Analysis of congenital deciduous teeth absence and its permanent teeth phenotype / 华西口腔医学杂志

OBJECTIVES@#This study aimed to investigate the clinical characteristics of congenital deciduous teeth absence and its permanent teeth performance type by using panoramic radiographs.@*METHODS@#A total of 15 749 panora-mic radiographs of 3-6-year-old children with deciduous dentition were collected from January 2020 to December 2021. The incidence of congenital deciduous teeth absence was observed, and the abnormality of permanent teeth was recor-ded. SPSS 24.0 software was used for statistical analysis.@*RESULTS@#The incidence of congenital deciduous teeth absence was 2.54% (400/15 749), which was found in 217 girls and 183 boys, and the difference between the genders was statistically significant (P=0.003). The absence of one and two deciduous teeth accounted for 99.75% (399/400) of the subjects. In addition, 92.63% (490/529) of mandibular deciduous lateral incisor was congenitally absent, 44.80% (237/529) of deciduous teeth was absent in the left jaw, and less than 55.20% (292/529) was absent in the right; the difference between them was statistically significant (P=0.017). The absence of 96.41% (510/529) deciduous teeth in the mandibular was significantly more than that of 3.59% (19/529) in the maxillary, and the difference between was statistically significant (P=0.000). Furthermore, 68.00% (272/400) and 32.00% (128/400) of deciduous teeth were absent in unilateral and bilateral, respectively, and the difference was statistically significant (P=0.000). Four types of congenital deciduous teeth absence with permanent teeth were observed as follows: 1) 73.91% (391/529) of permanent teeth was absent; 2) 20.60% (109/529) of permanent teeth was not absent; 3) the number of fused permanent teeth accounted for 4.91% (26/529); 4) the number of supernumerary teeth was 0.57% (3/529).@*CONCLUSIONS@#Although the absence of congenital deciduous teeth is less common than that of permanent teeth, it affects deciduous and permanent teeth to some extent. Dentists should pay attention to trace and observe whether abnormalities are present in the permanent teeth and take timely measures to maintain children's oral health.

Use of pulp tissue of deciduous teeth for gender determination - A comparative molecular analysis study

Aim: The present study aimed to evaluate the effectiveness of pulp tissue collected from deciduous teeth for the determination of gender using polymerase chain reaction (PCR). Materials and Methods: 140 extracted deciduous teeth were selected. The control group comprised 20 teeth that were subjected to DNA analysis immediately. Whereas Group I and Group II consisted of 60 teeth which were stored in the open environment and salt water, respectively, for a period of 3, 9, and 15 months. DNA was isolated and quantified followed by the amplification of X and Y chromosomes by PCR and compared with the actual gender of the child. The data were analysed using the Shapiro?Wilk test, the independent sample t?test, paired t?test, and the Chi?square test. Result: The PCR analysis results of Group I showed a more correct interpretation of gender as compared to Group II on storage for a period of 15 months. The PCR analysis results of the Control group showed a 100% accuracy rate as compared to the samples in Groups I and II. Conclusions: Gender could be effectively determined from the samples evaluated immediately after extraction. But the period of storage and the method of storage conditions affected the quality of isolated DNA and thus decreased the ability of gender determination

linical performance of one shade universal composite resin and nanohybrid composite resin as full coronal esthetic restorations in primary maxillary incisors A randomized controlled trial

Background: Strip crowns are the first treatment of choice for restoring anterior teeth affected with early childhood caries. However, shade matching of resin composites is still an issue. The broad color matching ability of a recently introduced single shade composite, Omnichroma eliminates the need for shade-matching procedure, reduces composite inventory, and minimizes chair-side time. Aim: The aim is to evaluate the color match, color stability, and retention of one shade universal composite resin, Omnichroma and nanohybrid resin composite, Tetric-N-Ceram. Settings and Design: The study design involves split-mouth randomized controlled trial. Materials and Methods: The study was conducted on 25 children aged 3–5 years with multi-surface caries lesions in primary maxillary anterior teeth. Teeth were allocated to two groups randomly: Group 1 – One shade universal composite, Omnichroma (n = 25), Group 2 – Nanohybrid composite, Tetric-N-Ceram (n = 25). After caries excavation and tooth preparation, teeth were restored with corresponding materials using strip crowns. Color match at baseline, color stability, and retention after 6- and 12-month follow-up were evaluated using the Modified United States Public Health Services criteria. Statistical Analysis: The Mann–Whitney U test and Wilcoxon signed-rank test were used to analyze the data. Results: On comparison of Omnichroma and Tetric-N-Ceram groups, no statistically significant difference was observed in the color match at baseline (P = 0.716) as well as color stability (P = 0.575 at 6 months and 0.990 at 12 months) and retention (P = 0.153 at 6 months and 0.226 at 12 months) at both 6- and 12-month intervals. On intragroup comparison, the difference in the color stability at 6 and 12-month interval was statistically significant (P = 0.001) for both the groups, indicating that the color stability of restorations was better at 6-month interval compared to 12-month interval. In both Omnichroma and Tetric-N-Ceram groups, retention of restorations was better at 6-month interval compared to 12-month interval and this difference was statistically significant (P = 0.025 and 0.014, respectively). Conclusion: The clinical performance of Omnichroma in terms of color match, color stability, and retention was comparable to nanohybrid composite, Tetric-N-Ceram.

A systematic review of randomized controlled trials on survival rate of atraumatic restorative treatment compared with conventional treatment on primary dentition

Background: In this COVID era, it's critical to promote nonaerosol procedures. Atraumatic restorative treatment (ART) is one of them, and it's particularly effective in children for lowering anxiety, enhancing dental health, and giving restorative care. Aim: The aim of this study was to assess the survival rate of ART compared with conventional treatment procedures in primary dentition. Materials and Methods: The review was done in accordance with the Preferred Reporting Items for Systematic reviews and Meta-analysis statement and is been registered in PROSPERO (CRD42021213729). The studies included comprised clinical investigations with randomized controlled trials (RCTs) which compared the survival rate of ART and conventional restorative treatments using the same or different restorative materials to treat carious lesion. RCTs in which ART was compared with conventional treatment on patients in the age group of 6–10 years with minimum follow-up of 6 months. Studies available as open access and free full text in PubMed, DOAJ, and Google Scholar databases, and published in English Language only were included in the study. Cochrane's collaboration tool for RCTs was used for the assessment of risk of bias. Results: The survival rate of single surface and multiple surface in primary dentition treated according to the ART compared with conventional treatment was found to be similar. Conclusion: The ART approach is equally helpful in managing dental caries in children and this method may be considered a useful intervention in clinical practice to enhance the dental health of children.

Application of chronic disease management model in early childhood caries / 口腔疾病防治

@#Early childhood caries (ECC) is not only harmful to children's oral cavity and even the whole body, the government and relevant health departments pay more and more attention to the prevention and treatment of early childhood caries. However, at present, the primary treatment for ECC is the traditional filling therapy. The chronic disease management model can conduct regular testing of chronic non-communicable diseases and their risk factors, and provide long-term and effective professional management to patients by supervision and advice by doctors, nurses and pharmacists. This model has a good effect on slowing down the development of the disease, improving the quality of life of patients and saving public health resources. As a common chronic non-communicable disease, ECC is very suitable for prevention and treatment through chronic disease management. In recent years, chronic disease management models have also been increasingly used in the management of caries. The current common chronic disease management models include the chronic care model, innovative care for chronic condition, and British chronic disease management system models. And above models have certain applications in the management of ECC. How to establish the caries risk assessment system suitable for the diagnosis and treatment model of our country, and how to screen the children with high risk of caries by step-by-step prevention and control network for personalized prevention needed to be further studied in the future.

Use of the amber teething necklace by the child population: risks versus benefits / Uso do colar de âmbar pela população infantil: riscos x benefícios

Abstract Objective: Based on scientific evidence, the objective of the present study is to report the possible risks and benefits of the amber teething necklace for children who use it. Data source: This is an integrative literature review, carried out based on the following guiding question: "Does the amber teething necklace have therapeutic properties that justify its usage during tooth eruption?". The consulted databases were LILACS (Latin American and Caribbean Health Sciences Literature) and PubMed (National Center for Biotechnology Information), with the following descriptors: "Amber," "Deciduous teeth," "Strangulation," and "Local symptoms." Data synthesis: A total of five scientific articles were selected, which indicates an insufficient basis regarding the benefits associated with the use of the amber teething necklace. Conversely, there is a convergence regarding the possibility of health risks such as strangulation, asphyxiation, and swallowing of beads. Conclusions: Health professionals should discourage the use of the amber teething necklace by children insofar more studies on the topic are carried out.

Resumo Objetivo: Com base em evidências científicas, a proposta do presente trabalho é relatar os prováveis riscos e benefícios do uso do colar de âmbar pela população infantil. Fontes de dados: Trata-se de uma revisão integrativa da literatura, realizada a partir da elaboração da questão norteadora: "O colar de âmbar apresenta propriedades que justifiquem seu uso durante a erupção dentária?''. As bases de dados utilizadas foram LILACS (Literatura Latino-americana e do Caribe em Ciências da Saúde), PubMed (National Center for Biotechnology Information), por meio dos descritores: Âmbar; Dentes decíduos; Estrangulamento; Sintomas locais. Síntese dos dados: Após a busca dos dados, foram selecionados cinco artigos, os quais apontam insuficiente embasamento científico que comprove os benefícios relacionados ao uso do colar de âmbar. Em contrapartida, existe uma convergência quanto à possibilidade de riscos à saúde, como estrangulamento, asfixia e deglutição das pedras. Conclusões: Conclui-se que os profissionais da saúde devem desencorajar o seu uso por crianças até que pesquisas clínicas bem delineadas sejam disponibilizadas.

Dental stem cells in intraoral regenerative therapy: a systematic review / Células-tronco dentárias na terapia regenerativa intraoral: uma revisão sistemática

Objective: 1) To critically review the published literature on applications of dental stem cells in the regeneration of intraoral tissues. 2) To provide an evidence-based level on research regarding application of dental stem cells in intraoral tissues regeneration. Methodology: This systematic review is conducted as per the JBI guidelines and reported as per the PRISMA. An initial literature search of papers published between 2004 and 2018 yielded 421 manuscripts. Nineteen studies satisfied the inclusion / exclusion criteria and were included for qualitative synthesis. Studies were categorized as animal (11) and human (8) trials. Five independent reviewers critically assessed the included studies. Risk of bias was assessed using SYstematic Review Centre for Laboratory animal Experimentation (SYRCLE) bias risk tool, robins-I tool for non-randomised clinical trial and Cochrane Collaboration's Tool for randomised clinical trial. Evidence levels were assessed based on JBI Criteria. Results: Animal trials mainly focused on periodontal regeneration. A high or unclear Risk of bias was more commonly found amongst animal studies. Laboratory, clinical and radiographic evaluation were used to assess the outcome. A total of Eight Human studies were conducted on a total samples size of 153 upon a wide age ranging from seven years to 60 years. Nearly 70% of the human studies used DPSC for regenerating alveolar bone defects. Conclusion: Appropriate well designed double-blind randomized clinical trials of longer duration are yet to be performed. Evidence for the included studies were 1C and 1D as per the JBI Criteria. Stem cell therapy demonstrated promising results in Periodontal tissue and alveolar bone regeneration. However, the number of studies to claim such a benefit are very limited (AU)

Objetivo: 1) Revisar criticamente a literatura publicada sobre aplicações de células-tronco dentárias na regeneração de tecidos intraorais. 2) Fornecer um nível baseado em evidências sobre pesquisas relacionadas à aplicação de células-tronco dentárias na regeneração de tecidos intraorais. Metodologia: Esta revisão sistemática é conduzida de acordo com as diretrizes do JBI e relatada de acordo com o PRISMA. Uma pesquisa bibliográfica inicial de artigos publicados entre 2004 e 2018 resultou em 421 manuscritos. Dezenove estudos satisfizeram os critérios de inclusão / exclusão e foram incluídos para síntese qualitativa. Os estudos foram categorizados como ensaios em animais (11) e humanos (8). Cinco revisores independentes avaliaram criticamente os estudos incluídos. O risco de viés foi avaliado usando a ferramenta de risco de viés do Centro de Revisão Sistemática para Experimentação com Animais de Laboratório (SYRCLE), a ferramenta robins-I para ensaios clínicos não randomizados e a Ferramenta da Colaboração Cochrane para ensaios clínicos randomizados. Os níveis de evidência foram avaliados com base nos critérios JBI. Resultados: Os ensaios em animais focaram principalmente na regeneração periodontal. Um risco alto ou pouco claro de viés foi mais comumente encontrado entre os estudos com animais. Avaliações laboratorial, clínica e radiográfica foram utilizadas para avaliar o resultado. Um total de oito estudos em humanos foram conduzidos em um tamanho total de amostras de 153 com ampla faixa etária, variando de sete a 60 anos. Quase 70% dos estudos em humanos usaram DPSC para regeneração de defeitos ósseos alveolares. Conclusão: Ensaios clínicos randomizados duplo-cegos apropriados e bem elaborados de maior duração ainda precisam ser realizados. As evidências para os estudos incluídos foram 1C e 1D de acordo com os critérios JBI. A terapia com células-tronco demonstrou resultados promissores na regeneração do tecido periodontal e do osso alveolar. No entanto, o número de estudos para reivindicar tal benefício é muito limitado (AU)

Condición Periodontal de los Dientes Temporales Adyacentes a la Hendidura Alveolar en Pacientes con Labio y Paladar Hendido Unilateral No Sindrómico, Hospital Nacional de Niños "Dr. Carlos Sáenz Herrera", Caja Costarricense de Seguro Social

RESUMEN: Los dientes adyacentes a la hendidura alveolar, en pacientes con labio y paladar hendido, presentan mayor incidencia de problemas periodontales, según la literatura. El objetivo de este trabajo fue evaluar si los dientes temporales adyacentes a la hendidura alveolar presentan mayor incidencia de problemas periodontales en niños con labio y paladar hendido unilateral completo no sindrómico, nacidos en 2010 y 2011, atendidos en el Hospital Nacional de Niños "Dr. Carlos Sáenz Herrera", Caja Costarricense de Seguro Social. Este estudio prospectivo, transversal, descriptivo, e intervencional evaluó variables epidemiológicas, clínicas y radiográficas (placa bacteriana, profundidad de bolsa, nivel de inserción, recesión gingival, sangrado, encía queratinizada e insertada, cálculo y movilidad dental, tipo de hendidura alveolar). Se utilizó técnicas de análisis estadísticos descriptivas (distribución de frecuencias, cruce de variables y construcción de intervalos de confianza). El análisis de datos y procesamiento estadístico se realizó en SPSS versión 17.0 y en Excel. El grupo constó de 17 pacientes, con edad promedio de 5 años. Se encontró 47 % de placa dental y 0 % de cálculo dental. La profundidad de bolsa y el sangrado fueron estadísticamente mayores para los dientes dentro de la hendidura alveolar. Los dientes adyacentes a la hendidura presentaron menor cantidad de encía queratinizada e insertada. Referente a la movilidad dental no existe diferencia estadísticamente significativa. Solo un diente presentó recesión gingival. La hendidura alveolar completa predominó radiográficamente. Los dientes cercanos a la hendidura alveolar tienen mayor predisposición a problemas periodontales, por lo que es relevante el seguimiento regular de la salud periodontal.

ABSTRACT: The teeth adjacent to the alveolar cleft, in patients with cleft lip and palate, present a higher incidence of periodontal problems, according to the literature. The purpose of this study was to evaluate whether the temporary teeth adjacent to the alveolar cleft present a higher incidence of periodontal problems in children with non-syndromic complete unilateral cleft lip and palate, born in 2010 and 2011, treated at the Hospital Nacional de Niños "Dr. Carlos Sáenz Herrera", Caja Costarricense de Seguro Social. This prospective, cross-sectional, descriptive, and interventional study evaluated epidemiological, clinical and radiographic variables (bacterial plaque, pocket depth, insertion level, gingival recession, bleeding, keratinized and inserted gingiva, dental calculus and mobility, type of alveolar cleft). It used descriptive statistical analysis techniques frequency distribution, crossing of variables and construction of confidence intervals. Data analysis and statistical processing was performed in SPSS version 17.0 and in Excel. The group consisted of 17 patients, with an average age of 5 years. 47 % dental plaque and 0 % dental calculus were found. Pocket depth and bleeding were statistically higher for teeth in the alveolar cleft. The teeth adjacent to the cleft had less keratinized and inserted gingiva. Regarding dental mobility, there is no statistically significant difference. Only one tooth had gingival recession. The complete alveolar cleft predominated radiographically. Teeth close to the alveolar cleft have a greater predisposition to periodontal problems, so regular monitoring of periodontal health is relevant.

Crown formation times of deciduous teeth and age at death in neolithic newborns / Tiempos de formación de la corona de los dientes deciduos y edad al morir en neonatos neolíticos

SUMMARY: The aim of the present study was to investigate the possibility of estimating crown formation times of immature deciduous teeth and age at death in Neolithic newborns. In the Neolithic-Mesolithic transition, the health of the population deteriorated. Leaving the intrauterine environment for the newborn is the first obstacle in the process of adaptation and survival in the outside world. The fetus is protected by the mother's immune system and receives the necessary nutrients through the umbilical cord, but external factors indirectly affect its development. At birth deciduous teeth are not fully formed and are only partially mineralized. Variations in the rhythmic activity of ameloblasts and the secretion of the enamel matrix lead to the formation of incremental lines in the enamel. The sample consisted of unerupted deciduous teeth removed from the baby jaws from Neolithic archaeological graves, LepenskiVir Serbia. The skeletal age of the babies was from 38 to 40 gestational weeks. The daily enamel apposition rate was obtained for each tooth. The age of individuals was estimated using crown formation time. The average value of daily secretion rates for the primary teeth from the Neolithic age was 3.78 µm. There was no statistically significant difference in age at death determined by skeletal age assessment and crown formation time. Three babies were born preterm. The results of the present study show that the calculation of the time required for the formation of deciduous tooth enamel is applicable to archaeological samples of newborns.The age estimation using crown formation time together with the analysis of other anthropological parameters, can contribute to a more accurate determination of neonatal death in anthropological, archaeological and forensic contexts.

RESUMEN: El objetivo del estudio fue investigar la posibilidad de estimar el tiempo de formación de la corona de los dientes deciduos inmaduros y la edad, al momento de la muerte en neonatos neolíticos. Durante la transición Neolítico-Mesolítico, la salud de la población deterioró significativamente. Para el recién nacido dejar el medio intrauterino es el primer obstáculo en el proceso de adaptación y supervivencia en el mundo exterior. El feto está protegido por el sistema inmunológico de la madre y recibe los nutrientes necesarios a través del cordón umbilical, pero factores externos afectan indirectamente su desarrollo. Al nacer, los dientes deciduos no están completamente formados y solo están parcialmente mineralizados. Las variaciones en la actividad rítmica de los ameloblastos y la secreción de la matriz del esmalte conducen a la formación de líneas incrementales en el esmalte. La muestra consistió en dientes sin erupción extraídos de las mandíbulas de neonatos de tumbas arqueológicas neolíticas, LepenskiVir Serbia. La edad esquelética de los bebés fue de 38 a 40 semanas de gestación. Se obtuvo la tasa diaria de aposición de esmalte para cada diente. La edad de los individuos se estimó utilizando el tiempo de formación de la copa. El valor promedio de las tasas de secreción diaria para los dientes temporales del Neolítico fue de 3,78µm. No hubo diferencia estadísticamente significativa en la edad al momento de la muerte determinada por la evaluación de la edad esquelética y el tiempo de formación de la corona. Tres bebés nacieron prematuros. Los resultados del presente estudio muestran que el cálculo del tiempo requerido para la formación del esmalte dental deciduo es aplicable a muestras arqueológicas de recién nacidos. La estimación de la edad utilizando el tiempo de formación de la corona junto con el análisis de otros parámetros antropológicos, puede contribuir a una mayor determinación precisa de la muerte neonatal en contextos antropológicos, arqueológicos y forenses.

Evaluación clínica de acondicionamiento dentinario y presentaciones de ionómeros fotoactivados en odontopediatría / Clinical evaluation of dentin conditioning and different presentations of light cured glass ionomer in primary dentition

Objetivo: Comparar clínicamente el comportamiento, el tiempo operatorio requerido, el costo y la dificultad de diferentes técnicas de restauración en piezas primarias, empleando ionómero vítreo fotoactivado (IVF) polvo/líquido, con y sin uso de acondicionamiento dentinario, y en cápsulas, con acondicionamiento. Materiales y métodos: El diseño de este estudio fue experimental y comparativo. Se realizaron, en 18 pacientes de 7±2 años, 33 restauraciones con IVF de una o más piezas primarias vitales con lesiones amelodentinarias en 1 o 2 superficies. Según su día de concurrencia a la Cátedra de Odontología Integral Niños, se empleó: A) IVF polvo/líquido, con acondicionamiento (3M™ VitremerTM); B) IVF polvo/líquido, sin acondicionamiento (3M™ VitremerTM); y C) IVF en cápsulas, con acondicionamiento (Riva Light Cure). Las restauraciones fueron evaluadas clínicamente al inicio y a los 12 meses según los siguientes criterios: pérdida total, pérdida total con caries, requerimiento de reemplazo por pérdida parcial, requerimiento de reemplazo por caries, aceptable con deterioro, en condiciones. El grado de dificultad se analizó utilizando una planilla diseñada para tal fin. El tiempo operatorio requerido se midió sin considerar el tiempo de inserción. Resultados: El tiempo operatorio requerido fue de 2 minutos, 15 segundos en A; 1 minuto, 25 segundos en B; y 1 minuto, 10 segundos en C, sin considerar el tiempo de inserción. El costo fue 61,11% mayor para C. La dificultad fue de 3,2±0,6 para A y B, y de 1,5±0,7 para C (ANOVA; P<0,001). El comportamiento clínico no registró diferencias significativas entre los grupos (Fisher; P=0,339). Conclusión: Los ionómeros de restauración fotoactivados encapsulados utilizados en este estudio presentaron menor dificultad de manipulación, mayor costo y similar comportamiento clínico a un año que las presentaciones polvo-líquido, con o sin uso de acondicionamiento previo en piezas primarias (AU)

Aim: To assess the clinical performance, operative time required, cost and technical difficulties of different restorative techniques in primary teeth, using light cured glass ionomers (LCG), powder/liquid, with and without dentin conditioning and light cured glass ionomer in capsules with conditioning. Materials and methods: The design of this study was experimental and comparative. 33 restorations with LCG were performed in 18 patients, 7 ± 2-years-old, in one or more vital primary teeth with carious lesions involving one or more tooth surfaces. Patients were assigned to one of the three groups according to the day of the week in which they attended to the Pediatric Department of the Dental School: A) LCG powder/liquid, with conditioning (3M™ VitremerTM); B) LCG powder/liquid without conditioning (3M™ VitremerTM); and C) LCG in capsules with conditioning (Riva Light Cure). The restorations were clinically evaluated at baseline and after 12 months according to the following criteria: complete loss of the restoration, complete loss with caries, need of replacement because of partial loss, need of replacement because of caries, good condition with some wear and good condition. Technical difficulties were analyzed using a data sheet designed for that purpose. The operative time required was evaluated without considering the insertion time. Results: Time operative time required was 2 minutes 15 seconds in A, 1 minute 25 seconds in B and 1 minute 10 seconds in C. Cost was 61.11% higher for C. Difficulty was 3.2±0.6 for A and B and 1.5±0.7 for C (ANOVA; P<0.001). No significant differences were observed among the three groups in relation to the clinical performance (Fisher; P=0.339). Conclusions: In these 12 months, study in primary teeth, the light cured glass ionomers used dispensed in capsules showed to be the easiest to handle, had higher cost and similar clinical performance than the powder liquid presentations with and without dentin conditioner (AU)

Research progress on dental pulp stem cells in the repair of peripheral nerve injury / 口腔疾病防治

@#Peripheral nerve injury (PNI) is a common disease in the oral cavity that can easily lead to loss of function and abnormal appearance. The application of dental pulp stem cells (DPSCs) combined with tissue engineering in the repair of PNI is a research hotspot. DPSCs have the advantages of abundant sources, simple extraction, low immunogenicity and a high proliferation rate in vitro. They can differentiate into Schwann cells (SCs). SCs can induce autophagy and secrete key neurotrophic factors, such as nerve growth factor, brain-derived neurotrophic factor, ciliary neurotrophic factor and glial cell-derived neurotrophic factor. SCs are beneficial for the repair of nerve injury. DPSCs in different periods have differences in immune regulation, anti-inflammatory effects, expression of neural markers, angiogenesis and so on, which provide more diversified choices for nerve repair. At present, the introduction of tissue engineering provides a more controllable and improved microenvironment for DPSCs, which is conducive to the application and development of DPSCs in regenerative medicine and tissue engineering. However, there are still many problems to be solved, such as the selection of stem cells, functional link recovery, uncontrollable direction of axon regeneration, regulation of the peripheral nervous system and mechanism of repair.

The primary investigation and experiment of a community-based family dentist model for children aged 1-3 years old in Wuhan / 口腔疾病防治

Objective @#To explore the effect of a community family doctor model on caries management for children aged 1 to 3 years in Wuhan, and to provide basis for community prevention and control of children’s caries.@*Methods@#Using stratified randomization and paired sampling, 1 000 children aged 1 to 3 years were selected from the core community of the Wuhan Donghu High-tech Zone. The trial group was followed up 4 times a year at home or in the clinic, and the control group was followed up only at the baseline and the endpoint (2 years later). Caries and caries status were examined at baseline and 2 years later, and brushing behavior was investigated by questionnaire. @* Results @#The prevalence/dmft in the test group and control group after two years were 15.8%/1.41 and 46.6%/3.25, respectively, and the difference was statistically significant. The frequency with which parents helped their children to brush in the test group improved significantly compared to that of the control group.@* Conclusion @#For children aged 1 to 3 years, the dental family doctor model of caries prevention is economical and effective, and its application and promotion are recommended.

Therapeutic applications of stem cells from human exfoliated deciduous teeth: a review

Dental stem cells have been found to have the ability to differentiate into nerve cells, adipose cells, chondrocytes, osteoblasts, myocytes, hepatocytes, and odontoblasts. They can be derived from permanent teeth or deciduous teeth. Stem cells from human exfoliated deciduous teeth (SHED) have a higher proliferation rate and higher osteogenic and neurogenic potential than dental pulp stem cells (DPSC). Therefore, SHEDs are an attractive cell source for tissue regeneration. A large plethora of in vitro and animal studies have been conducted in the last few decades that has demonstrated the potential uses of these cells for the treatment of oral and non-oral diseases. The aim of this article was to review the potential therapeutic applications of stem cells derived from human exfoliated deciduous teeth. A Medline search was done, including international literature, published in English between 2003 and 2020. In this area, further research is needed to ensure the applicability of SHED in the treatment of diseases in humans.

Estudo longitudinal dos traumatismos severos em dentes decíduos: complicações clínicas e radiográficas / Longitudinal study of severe traumatisms on primary teeth: clinical and radiographic complications

O objetivo é avaliar a frequência dos traumatismos em dentes decíduos, as sequelas advindas das injúrias envolvendo os tecidos de sustentação, bem como a associação destas injúrias às sequelas clínicas e radiográficas. Trata-se de um estudo clínico longitudinal, no qual foram avaliados 342 dentes traumatizados, atendidas no serviço odontológico de uma instituição pública, as avaliações foram realizadas após o traumatismo e decorrido 24 meses. Os dados foram submetidos a uma análise descritiva e ao teste Qui-quadrado (p≤0,05). A maior frequência de traumas acorreu na idade 24-35 meses, o principal fator etiológico à queda da própria altura (77,8 %), gênero masculino (59,5%), arco dentário o superior (96,5%), dente 51 (43,1%); 70,6% possuíam mais de um dente afetado e 8,2% histórico de trauma; a injúria mais prevalente foi a luxação lateral (33,6%). Na proservação, houve associação entre tipo de injúria ao tecido de suporte com a presença de sequelas radiográficas (p=0,02) e perda precoce (p=0,01). Conclui-se que as principais sequelas observadas foram a descoloração coronária e reabsorção radicular inflamatória e houve associação significante entre as variáveis tipo de injúria ao tecido de sustentação com a presença de sequelas radiográficas e a perda precoce do dente decíduo traumatizado.

The objective is to evaluate the frequency of trauma in primary teeth, the sequelae resulting from injuries involving the supporting tissues, as well as the association of these injuries with clinical and radiographic sequelae. This was a longitudinal clinical study, in which 342 traumatized teeth, assisted at the dental service of a public institution, were evaluated after the trauma and after 24 months. The data were submitted to a descriptive analysis and the Chi-square test (p≤0.05). The highest frequency of trauma occurred at age 24-35 months, the main etiological factor being the decrease of height (77.8%), male gender (59.5%), dental arch (96.5%), tooth 51 (43.1%); 70.6% had more than one affected tooth and 8.2% had a history of trauma; the most prevalent injury was lateral luxation (33.6%). In the proservation, there was an association between type of injury to the supporting tissue with the presence of radiographic sequelae (p = 0.02) and early loss (p = 0.01). In conclusion, the main sequelae observed were tooth crown discoloration and inflammatory root resorption and there was a significant association between the type of support tissue injury and the presence of radiographic sequelae and the early loss of the traumatized deciduous tooth.

Comparative Evaluation of Bond Strength of Self-Etching and Total Etch Dental Adhesive Systems to Dentin of Deciduous and Permanent Teeth / Evaluación Comparativa de la Fuerza de Unión de los Sistemas de Adhesivo Dental Autograbado y Grabado Total para la Dentina de Dientes Deciduos y Permanentes

ABSTRACT: The aim of this study was to analyze the bond strength of total-etch and self-etch adhesive systems to dentin of primary and permanent teeth. Methods: Thirty sound naturally exfoliated primary molars deciduous teeth (DT) and thirty sound permanent bicuspids permanent teeth (PT) were randomly divided into six groups (n=10 per group) according to two commercial adhesive systems: Adper Single Bond 2; 3M ESPE (Total-etch) and Adper Easy Bond; 3M ESPE (selfetch and total-etch). Specimens submitted to cyclic loading in a universal Instron testing machine. Bond strength values (MPa) were analyzed by ANOVA test and Duncan post hoc test (a=0.05). Results: Mean values were higher in PT compared to DT. In deciduous teeth, no significantly differences observed. Total etch AdperTM Single Bond 2 showed significantly higher bond strength than self-etch AdperTM with additional acid etching in PT (p=0.031). Conclusion: Our findings suggest that the highest bond strength was found in dentin tissue of PT with total etch AdperTM employing the adhesive the Single Bond 2 of one step self-etch.

RESUMEN: El objetivo de este estudio fue analizar la fuerza de unión de los sistemas adhesivos de grabado total y autograbado a la dentina de los dientes primarios y permanentes. Métodos: treinta sonidos exfoliaron naturalmente los molares primarios dientes caducifolios (DT) y treinta sonidos. Los dientes permanentes de los premolares permanentes (PT) se dividieron aleatoriamente en seis grupos (n = 10 por grupo) de acuerdo con dos sistemas adhesivos comerciales: Adper Single Bond 2; 3M ESPE (Grabado total) y Adper Easy Bond; 3M ESPE (autograbado y grabado total). Muestras sometidas a carga cíclica en una máquina universal de pruebas Instron. Los valores de resistencia de la unión (MPa) se analizaron mediante la prueba ANOVA y la prueba post hoc de Duncan (a = 0.05). Resultados: Los valores medios fueron mayores en PT en comparación con DT. En dientes deciduos, no se observaron diferencias significativas. Total etch AdperTM Single Bond 2 mostró una fuerza de unión significativamente mayor que la autograbado AdperTM con grabado ácido adicional en PT (p = 0.031). Conclusión: Nuestros hallazgos sugieren que la mayor fuerza de unión se encontró en el tejido de dentina de PT con grabado total AdperTM empleando el adhesivo Single Bond 2 de autograbado de un solo paso.

Avaliação da citotoxicidade in vitro de diferentes pastas endodônticas utilizadas em odontopediatria / In vitro cytotoxic effects of different endodontic pastes used in pediatric dentistry

Objetivo: O presente estudo teve como objetivo avaliar o potencial citotóxico de três diferentes pastas endodônticas em cultura celular de osteoblastos humanos. Material e Métodos: As pastas endodônticas Calen PMCC (SSWhite Artigos Dentários LTDA, Rio de Janeiro, Brasil), Feapex (Fórmula e Ação, São Paulo, Brasil) e CTZ (Lenzafarm, Belo Horizonte, Brasil) foram preparadas e eluídas em meio de cultura celular durante 24 horas em estufa a 37°C e 5% de CO2. Foram realizadas quatro diluições distintas desses meios nas concentrações 1: 1, 1: 2, 1: 4 e 1: 8. Culturas de células de Osteoblastos Humanos da linhagem Saos-2 foram expostas a estas diluições durante 24 horas. O controle negativo foi realizado expondo as células ao meio de cultura sem contato com nenhuma pasta endodôntica. A citotoxicidade desses meios foi avaliada utilizando o ensaio MTT e os resultados foram transformados em porcentagens de células viáveis em relação ao grupo controle negativo. A análise estatística foi realizada com nível de significância de 5%, utilizando ANOVA seguido do teste de Tukey. Resultados: A viabilidade celular foi significativamente alterada de acordo com o material testado (p <0,05) e sua concentração (p <0,05). Em todas as concentrações testadas, a pasta Feapex apresentou maior viabilidade celular comparada aos demais materiais (p <0,05). Embora não tenha sido observada diferença estatisticamente significante entre a pasta Calen PMCC e a pasta CTZ nas concentrações de 1: 1 e 1: 2 (p> 0,05), a pasta CTZ apresentou maior citotoxicidade nas concentrações de 1: 4 e 1: 8 (p <0,05 ). De forma geral, a citotoxicidade diminuiu com o aumento da diluição do material. Conclusão: De acordo com os resultados do presente estudo, a pasta endodôntica Feapex parece ser a melhor opção para utilização entre as pastas analisadas, pois apresentou menor citotoxicidade que as pastas Calen PMCC e CTZ

Objective: The aim of the present study was to evaluate the cytotoxic potential of three different endodontic filling materials on human osteoblast cell cultures. Material and Methods: The endodontic pastes Calen PMCC (SSWhite Dental Articles LTDA, Rio de Janeiro, Brazil), Feapex (Formula and Action, São Paulo, Brazil) and CTZ (Lenzafarm, Belo Horizonte, Brazil) were eluted in cell culture medium during 24 hours in an oven at 37°C and 5% CO2. Four distinct dilutions of these media were performed at the concentrations 1:1, 1:2, 1:4 and 1:8. Cell cultures of Saos-2 Human Osteoblast-like were exposed to these dilutions for 24 hours. The negative control group was performed by exposing the cells to culture medium without contact with any endodontic paste. The cytotoxic potential of these media was evaluated using the MTT assay and the results were transformed into viable cell percentages in relation to the negative control group. Statistical analysis was submitted with a significance level of 5%, using univariate Analysis of Variance (ANOVA) followed by Tukey's test. Results: Cell viability was significantly altered according to the material tested (p<0.05) and its concentration (p<0.05). Feapex samples presented higher cell viability than the other materials in all concentrations tested (p<0.05). Although no statistically significant difference was observed between Calen PMCC paste and CTZ paste at concentrations of 1: 1 and 1: 2 (p>0.05), CTZ paste showed a higher cytotoxicity at concentrations of 1: 4 and 1: 8 (p<0.05). In general, cytotoxicity decreases with increasing material dilution. Conclusion: According to the results of the present study, Feapex endodontic paste seems to be the better option for use among the analyzed pastes, since it presented lower cytotoxicity than Calen PMCC and CTZ pastes

Comparison of odontoblast differentiation capacity between stem cells from human exfoliated deciduous teeth and dental pulp stem cells / 中南大学学报(医学版)

OBJECTIVES@#To explore the difference in odontoblast differentiation capacity between stem cells from human exfoliated deciduous teeth (SHED) and dental pulp stem cells (DPSCs), and to examine the expression level of ephrinB1 in odontoblast differentiation of these stem cells.@*METHODS@#The stems cells were divided into a SHED group and a DPSCs group. After odontoblast differentiation induction, the above 2 groups were also randomly divided into a 3 d group and a 7 d group, respectively.The calcium deposition was detected by alkaline phosphatase (ALP) staining and alizarin red staining.The mRNA and protein expressions of ephrinB1, dentin matrix protein-1 (DMP-1) and dentin sialophosphoprotein (DSPP) were detected by real-time PCR and Western blotting.@*RESULTS@#ALP staining and alizarin red staining showed that there was stronger mineralization capacity in the SHED group than that in the DPSCs group. The relative mRNA and protein expressions of DMP-1, DSPP, and ephrinB1 in the SHED group were higher than those in the DPSCs group except for the protein expression of DMP-1 in the SHED 3 d group (all <0.05).@*CONCLUSIONS@#SHED has stronger odontoblast differentiation capacity than DPSCs. In addition, ephrinB1 may be involved in the processes of odontoblast differentiation in the SHED and DPSCs.

Structural characteristics of the deciduous teeth of Tibetan miniature pigs / 南方医科大学学报

OBJECTIVE@#To explore the histological structure of the deciduous teeth and the tooth germs of Tibetan miniature pigs for studies of dental tissue diseases and tooth regeneration.@*METHODS@#The structure of the deciduous teeth of Tibetan miniature pigs was observed by X-ray. The ultrastructure of the enamel and dentin of deciduous teeth was characterized by scanning electron microscopy. The jaws and teeth were three-dimensionally reconstructed using Mimics software based on Micro-CT scanning of the deciduous teeth. Image J software was used to calculate the gray value and the mineralization density of the deciduous teeth. Hisotological structure of the tooth germ and the pulp tissue of Tibetan miniature pigs was observed using HE staining.@*RESULTS@#The deciduous teeth of Tibetan miniature pigs were composed of enamel, dentin and medullary pulp tissue. The permanent tooth germ were formed during the deciduous dentition. The enamel and dentin ultrastructure of deciduous teeth were consistent with that of human deciduous teeth. The enamel and dentin mineralization densities were 2.47±0.09 g/cm and 1.72±0.07 g/cm, respectively. The pathological structures of tooth germ and pulp tissue were similar to those of human teeth, and the pulp tissue of the deciduous teeth was in an undifferentiated state.@*CONCLUSIONS@#The deciduous teeth of Tibetan miniature pig have similar anatomy, ultrastructure and histopathological structure to human teeth and can serve as a good animal model for studying human dental tissue diseases and the mechanisms of tooth regeneration.

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

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

Characterization of the biological effect of BiodentineTM on primary dental pulp stem cells

Biodentine™ is relatively a new tricalcium silicate cement that has gained great attention of the researchers due to its biological potential in comparison with other materials. The aim of this study was to investigate the optimum concentrations of Biodentine in relation to its stimulatory or inhibitory effect on proliferation, migration and adhesion of stem cells of human exfoliated deciduous teeth (SHED). The cell cultures of SHED were treated with Biodentine™ extract at four different concentrations; 20mg/ml, 2mg/ml, 0.2mg/ml and 0.02mg/ml. Cells cultured without Biodentine™ were kept as a blank control. The proliferation potential of SHED cells was evaluated by MTT viability analysis for 6 days. Migration potential was investigated by wound healing and transwell migration assays. The growth, survival and communication potential of these cells was determined by Adhesion assay. Results: A significant increase was observed in the proliferation and migration of SHED at (2mg/ml, 0.2mg/ml and 0.02mg/ml) while higher concentration of Biodentine™ (20mg/ml) exhibited cytotoxic effect on the cells. However, three tested Biodentine™ concentrations were similar in effect (non-significant) to adhesion ability of cells when compared with blank control. Conclusion: Our findings suggest that lower concentrations of Biodentine™ can be considered as the optimum concentrations to enhance the stimulatory effect of Biodentine on SHED.