Research progress on cemental tears in terms of clinical diagnosis and treatment / 口腔疾病防治

@#A cemental tear is defined as an incomplete or complete detachment of the cementum along the dentino-cemental junction (CDJ) or the incremental line within the body of the cementum, which can also involve part of the root dentine adjacent to the cementum. The pathogenesis of cemental tears is not fully elucidated. From the literature review, possible predisposing factors were identified, including tooth type, sex, age, periodontitis, previous periodontal treatment or root canal treatment, history of dental trauma, and occlusal trauma or excessive occlusal force. The morphology of cemental tears can be either piece-shaped or U-shaped, which usually contributes to periodontal and periapical breakdown. Clinically, cemental tears have a unitary periodontal pocket and present with symptoms mimicking localized periodontitis, apical periodontitis, and vertical root fractures. Imaging examination is of great significance for the clinical diagnosis of cemental tears, which often manifest as thin ‘prickle-like’ radiopaque masses located longitudinally adjacent to the affected root surface. Exploratory surgery is needed in some cases. Although intraoperative cemental fragments and cemental lines on the root surface can assist in the diagnostic process, histopathology examination is the gold standard for the diagnosis of cemental tears. The treatment methods vary depending on the timing of the correct diagnosis and the clinical or radiological manifestations. With the development of regenerative biomaterials and the development of intentional replantation, an increasing number of affected teeth can survive for a long time. The aim of this review is to systematically describe the biological basis and predisposing factors, clinical features, radiographic and histological characteristics, diagnosis and clinical management of cemental tears, and treatment outcomes to help make a clear diagnosis and develop a personalized treatment plan.

Research progress on immunomodulatory properties of periodontal ligament stem cells / 口腔疾病防治

@#Periodontal ligament stem cells (PDLSCs) have the potential for multidirectional differentiation and are the preferred seed cells for periodontal tissue regeneration. In recent years, a large number of studies have confirmed that PDLSCs also possess broad immunomodulatory properties. Therefore, in-depth exploration of their specific molecular mechanisms is of great significance for the treatment of periodontitis. The aim of this paper is to summarize the research progress on the regulation of PDLSCs on various immune cells and the effect of the inflammatory environment on the immune characteristics of PDLSCs to provide an important theoretical basis for the allotransplantation of PDLSCs and improve the therapeutic effect of periodontal tissue regeneration. Studies have shown that PDLSCs possess a certain degree of immunosuppressive effect on both innate and acquired immune cells, and inflammatory stimulation may lead to the impairment of the immunoregulatory properties of PDLSCs. However, current studies are mainly limited to in vitro cell tests and lack in-depth studies on the immunomodulatory effects of PDLSCs in vivo. In vivo studies based on cell lineage tracing and conditional gene knockout technology may become the main directions for future research.

Uso de L-PRF en defectos infraóseos de pacientes con estadios avanzados de periodontitis / Use of L-PRF in intrabone defects in patients with advanced stages of periodontitis

Objetivo: El propósito de este estudio fue observar el efecto del uso de L-PRF en defectos infraoseos de pacientes con periodontitis en estadios avanzados. Métodos: Se incluyeron 32 defectos infraoseos de 12 pacientes con diagnóstico de Periodontitis estadio III y IV (Workshop 2018). Se realizó raspaje a campo abierto con colocación de membrana de L-PRF. Se incluyeron defectos infraóseos de 1-2-3 paredes y cráter óseo. Se registró la profundidad de sondaje (PS), nivel de inserción clínica (NIC), índice de placa (IP) e índice de sangrado (IS). Se realizaron radiografías periapicale digitales antes de la cirugía y al cuarto mes para observar el llenado óseo. Resultados: De los 32 defectos el 75 % mostró disminución de la profundidad de sondaje (PS) y el 66 % mejoro el nivel de inserción clínica (NIC). Se realizó un análisis de correlación pre y posquirúrgico en PS: MV (p = 0,02), MP/L (p = 0,00), DP/L (p = 0,00) y V (p =0,00). El porcentaje de llenado óseo fue de 62,96 % (DS± 3,88). Conclusiones: La mayoría de los defectos infraóseos mostraron radiográficamente llenado óseo parcial o total con el uso de membranas L-PRF. Además, se mejoraron los parámetros clínicos de profundidad de sondaje y nivel de inserción clínica.

Objective: The purpose of this study was to observe the effect of L-PRF (Leuko- cyte-Platelet Rich Fibrin) usage in intraosseous defects in patients with advanced-stages of periodontitis. Methods: Thirty-two intraosseous defects in 12 patients diagnosed with stage III and IV periodontitis (Workshop 2018) were included in the study. Open flap debridement was performed with the placement of L-PRF membranes. Included defects consisted of 1-2-3 wall defects and osseous craters. Parameters such as probing depth (PD), clinical attachment level (CAL), plaque index (PI), and bleeding index (BI) were recorded. Digital periapical radiographs were taken before surgery and at the fourth month to assess bone fill. Results: Out of the 32 defects, 75% showed a reduction in probing depth (PD), and 66% showed improvement in clinical attachment level (CAL). Pre- and post-surgical correlation analysis was performed for PD: MV (p = 0.02), PI/L (p = 0.00), BI/L (p = 0.00), and CAL (p = 0.00). The percentage of bone fill was 62.96% (±3.88 SD). Conclusion: The majority of intraosseous defects exhibited partial or complete radiographic bone fill with the use of L-PRF membranes. Furthermore, clinical parameters such as probing depth and clinical attachment level improved.

Neo-osteogenesis using an intentionally exposed polypropylene membrane after tooth extraction versus guided bone regeneration technique: a single-blind randomized controlled trial / Neo-osteogénesis utilizando una membrana de polipropileno expuesta intencionalmente después de la extracción del diente versus técnica de regeneración ósea guiada: ensayo clínico aleatorizado ciego / Neo-osteogênese utilizando uma membrana de polipropileno exposta intencionalmente após extração dentária versus técnica de regeneração óssea guiada: ensaio clínico randomizado e cego

Introduction: The intentionally exposed polypropylene (PP) membrane has been proposed for guided bone regeneration (GBR) of the alveo lar bone after extraction; however, there are biological limitations to this proposal. This study aimed to describe the effects of the PP membrane on neo-osteogenesis after tooth extraction, comparing to intentionally ex posed and primary soft tissue coverage techniques. Methodology: This clinical trial followed the TIDieR checklist and guide. Clinical and histo logical parameters of alveolar repair were compared between groups: 1 (control group), without regenerative procedure; 2, GBR; and 3, inten tionally exposed membrane. Results: Group 3 showed slight effect on the quality of new bone, compared to the control group. Although the GBR was underestimated by the early exposure of the membrane, alveo lar repair and newly formed bone were superior to the other groups. Poly propylene membrane intentionally exposed compromised the volume density of the immature and mineralized bone matrix, the osteoblast and osteocyte count, and stimulated the granulation tissue formation and local inflammatory infiltrate. Conclusions: Despite the exposure of the PP membrane in GBR, this technique improved the quality of new bone and alveolar repair compared to the surgical technique of intentional exposure and alveolus only sutured.

RESUMEN Introducción: La membrana de polipropileno (PP) intencionalmente expuesta ha sido propuesta para la regeneración ósea guiada (GBR) del hueso alveolar después de la extracción; sin embargo, existen limitaciones biológicas a esta propuesta. Este estudio tuvo como objetivo describir los efectos de la membrana de PP en la neo-osteogénesis después de la extracción del diente, en comparación con las técnicas de cobertura de tejido blando primarias y expuestas intencionalmente. Metodología: Este ensayo clínico siguió la lista de verificación y la guía TIDieR. Se compararon los parámetros clínicos e histológicos de la reparación alveolar entre los grupos: 1 (grupo control), sin procedimiento regenerativo; 2, GBR; y 3, membrana expuesta intencionalmente. Resultados: el grupo 3 mostró un ligero efecto sobre la calidad del hueso nuevo, en comparación con el grupo de control. Aunque la GBR fue subestimada por la exposición temprana de la membrana, la reparación alveolar y el hueso neoformado fueron superiores a los otros grupos. La membrana de polipropileno expuesta intencionalmente comprometió la densidad de volumen de la matriz ósea inmadura y mineralizada, el recuento de osteoblastos y osteocitos, y estimuló la formación de tejido de granulación y el infiltrado inflamatorio local. Conclusiones: A pesar de la exposición de la membrana de PP en GBR, esta técnica mejoró la calidad del hueso nuevo y la reparación alveolar en comparación con la técnica quirúrgica de exposición intencional y alvéolo solo suturado.

Introdução: A membrana de polipropileno (PP) intencionalmente exposta tem sido proposta para regeneração óssea guiada (ROG) do osso alveolar após exodontia; no entanto, existem limitações biológicas a esta proposta. Este estudo teve como objetivo descrever os efeitos da membrana de PP na neo-osteogênese após a extração dentária, comparando com as técnicas de exposição intencional e cobertura primária de tecidos moles. Metodologia: Este ensaio clínico seguiu a lista de verificação e o guia TIDieR. Parâmetros clínicos e histológicos do reparo alveolar foram comparados entre os grupos: 1 (grupo controle), sem procedimento regenerativo; 2, GBR; e 3, membrana intencionalmente exposta. Resultados: O Grupo 3 apresentou leve efeito na qualidade do novo osso, em comparação com o grupo controle. Embora o GBR tenha sido subestimado pela exposição precoce da membrana, o reparo alveolar e o osso neoformado foram superiores aos outros grupos. A exposição intencional da membrana de polipropileno comprometeu a densidade volumétrica da matriz óssea imatura e mineralizada, a contagem de osteoblastos e osteócitos e estimulou a formação de tecido de granulação e infiltrado inflamatório local. Conclusões: Apesar da exposição da membrana PP na ROG, esta técnica melhorou a qualidade do novo osso e da reparação alveolar em comparação com a técnica cirúrgica de exposição intencional e alvéolo apenas suturado.

Dolor y edema posquirúrgico en la regeneración cutánea nasal con fibrina rica en plaquetas y leucocitos

Introducción: La reconstrucción de defectos cutáneos nasales requiere del uso de procedimientos orientados a obtener la menor probabilidad de complicaciones posoperatorias en el menor período de tiempo posible. Novedosas técnicas utilizan los concentrados plaquetarios por sus propiedades moduladoras del dolor y el edema posoperatorio. Objetivo: Determinar el comportamiento del dolor y el edema posquirúrgico en la regeneración de defectos cutáneos nasales con el uso de la membrana de fibrina autóloga, rica en plaquetas y leucocitos. Método: Se realizó una investigación cuasiexperimental, con diseño antes-después, sin grupo control en el Servicio de Cirugía Maxilofacial del Hospital Universitario "Arnaldo Milián Castro" de la ciudad de Santa Clara, Villa Clara, Cuba, desde septiembre de 2015 a junio de 2019. La muestra seleccionada aleatoriamente fue de 46 pacientes. A partir de una autodonación de sangre del paciente se obtuvo una membrana de fibrina rica en plaquetas y leucocitos, la cual fue suturada en el defecto quirúrgico nasal. Resultados: La edad media fue 62,71 años y el 60,87 % de la muestra correspondió al sexo masculino. Se presentaron el dolor en el 23,91 % y el edema en el 28,26 % de la muestra estudiada. Conclusiones: Se encontraron escasas complicaciones posoperatorias como el dolor y el edema, las que se manifestaron predominantemente de intensidad leve. Existió asociación entre estas complicaciones y la edad, la cantidad de subunidades anatómicas afectadas, la diabetes mellitus y el tabaquismo.

Introduction: The reconstruction of nasal skin defects requires the use of procedures aimed at obtaining the lowest probability of postoperative complications in the shortest period of time possible. Novel techniques use platelet concentrates for their modulating properties of pain and postoperative edema. Objective: To determine the behavior of pain and post-surgical edema in the regeneration of nasal skin defects with the use of autologous platelet- and leukocyte-rich fibrin membrane. Method: A quasi-experimental research was carried out, with a before-after design, without a control group, in the Maxillofacial Surgery Service at Arnaldo Milián Castro University Hospital in Santa Clara, Villa Clara, Cuba, from September 2015 to June 2015. 2019. The randomly selected sample was 46 patients. A fibrin membrane rich in platelets and leukocytes was obtained from a patient's blood self-donation, which was sutured in the nasal surgical defect. Results: The mean age was 62.71 years and 60.87% of the sample was male. Pain was present in 23.91% and edema in 28.26% of the studied sample. Conclusions: Few postoperative complications such as pain and edema were found, showing to be mild predominantly. There was association between these complications and age, the number of affected anatomical subunits, diabetes mellitus and smoking habit.

In vitro evaluation of membranes for regenerative procedures against oral bacteria

Abstract The current literature on guided bone regeneration (GBR) and guided tissue regeneration (GTR) membrane contamination reports that the physicochemical characteristics of these biomaterials might influence affinity to bacteria, which appears to be a major drawback for the clinical outcome of the regenerative procedures. Thus, this study aimed to evaluate, in vitro, a multispecies biofilm adherence and passage of bacteria through different types of commercially available membranes for GTR/GBR. Four types of membranes were tested (n=12): LC) Lumina Coat®; JS) Jason®; BG) Biogide®; and LP) Lumina PTFE®. Aluminum foil (AL) simulated an impermeable barrier and was used as the control. The membranes were adapted to specific apparatus and challenged with a mixed bacterial culture composed of A. actinomycetemcomitans b, S. mutans, S. mitis, and A. israelii. After 2 h or 7 days, bacterial adhesion and passage of bacteria were evaluated through CFU counting, which was analyzed by two-way ANOVA e post hoc Tukey, at a 5% significance level. Representative areas of two membranes of each group were analyzed through scanning electron microscopy (SEM) to assess the morphology and organization of the biofilm over the membrane fibers. LC and LP presented similar values of adhered bacterial cells (p > 0.05), significantly inferior when compared to the other groups, in both time points (p < 0.05). All the tested groups were permeable to bacterial cells, with no significant difference between the trial period of 2 h and 7 days (p > 0.05). SEM analyses demonstrated that adhered bacteria number increased throughout the time points (2 h < 7 days). Commercially available biological membranes demonstrated intense bacterial adherence and passage of bacteria, which increased throughout the trial period.

Resumo O objetivo deste estudo foi avaliar, in vitro, a aderência do biofilme multiespécie e a passagem de bactérias através dos diferentes tipos de membranas disponíveis comercialmente para RTG/ROG. Quatro tipos de membranas foram testados (n=12): LC) Lumina Coat®; JS) Jason®; BG) Biogide®; e LP) Lumina PTFE®. Papel alumínio (AL) simulou uma barreira impermeável e foi usado como controle negativo. As membranas foram adaptadas à um aparato específico e desafiadas com uma cultura bacteriana mista composta de A. actinomycetemcomitans b, S. mutans, S. mitis, e A. israelii. Após 2 h ou 7 dias, a aderência e passagem bacteriana foi avaliada através da contagem de UFCs. Duas membranas de cada grupo foram analisadas através da microscopia eletrônica de varredura (MEV). LC e LP apresentaram valores semelhantes de células bacterianas aderidas (p < 0.05), significativamente inferiores quando comparados aos outros grupos, em ambos os períodos experimentais (p < 0.05). Desde a análise inicial, todos os grupos testados foram permeáveis às células bacterianas, sem diferença significativa entre o período experimental de 2 h e 7 dias (p > 0.05). As análises em MEV demonstraram que o número de bactérias aderidas aumentou com o tempo (2 h < 7 days). Membranas biológicas comercialmente disponíveis demonstraram intensa aderência bacteriana e passagem de bactérias, que aumentou durante os períodos experimentais.

Efficacy of treatment of class II furcation lesions using membrane associated with bone grafting in mandibular molars compared to membrane only: a systematic review and meta-analysis / Eficacia del tratamiento de lesiones de furca grado II utilizando membrana asociada con injerto óseo en molares mandibulares en comparación con solamente membrana: revisión sistemática y metanálisis

Objective: The objective of the present systematic review and meta-analysis was to compare treatment with membrane associated with bone grafting and treatment exclusively with membrane in the approach of Class II furcation defects in mandibular molars. Materials and Methods: The Preferred Reporting Items for Systematic Reviews and Meta-analyses statement was followed. Searches were conducted in five databases (PubMed, Web of Science, Scopus, Ovid, and Lilacs), in Septem-ber 2021, without restriction regarding publication year or language. Studies comparing membranes associated with bone grafting and membranes exclusively in the treatment of Class II furcation lesions were included. Cross-sectional, case-control studies, and reviews were excluded. Study selection, data extraction, and risk of bias assessment (MINORS) were performed by two review authors. The certainty of the evidence (GRADE) was evaluated and meta-analysis was performed. Mean difference (MD) and 95% confidence interval (CI) were provided. Results: Four hundred eighty-six references were iden-tified and four studies were included. Greater reduction in probing depth [MD = 0.32 (CI = 0.09, 0.56)] and greater clinical attachment level gain [MD = 0.41 (CI = 0.24, 0.57)] were observed when membrane and bone grafting were used. The risk of bias of included studies was low. Conclusions: This present systematic review and meta-analysis demonstrated that treatment of Class II furcation defects in mandibular molars using membrane and bone grafing is significantly more efficacious than treatment with the exclusive use of membrane.

Objetivo: El objetivo de la presente revisión sistemática y metanálisis fue comparar el tratamiento con membrana asociado a injerto óseo y el tratamiento exclusivamente con membrana en el abordaje de lesiones de furca grado II en molares mandibulares. Materiales y Métodos: Se siguió la declaración de elementos de informe preferidos para revisiones sistemáticas y metanálisis (PRISMA). Las búsquedas se realizaron en cinco bases de datos (PubMed, Web of Science, Scopus, Ovid y Lilacs), en septiembre de 2021, sin restricción de año de publicación o idioma. Se incluyeron estudios que compararon membranas asociadas con injertos óseos y membranas exclusivamente en el tratamiento de lesiones de furca de grado II. Se excluyeron los estudios transversales, de casos y controles y las revisiones. Dos revisores realizaron la selección de estudios, la extracción de datos y la evaluación del riesgo de sesgo (MINORS). Se evaluó la certeza de la evidencia (GRADE) y se realizó un metanálisis. Se proporcionaron la diferencia de medias (DM) y el intervalo de confianza (IC) del 95%. Resultados: Se identificaron 486 referencias y se incluyeron cuatro estudios. Se observó una mayor reducción en la profundidad de sondaje [DM = 0,32 (IC = 0,09, 0,56)] y una mayor ganancia en el nivel de inserción clínica [DM = 0,41 (IC= 0,24, 0,57)] cuando se utilizaron injertos de membrana y hueso. El riesgo de sesgo de los estudios incluidos fue bajo. Conclusión: La presente revisión sistemática y metanálisis demostró que el tratamiento de los defectos de furca de grado II en molares mandibulares utilizando membrana e injertos de hueso es significativamente más eficaz que el tratamiento con el uso exclusivo de membrana.

Tratamiento de una lesión primaria por loxoscelismo cutáneo, complicada por infección, con solución electrolizada de superoxidación con pH neutro (SES). Informe de un caso / Treatment of a Primary Lesion of Cutaneous Loxoscelismo, Complicated by Infection, with Neutral Electrolyzed Water (SES). A Case Report

Resumen Las lesiones por loxoscelismo cutáneo pueden complicarse con infecciones concomitantes debido a que el diagnóstico es presuntivo y no existe un esquema de tratamiento específico. Las soluciones electrolizadas de superoxidación de pH neutro (SES) han mostrado ser eficaces en el tratamiento de lesiones cutáneas severas por sus efectos antisépticos y de regeneración del tejido, por lo que podrían ser un método de curación para las lesiones por loxoscelismo cutáneo. Presentamos el caso de un paciente del sexo masculino, de 73 años, cardiópata, diagnosticado con loxoscelismo cutáneo en el tobillo izquierdo que recibió tratamiento convencional de antibióticos, antiinflamatorios, antihistamínicos y analgésicos, y fue dado de alta. Sin embargo, la lesión evolucionó y fue tratada de manera casera con remedios tradicionales; esta se extendió 360° y presentaba exudado fétido al momento en que decidió regresar al hospital. En la clínica de heridas se optó por manejar la lesión en primera instancia con lavados con SES y desbridamiento, seguido de lavados con SES y apósitos de gel SES 3 veces al día, por 3 días, logrando el control de la infección en este tiempo. Posteriormente, con el régimen basado en la aplicación de SES cada 48 horas, se observó la aparición del tejido de granulación al día 7, y la reepitelización en el día 45 de iniciado el abordaje con SES; el cierre total de la lesión se logró el día 67. El esquema de tratamiento basado en el uso de soluciones electrolizadas de superoxidación de pH neutro mostró ser eficaz en el control de la infección y en la inducción del proceso de regeneración del tejido que llevó al cierre de la herida sin complicaciones para el paciente.

Abstract Cutaneous loxoscelism wounds can be complicated by concomitant infections because the diagnosis is presumptive and there is no specific treatment scheme. Neutral electrolyzed water (SES) has been shown to be effective in the treatment of severe skin lesions due to their antiseptic and tissue regeneration effects and could therefore be a healing method for skin loxoscelism lesions. We present the case of a 73-year-old male patient with heart disease, diagnosed with cutaneous loxoscelism in the left ankle, who received conventional treatment of antibiotics, anti-inflammatories, antihistaminics, and analgesics. He was discharged. However, the injury developed and was treated at home with traditional remedies. It extended 360° and presented a fetid exudate at the time he decided to return to the hospital. In the clinic it was decided to manage the lesion in the first instance with washes with SES and debridement, followed by washes with SES and SES gel dressings three times a day for 3 days, achieving control of the infection at that moment. Subsequently, with the regimen based on the application of SES every 48 hours, the appearance of granulation tissue was observed on day 7, and re-epithelialization on day 45 after starting the SES approach, the total closure of the lesion was achieved on day 67. The treatment scheme based on the use of neutral electrolyzed water proved to be effective in controlling the infection and in inducing the tissue-generation process that led to the closure of the wound without complications for the patient.

Effect of angiopoietin 4 on odontogenic differentiation of dental pulp stem cells / 口腔疾病防治

Objective @# To investigate the effects of angiopoietin 4 (ANGPT4) on the odontogenic differentiation of human dental pulp stem cells. @* Methods @#This study has been reviewed and approved by the Ethics Committee, and informed consent has been obtained from patients. Human premolars were fixed, decalcified, dehydrated, embedded, and sectioned. Immunofluorescence staining was used to observe the expression and localization of ANGPT4. Human dental pulp stem cells (hDPSCs) were isolated and cultured in vitro. The growth state and morphology of hDPSCs were observed under an inverted phase contrast microscope. The expression of cell surface-related molecular markers was detected by flow cytometry. Alkaline phosphatase and alizarin red S staining were used to detect the odontogenic differentiation potential of hDPSCs. Oil-red O staining was used to detect the adipogenic differentiation potential of hDPSCs. RNA was extracted from hDPSCs at different time points after odontogenic induction, and RT-qPCR was used to analyze the mRNA expression of ANGPT4 and odontogenic-related genes during the odontogenic differentiation of hDPSCs in vitro. siRNA gene silencing technology was used to silence the expression of ANGPT4 in hDPSCs, and the silencing efficiency was detected by RT-qPCR and Western Blot. After silencing ANGPT4 in hDPSCs for 24 h, odontogenic induction was performed. Alkaline phosphatase and alizarin red S staining were performed on the 7th and 14th of induction to detect the odontogenic differentiation ability of hDPSCs after silencing ANGPT4@*Results @# Immunofluorescence staining of human premolars showed that ANGPT4 was expressed in odontoblasts and sub-odontoblastic cell-rich zone. hDPSCs were in good condition after 14 days of isolation and culture. Under the microscope, multiple cell colonies were observed, and the cell morphology was uniform and long spindle-shaped. The results of flow cytometry showed that hDPSCs expressed mesenchymal stem cell markers CD105 (90.42%) and CD90 (97.15%), but did not express hematopoietic cell markers CD45 (0.01%) and CD34 (0.08%). After odontogenic and adipogenic induction of hDPSCs, alkaline phosphatase staining, alizarin red S staining and oil red O staining were positive. The results of RT-qPCR after the odontogenic induction of hDPSCs showed that ANGPT4 was highly expressed on the 5th, 7th, 11th and 14th days of differentiation of hDPSCs (P<0.05), with the highest expression level on the 5th day. After hDPSCs were transfected with si-ANGPT4, the expression of ANGPT4 mRNA and protein was significantly down-regulated (P<0.05). The results of alkaline phosphatase staining showed that ALP staining intensity and area in the si-ANGPT4 group were significantly lower than those in the negative control. Alizarin red S staining showed that the formation of calcium nodules in the si-ANGPT4 group was significantly lower than that in the negative control.@* Conclusion@#ANGPT4 was expressed in odontoblasts and sub-odontoblastic cell-rich zone of human premolars. ANGPT4 may be a factor to promote the odontogenic differentiation of hDPSCs.

Research progress of periodontal tissue regeneration by combined biomaterials of dental derived mesenchymal stem cells / 口腔医学

@#The ultimate treatment goal of periodontitis is the structural and functional regeneration of periodontium. However, existing methods for periodontal regeneration have difficulties in regenerating the hierarchical structure. Therefore, stem cell-based tissue engineering has attracted more and more attention for its advantages of self-renewal and multi-lineage differentiation potential. This review summarized the progress of research on periodontal tissue regeneration by combined biomaterials of dental-derived stem cells. It is pointed out that the application of autologous stem cell transplantation is limited by the donor source, and the subsequent research should focus on the development of multi-phase scaffold materials and the attempt to establish a stem cell bank.

An experimental study on the biological characteristics of SDF-1/CS/β-GP composite bio-membrane in vitro / 口腔医学

Objective@#To prepare a composite membrane by chitosan/β-sodium glycerophosphate(CS/β-GP) thermosensitive hydrogel combined with stromal cell derived factor-1(SDF-1) and observe its biological characteristics in vitro.@*Methods@#Different doses of SDF-1 were added into CS/β-GP solution and then the thermosensitive gel time was measured. The SDF-1/CS/β-GP solution was membrane paved and dried to prepare composite membranes. The morphological characteristics were observed by scanning electron microscope(SEM). Composite membranes were placed into cell culture medium, and the supernatant(n=3) was extracted after standing at 6, 12, 24, 36, 48, 60 h, respectively. The concentration of SDF-1 in the solution was measured. Bone mesenchymal stem cells(BMSCs) were cultured in the Transwell room, and the composite membranes containing different concentrations of SDF-1 were placed in the lower chamber. There were four groups(n=3): Group M0 used CS/β-GP membrane(control group), Group M1, M2, M3 used SDF-1/CS/β-GP membrane(SDF-1 was 100, 200, 400 ng/mL respectively). After culture for 6, 12 and 24 h, the cells under the membrane were preserved and Giemsa stained and counted. The absorbance(OD) value was measured by MTT method to calculate the cell proliferation rate. SPSS 19.0 was used for multi-factor analysis of variance.@*Results @#After adding a certain amount of SDF-1 into CS/β-GP solution, the gel time did not change significantly(P>0.05). The SDF-1/CS/β-GP membrane was translucent and porous at 37 ℃. In this experiment, the volumic mass of SDF-1 released by SDF-1/CS/β-GP composite membrane increased gradually with the experimental time(P<0.01). Transwell cell chemotaxis test showed that the number of BMSCs cells with directional migration increased with the prolongation of observation time(P<0.01) and the increase of SDF-1 volumic mass(P<0.01). In MTT test, the OD value of migration cell solution increased with the prolongation of time(P<0.01) and the increase of SDF-1 volumic mass(P<0.01). @*Conclusion@# The SDF-1/CS/β-GP composite membrane has a porous structure and biological activity of chemotactic BMSCs directional migration. It is a potential membrane for guided tissue regeneration.

Cross-regulation of Wnt/β-catenin and NF-κB signaling pathway and their involvement in the differentiation of mesenchymal stem cells / 口腔医学

@#Both Wnt/β-catenin signaling pathway and NF-κB signaling pathway are highly conservative pathways that regulate a variety of biological processes, and their cross-regulation have attracted attention in many biological and medical research fields. In this review, we summarize the cross-regulation between Wnt/β-catenin signaling pathway and NF-κB signaling pathway and discuss their involvement in the multi-directional differentiation of mesenchymal stem cells.

Multi-disciplinary treatment of severe palatal radicular groove of maxillary lateral incisor: A case report and literature review / 中南大学学报(医学版)

Palatal radicular groove is a developmental malformation of maxillary incisors, lateral incisors in particular, which often causes periodontal destruction. This paper reports a case of combined periodontal-endodontic lesions induced by palatal radicular groove, which was initially misdiagnosed as a simple periapical cyst. After root canal therapy and periapical cyst curettage, the course of disease was prolonged, resulting in the absence of buccal and maxillary bone plates in the affected tooth area. After the etiology was determined, the affected tooth was extracted and guide bone tissue regeneration was performed at the same time, followed by implantation and restoration at the later stage, leading to clinical cure. The palatal radicular groove is highly occult, and the clinical symptoms are not typical. If the abscess of the maxillary lateral incisor occurs repeatedly, and the abscess of the maxillary lateral incisor has not been cured after periodontal and root canal treatment, cone-beam computed tomographic and periodontal flap surgery should be considered.

Applicatoin of chitosan-based hydrogel in oral tissue engineering / 中南大学学报(医学版)

Pulpitis, periodontitis, jaw bone defect, and temporomandibular joint damage are common oral and maxillofacial diseases in clinic, but traditional treatments are unable to restore the structure and function of the injured tissues. Due to their good biocompatibility, biodegradability, antioxidant effect, anti-inflammatory activity, and broad-spectrum antimicrobial property, chitosan-based hydrogels have shown broad applicable prospects in the field of oral tissue engineering. Quaternization, carboxymethylation, and sulfonation are common chemical modification strategies to improve the physicochemical properties and biological functions of chitosan-based hydrogels, while the construction of hydrogel composite systems via carrying porous microspheres or nanoparticles can achieve local sequential delivery of diverse drugs or bioactive factors, laying a solid foundation for the well-organized regeneration of defective tissues. Chemical cross-linking is commonly employed to fabricate irreversible permanent chitosan gels, and physical cross-linking enables the formation of reversible gel networks. Representing suitable scaffold biomaterials, several chitosan-based hydrogels transplanted with stem cells, growth factors or exosomes have been used in an attempt to regenerate oral soft and hard tissues. Currently, remarkable advances have been made in promoting the regeneration of pulp-dentin complex, cementum-periodontium-alveolar bone complex, jaw bone, and cartilage. However, the clinical translation of chitosan-based hydrogels still encounters multiple challenges. In future, more in vivo clinical exploration under the conditions of oral complex microenvironments should be performed, and the combined application of chitosan-based hydrogels and a variety of bioactive factors, biomaterials, and state-of-the-art biotechnologies can be pursued in order to realize multifaceted complete regeneration of oral tissue.

Key points to execute internal horizontal mattress suture in tissue augmentation / 口腔疾病防治

@#Ideal sutures can provide great fixation, wound closure and a stable environment for healing of the surgical site. Tension-free apposition sutures are important for tissue regeneration and could tackle insufficient amounts of soft and hard tissue, especially in missing tooth sites that require implantation. The internal horizontal mattress suture, similar to the conventional horizontal mattress suture, forms a rectangle that can be bisected by the incision with both intrusion and extrusion of the needle on each side. On the basis of the rectangle, the internal horizontal mattress suture emphasizes that the suture should be located below the incision, so the eversion of the wound margin is the highlight of this procedure. The internal horizontal mattress suture could stabilize the graft on the targeting tissue, realize the fixation of the collagen membrane, apically repositioned flap and soft tissue graft, reduce the tension on the incision, and further release the tension of the incision margin. Beyond the primary need for fixation and wound closure, internal horizontal mattress sutures can also achieve stress interruption that reduces the interference of the surrounding muscle and can better master wound tension with the assistance of interrupted sutures. Given the above advantages, horizontal internal mattress sutures have great potential in the application of implant-related regenerative surgery. In this review, according to our experience in clinical practice and the literature, we summarize the advantages of internal horizontal mattress sutures in tissue augmentation. In addition, the sites and sequence to insert the needle and the spatial relationship between the suture and incision are clarified with the rationale of the naming pattern, which is conducive to experience exchange and clinical practice.

Application of hydrogel-loaded stem cell exosomes in the field of tissue regeneration / 生物工程学报

In recent years, mesenchymal stem cell (MSCs)-derived exosomes have attracted much attention in the field of tissue regeneration. Mesenchymal stem cell-derived exosomes are signaling molecules for communication among cells. They are characterized by natural targeting and low immunogenicity, and are mostly absorbed by cells through the paracrine pathway of mesenchymal stem cells. Moreover, they participate in the regulation and promotion of cell or tissue regeneration. As a scaffold material in regenerative medicine, hydrogel has good biocompatibility and degradability. Combining the two compounds can not only improve the retention time of exosomes at the lesion site, but also improve the dose of exosomes reaching the lesion site by in situ injection, and the therapeutic effect in the lesion area is significant and continuous. This paper summarizes the research results of the interaction of exocrine and hydrogel composite materials to promote tissue repair and regeneration, in order to facilitate research in the field of tissue regeneration in the future.

Efficiency analysis of commercial polymeric membranes for bone regeneration in rat cranial defects

Purpose: To evaluate the in vivo efficiency of commercial polymeric membranes for guided bone regeneration. Methods: Rat calvarial critical size defects was treated with LuminaCoat (LC), Surgitime PTFE (SP), GenDerm (GD), Pratix (PR), Techgraft (TG) or control (C-) and histomorphometric analysis determined the percentage of new bone, connective tissue and biomaterial at 1 or 3 months. Statistical analysis used ANOVA with Tukey's post-test for means at same experimental time and the paired Student's t test between the two periods, considering p < 0.05. Results: New bone at 1 month was higher for SP, TG and C-, at 3 months there were no differences, and between 1 and 3 months PR had greater increase growthing. Connective tissue at 1 month was higher for C-, at 3 months for PR, TG and C-, and between 1 and 3 months C- had sharp decline. Biomaterial at 1 month was higher for LC, in 3 months for SP and TG, and between 1 and 3 months, LC, GD and TG had more decreasing mean. Conclusion: SP had greater osteopromotive capacity and limitation of connective ingrowth, but did not exhibit degradation. PR and TG had favorable osteopromotion, LC less connective tissue and GD more accelerated biodegradation.

Stem cell-derived exosomes from human exfoliated deciduous teeth promote angiogenesis in hyperglycemic-induced human umbilical vein endothelial cells

Abstract Objective To investigate the angiogenesis in human umbilical vein endothelial cells (HUVEC) under high glucose concentration, treated with exosomes derived from stem cells from human exfoliated deciduous teeth (SHED). Methodology SHED-derived exosomes were isolated by differential centrifugation and were characterized by nanoparticle tracking analysis, transmission electron microscopy, and flow cytometric assays. We conducted in vitro experiments to examine the angiogenesis in HUVEC under high glucose concentration. Cell Counting Kit-8, migration assay, tube formation assay, quantitative real-time PCR, and immunostaining were performed to study the role of SHED-derived exosomes in cell proliferation, migration, and angiogenic activities. Results The characterization confirmed SHED-derived exosomes: size ranged from 60-150 nm with a mode of 134 nm, cup-shaped morphology, and stained positively for CD9, CD63, and CD81. SHED-exosome significantly enhanced the proliferation and migration of high glucose-treated HUVEC. A significant reduction was observed in tube formation and a weak CD31 staining compared to the untreated-hyperglycemic-induced group. Interestingly, exosome treatment improved tube formation qualitatively and demonstrated a significant increase in tube formation in the covered area, total branching points, total tube length, and total loop parameters. Moreover, SHED-exosome upregulates angiogenesis-related factors, including the GATA2 gene and CD31 protein. Conclusions Our data suggest that the use of SHED-derived exosomes potentially increases angiogenesis in HUVEC under hyperglycemic conditions, which includes increased cell proliferation, migration, tubular structures formation, GATA2 gene, and CD31 protein expression. SHED-exosome usage may provide a new treatment strategy for periodontal patients with diabetes mellitus.

Resultados estéticos en defectos nasales posquirúrgicos regenerados con fibrina autóloga rica en plaquetas y leucocitos / Aesthetic results in post-surgical nasal defects regenerated with autologous platelet- and leukocyte-rich fibrin

Introducción: En la reconstrucción de los defectos cutáneos nasales se han utilizado varias técnicas a nivel mundial. Novedosas prácticas utilizan los concentrados plaquetarios por sus propiedades moduladoras y favorecedoras de la regeneración tisular. Objetivo: Determinar los resultados estéticos asociados al uso de la membrana de fibrina autóloga rica en plaquetas y leucocitos, para la regeneración de defectos cutáneos nasales posquirúrgicos. Métodos: Se realizó un estudio cuasiexperimental, longitudinal y prospectivo en el Servicio de Cirugía Maxilofacial del Hospital Universitario "Arnaldo Milián Castro" de la ciudad de Santa Clara, Villa Clara, Cuba, desde septiembre de 2015 hasta junio de 2019. Se efectuó un muestreo intencional, no probabilístico, de 31 pacientes. A partir de una donación de sangre del paciente, se obtuvo una membrana de fibrina rica en plaquetas y leucocitos, la que fue suturada en el defecto nasal posquirúrgico. Se estudiaron variables como el resultado estético, evaluado sobre la base de parámetros como la elasticidad, el color, el volumen y la superficie. Resultados: La edad media fue 62,71 ± 11,09 años y el 61,29 por ciento de la muestra correspondió al sexo masculino. Mostraron un buen resultado estético el 90,32 por ciento de los pacientes, lo que se asoció de forma significativa al grado de epitelización. Conclusiones: Se obtuvo un buen resultado estético en los pacientes donde se utilizó la membrana de fibrina autóloga rica en plaquetas y leucocitos, con independencia de la presencia de diabetes mellitus y hábitos tóxicos. El resultado estético estuvo asociado significativamente al grado de epitelización y a la edad(AU)

Introduction: In the reconstruction of nasal skin defects, several techniques have been used worldwide. Innovative practices use platelet concentrates for their modulating properties and favoring tissue regeneration. Objective: Determine the aesthetic results associated with the use of autologous fibrin rich in platelets and leukocytes, for the regeneration of post-surgical nasal skin defects. Methods: A quasi-experimental, longitudinal and prospective study was conducted in the Maxillofacial Surgery Service of "Arnaldo Milián Castro" University Hospital in the city of Santa Clara, Villa Clara province, Cuba, from September 2015 to June 2019. An intentional, non-probabilistic sampling of 31 patients was carried out. From a blood donation from the patient, a fibrin membrane rich in platelets and leukocytes was obtained, which was sutured in the post-surgical nasal defect. Variables such as the aesthetic result were studied, evaluated on the basis of parameters such as elasticity, color, volume and surface. Results: The mean age was 62.71 ± 11.09 years and 61.29 percent of the sample corresponded to the male sex. A good aesthetic result was shown by 90.32 percent of the patients, which was significantly associated with the degree of epithelialization. Conclusions: A good aesthetic result was obtained in patients where the fibrin membrane rich in leukocytes and autologous platelets was used, regardless of the presence of diabetes mellitus and toxic habits. The aesthetic result was significantly associated with the degree of epithelialization and age(AU)

Sponges with colloidal silver nanoparticles help restore bone lost in endo-periodontal injuries

Introduction: Endo-periodontal lesions can lead to the formation of severe intraosseous defects in the periodontium; which can lead to tooth loss. Objective: Demonstrate that surgical periodontal therapy with the help of gelatin sponges, with colloidal silver nanoparticles, restores bone tissue lost in endo-periodontal lesions. Case presentation: 55-year-old male patient without systemic alterations, diagnosed with grade 3 endo-periodontal lesion in patients with periodontitis. It was treated first with ducts and then with periodontal surgery combined with gelatin sponges, which contain colloidal silver nanoparticles, and were placed filling the 2-wall bone defect involving > 80 percent of the root length, with 24 months of radiographic and clinical follow-up. Conclusions: Based on the case report, surgical periodontal therapy and filling of bone defects with gelatin sponges, which contain colloidal silver nanoparticles, were sufficient to restore the lost bone at a 24-month follow-up. However, further studies are needed to assess the clinical benefit of this material for the treatment of intraosseous defects(AU)