traumatic ulcer rats that received RGCBE for seven days), group K3-3 (traumatic ulcer rats that received DPMSCS for three days), and group K3-7 (traumatic ulcer rats that received DPMSCS for seven days). An ulcer was made with an amalgam stopper on the right buccal mucosa of the rats. DPMSCS 50% gel was applied to the ulcer on the left buccal mucosa. The ulcer diameter was measured on day 3 and day 7. Results: There was a significant difference in the diameter of the ulcer, the number of neutrophils, and fibroblasts in the treatment group compared to the control group on day 7. Conclusion: A combination of DPMSCS and RGCBE 50% accelerates traumatic ulcer wound healing by lowering ulcer diameter, decreasing neutrophil counts, and increasing fibroblast proliferation in vivo.

A 12-month Follow-Up Study of Pulp Oxygen Saturation in Deciduous Molars After Selective and Nonselective Carious-Tissue Removal: A Randomized Pilot Trial

ABSTRACT Objective: To compare the pulp vitality of deciduous molars before and after selective caries removal (SCR) or nonselective caries removal to hard dentin (NSCR) over one year, using oxygen saturation percentage (%SaO2). Material and Methods: Deciduous molars with deep occlusal/proximal-occlusal caries lesions were randomized to SCR (n=22) or NSCR groups (n=22). After the caries removal, the teeth were protected with calcium hydroxide cement and restored with composite resin (Filtek Z250). The pulp condition diagnosis was evaluated at baseline, immediately after caries removal, and follow-up (7 days, 1-, 6- and 12-months) by %SaO2. Pulp exposure and pulp necrosis were primary outcomes, and %SaO2 was secondary. Results: Intraoperative pulp exposure occurred in four teeth of the NSCR group (18.2%) and one tooth of the SCR group (4.5%) (p>0.05). Two cases of pulp necrosis occurred in the NSCR group (10%). No difference in %SaO2 pulp was observed in the inter-and intragroup comparison over time (p>0.05). Conclusion: Advantageously, the %SaO2 minimizes preoperatory pulp vitality diagnosis subjectivity before SCR/ NSCR treatments. Furthermore, the pilot study results suggest the pulp response of deciduous molars, when evaluated by clinical, radiographic, and pulp %SaO2 seems not to differ between teeth treated with SCR or NSCR.

Aspectos clínicos y forenses del color rosa de los dientes: reporte de un caso / Clinical and forensic aspects of the pink color of teeth: report of a case

La coloración rosa de los dientes puede originarse por diferentes factores. En el ámbito forense se ha descrito al fenómeno denominado post mortem pink teeth como un signo asociado a muertes violentas de etiología diversa. En la práctica clínica también es posible observar pacientes con dientes rosados, fre-cuentemente ocasionados por traumatismos o iatro-genia proveniente de ortodoncia, cuyo mecanismo de producción obedece a distintas etiopatogenias, destacándose las reabsorciones dentinarias inter-nas, cemento-dentinarias externas y calcificaciones dentinarias. El presente artículo expone el caso de un individuo adulto con antecedente de trauma óseo-dentario por accidente vial que, luego de un prolon-gado tiempo, asiste al Servicio de Urgencias Odon-tológicas y Orientación de Pacientes de la Facultad de Odontología de la Universidad de Buenos Aires, en donde se le detecta, a modo de hallazgo exploratorio, una ostensible coloración rosada en el canino infe-rior derecho. La situación motivó un pormenorizado abordaje clínico y radiográfico, indagando respecto a los probables factores que intervinieron en su ge-neración y desarrollo (AU)

The pink coloration of the teeth can be caused by dif-ferent factors. In the forensic field, the phenomenon called post mortem pink teeth has been described as a sign associated with violent deaths of various etiology. In clinical practice, it is also possible to ob-serve patients with pink teeth, frequently caused by trauma or iatrogenesis from orthodontics, whose production mechanism is due to different etiopatho-genesis, highlighting internal dentin resorption, ex-ternal cemento-dentinal resorption and dentin calci-fications. This article presents the case of an adult individual with a history of bone-dental trauma due to a road accident who, after a long time, attends the Dental Emergency and Patient Guidance Service of the Faculty of Dentistry of the University of Bue-nos Aires, where an ostensible pink coloration was detected in the lower right canine as an exploratory finding. The situation motivated a detailed clinical and radiographic approach, inquiring about the probable factors that intervened in its generation and development (AU)

Revascularização pulpar, uma nova opção na terapêutica endodôntica: revisão da literatura e caso clínico em paciente adulto / Pulpar revascularization, a new option in endodontc therapy: literature review and case report in adult patient

Introdução: A revascularização pulpar é uma terapêutica que visa regenerar parte do complexo dentino pulpar, proporcionando a continuidade do desenvolvimento radicular, sanando a fragilidade e propensão a fratura que a apicificação apresentava. É um tratamento direcionado a dentes diagnosticados com rizogênese incompleta. Entretanto, a possibilidade de realização da técnica em dentes maduros tem sido alvo de pesquisas e estudo. Objetivo: O objetivo deste estudo, é apresentar através da revisão de literatura e caso clínico, os benefícios dos procedimentos endodônticos regenerativos (REPs), em dentes jovens e maduros, em relação à apicificação. Metodologia: O estudo é uma revisão de literatura, desenvolvida através de pesquisa exploratória e realizada uma abordagem qualitativa. Para a coleta de dados, foi aplicada a técnica de análise documental e revisão bibliográfica consultando PUBMED, Scielo, Google Acadêmico e monografias acadêmicas. O caso clínico foi realizado de acordo com o protocolo atualizado pela AAE em 2016. Discussão: A revascularização pulpar tem mostrado ser um tratamento promissor na endodontia, é preconizada a desinfecção e medicação intracanal, já que não pode haver instrumentação mecânica. Os agentes irrigadores devem ser bactericidas, bacteriostáticos e devem ter baixo teor de toxicidade, já a medicação intracanal deve ter papel inibidor em bactérias gram positivas e gram negativas. Conclusão: A apicificação mesmo com o uso de MTA, que não exige trocas excessivas de medicações, não sana as necessidades que um dente com rizogênese incompleta requer. Sendo assim, a revascularização foi eleita o tratamento de melhor prognóstico para dentes jovens e necrosados. O caso clínico demonstrou qualidade moderada, no tratamento regenerativo em um dente maduro com reabsorção externa, abrindo novas perspectivas para os (REPs)(AU)

Introduction: Pulp revascularization is a therapy that aims to regenerate part of the pulp dentin complex, providing continuity of root development, remedying the fragility and propensity to fracture that apexification presented. It is a treatment aimed at teeth diagnosed with incomplete rhizogenesis. However, the possibility of performing the technique on mature teeth has been the subject of research and study. Objective: The aim of this study is to present, through literature review and clinical case, the benefits of regenerative endodontic procedures (REPs), in young and mature teeth, in relation to apexification. Methodology: The study is a literature review, developed through exploratory research and carried out a qualitative approach. For data collection, the technique of document analysis and bibliographic review was applied, consulting PUBMED, Scielo, Academic Google and academic monographs. The clinical case was performed according to the protocol updated by the SEA in 2016. Discussion: Pulp revascularization has shown to be a promising treatment in endodontics, intracanal disinfection and medication is recommended, as there can be no mechanical instrumentation. Irrigating agents must be bactericidal, bacteriostatic and must have a low level of toxicity, whereas intracanal medication must have an inhibiting role in gram positive and gram negative bacteria. Conclusion: Apexification, even with the use of MTA, which does not require excessive medication changes, does not meet the needs that a tooth with incomplete rhizogenesis requires. Therefore, revascularization was chosen as the treatment with the best prognosis for young and necrotic teeth. The clinical case demonstrated moderate quality in regenerative treatment in a mature tooth with external resorption, opening new perspectives for (REPs)(AU)

Evaluación del estatus del tejido pulpar postratamiento oncológico / Assessment of the status of the pulp tissue post oncological treatment

La OMS cataloga al cáncer como uno de los principales problemas en el ámbito mundial, los pacientes sometidos a terapia oncológica son más vulnerables a desarrollar complicaciones en los tejidos de la cavidad bucal entre las que tenemos: mucositis, infecciones, osteorradionecrosis. En el manejo endodóntico hay que tomar en consideración que los trata- mientos como yodoterapia, radioterapia y quimioterapia pueden generar efectos sobre el complejo dentinopulpar. El objetivo de este artículo es determinar el estatus del tejido pulpar postratamiento oncológico mediante la revisión sistemática en bases de datos de gran relevancia científica, como PubMed, Scielo, Medigraphic, Science direct. Se concluye que el sistema estomatognático es un receptor importante de estos efectos y secuelas en pacientes con terapia oncológica, el tejido pulpar no está libre de estas secuelas ya que genera daño celular, como la hipovascularidad, hipocelularidad e hipoxia la cual incrementa el riesgo de necrosis de la región (AU)

The WHO lists cancer as one of the main problems worldwide, patients undergoing oncological therapy are more vulnerable to developing complications in the tissues of the oral cavity among which we have: mucositis, infections, osteoradionecrosis. In endodontic management, it should be taken into consideration that treatments such as iodine therapy, radiotherapy, and chemotherapy can generate effects on the dentin-pulp complex. This article aims to determine the status of the pulp tissue after oncologic treatment. Through a systematic review in databases of great scientific relevance, such as PubMed, Scielo, Medigrafhic, Science direct. It is concluded that the stomatognathic system is an important receptor of these effects and sequelae in patients with oncological therapy, the pulp tissue is not free of these sequelae as it generates cellular damage because of the hypo vascularity, hypocellularity, and hypoxia which increases the risk of necrosis of the region (AU)

Células madre en odontología: nuevas perspectivas / Stem cells in dentistry: new perspectives

En el campo de la odontología, prevalecen actualmente alternativas terapéuticas con una filosofía conservadora. Sin embargo, con el advenimiento de los tratamientos con células madre (CM), se amplían las posibilidades terapéuticas, que buscan la combinación y el equilibrio entre la intervención tradicional y las posibilidades de reposición de estructuras anatómicas dañadas, a través de la regeneración de tejidos utilizando células madre o sus derivados (AU)

In the dentistry field, therapeutic alternatives with a conservative philosophy currently prevail. However, with the advent of stem cell (SC) treatments, therapeutic possibilities are expanding, seeking a combination and balance between traditional intervention and the pos- sibility of replacing damaged anatomical structures through tissue regeneration, using stem cells or their derivatives (AU)

Synthesis, characterization, and evaluation of nano-hydroxyapatite based experimental calcium silicate cement as a root repair material / Síntesis, caracterización y evaluación de cemento experimental de silicato de calcio a base de nanohidroxiapatita como material de reparación radicular

Introduction: This study aimed to prepare a new root repair material including Portland cement, bismuth oxide, and nano-hydroxyapatite and analyze its physicochemical properties and its effects on the proliferation and differentiation of human dental pulp stem cells (hDPSCs). Material and Methods: Bismuth oxide as a radiopaque component and nano-hydroxyapatite particles were added to white Portland cement at 20% and 5% weight ratio, respectively. Characterization of the prepared cement was done using conventional methods. To examine the bioactivity of this new material, atomic absorption spectroscopy (AAS) was used for the investigation of the rate of calcium ions dissolution in simulated body fluid media. The viability of hDPSCs was assessed by an MTT assay after 1, 3 and 7 days. The odontogenic potential of this substance was evaluated by measuring alkaline phosphatase activity and alizarin red S staining. Results: Based on the bioactivity results, the cement presented high bio-activity, corroborating sufficiently with the calcium release patterns. The cell viability was significantly increased in new root repair material containing hydroxyapatite nanoparticles after 3 and 7 days (p<0.05). Conclusion: Moreover, alkaline phosphatase activity increased over 7 days in all experimental groups. The new cement containing nano-hydroxyapatite particles could be a good root repair material.

Objetivo: Este estudio tuvo como objetivo preparar un nuevo material de reparación de raíces que incluye cemento Portland, óxido de bismuto y nano-hidroxiapatita y analizar sus propiedades fisicoquímicas y sus efectos sobre la proliferación y diferenciación de células madre de pulpa dental humana. Material y Métodos: El óxido de bismuto como compo-nente radiopaco y las partículas de nano-hidroxiapatita se agregaron al cemento Portland blanco en una proporción en peso del 20 % y el 5 %, respectivamente. La caracterización del cemento preparado se realizó utilizando métodos con-vencionales. Para examinar la bioactividad de este nuevo material, se utilizó la espectroscopia de absorción atómica para investigar la velocidad de disolución de los iones de calcio en medio fluido corporal simulado. La viabilidad de las células madre de pulpa dental humana se evaluó mediante un ensayo MTT después de 1, 3 y 7 días. El potencial odontogénico de esta sustancia se evaluó midiendo la actividad de la fosfatasa alcalina y la tinción con rojo de alizarina S.Resultados: Con base en los resultados de bioactividad, el cemento presentó alta bioactividad, corroborando suficientemente con los patrones de liberación de calcio. La viabilidad celular aumentó significativamente en el nuevo material de reparación de raíces que contenía nanopartículas de hidroxiapatita después de 3 y 7 días (p<0,05). Conclusión: Además, la actividad de la fosfatasa alcalina aumentó durante 7 días en todos los grupos experimentales. El nuevo cemento que contiene partículas de nanohidroxiapatita podría ser un buen material de reparación radicular.

Comparative evaluation of dental pulp tests in pulpal status diagnostics / Evaluación comparativa de pruebas de pulpa dental en el diagnóstico del estado pulpar

Introduction: The purpose of this study was to evaluate the effectiveness and compare the accuracy of pulp tests in the diagnosis of teeth pulpal health. Material and Methods: Traumatized (n=71) and non-traumatized (n=71) teeth from 42 patients were evaluated. Each tooth underwent cold, heat, electric and oximetry tests, followed by radiographic examination and calculation of the sensitivity, specificity, PPV, NPV and accuracy. Results: Clinical and radiographic examination showed no alteration for the 71 teeth from the intact contralateral group. From the traumatized group, 29 teeth presented complete endodontic treatment, 17 presented periapical alterations that required endodontic treatment and 25 teeth did not present conclusive radiographic alteration. The cold test showed a significantly higher proportion of correct results, while the electric test showed a significantly lower proportion. The data showed higher accuracy for the cold, followed by oximeter and heat tests, while the electric test presented the lowest accuracy. Cold and oximeter tests proved superior over the electric and heat tests, while the electric test showed better parameters when diagnosing diseased pulp. Conclusion: Combining two pulp tests seems reasonable for improving the pulp diagnoses using both oximeter and cold or oximeter and heat tests to detect healthy pulp; or cold and electric tests to define diseased pulp.

Introducción: El propósito de este estudio fue evaluar la efectividad y comparar la precisión de las pruebas pulpares en el diagnóstico de la salud pulpar de los dientes. Material y Métodos: Se evaluaron dientes traumatizados (n=71) y no traumatizados (n=71) de 42 pacientes. Cada diente se sometió a pruebas de frío, calor, eléctricas y de oximetría, seguidas de examen radiográfico y cálculo de la sensibilidad, especificidad, VPP, VPN y precisión. Resultados: El examen clínico y radiográfico no mostró alteración en los 71 dientes del grupo contralateral intacto. Del grupo traumatizado, 29 dientes presentaron tratamiento endodóntico completo, 17 presentaron alteraciones peri-apicales que requirieron tratamiento endodóntico y 25 dientes no presentaron alteración radiográfica concluyente. La prueba en frío mostró una proporción significativamente mayor de resultados correctos, mientras que la prueba eléctrica mostró una proporción significativamente menor. Los datos mostraron mayor precisión para la prueba de frío, seguida de las pruebas de oxímetro y calor, mientras que la prueba eléctrica presentó la menor precisión. Las pruebas de frío y oxímetro demostraron ser superiores a las pruebas eléctricas y de calor, mientras que la prueba eléctrica mostró mejores parámetros al momento de diagnosticar pulpa enferma. Conclusión: La combinación de dos pruebas pulpares parece razonable para mejorar los diagnósticos pulpares utilizando tanto el oxímetro como las pruebas de frío u oxímetro y calor para detectar una pulpa sana; o pruebas de frío y eléctricas para definir pulpa enferma.

Frecuencia de tratamientos pulpares en una población pediátrica peruana: un estudio retrospectivo en un centro dental especializado de 2015 a 2019 / Frequency of Pulp Treatments in a Peruvian Pediatric Population: a Retrospective Study in a Specialized Dental Center from 2015 to 2019

Resumen Los tratamientos pulpares constituyen uno de los tipos de procedimientos más realizados en pacientes pediátricos, cuyo objetivo primordial es devolver la función masticatoria, estética y fonética. El objetivo del presente estudio fue determinar la frecuencia de los tratamientos pulpares realizados en pacientes de 3 a 11 años de edad atendidos en el Servicio de Odontopediatría del Centro Dental Docente Cayetano Heredia desde enero de 2015 hasta diciembre de 2019. Se realizó la búsqueda de las historias clínicas de pacientes atendidos en el Servicio de Odontopediatría que hayan contado con los criterios de inclusión y exclusión. Se recogieron datos sobre edad, sexo, tipo de dentición y pieza dentaria, para la elaboración de una base de datos, y posteriormente tablas de contenido. De una muestra de 514 historias clínicas virtuales, con 1166 tratamientos pulpares realizados, el tratamiento pulpar indirecto fue el más realizado para ambos sexos, 41.17% (n=247) para el sexo femenino y 34.98% (n=198) para el sexo masculino. Según rango de edad, 3 a 5 años de edad son los pacientes que más tratamiento pulpar indirecto se realizaron con 39.06% (n=359). La mayoría de pacientes que presentaban dentición decidua se les realizaron el tratamiento de tratamiento pulpar indirecto con 39.32% (n=326). Siendo la pieza dental mayormente tratada con tratamiento pulpar indirecto la 84 con 41.18 % (n=70). El tratamiento pulpar que más se realizó dentro de nuestro estudio fue el tratamiento pulpar indirecto seguido de la pulpectomía y pulpotomía. El sexo femenino, grupo etario de 3 a 5 años y dentición decidua fueron los que más recibieron tratamientos pulpares. Los dientes con mayor frecuencia de tratamientos pulpares fueron la segunda molar inferior izquierda y la primera molar inferior derecha, y las que de menor frecuencia fueron las caninos inferiores derecho e izquierdo.

Abstract Pulp treatments are one of the types of procedures most performed in pediatric patients, whose primary objective is to restore the masticatory, aesthetic and phonetic function. The objective of this study was to determine the frequency of pulp treatments performed in patients from 3 to 11 years of age treated at the Pediatric Dentistry Service of the Centro Dental Docente Cayetano Heredia from January 2015 to December 2019. The search for the medical records of patients treated at the Pediatric Dentistry Service who have met the inclusion and exclusion criteria. Data were collected on age, sex, type of dentition and tooth, for the elaboration of a database, and later tables of contents. Of a sample of 514 virtual medical records, with 1166 pulp treatments performed, indirect pulp treatment was the most performed for both sexes, 41.17% (n=247) for females and 34.98% (n=198) for males. According to age range, 3 to 5 years of age are the patients who received more indirect pulp treatment with 39.06% (n=359). The majority of patients with deciduous dentition underwent indirect pulp treatment with 39.32% (n=326). Being the tooth most treated with indirect pulp treatment 84 with 41.18% (n=70). The pulp treatment that was most performed in our study was indirect pulp treatment followed by pulpectomy and pulpotomy. The female sex, age group 3 to 5 years and deciduous dentition were the ones that received the most pulp treatments. The teeth with the highest frequency of pulp treatments were the second lower left molar and the first lower right molar, and those with the least frequency were the lower right and left canines.

Uso de dientes bovinos como elección para trabajos de investigación en odontología / The use of bovine teeth as a choice for dental investigation papers

Los dientes animales de las diferentes especies (hu- mano, equino, cerdo, etc.) están constituidos histológi- camente por cuatro tejidos fundamentales. Ellos son: esmalte, dentina, cemento y pulpa dental. Su compo- sición, estructura, morfología y tamaño son disímiles para cada género. Según numerosas investigaciones, los dientes de bovino serían los de elección por ser de fácil obtención y por tener muy pocas, o ninguna, diferencias tanto a nivel macro como microscópico con respecto a los dientes humanos. El objetivo de la presente revisión es aportar información actualizada acerca de las características histológicas de los tejidos dentarios bovinos y profundizar el conocimiento de las similitudes y diferencias de los dientes bovinos y humanos dando soporte a otros estudios compa- rativos y promoviendo la utilización de las piezas dentarias bovinas en trabajos de investigación en odontología (AU)

The animal teeth of the different species (human, equine, pig, etc.) are histologically constituted by four fundamental tissues: enamel, dentin, cement and dental pulp. Their composition, structure, morphology and size are dissimilar for each gender. According to numerous investigations, bovine teeth would be the ones of choice because they are easy to obtain and have very few or no differences, both at the macro and microscopic levels, with respect to human teeth. The objective of this review is to provide updated information about the histological characteristics of bovine dental tissues and deepen the knowledge of the similarities and differences between bovine and human teeth, supporting other comparative studies and promoting the use of bovine dental pieces in research work in dentistry (AU)

Lineamientos para el uso de terapias pulpares en dientes primarios con pulpas no-vitales / Diretriz sobre o uso de terapia pulpar devitalizada para dentes decíduos / Guidelines for the use of pulp therapy in primary teeth with non-vital pulps

Objetivo: Presentar lineamientos basados en evidencia para el tratamiento de pulpas no vitales debidas a caries profundas o traumatismos en dientes primarios. Métodos: el Grupo de Trabajo de la Academia Americana de Odontología Pediátrica AAPD realizó una revisión sistemática/meta-análisis de estudios acerca de terapia para pulpa no vital en dientes primarios, producto de caries o trauma, usando el enfoque GRADE para determinar el nivel de certeza de la evidencia para recomendaciones clínicas. Resultados: La determinación de GRADE fue de elevada a muy baja. Al comparar dientes con o sin resorción radicular, el éxito de la pulpectomía fue mayor (p<0,001) en los que no presentaban resorción radicular antes del tratamiento. El éxito de las pulpototmías obturadas con ZO/yodoformo/HC EndoflasTM(Laboratorios Sanlor, Cali, Colombia) y ZOE (óxido de zinc con eugenol) no fue diferente al yodoformo(yodoformo + hidróxido de calcio, VitapexTM o MetapexTM) después de 18 meses (p= 0,55); sin embargo el éxito de ZO/iodoformo/HC y ZOE fue cercano al 90% mientras que el del yodoformo fue 71% o menor. El análisis de red demostró que ZO/iodoformo/HC y ZOE son mejores que yodoformo. ELRP fue mejor que pulpectomía (p<0,001) en dientes con resorción radicular previa al tratamiento, pero la pulpectomía fue superior si las raíces estaban íntegras (p= 0,09). La instrumentación de los conductos radiculares fue significativamente más rápida (p<0,001) que la instrumentación manual, pero la calidad de la obturación no presentó diferencia (p= 0,09) y ambas técnicas presentaron éxito similar. El análisis de red clasificó al ZO/iodoformo/HC como mejor, ZOE en segundo lugar, y yodoformo en último lugar a los 18 meses. La tasa de éxito no fue impactada por el método de obturación, método de determinación de la longitud radicular, tipo de diente, número de citas, agentes de irrigación, remoción de la capa de desechos dentinarios o momento/tipo de restauración definitiva. Conclusiones: La tasa de éxito a 18 meses para pulpectomías demuestran que ZO/iodoformo/HC y ZOE son superiores al yodoformo. Las indicaciones de ELRP están limitadas a dientes con resorción radicular y requiere la realización de un seguimiento cercano.

Objetivo: Apresentar uma orientação baseada em evidência para terapias pulpar não vitais de cárie profundas ou trauma em dentes deciduos. Métodos: Um grupo de trabalho da AAPD realizou uma revisão/análise sistemática para estudos não vitais de dentes deciduos resultantes de trauma ou cárie e utilizou a abordagem GRADE para avaliar o nível de certeza de evidência para recomendações clínicas. Resultados: O GRADE foi avaliado de nível alto à muito baixo. Comparando os dentes com/sem reabsorção radicular, o sucesso da pulpectomia foi melhor (p<0,001) naqueles sem reabsorção radicular pré-operatória. OZ/iodofórmio/HC (óxido de zinco + iodofórmio + hidróxido de cálcio; EndoflasTM) e OZE (óxido de zinco e eugenol) o sucesso da pulpectomia não diferiu do iodofórmio (iodofórmio + hidróxido de cálcio; VitapexTM, MetapexTM) (p= 0,55) após 18 meses; contudo, as taxas de sucesso de OZ/iodofórmio/HC e OZE permaneceram perto de 90% enquanto que o iodofórmio foi de 71% ou menos. As taxas de análise da rede mostraram que o OZ/iodofórmio/HC e OZE era melhor do que o iodofórmio. LERT foi melhor (p<0,001) do que a pulpectomia nos dentes com reabsorção radicular pré-operatória, mas os resultados da pulpectomia foram melhores (p= 0,.09) se as raízes estivessem intactas. A instrumentação rotatória dos canais radiculares foi significativamente mais rápida (p<0,001) do que manual, mas a qualidade do preenchimento não diferiu (p= 0.09) e ambos tiveram sucesso comparável. A análise de rede classificou OZ/iodofórmio/HC como o melhor, OZE segundo, e iodofórmio como o mais baixo aos 18 meses. As taxas de sucesso não foram influenciadas pelo método de obturação ou determinação do comprimento da raiz, tipo de dente, número de visitas, irrigantes, remoção da lama dentinária, ou tempo/tipo de restauração final. Conclusões: As taxas de sucesso da pulpectomia de 18 meses favoreceram pulpectomias com OZ/iodofórmio/HC e OZE sobre iodofórmio. O LERT demonstrou indicação limitada para dentes com raízes reabsorvidas e requer um acompanhamento assíduo.

Abstract: Purpose: To present an evidence-based guideline for non-vital pulp therapies due to deep caries or trauma in primary teeth. Methods: The authors, working with the American Academy of Pediatric Dentistry, conducted a systematic review/meta-analysis for studies on non-vital primary teeth resulting from trauma or caries and used the GRADE approach to assess level of certainty of evidence for clinical recommendations. Results: GRADE was assessed from high to very low. Comparing teeth with/without root resorption, pulpectomy success was better (P<0.001) in those without preoperative root resorption. Zinc oxide plus iodoform plus calcium hydroxide ([ZO/iodoform/CH]; EndoflasTM) and zinc oxide and eugenol (ZOE) pulpectomy success did not differ from iodoform (iodoform plus calcium hydroxide; VitapexTM, MetapexTM) (P=0.55) after 18-months; however, ZO/iodoform/CH and ZOE success rates remained near 90 percent while iodoform was 71 percent or less. Network analysis ratings showed ZO/iodoform/CH and ZOE better than iodoform. Lesion sterilization tissue repair (LSTR) was better (P<0.001) than pulpectomy in teeth with preoperative root resorption, but pulpectomy results were better (P=0.09) if roots were intact. Rotary instrumentation of root canals was significantly faster (P<0.001) than manual, but the quality of fill did not differ (P=0.09) and both had comparable success. Network analysis ranked ZO/iodoform/CH the best, ZOE second, and iodoform lowest at 18 months. Success rates were not impacted by method of obturation or root length determination, type of tooth, number of visits, irrigants, smear layer removal, or timing/type of final restoration. Conclusions: Pulpectomy 18-month success rates supported ZO/iodoform/CH and ZOE pulpectomy over iodoform.

Tooth and pulp chamber automatic segmentation with artificial intelligence network and morphometry method in cone-beam CT / Segmentación automática de cámaras dentales y pulpares con red de inteligencia artificial y método de morfometría en TC de haz cónico

SUMMARY: This study aims to extract teeth and alveolar bone structures in CBCT images automatically, which is a key step in CBCT image analysis in the field of stomatology. In this study, semantic segmentation was used for automatic segmentation. Five marked classes of CBCT images were input for U-net neural network training. Tooth hard tissue (including enamel, dentin, and cementum), dental pulp cavity, cortical bone, cancellous bone, and other tissues were marked manually in each class. The output data were from different regions of interest. The network configuration and training parameters were optimized and adjusted according to the prediction effect. This method can be used to segment teeth and peripheral bone structures using CBCT. The time of the automatic segmentation process for each CBCT was less than 13 min. The Dice of the evaluation reference image was 98 %. The U-net model combined with the watershed method can effectively segment the teeth, pulp cavity, and cortical bone in CBCT images. It can provide morphological information for clinical treatment.

RESUMEN: El objetivo del presente estudio fue extraer estructuras dentarias y óseas alveolares desde imágenes CBCT automáticamente, lo cual es un paso clave en el análisis de imágenes CBCT en el campo de la estomatología. En este estudio, se utilizó la segmentación de tipo emántica para la segmentación automática. Se ingresaron cinco clases de imágenes CBCT marcadas, para el entrenamiento de la red neuronal U-net. El tejido duro del diente (incluidos esmalte, dentina y cemento), la cavidad de la pulpa dentaria, hueso cortical, hueso esponjoso y otros tejidos se marcaron manualmente en cada clase. Los datos se obtuvieron de diferentes regiones de interés. La configuración de la red y los parámetros de entrenamiento se optimizaron y ajustaron de acuerdo con un análisis predictivo. Este método se puede utilizar para segmentar dientes y estructuras óseas periféricas mediante CBCT. El tiempo del proceso de segmentación automática para cada CBCT fue menor a 13 min. El "Dice" de evaluación de la imagen de referencia fue de 98 %. El modelo U-net combinado con el método "watershed"puede segmentar eficazmente los dientes, la cavidad pulpar y el hueso cortical en imágenes CBCT. Puede proporcionar información morfológica para el tratamiento clínico.