Root Canal Treatment of Mandibular First Premolar with 3 Canals: A Case Report

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

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

Actualización de las técnicas para el tratamiento de las recesiones periodontales

Introducción: A lo largo de los años se ha propuesto una notable variedad de protocolos quirúrgicos periodontales, cuyo enfoque pasó de la simple resolución de defectos de tejidos blandos a la realización de procedimientos predecibles y mínimamente invasivos. Inicialmente se usaba el injerto gingival libre. Posteriormente se han probado diversas técnicas, incluidas aquellas con sustitutos de tejidos blandos, como membranas tipo Alloderm. Hoy en día se considera el gold standard el injerto de tejido conectivo subepitelial asociado al colgajo de avance coronal. Por último, se ha examinado la técnica Pinhole, con mayor preservación de tejido y resultado más estético. Objetivos: El objetivo de esta revisión fue la comparación de técnicas actualizadas para el tratamiento de recesiones múltiples en maxilar superior e inferior. El resultado del procedimiento se evaluó en términos de cobertura radicular completa, reducción de la recesión, ganancia en altura y volumen, resultado estético, dolor postoperatorio y morbilidad del lecho donante y receptor del paciente. Material y métodos: Se realizaron búsquedas electrónicas y manuales para recopilar estudios de boca dividida, ensayos clínicos controlados aleatorios, series de casos, estudios piloto, libros de periodoncia, estudios de casos, revisiones sistemáticas y metanálisis, incluyendo los defectos de recesiónes gingivales múltiples, en maxilar y mandibular, de las cuatro clases de Miller, debido a su extensa evidencia. Resultados: Se incluyeron treinta y cuatro publicaciones y se extrajeron datos sobre el resultado de las técnicas quirúrgicas de dieciocho artículos. La evaluación clínica analizó la cantidad de cobertura radicular completa, la reducción de la recesión y la ganancia de altura y volumen, mientras que la perspectiva del paciente se expresó en términos de satisfacción estética y posibles complicaciones postoperatorias. Los procedimientos de los últimos diez años mostraron mejores resultados en todos los factores mencionados anteriormente. Conclusión: La predictibilidad y la estabilidad del tratamiento a largo plazo representan los factores que guían el proceso de elección de la técnica y que añaden valor a los procedimientos más actualizados. Se observaron progresos tanto a nivel estético, al reducir las discrepancias entre el área intervenida y el tejido circundante, como a nivel postoperatorio, al aminorar las molestias del paciente. Los desafíos propios de esta rama pronto podrían encontrar respuesta gracias a su rápida evolución, la cual permite concebir más avances.

Background: Along the years, a remarkable variety of periodontal surgical protocols has been proposed, the focus of which has shifted from the mere resolution of a soft tissue defect to the performance of predictable and minimally invasive procedures. Initially, the free gingival graft was used. Subsequently, many different techniques were experimented, including those using soft tissue substitutes, such as the Alloderm membrane. Nowadays, the association of the connective tissue graft with the coronally advanced flap is considered the gold standard. Finally, the Pinhole technique, being a more conservative method in terms of tissue preservation and aesthetic outcome, was proposed. Objectives: The aim of this review was the comparison of the updated techniques for the treatment of multiple periodontal recessions, affecting both maxilla and mandible. The procedure outcome was assessed in terms of complete root coverage, recession reduction, gain in height and volume, aesthetic outcome, patient's post-operative pain and morbidity of donor and recipient sites. Material and methods: Electronic and hand searches were performed to collect split- mouth studies, randomized controlled clinical trials, case series, pilot studies, periodontal books, case studies, systematic reviews and meta-analysis, including maxillary and mandibular multiple gingival recession defects of all four Miller's classes, for its extensive evidence. Results: Thirty-four publications were included and data regarding the surgical techniques outcome were extracted from eighteen articles. The clinical evaluation analyzed the amount of complete root coverage, recession reduction and gain in height and volume, while the patient's perspective was expressed in terms of aesthetic satisfaction and possible postoperative complications. Procedures in the last ten years showed better results in all the above-mentioned factors. Conclusion: Procedural predictability and long-lasting treatment stability embody the factors driving the technique election process and adding value to more updated procedures. Progress was observed both at an aesthetic level, by reducing the discrepancias between the surgical region and the surrounding tissue, and at a postoperative level, by reducing patient discomfort. The challenges inherent to this branch could soon find answers thanks to its prompt evolution, which allows for further advances to be conceived.

Actualización de las técnicas para el tratamiento de las recesiones periodontales / Update of techniques for the treatment of periodontal recessions

RESUMEN Introducción: A lo largo de los años se ha propuesto una notable variedad de protocolos quirúrgicos periodontales, cuyo enfoque pasó de la simple resolución de defectos de tejidos blandos a la realización de procedimientos predecibles y mínimamente invasivos. Inicialmente se usaba el injerto gingival libre. Posteriormente se han probado diversas técnicas, incluidas aquellas con sustitutos de tejidos blandos, como membranas tipo Alloderm. Hoy en día se considera el gold standard el injerto de tejido conectivo subepitelial asociado al colgajo de avance coronal. Por último, se ha examinado la técnica Pinhole, con mayor preservación de tejido y resultado más estético. Objetivos: El objetivo de esta revisión fue la comparación de técnicas actualizadas para el tratamiento de recesiones múltiples en maxilar superior e inferior. El resultado del procedimiento se evaluó en términos de cobertura radicular completa, reducción de la recesión, ganancia en altura y volumen, resultado estético, dolor postoperatorio y morbilidad del lecho donante y receptor del paciente. Material y métodos: Se realizaron búsquedas electrónicas y manuales para recopilar estudios de boca dividida, ensayos clínicos controlados aleatorios, series de casos, estudios piloto, libros de periodoncia, estudios de casos, revisiones sistemáticas y metanálisis, incluyendo los defectos de recesiónes gingivales múltiples, en maxilar y mandibular, de las cuatro clases de Miller, debido a su extensa evidencia. Resultados: Se incluyeron treinta y cuatro publicaciones y se extrajeron datos sobre el resultado de las técnicas quirúrgicas de dieciocho artículos. La evaluación clínica analizó la cantidad de cobertura radicular completa, la reducción de la recesión y la ganancia de altura y volumen, mientras que la perspectiva del paciente se expresó en términos de satisfacción estética y posibles complicaciones postoperatorias. Los procedimientos de los últimos diez años mostraron mejores resultados en todos los factores mencionados anteriormente. Conclusión: La predictibilidad y la estabilidad del tratamiento a largo plazo representan los factores que guían el proceso de elección de la técnica y que añaden valor a los procedimientos más actualizados. Se observaron progresos tanto a nivel estético, al reducir las discrepancias entre el área intervenida y el tejido circundante, como a nivel postoperatorio, al aminorar las molestias del paciente. Los desafíos propios de esta rama pronto podrían encontrar respuesta gracias a su rápida evolución, la cual permite concebir más avances.

ABSTRACT Background: Along the years, a remarkable variety of periodontal surgical protocols has been proposed, the focus of which has shifted from the mere resolution of a soft tissue defect to the performance of predictable and minimally invasive procedures. Initially, the free gingival graft was used. Subsequently, many different techniques were experimented, including those using soft tissue substitutes, such as the Alloderm membrane. Nowadays, the association of the connective tissue graft with the coronally advanced flap is considered the gold standard. Finally, the Pinhole technique, being a more conservative method in terms of tissue preservation and aesthetic outcome, was proposed. Objectives: The aim of this review was the comparison of the updated techniques for the treatment of multiple periodontal recessions, affecting both maxilla and mandible. The procedure outcome was assessed in terms of complete root coverage, recession reduction, gain in height and volume, aesthetic outcome, patient's post-operative pain and morbidity of donor and recipient sites. Material and methods: Electronic and hand searches were performed to collect split- mouth studies, randomized controlled clinical trials, case series, pilot studies, periodontal books, case studies, systematic reviews and meta-analysis, including maxillary and mandibular multiple gingival recession defects of all four Miller's classes, for its extensive evidence. Results: Thirty-four publications were included and data regarding the surgical techniques outcome were extracted from eighteen articles. The clinical evaluation analyzed the amount of complete root coverage, recession reduction and gain in height and volume, while the patient's perspective was expressed in terms of aesthetic satisfaction and possible postoperative complications. Procedures in the last ten years showed better results in all the above-mentioned factors. Conclusion: Procedural predictability and long-lasting treatment stability embody the factors driving the technique election process and adding value to more updated procedures. Progress was observed both at an aesthetic level, by reducing the discrepancias between the surgical region and the surrounding tissue, and at a postoperative level, by reducing patient discomfort. The challenges inherent to this branch could soon find answers thanks to its prompt evolution, which allows for further advances to be conceived.

Quality analysis of four filling techniques in ovoid root canals prepared with M® instruments

Aims: This study aimed to assess the quality of various filling techniques in ovoid root canals prepared using M® instruments. Materials and Methods: Sixty ovoid root canals underwent endodontic treatment with M® instruments and were subsequently divided randomly into four experimental groups, each employing a different obturation technique: TU - single cone; TL - active lateral condensation; TH - Tagger hybrid; TS - Schilder technique. Digital radiographs were taken in both mesiodistal and buccolingual directions to examine the filled teeth. The percentage of filling material and empty spaces was quantified using Photoshop® software. Data were subjected to statistical analysis using the one-way ANOVA test and T test (? = 0.05). Results: In the TL and TS groups, there was a significantly lower average percentage of unfilled spaces compared to the TU and TH groups (P<0.0001). When analyzing the radiographic directions, the mesiodistal view exhibited the highest mean percentage of unfilled spaces, with differences in filling quality observed only in the TU and TL groups. Conclusions: Active lateral condensation and Schilder techniques demonstrated superior performance in achieving effective filling of ovoid root canals.

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.

Características clínicas y radiográficas de reabsorciones radiculares externas / Clinical and radiographic characterization of external root resorption

Introducción La siguiente revisión bibliográfica se realizó con el propósito de reconocer las características clínicas y radiográficas que deben ser evaluadas para el diagnóstico de las reabsorciones radiculares externas incluyendo también sus tratamientos. Metodología Se llevó a cabo una búsqueda en las bases de datos MEDLINE/PubMed, Cochrane Library y Google Scholar bajo el término , incluyendo estudios experimentales y revisiones bibliográficas desde 2010 a 2022 en español e inglés, incluyendo finalmente 17 artículos. Resultados Los resultados obtenidos señalaron que cada tipo de reabsorción radicular externa presenta características clínicas específicas que las diferencian. Estas diferencias son: para la reabsorción externa inflamatoria la vitalidad pulpar negativa; para la reabsorción externa de reemplazo la ausencia de movilidad y percusión metálica; para la reabsorción externa cervical una coloración rosada de la corona; la reabsorción externa superficial no presenta ningún tipo de sintomatología clínica y la reabsorción de colapso apical transitorio presenta un cambio de coloración transitorio. Conclusión Las reabsorciones radiculares externas requieren un diagnóstico preciso y temprano. Se debe realizar un examen clínico con énfasis en sondaje, coloración, movilidad y pruebas de vitalidad.

Introduction The following bibliographic review was carried out with the purpose of recognizing the clinical and radiographic characteristics that must be considered in the diagnosis of external root resorption, including treatments. Methods A bibliographic search was carried out in PubMed/Medline, Cochrane Library and Google Scholar databases under the term "external root resorption", from 2010 to 2022 in Spanish and English. Experimental studies and bibliographic reviews were selected, and finally 17 articles were included. Results The results obtained indicated that each type of resorption presents specific clinical characteristics that differentiate them, these are: for external inflammatory resorption a negative pulp vitality; for replacement external resorption the absence of mobility and metallic percussion; for cervical external resorption a pink coloration of the crown; superficial external resorption does not present any type of clinical symptoms and transient apical collapse presents a transient change in color. Conclusion External root resorptions require accurate and early diagnosis. A clinical examination should be performed with emphasis on the following: probing, coloration, mobility, and vitality tests.

Morphology of the Second Mesiobuccal Canal in the Maxillary Second Molar / Morfología del Segundo Canal Mesiovestibular en el Segundo Molar Maxilar

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.

Reabsorción radicular en premolares, posterior a ortodoncia de autoligado, utilizando tomografía computarizada

Este Estudio tuvo por objetivo determinar la incidencia de reabsorción radicular externa en premolares superiores e inferiores permanentes al finalizar el tratamiento de ortodoncia. Esta investigación fue realizada en pacientes entre 18 y 35 años que recibieron tratamiento de ortodoncia, sin extracciones, con técnica de autoligado en la ciudad de Guadalajara. Se consideraron 120 premolares, realizando mediciones longitudinales en las tomografías computarizadas de haz cónico al inicio y término del tratamiento. Utilizando el software Implant Viewer 3. Los valores registrados en el primer y segundo premolar superior tanto del lado derecho como izquierdo al inicio y término del tratamiento fluctuaron entre -4.946 y -7.801; p ≤ 0.0005 encontrándose diferencias estadísticas significativas. Mientras que en el primer y segundo premolar inferior tanto del lado derecho como izquierdo, fluctuaron entre -4.864 y -5.28; p ≤ 0.0005 encontrándose diferencias estadísticas significativas. Se concluye en este estudio que los dientes sometidos a movimientos durante el tratamiento de ortodoncia sufren modificaciones en el contorno de la raíz, cambios con consecuencias mínimas que no comprometen la funcionalidad del diente. Los premolares superiores presentaron mayores rangos de reabsorción radicular que los premolares inferiores.

The aim of this study is to determine the incidence of root resorption in permanent upper and lower premolars at the end of an orthodontic treatment. This research was carried out in patients aged between 18 and 35 years old who received orthodontic treatment, without extractions, with a self-ligating technique in the city of Guadalajara, Mexico. In this study, 120 premolars were considered, making longitudinal measurements with cone beam computed tomography at the beginning and the end of the treatment, using the Implant Viewer 3 software. The values recorded in the upper first and second premolars on both the right and left sides at the beginning and the end of the treatment fluctuated between -4.946 and -7.801; p ≤ 0.0005, finding statistically significant differences. In the lower first and second premolars on both the right and left sides, they fluctuated between -4.864 and -5.28; p ≤ 0.0005, also finding statistically significant differences. It is concluded that teeth subjected to movements during orthodontic treatment suffer modifications in the contour of the root, changes with minimal consequences that do not compromise their functionality. The upper premolars showed higher ranges of root resorption than the lower premolars.

Displasia dentinaria tipo I: Manejo clínico y estudio histológico a propósito de dos casos

La displasia dentinaria tipo I (DD-I) corresponde a una alteración dentinaria de heterogeneidad genética y penetrancia completa, en donde se presenta un defecto en el desarrollo de las raíces de los dientes tanto temporales como definitivos. Clínicamente se observan dientes con extrema movilidad junto con antecedentes de exfoliación prematura o espontánea. Los defectos estructurales de los tejidos dentarios, tales como DD-I; implican un desafío ya que son pocos los casos documentados en la literatura que hablan de esta condición. Además implican un tratamiento multidisciplinario y altamente invasivo. El objetivo de este artículo es presentar dos casos de DD-I, enfatizando en su tratamiento y características histopatológicas.

Dentin Dysplasia Type I (DD-I) consists of a pathological dentinary alteration with genetic heterogeneity that results in a defectuous development of dental roots both in primary and secondary dentition. Clinically we can appreciate teeth with extreme pathological mobility and premature or spontaneous exfoliation. Alterations within normal dental structure, such as DD-I imply a challenge for the common practitioner, because of the scarce number of case reports with in the scientific literature regarding this condition and also, because of the need for a highly invasive and multidisciplinary approach they require. The aim of this article is to present two DD-I cases, emphasizing on their treatment and histopathological features.

Periradicular and Peri-Implant Lesions Associated with Apical Impact of Osseointegrated Implants in Tooth Roots: Clinical Case Reports

This clinical case report aims to describe the development of periradicular and perimplant cystic lesions resulted from the intimate contact of the apical region of osseointegrated implants of dental roots, and discuss the reasons fo r failure of the guided bone regeneration procedure associated with platelet rich fibrin and leukocytes, this process was used to the treatment of the first case. Case Reports. Three cases were reported, two cases described the close contact between the tooth roots and the osseointegrated implants and another with a distance of 1.08 mm. All cases realized a radiographic, and they had not periapical lesions before contact with the apical region of the osseointegrated implants on the roots of the teeth. In the case with the largest cystic extension, the procedure was: removal of the osseointegrated implant with apicectomy of the neighboring teeth, excisional biopsy of the lesion, and grafting using the technique of guided bone regeneration associated with L-PRF. All three cases, endodontic treatment was performed on the neighboring teeth within 2 years of survival of the osseointegrated implants in order to reverse the existing lesion. Results. The diagnostic hypothesis of the three cases was periradicular and peri-implant lesion, arising from a contact of the apical region of the osseointegrated implant with the adja cent tooth. The distance of 1.08 mm between the apices did not ensure normality of the periradicular and peri-implant tissues. The intimate contact caused lesions of different extents and root fractures. Conclusion. Premature contact of the osseointegrated implant with the root region of the neighboring tooth may lead to the development of periradicular and peri-implant lesions, suggesting that it is not possible to control this infectious process with endodontic treatment of the injured tooth.

Este reporte de caso clínico tuvo como objetivo describir el desarrollo de lesiones quísticas perirradiculares y periimplantarias resultantes del contacto íntimo de la región apical de implantes osteointegrados de raíces dentales, y además discutir las razones del fracaso del procedimiento de regeneración ósea guiada asociado a fibrina rica en plaquetas y leucocitos. Este proceso se utilizó para el tratamiento del primer caso. Se reportaron tres casos, en dos casos se describieron el estrecho contacto entre las raíces de los dientes y los implantes osteointegrados y en el otro se determinó una distancia de 1,08 mm. En los tres casos se realizó una radiografía y se determinó que no existían lesiones periapicales, antes del contacto con la región apical de los implantes osteointegrados, en las raíces de los dientes. En el caso de mayor extensión quística, el procedimiento fue: extracción del implante osteointegrado con apicectomía de los dientes vecinos, biopsia excisional de la lesión e injerto mediante la técnica de regeneración ósea guiada asociada a L-PRF. En los tres casos, el tratamiento de endodoncia se realizó en los dientes vecinos dentro de los 2 años de supervivencia de los implantes osteointegrados para revertir la lesión existente. La hipótesis diagnóstica de los tres casos fue lesión perirradicular y periimplantaria, originada por un contacto de la región apical del implante osteointegrado con el diente adyacente. La distancia de 1,08 mm entre los ápices no aseguraba la normalidad de los tejidos perirradiculares y periimplantarios. El contacto íntimo provocó lesiones de diferente extensión y fracturas radiculares. El contacto prematuro del implante osteointegrado con la región radicular del diente vecino puede conducir al desarrollo de lesiones perirradiculares y periimplantarias, lo que sugiere que no es posible controlar este proceso infeccioso con tratamiento endodóntico del diente lesionado.

Descripción de la Morfología del Sistema de Canales Radiculares en Premolares Maxilares Mediante Tomografía Computarizada Cone Beam en una Población Chilena

El tratamiento endodóntico requiere detallados conocimientos sobre la morfología radicular. En premolares maxilares, se ha reportado variabilidad en el número de raíces y morfología del sistema de canales radiculares (SCR). La causa más frecuente de fracaso endodóntico son los conductos no tratados. Por lo tanto, una mejor compresión de la morfología del SCR y sus variaciones es crucial para el tratamiento endodóntico. El objetivo de esta investigación fue describir la frecuencia del número de raíces y morfología del SCR en premolares maxilares, mediante exámenes de tomografía computarizada Cone Beam (CBCT) en una población chilena. Se realizó un estudio observacional descriptivo de corte transversal donde se observó la morfología del sistema de canales radiculares de primeros y segundos premolares maxilares a través de exámenes CBCT, agrupándolos de acuerdo con la Clasificación de Vertucci. Se observaron 228 exámenes CBCT, donde se incluyeron 268 primeros premolares superiores y 233 segundos premolares maxilares. Se determinó que en primeros premolares maxilares un 56,3 % presentó una raíz, un 43,3 %, siendo más frecuente una morfología del SCR tipo IV. En los segundos premolares maxilares, se determinó la presencia de una raíz en el 95,7 % de los casos, siendo más frecuente una morfología del SCR tipo I. Estos resultados pueden ser de interés para endodoncistas, ya que conocer la morfología del SCR de premolares maxilares permite mejorar la planificación de la terapia endodóntica realizada en estos dientes.

Endodontic treatment requires detailed knowledge of root morphology. In maxillary premolars, variability in root number and root canal system (RCS) morphology has been reported. The most frequent cause of endodontic failure is non treated canals. Therefore, a better understanding of RCS morphology and its variations is crucial for endodontic treatment. The aim of this research was to describe the frequency of root number and SCR morphology in maxillary premolars, by means of Cone Beam Computed Tomography (CBCT) examinations in a Chilean population. A cross-sectional descriptive observational study was carried out in which the morphology of the root canal system of maxillary first and second premolars was observed through CBCT examinations, grouping them according to the Vertucci Classification. A total of 228 CBCT examinations were observed, which included 268 upper first premolars and 233 maxillary second premolars. It was determined that in maxillary first premolars 56.3 % presented one root, 43.3 %, being more frequent a SCR type IV morphology. In maxillary second premolars, the presence of one root was determined in 95.7 % of the cases, being more frequent a SCR type I morphology. These results may be of interest to endodontists, since knowing the morphology of the RCS of maxillary premolars allows improving the planning of endodontic therapy performed on these teeth.

Microcomputed-Tomographic Analysis of the Root Canal Morphology of the Mandibular First Molars in a Malaysian Subpopulation Using Two Classification Systems / Análisis por Tomografía Microcomputada de la Morfología del Conducto Radicular de los Primeros Molares Mandibulares en una Subpoblación de Malasia Utilizando dos Sistemas de Clasificación

SUMMARY: This work investigated the morphology of the root canal system of the mandibular first molar in a Malaysian subpopulation. Using micro-computed tomography with an isotropic resolution of 22 µm, 140 mandibular first molars were scanned. MIMICS software was used for segmentation, 3-D reconstruction and analysis of the acquired images. The canal configuration was described using Vertucci [supported by the supplementary configurations proposed by Sert & Bayirli (2004)] and Ahmed et al. (2027), coding systems. The chi-square test was used to assess the association between qualitative variables. By non-considering intercanal communications, Vertucci types IV (17.1%) and I (76.4%) were the most frequently reported configurations in the mesial and distal roots, respectively. Of the reported configurations, 24.3% and 4.3% were non-classifiable by Vertucci system in the mesial and distal roots, respectively. Up to 63.6% and 9.3% of the reported configurations were non- classifiable, and type I was the most frequent when considering intercanal communications (7.1% and 76.4% in the mesial and distal roots, respectively). According to Ahmed et al., system, almost half of the sample had more than four digits (47.9%), followed by the 3-digits category (20.71%). In both systems, a significant association was found between the canal configuration and the root type (p<0.001). The mandibular first molar of this Malaysian subpopulation demonstrated a wide range of root canal morphology. When compared to the Vertucci system, the system developed by Ahmed et al., successfully classified all molars configurations despite their level of complexity. The complex canal anatomy of mandibular first molars in this subpopulation warrants special attention during root canal treatment procedures.

En este trabajo se investigó la morfología del sistema de conductos radiculares del primer molar mandibular en una subpoblación de Malasia. Utilizando tomografía microcomputada con una resolución isotrópica de 22 µm, se escanearon 140 primeros molares mandibulares. Se utilizó el software MIMICS para segmentar (enmascarar), reconstruir en 3D, visualizar y analizar las imágenes adquiridas. La configuración del canal se describió utilizando Vertucci respaldado por las configuraciones complementarias propuestas por Sert & Bayirli (2004)] y Ahmed et al. (2017, 2020), sistemas de codificación. Se utilizó la prueba de chi-cuadrado para evaluar la asociación entre variables cualitativas. Sin considerar las comunicaciones intercanales, los tipos Vertucci IV (17,1%) y I (76,4%) fueron las configuraciones reportadas con mayor frecuencia en las raíces mesiales y distales, respectivamente. De las configuraciones reportadas, el 24,3 % y el 4,3 % fueron no clasificables por el sistema de Vertucci en las raíces mesial y distal, respectivamente. Hasta el 63,6 % y el 9,3 % de las configuraciones reportadas fueron no clasificables, siendo la tipo I la más frecuente al considerar las comunicaciones intercanales (7,1 % y 76,4 % en las raíces mesiales y distales, respectivamente). Según Ahmed et al. (2017, 2020) en el sistema, casi la mitad de la muestra tenía más de cuatro dígitos (47,9 %), seguido por la categoría de 3 dígitos (20,71 %). En ambos sistemas se encontró una asociación significativa entre la configuración del canal y el tipo de raíz (p<0,001). El primer molar mandibular de esta subpoblación de Malasia demostró una amplia gama morfológica del conducto radicular. En comparación con el sistema Vertucci, el sistema desarrollado por Ahmed et al. (2017, 2020) clasificaron con éxito todas las configuraciones de los molares a pesar de su nivel de complejidad. La compleja anatomía del canal de los primeros molares mandibulares en esta subpoblación merece una atención especial durante los procedimientos de tratamiento de conducto.

Micro-CT evaluation of the presence of voids in endodontic obturation / Evaluación microtomográfica de la presencia de vacíos en la obturación endodóntica

ABSTRACT Identifying the presence, size, type and location of voids in an endodontic obturation is of great clinical importance because it enables evaluation of the three-dimensionality of the sealing techniques, which can be related to the success of the endodontic treatment. Aim To analyze by micro-CT the presence of voids in lower single-rooted premolar root canal obturations prepared using the single cone and ultrasound vibration technique. Materials and methods Twenty extracted single-rooted lower premolars were selected, and the root canal prepared surgically and chemically. In GROUP 1 - Without Vibration, the canal was obturated with a single cone and bioceramic, without applying vibration. In GROUP 2 - With Vibration, the gutta-percha cone inside the root canal was held with a cotton plier to which ultrasound vibration was applied for 3 periods of 3 seconds each. A micro-CT scanner was used to acquire and reconstruct images for analysis. Results No significant difference was found between obturation techniques, though there were differences between thirds, with the cervical third having a higher percentage of voids than the middle and apical thirds. Conclusions The results suggest that the volume of closed, open and total voids does not differ between treatments with and without ultrasound vibration. In the cervical third, the highest volume of voids was related to oval geometry in the teeth evaluated.

RESUMEN La presencia de vacíos en la obturación endodóntica, su tamaño y el tipo y localización tiene gran importancia clínica ya que permite evaluar la tridimensionalidad de las técnicas de sellado y relacionarlas con el éxito del tratamiento endodóntico. Objetivo analizar mediante microtomografía la presencia de vacíos en la obturación del conducto radicular de premolares inferiores unirradiculares, utilizando la técnica de cono único y vibración con ultrasonido. Materiales y Método se seleccionaron 20 premolares inferiores unirradiculares a los que se les realizó la preparación quirúrgica y química del conducto radicular. Se realizó la obturación con cono único y biocerámico GRUPO 1- sin vibración. En el GRUPO 2 - con vibración se aplicó vibración por ultrasonido, se tomó del cono de gutapercha colocado en el interior del conducto con pinza de algodón que fue vibrada durante 3 períodos de 3 segundos cada uno. Las mismas fueron adquiridas y reconstruidas en un microtomógrafo para posterior análisis de las imágenes obtenidas. Resultados No se evidenciaron diferencias significativas entre ambas técnicas de obturación comparadas, pero si entre los tercios analizados, siendo el cervical el que mayor porcentaje de vacíos presenta en comparación a los cortes correspondientes al tercio medio y apical. Conclusiones Los resultados sugieren que el volumen de vacíos cerrados, abiertos y total no varía en los tratamientos donde se aplica vibración por ultrasonido. En el tercio cervical, el mayor volumen de vacíos se relaciona con la geometría oval que presentaron las piezas dentarias evaluadas en este estudio.

Efficacy of WaveOne Gold and ProDesign RT systems in removing filling material: a micro-CT analysis / Eficácia dos sistemas WaveOne Gold e ProDesign RT na remopáo material obturador: uma análise micro-CT

ABSTRACT The remaining filling material after retreatment can harbor bacteria and organic tissues that can influence the outcome of the therapy. Aim The aim of this study was to evalúate, by micro-CT, the amount of filling material remaining in the root canal after its removal using WaveOne Gold or ProDesign RT. Material and Method Forty human mandibular canines were instrumented with the ProTaper Next system up to the X2 instrument (25.06) and filled with gutta-percha cones and AHPlus. Teeth were divided into 2 groups (n=20): WaveOne Gold 25.07 (WOG) and ProDesign RT 25.08 (PRT) for filling removal, after which they were scanned in a micro-CT device to quantify the volume of remaining filling material. The data were subjected to log 10 transformation, Student 's t-test was performed to account for multiple observationsper sample, significance was set at 5%. Results Student 's t-test showed that there was no difference between the two systems regarding the volume of remaining filling material in the thirds: apical (p = 0.392), middle (p = 0.065), or cervical (p = 0.918). Conclusión Remaining filling material was present in all groups and both systems were similar in removing root filling material in mandibular canines.

RESUMO A permanencia de material obturador após o retratamento pode abrigar bactérias e tecidos orgánicos que podem influenciar o resultado da terapia. Objetivo O objetivo deste estudo foi avaliar, por micro-CT, a quantidade de material obturador remanescente no canal radicular após a desobturagdo com WaveOne Gold e ProDesign RT. Material e Método Quarenta caninos inferiores humanos foram instrumentados com o sistema ProTaper Next até o instrumento X2 (25.06) e obturados com cones de guta-percha e AHPlus. Os dentes foram divididos em dois grupos (n=20): WaveOne Gold 25.07 (WOG) e ProDesign RT 25.08 (PRT) e escaneados em micro-CT para quantificagdo do volume de material obturador remanescente. Os dados foram submetidos á transformando log10, o teste t de Student foi realizado para contabilizar múltiplas observagoes por amostra, a significáncia foi fixada em 5%. Resultados O teste t de Student mostrou que ndo houve diferenga no volume de material obturador remanescente entre os dois sistemas nos tergos: apical (p = 0,392), médio (p = 0,065) ou cervical (p = 0,918). Conclusao O material obturador remanescente estavapresente em todos os grupos e ambos os sistemas foram semelhantes na remogdo do material obturador radicular nos caninos inferiores.

Nivel de ansiedad y dolor dental en diferentes momentos en el tratamiento de conductos durante la pandemia por COVID-19 / Level of anxiety and dental pain at different times in root canal treatment during the COVID-19 pandemic / Nível de ansiedade e dor dentária em diferentes momentos do tratamento de canal durante a pandemia de COVID-19

RESUMEN Objetivo : Evaluar el nivel de ansiedad dental (AD) y dolor dental (DD) en diferentes momentos en el tratamiento de conductos durante la pandemia por COVID-19. Materiales y métodos : Estudio observacional, descriptivo y longitudinal. La muestra estuvo constituida por 68 participantes de la Clínica Estomatológica del Hospital Militar Central (HMC), que cumplieron con los criterios de inclusión y exclusión. El procedimiento consistió en el registro del nivel de AD y DD de los pacientes en distintos momentos del tratamiento de conductos mediante una escala visual analógica (EVA). Resultados : Antes del procedimiento, los participantes mostraron 3,66 ± 1,83 de AD y 4,54 ± 1,79 de DD; durante el procedimiento, obtuvieron valores de 3,13 ± 1,96 y 2,09 ± 1,39 de AD y 2,96 ± 1,57 y 1,82 ± 1,09 de DD; y al culminar el procedimiento, tuvieron 0,75 ± 0,74 de AD y 0,53 ± 0,72 de DD. Conclusiones : La AD y el DD estuvieron presentes antes de iniciar el tratamiento, pero, conforme se avanzaba con el procedimiento, sus niveles fueron disminuyendo.

ABSTRACT Objective : To evaluate the level of dental anxiety (DA) and dental pain (DD) at different times in root canal treatment during the COVID-19 pandemic. Materials and methods : Observational, descriptive, and longitudinal study. The sample consisted of 68 participants from the Stomatology Clinic of the Hospital Militar Central (HMC), who met the inclusion and exclusion criteria. The procedure consisted of recording the level of AD and DD of the patients at different times during root canal treatment using a visual analog scale (VAS). Results : Before the procedure, participants showed 3.66±1.83 of AD and 4.54±1.79 of DD; during the procedure, they obtained values of 3.13±1.96 and 2.09±1.39 of AD and 2.96±1.57 and 1.82±1.09 of DD; and at the end of the procedure, they had 0.75±0.74 of AD and 0.53±0.72 of DD. Conclusions : AD and DD were found to be present before starting treatment, but as the procedure progressed their levels decreased.

RESUMO Objetivo : avaliar o nível de ansiedade dentária (AD) e dor dentária (DD) em diferentes momentos do tratamento de canal durante a pandemia da COVID-19. Materiais e métodos : Estudo observacional, descritivo e longitudinal. A amostra foi composta por 68 participantes da Clínica de Estomatologia do Hospital Militar Central (HMC), que atenderam aos critérios de inclusão e exclusão. O procedimento consistiu em registar o nível de DA e DD dos pacientes em diferentes momentos durante o tratamento do canal radicular, utilizando uma escala visual analógica (EVA). Resultados : antes do procedimento, os participantes apresentavam 3,66±1,83 de DA e 4,54±1,79 de DD; durante o procedimento, obtiveram valores de 3,13±1,96 e 2,09±1,39 de DA e 2,96±1,57 e 1,82±1,09 de DD; e, no final do procedimento, apresentavam 0,75±0,74 de DA e 0,53±0,72 de DD. Conclusões : A DA e a DD estavam presentes antes do início do tratamento, mas à medida que o procedimento avançava, os seus níveis diminuíram.

Effect of ethyl acetate extract from Mimosa pudica root on acute myeloid leukemia in mice / 中国药房

OBJECTIVE To study the inhibitory effect of ethyl acetate extract from Mimosa pudica root （ethyl acetate extract for short） on acute myeloid leukemia in mice. METHODS Different concentrations of ethyl acetate extract （0.062 5， 0.125， 0.25， 0.5 mg/mL） were used to treat acute myelomonocytic leukemia cell lines WEHI-3， and their effects on cell viability were investigated. Fifty BALB/C mice were randomly divided into blank control group， model group， positive control group （5- fluorouracil， 13 mg/kg）， and ethyl acetate extract low-dose and high-dose groups （50， 200 mg/kg）， with 10 mice in each group. Except for the blank control group， the leukemia model was constructed by intraperitoneal injection of WEHI-3 cells in other groups， and from the second day of modeling， corresponding drugs/water were orally administered once a day for 14 consecutive days. After the last administration， the liver and spleen indexes of mice were measured， and liver tissue pathological morphology observation， hematological analysis， and white blood cell differentiation detection were performed； the levels of cytokine [interleukin-2 （IL-2）， IL-3， interferon-γ （IFN-γ）， tumor necrosis factor-α （TNF-α）] in serum were determined； the levels of leukocyte surface markers [cluster of differentiation 3 （CD3）， CD19， CD11b， CD107b （Mac-3）] in whole blood were all detected. RESULTS After treated with 0.062 5-0.5 mg/mL ethyl acetate， the inhibition rate of cell proliferation were increased significantly （P＜0.05）. After intervention with high-dose ethyl acetate， the liver and spleen index， serum level of TNF-α， the levels of CD11b and Mac-3 in blood were significantly reduced （P＜0.05）， while serum levels of IL-2， IL-3 and IFN-γ， and the levels of CD3 and CD19 in blood were increased significantly （P＜0.05）. Occasional lymphocyte infiltration was present in the liver parenchyma， with almost no infiltration of inflammatory cells； hematology improvement and weakened white blood cell differentiation were found. CONCLUSIONS The ethyl acetate extract of M. pudica root can inhibit the proliferation of WEHI-cells， and improve symptoms in acute myeloid leukemia mice， the mechanism of which may be associated with enhancing the immune function.

Effect of ethyl acetate extract from Mimosa pudica root on acute myeloid leukemia in mice / 中国药房

OBJECTIVE To study the inhibitory effect of ethyl acetate extract from Mimosa pudica root （ethyl acetate extract for short） on acute myeloid leukemia in mice. METHODS Different concentrations of ethyl acetate extract （0.062 5， 0.125， 0.25， 0.5 mg/mL） were used to treat acute myelomonocytic leukemia cell lines WEHI-3， and their effects on cell viability were investigated. Fifty BALB/C mice were randomly divided into blank control group， model group， positive control group （5- fluorouracil， 13 mg/kg）， and ethyl acetate extract low-dose and high-dose groups （50， 200 mg/kg）， with 10 mice in each group. Except for the blank control group， the leukemia model was constructed by intraperitoneal injection of WEHI-3 cells in other groups， and from the second day of modeling， corresponding drugs/water were orally administered once a day for 14 consecutive days. After the last administration， the liver and spleen indexes of mice were measured， and liver tissue pathological morphology observation， hematological analysis， and white blood cell differentiation detection were performed； the levels of cytokine [interleukin-2 （IL-2）， IL-3， interferon-γ （IFN-γ）， tumor necrosis factor-α （TNF-α）] in serum were determined； the levels of leukocyte surface markers [cluster of differentiation 3 （CD3）， CD19， CD11b， CD107b （Mac-3）] in whole blood were all detected. RESULTS After treated with 0.062 5-0.5 mg/mL ethyl acetate， the inhibition rate of cell proliferation were increased significantly （P＜0.05）. After intervention with high-dose ethyl acetate， the liver and spleen index， serum level of TNF-α， the levels of CD11b and Mac-3 in blood were significantly reduced （P＜0.05）， while serum levels of IL-2， IL-3 and IFN-γ， and the levels of CD3 and CD19 in blood were increased significantly （P＜0.05）. Occasional lymphocyte infiltration was present in the liver parenchyma， with almost no infiltration of inflammatory cells； hematology improvement and weakened white blood cell differentiation were found. CONCLUSIONS The ethyl acetate extract of M. pudica root can inhibit the proliferation of WEHI-cells， and improve symptoms in acute myeloid leukemia mice， the mechanism of which may be associated with enhancing the immune function.

Measurement of the relationship between maxillary premolar roots and the maxillary sinus floor using cone beam CT and analysis of the impact on immediate implantation / 口腔疾病防治

Objective@#To analyze the spatial relationship between the roots of maxillary anterior premolars and the maxillary sinus, thus providing an anatomical basis for timing, planning, surgical approaches, and implant selection at this site.@*Methods@#Cone beam CT (CBCT) images were collected from 264 patients (aged 20-65 years) who visited the Ruihua Dental Clinic between January 2017 and March 2023. The minimum distance from the apex of the maxillary anterior premolar roots to the lower wall of the maxillary sinus was measured on the coronal plane. The classification of the vertical relationship between the tooth root and the lower wall of the maxillary sinus was performed, and comparisons were made bilaterally, between genders, and among different age groups.@*Results@#The minimum distance (Q50) from the apex of the first maxillary premolar root to the lower wall of the maxillary sinus was 7.34 mm for the single-root type, 7.80 mm for the buccal root of the double-root type, and 7.36 mm for the palatal root. For the second maxillary premolar, the median distance was 2.56 mm for the single root type, 1.73 mm for the buccal root type, and 1.23 mm for the palatal root type. There was a significant difference in the shortest distance from the apex of the right second maxillary premolar single root to the lower wall of the maxillary sinus among the different age groups (P<0.05), with the 20-29-year-old group having the smallest median distance (1.52 mm) and the ≥ 40-year-old group having the largest (4.44 mm). There was no significant difference in the effect of sex or laterality on distance (P>0.05). The most common vertical relationship between the apex of the maxillary anterior premolar roots and the lower wall of the maxillary sinus was noncontact. There was no significant difference in the vertical relationship classification between the single-root and double-root types (P>0.05).@*Conclusion@#Most maxillary first premolar roots can provide sufficient bone height, which makes it easy to achieve immediate implantation. The maxillary second premolar root frequently involves insufficient bone, which is necessary to make full use of the bone wall of the extraction socket or the sinus floor cortical bone to achieve initial stability. The vertical relationship between the premolar root and maxillary sinus was influenced by age and dental position. Younger age groups often exhibit inadequate bone height, and the indication for immediate implantation should be carefully considered. The number of roots does not significantly affect the relationship between the sinus and root; however, double-rooted premolars offer more support for immediate implantation and socket healing due to the small root diameter and bony separation between the roots.

Clinical observation of antibacterial photodynamic therapy assisted subgingival curettage for the treatment of chronic periodontitis / 口腔疾病防治

Objective@#To investigate the efficacy of antibacterial photodynamic therapy (aPDT) as an adjunct to subgingival scaling and root planning in the treatment of chronic periodontitis.@*Methods@#This study followed medical ethics guidelines, and informed consent was obtained from all patients. Sixteen patients were recruited for this randomized split-mouth controlled trial. The control group underwent subgingival scaling and root planning (SRP), while the experimental group received subgingival scaling and root planing plus aPDT treatment using Perowave® with a toluidine blue O solution photosensitizer. The probing pocket depth (PD), recession, plaque index (PLI), bleeding index (BI) and proportion of positive sites of bleeding on probing (BOP) (BOP%) at all sites were examined at baseline (before treatment) and at 1, 3 and 6 months after treatment.@*Results@#Follow-up was completed for 13 patients. On the control side, 356 teeth were tested at 2 136 sites. A total of 360 teeth on the test side and 2 160 sites were included in the study. Before treatment, there was no significant difference in the baseline indicators between the two groups. After treatment, both groups showed significant improvement in clinical parameters, including PD, PLI, BI, and BOP%,compared with baseline. At 3 months, the BOP% and PLI in the experimental group were significantly lower than those in the control group (P<0.05). The improvement in BOP% and PLI in the experimental group was significantly greater than that in the control group 3 months after treatment (P<0.05).@*Conclusion@#aPDT, as an adjuvant treatment to SRP for chronic periodontitis, can improve gingival bleeding and control periodontal inflammation in the early stage.

Performance of calcium sulfate-based root canal sealers for deciduous teeth / 口腔疾病防治

Objective@#To investigate the physicochemical and biological properties of a new calcium sulfate-based root canal sealer for deciduous teeth containing calcium sulfate hemihydrate, barium sulfate, chlorhexidine acetate, and polyethylene glycol 400 (PEG 400).@*Methods@#This study was reviewed and approved by the Ethics Committee. The calcium sulfate hemihydrate and barium sulfate powders with different mass percentages were mixed with liquid PEG 400 at a powder-to-liquid ratio of 3∶1, and chlorhexidine acetate was added to a concentration of 0.2 mg/mL according to the volume of PEG 400. The above materials were mechanically ground at 250 r/min for 24 h to obtain a calcium sulfate-based root canal sealer for deciduous teeth. The sealer was classified into different groups according to mass percentages of components. The mass percentages of components were optimized by performing time, fluidity, and radiopacity experiments, and then the pH, mass loss in vitro, and microscopic morphology of the optimal sealer were evaluated. The antimicrobial properties of the sealer were evaluated by a bacterial-material cocultivation method. The cytocompatibility of the sealer was evaluated by a CCK-8 assay and cytomorphological staining, and its biocompatibility was evaluated by a subcutaneous tissue embedding assay.@*Results@#After optimization, mass percentage of calcium sulfate hemihydrate was 80 wt%, and the mass percentage of barium sulfate was 20 wt%. The flowability and radiopacity of the sealer were in accordance with international standards. The pH stabilized between 6-7. On the 7th and 14th days, the pH in the water group was significantly greater than that in the PBS group (P<0.001), although the pH in both groups gradually increased (P>0.05). In vitro degradation experiments, the mass loss of the sealer was approximately 15.17% during the preimmersion period, and rate of mass loss decreased after 3 weeks, reaching only approximately 8.33%. X-ray diffraction (XRD) and scanning electron microscopy (SEM) revealed that the main component of the sealer after hydration was calcium sulfate dehydrate. In bacterial growth assays and cytological tests, the sealer showed significant inhibition of the growth of E. faecalis (P<0.001). After 1 and 4 days of culture, the cell viability in the 1∶10 and 1∶20 sealer extract dilution group was lower than that in the control group (P<0.05). On the 7th day, the 1∶20 sealer extract dilution had no significant effect on cell proliferation (P>0.05). Both the sealer group and the control group (Vitapex and zinc oxide eugenol) caused mild inflammatory reactions in tissue sections.@*Conclusion@#In this study, a new type of root canal sealer for deciduous teeth was designed based on calcium sulfate, which has good physicochemical properties and strong antibacterial properties and meets biocompatibility requirements. This study provides an idea for the development of a new type of root canal sealer for deciduous teeth.