Research progress on dental materials for preventing root caries / 口腔疾病防治

@#The high incidence and untreated rate of root caries, a common and frequently occurring oral disease with challenging treatment in elderly individuals, is the main cause of tooth loss among elderly people, as rapid development results in pulpitis and periapical periodontitis or residual crown and root, which has been regarded as one of the common chronic oral diseases seriously affecting the quality of life of elderly people. Thus, early intervention and prevention are important. Traditional dental materials for preventing root caries have been widely used in clinical practice; however, they have the disadvantages of tooth coloring, remineralization and low sterilization efficiency. A series of new dental materials for preventing root caries have gradually become a research hotspot recently, which have the advantages of promoting the mineralization of deep dental tissue, prolonging the action time and enhancing adhesion. Future caries prevention materials should be designed according to the characteristics of root surface caries and the application population and should be developed toward simplicity, high efficiency and low toxicity. This review describes current research regarding anti-caries prevention material application, serving as a theoretical underpinning for the research of root caries prevention materials, which is important for both promotion in the effective prevention of root caries and improvement in the status of oral health and the quality of life among old people.

Age estimation through the development of third molars in a case of multiple dismemberment / Estimación de la edad mediante el desarrollo de terceros molares en un caso de desmembramiento múltiple

El crimen organizado se ha convertido en un flagelo a nivel internacional conformado por grupos al margen de la ley que realizan todo tipo de actividades que involucran desde tráfico de personas, secuestros, extorsiones, narcotráfico y muchos otros delitos. Producto de este fenómeno, la desaparición y ejecución de personas es cada día más frecuente, en muchos casos los cuerpos son quemados o desmembrados para impedir o hacer más difícil la identificación. La odontología forense se ha convertido en una disciplina transcendental en la identificación de cadáveres y restos óseos, además de contar con múltiples métodos para estimar la edad aproximada de una persona. Se presenta el caso de un descuartizamiento múltiple de tres individuos masculinos donde era indispensable identificar si alguno correspondía a una persona menor de 18 años.

Organized crime has become an international scourge made up of outlaw groups that carry out all kinds of activities ranging from human trafficking, kidnapping, extortion, drug trafficking and many more. As a result of this phenomenon, the disappearance and execution of people is becoming more frequent every day, in many cases the bodies are burned or dismembered to prevent or make identification more difficult. Forensic odontology has become a transcendental discipline in the identification of corpses and skeletal remains, in addition to having multiple methods to estimate the approximate age of a person. The case of a multiple dismemberment of three male individuals is presented, where it was essential to identify a person under 18 years of age.

Low concentrations of grape seed extract maintain osteoblast morphology, cell adhesion, and mineralization

Abstract The increase in life expectancy has led to a higher incidence of osteoporosis, characterized by an imbalance in bone remodeling. Several drugs are used for its treatment, but most promote undesirable side effects. The present investigation evaluated the effects of two low concentrations of grape seed extract (GSE) rich in proanthocyanidins on MC3T3-E1 osteoblastic cells. The cells were cultured in an osteogenic medium and divided into control (C), 0.1 µg/mL GSE (GSE0.1), and 1.0 µg/mL GSE (GSE1.0) groups to evaluate cell morphology, adhesion, and proliferation, in situ alkaline phosphatase (ALP) detection, mineralization and immunolocalization of osteopontin (OPN). The data obtained were analyzed by statistical tests for a significance of 5%. Cell morphology was maintained with both GSE concentrations, whereas cell adhesion significantly increased within three days in all groups. Cell proliferation increased significantly at seven days of culture, followed by a significant decrease in all experimental periods, with no statistical difference among them. In situ detection of ALP and mineralization increased with time, but within each period, no statistical differences among groups were observed. The expression of osteopontin was distributed regularly with more intensity after 24 hours in the GSE0.1 group. After three days, OPN expression was more intense in the control group, followed by GSE0.1 and GSE1.0 groups. Data obtained suggest that low concentrations of GSE do not affect the morphology and may stimulate the functional activity of osteoblastic cells.

Resumo O aumento da expectativa de vida tem levado a uma maior incidência de osteoporose, caracterizada por um desequilíbrio na remodelação óssea. Vários medicamentos são utilizados para o seu tratamento, contudo, a maioria promove efeitos colaterais indesejáveis. A presente investigação avaliou os efeitos de duas baixas concentrações de extrato de semente de uva (GSE) rico em proantocianidinas em células osteoblásticas MC3T3-E1. As células foram cultivadas em meio osteogênico e divididas em grupos controle (C), 0,1 µg/mL de GSE (GSE0.1) e 1,0 µg/mL de GSE (GSE1.0) para avaliar morfologia, adesão e proliferação celular, detecção in situ de fosfatase alcalina (ALP), mineralização e imunolocalização da proteína osteopontina (OPN). Os dados obtidos foram analisados por testes estatísticos para um nível de significância de 5%. A proliferação celular aumentou significativamente aos sete dias de cultura, seguido de uma diminuição significativa em todos os períodos experimentais, sem diferença estatística entre eles. A detecção in situ de ALP e mineralização aumentou com o tempo, mas dentro de cada período não foram observadas diferenças estatísticas entre os grupos. A morfologia celular foi mantida com ambas as concentrações de GSE, enquanto a adesão celular aumentou significativamente aos três dias em todos os grupos. A expressão de osteopontina distribuiu-se regularmente com maior intensidade após 24 horas no grupo GSE0.1. Após três dias, a expressão de OPN foi mais intensa no grupo controle, seguida pelos grupos GSE0.1 e GSE1.0. Os dados obtidos sugerem que baixas concentrações de GSE não afetam a morfologia e podem estimular a atividade funcional das células osteoblásticas.

Effect of the chicken zp1 gene on osteoblast mineralization / 生物工程学报

The aim of this study was to clone the chicken zp1 gene encoding zona pellucida 1 (Zp1) and investigate its tissues expression profile and its effect on osteoblast mineralization. The expression level of zp1 was quantified in various tissues of laying hens and in the tibia of the pre- and post-sexual maturity by RT-qPCR. Zp1 overexpressed vector was transfected into chicken calvarial osteoblasts which were induced differentiation for 8 days, and the extracellular mineral and the expression of mineralization-related genes were detected. The full-length chicken zp1 gene is 3 045 bp, encoding 958 amino acids residuals, and has two N-glycosylation sites. The highest expression level of the zp1 gene was found in the liver, followed by the tibia and yolk membrane, while no expression was detected in the heart and eggshell gland. Compared with the pre-sexual maturity hens, the concentration of estrogen (E2) in plasma, the content of glycosaminoglycan (GAG) and the expression level of the zp1 gene in the tibia with post-sexual maturity were higher. The extracellular matrix and the level of osteoblast mineralization-related genes showed a significantly upregulated expression in chicken calvarial osteoblasts with Zp1 overexpressed and addition of estrogen. The expression of the zp1 gene is tissue-specific and positively regulated osteoblast mineralization under the action of estrogen, laying the foundation for elucidating the functional properties of Zp1 in chicken bones during the egg production period.

Dose-dependent effects of neem crude extract on human dental pulp cell and murine osteoblast viability and mineralization

Abstract Neem has been used as a medicine due to its beneficial properties such as anti-microbial effects. Neem products for oral application are on the rise. Before recommendation for therapeutic use in human, its effects on cellular activities need to be examined. Therefore, the aim of this study was to test the effects of the ethanolic neem crude extract on dental pulp cells and osteoblasts in terms of cell viability, mineralization, and gene expressions. The ethanolic neem extract derived from dry neem leaves was subjected to chemical identification using GC-MS. Human dental pulp stem cells (hDPSCs) and pre-osteoblasts (MC3T3) were treated with various concentrations of the neem crude extract. Cell viability, mineralization, and gene expressions were investigated by MTT assay, real-time PCR, and alizarin red S assay, respectively. Statistical analysis was performed by one-way ANOVA followed by Dunnett test. GC-MS detected several substance groups such as sesquiterpene. Low to moderate doses of the neem crude extract (4 - 16 µg/ml) did not affect hDPSC and MC3T3 viability, while 62.5 µg/ml of the neem extract decreased MC3T3 viability. High doses of the neem crude extract (250 - 1,000 µg/ml) significantly reduced viability of both cells. The neem crude extract at 1,000 µg/ml also decreased viability of differentiated hDPSC and MC3T3 and their mineralization. Furthermore, 4 µg/ml of neem inhibited viability of differentiated hDPSC. There is no statistical difference in gene expressions related to cell differentiation. In conclusion, the neem crude extract affected cell viability and mineralization. Cell viability altered differently depending on the doses, cell types, and cell stages. The neem crude extract did not affect cell differentiation. Screening of its effect in various aspects should be examined before the application for human use.

Resumo O Neem tem sido utilizado como medicamento devido às suas propriedades benéficas, tais como os efeitos antimicrobianos. Os produtos Neem para aplicação oral estão a aumentar. Antes da recomendação para uso terapêutico no ser humano, os seus efeitos nas atividades celulares precisam ser examinados. Por conseguinte, o objectivo deste estudo era testar os efeitos do extracto bruto de neem etanólico nas células de polpa dentária e osteoblastos em termos de viabilidade celular, mineralização e expressões genéticas. O extracto de neem etanólico derivado de folhas secas de neem foi sujeito a identificação química utilizando GC-MS. As células estaminais de polpa dentária humana (hDPSCs) e os pré-osteoblastos (MC3T3) foram tratados com várias concentrações do extrato bruto de neem. A viabilidade celular, mineralização, e expressões genéticas foram investigadas pelo ensaio MTT, PCR em tempo real, e o ensaio S vermelho de alizarina, respectivamente. A análise estatística foi realizada por ANOVA unidirecional seguida pelo teste Dunnett. O GC-MS detectou vários grupos de substâncias como o esquisterpeno. Doses baixas a moderadas do extracto bruto de neem (4 - 16 µg/ml) não afetaram a viabilidade do hDPSC e MC3T3, enquanto 62,5 µg/ml do extracto de neem diminuiu a viabilidade do MC3T3. Doses elevadas do extrato bruto de neem (250 - 1.000 µg/ml) reduziram significativamente a viabilidade de ambas as células. O extrato bruto de neem a 1.000 µg/ml também diminuiu a viabilidade de hDPSC e MC3T3 diferenciados e a sua mineralização. Além disso, 4 µg/ml de neem inibiu a viabilidade do hDPSC diferenciado. Não há diferença estatística nas expressões genéticas relacionadas com a diferenciação celular. Em conclusão, o extrato bruto do neem afetou a viabilidade celular e a mineralização. A viabilidade celular alterou-se diferentemente dependendo das doses, tipos de células, e fases celulares. O extrato bruto do neem não afetou a diferenciação celular. O rastreio do seu efeito em vários aspectos deve ser examinado antes da aplicação para uso humano.

Particle size of oyster shell meal and calcium: phosphorus ratios in broiler diets / Efeito do tamanho de partícula da farinha de ostras e relações cálcio: fósforo em dietas para frangos de corte

The effects of Ca:P total ratio and particle size of oyster shell meal (OSM) were evaluated in broiler diets. In Experiment 1, 800 broilers (22-42 days old) were distributed in a 2×2 factorial design, with two Ca:P ratios (1.7 and 2.0:1) and two OSM particle sizes (coarse = 1,354 µm and fine = 428 µm), totaling four treatments with 10 repetitions with 20 broilers. Feed intake, weight gain, and feed conversion ratio were calculated. In Experiment 2, 1,280 broilers were distributed in a 2×2×2 factorial design (1.7 and 2.0:1 Ca:P ratios; coarse and fine OSM; male and female broilers), with eight treatments and 16 repetitions with 10 broilers. Apparent metabolizability of dry matter, Ca, P, and apparent metabolizable energy (AME), as well as bone resistance, bone weight, ash, Ca, and P content in the tibia were assessed. Growth performance was not affected (P > 0.05). Coarse OSM increased tibia Ca content in male broilers (P < 0.001), and higher Ca:P ratio improved bone ash and bone resistance in both sexes (P < 0.001), but reduced P content in male broilers (P < 0.05); male broilers displayed heavier bones with higher ash content than females (P < 0.05). Metabolizability of Ca was improved with coarse OSM (P < 0.05); whereas metabolizability of DM, P, and AME was not affected (P > 0.05). In conclusion, diets with a Ca:P total ratio of 2.0:1 containing coarser OSM improved bone mineral composition, particularly in male broilers, and coarse OSM improved the metabolizability of Ca in broilers regardless of the Ca:P total ratio or broiler sex.

Dois experimentos foram conduzidos para avaliar os efeitos do tamanho de partícula da farinha de ostras (FO) e relação Ca:P total em dietas para frangos de corte. No primeiro experimento, 800 frangos (22 a 42 dias) foram distribuídos em um delineamento fatorial 2x2: 2 relações Ca:P (1,7 e 2,0:1) e dois tamanhos de partícula da FO (grossa = 1354 µm e fina = 428 µm), totalizando quatro tratamentos com 10 repetições de 20 aves. O consumo de ração, o ganho de peso e a conversão alimentar foram calculados. No segundo experimento, 1.280 frangos foram distribuídos em um fatorial 2x2x2 (relações Ca:P 1,7 e 2,0:1; FO grossa e fina; aves machos e fêmeas) com oito tratamentos e 16 repetições de 10 aves. Foram avaliados: metabolizabilidade aparente da matéria seca, Ca e P, energia metabolizável aparente (EMA), peso e resistência óssea, conteúdo de cinzas, Ca e P na tíbia. As variáveis de desempenho não foram afetadas (P > 0,05). O uso de FO grossa aumentou o conteúdo de Ca na tíbia de frangos machos (P < 0,001), e a relação Ca:P de 2,0:1 aumentou o conteúdo de cinzas e aprimorou resistência óssea em ambos os sexos (P < 0,001), porém reduziu P na tíbia dos machos (P < 0,05); frangos machos também tiveram ossos mais pesados e maior conteúdo de cinzas do que fêmeas (P < 0,05). A metabolizabilidade de Ca foi melhorada com FO grossa, enquanto a metabolizabilidade da matéria seca, P, e EMA não foram afetadas (P > 0,05). Conclui-se que as dietas com relação Ca:P de 2,0:1 e com FO grossa resultaram em melhor composição mineral óssea - particularmente em frangos machos - e a FO grossa melhorou a metabolizabilidade de Ca independentemente da relação Ca:P ou do gênero das aves.

Biomechanical Environment Regulates Biomimetic Mineralization of Bone Matrix / 医用生物力学

Bone defects have always been an important cause of threat to human health, and artificial biomimetic bone repair replacement materials are currently one of the most effective and feasible solution approaches to treat bone damage. To develop artificial bone biomimetic materials, an in vitro biomimetic mineralization system must be constructed first to study in vitro biomimetic mineralization mechanism of natural bone matrix. Collagen is a template for mineralization, and its properties such as crosslinking degree, diameter, osmotic pressure, and surface charge can all directly affect mineralization progress. The biochemical and mechanical environments in which mineralization occurs are also quite distinct in their effects on mineralization process, particularly noncollagenous proteins and fluid shear stress (FSS). FSS is considered to be the main mechanical stimulation of bone tissues in micro-environment, which is of great significance to bone growth, repair and health maintenance. FSS at different levels and loading regimes has significant effects on transformation of amorphous calcium phosphate to bone apatite, self-assembly and directional alignment of collagen fibrils, and formation of hierarchical intrafibrillar mineralization. In this paper, the factors affecting collagen mineralization and their mechanism were summarized, with focus on regulation of FSS on collagen mineralization, and development direction in future was also prospected.

The pivotal role of autophagy in bone cells:bone-related cell activity and bone metabolism / 中国组织工程研究

BACKGROUND:The importance of autophagy for maintaining cellular homeostasis and stress response has long been recognized.As a way for cells to selectively clear their damaged organelles to achieve the recycling of cellular components,autophagy has a pivotal role in bone metabolism.OBJECTIVE:To review the role and possible mechanisms of autophagy in regulating bone-related cell activity and function among bone marrow mesenchymal stem cells,osteoblasts,osteocytes,and osteoclasts.METHODS:PubMed was searched for studies related to autophagy using the keywords of "autophagy;bone marrow mesenchymal stem cells;osteoblasts;osteocytes;osteoclasts."RESULTS AND CONCLUSION:We finally included 84 papers.Autophagy plays an important role in bone metabolism.Autophagy is involved in maintaining the balance between mineralization and absorption,and then maintaining bone homeostasis.An appropriate autophagy inducer may also benefit bone remodeling.Abnormal autophagy can lead to disorders of bone balance,leading to diseases such as osteoporosis.We may prevent or treat bone-related diseases by regulating the level of autophagy as its function in maintaining the balance of mineralization and resorption in bone homeostasis.

Study on the inhibition and remineralization of enamel demineralization by polydopamine in vitro / 口腔疾病防治

Objective@#To investigate the inhibitory effect of polydopamine (PDA) on enamel demineralization in isolated teeth and the induction of hydroxyapatite (HA) production on the surface of demineralized enamel to provide a novel protocol for the prevention and treatment of enamel demineralization. @*Methods@#Twenty isolated bovine teeth were cut into 20 enamel slices and randomly divided into an experimental group and a control group, with 10 slices in each group. The enamel slices in the experimental group were immersed in 2 mg/mL freshly prepared dopamine solution and incubated for 24 hours at room temperature in the dark to prepare the PDA coating, while the control group was left untreated. Then, the isolated bovine teeth, with and without PDA coating, were immersed in artificial demineralization solution at 37 °C for 3 days, followed by 7 days in simulated body fluid (SBF), and the immersion solution was changed daily. The surface morphology of enamel was observed by scanning electron microscopy (SEM), the calcium/phosphorus ratio of the enamel surface was analyzed by energy dispersive spectroscopy (EDS), and the characteristic functional groups in enamel deposits were analyzed by Fourier transform infrared spectroscopy (FTIR).@* Results@#Compared with the control group, the number of demineralized pores produced after 3 d of enamel demineralization with polydopamine coating was less, and the diameter was smaller. EDS elemental analysis showed that the Ca/P ratio after enamel demineralization was 2.37 in the experimental group, which was smaller than the 2.53 ratio in the control group. In the remineralization experiment, after 7 days of remineralization of PDA coated enamel in the experimental group, lamellar grains were produced on the enamel surface, and the growth showed obvious directionality, growth regularity and uniform arrangement. In the control group, the surface of enamel was flocculent mineral deposit, and the crystallinity was poor. The FTIR results proved that the enamel surface deposit of PDA-coated enamel was HA after 7 d of remineralization. @*Conclusion @#PDA can affect the nucleation process of HA and promote the production of HA on the surface of demineralized enamel.

Histomorphometry evaluation of bone anabolism promoted by prostaglandin E1 and its relation to hypercalcemia / Evaluación histomorfométrica del anabolismo óseo en la reparación promovida por la prostaglandina E1 y su relación con la hipercalcemia

Abstract Background: At present, parathyroid hormone is the only existing anabolic bone therapy but produces hypercalcemia. Prostaglandin E1 (PGE1) has been suggested as a bone anabolic agent that allows bone modeling formation without producing hypercalcemia. This study aimed to corroborate these PGE1 properties. Methods: For 22 days, rabbits (n = 30) were divided into three groups (n = 10 each group) and received intravenous solutions: vehicle (control group), palate disjunction + vehicle (sham group), and palate disjunction + 50 mg of PGE1 (PGE1 group). On days 1, 3, and 22, palatine suture X-rays were taken. On day 22, bone formation markers were analyzed, and the rabbits were sacrificed. Bone palate undecalcified samples were processed. Histomorphometry software was used to analyze bone parameters, and the mineralization front was stained with toluidine blue. Scalloped lines reflect remodeling-based bone formation (RBF), and smooth lines reflect modeling-based formation (MBF). Results: X-rays showed more significant palatal disjunction in the PGE1 group; this group exhibited significant calcitriol serum increments. Hypercalciuria was observed in the PGE1 group, and resorption markers (N-telopeptides) remained stable. Sutural bones in the PGE1 group exhibited significant anabolism in structural parameters. RBF was 20%, and MBF was 6% in the sham group; in the PGE1 group, RBF was 8.6%, and MBF was 17%. In the PGE1 group, mineralization was significantly accelerated, but resorption remained stable. Conclusions: This model suggests that PGE1 favors palate disjunction, calcitriol synthesis, and shortens the mineralization. Therefore, PGE1 is an important bone anabolic molecule predominantly of modeling-based form and no hypercalcemia.

Resumen Introducción: La hormona paratiroidea es la única molécula anabólica ósea, pero ocasiona hipercalcemia. La prostaglandina E1 (PGE1) sugiere ser un anabólico óseo con formación por modelación predominante y generalmente no ocasiona hipercalcemia. El objetivo de este estudio fue corroborar estas propiedades de la PGE1. Métodos: Por 22 días, 30 conejos divididos en tres grupos (n = 10 cada grupo) recibieron una solución por vía intravenosa: vehículo (grupo control), disyunción palatina más vehículo (grupo sham) y disyunción palatina más 50 mg de PGE1 (grupo PGE1). A los días 1, 3 y 22 se obtuvieron radiografías de la sutura palatina. En el día 22 se analizaron los marcadores bioquímicos de formación ósea y se sacrificó a los conejos. Las suturas y los huesos suturales se procesaron sin descalcificar. La evaluación histomorfométrica fue digitalizada y el frente de mineralización ósea se tiñó con azul de toluidina. Las líneas irregulares reflejan resorción (remodelación) y las líneas rectas no resorción (modelación). Resultados: Radiográficamente, la disyunción palatina fue mayor en el grupo PGE1. Este grupo mostró una hipercalcitonemia significativa, pero la calcemia y los marcadores resortivos (N-telopéptidos) se mantuvieron estables. Por histomorfometría, los huesos suturales del grupo PGE1 mostraron anabolismo significativo en parámetros estructurales. En el grupo sham, la remodelación ósea fue del 20% y la modelación fue del 6%; en el grupo PGE1, la remodelación fue del 8.6% y la modelación fue del 17%. En este mismo grupo, la mineralización fue significativamente acelerada, pero la resorción se mantuvo igual. Conclusiones: Este modelo sugiere que la PGE1 favorece la disyunción palatina y el aumento del calcitriol, y acelera la mineralización y el anabolismo óseo por modelación predominante sin hipercalcemia.

Odontogenic gene expression profile of human dental pulp-derived cells under high glucose influence: a microarray analysis

Abstract Hyperglycemia, a major characteristic of diabetes, is considered to play a vital role in diabetic complications. High glucose levels have been found to inhibit the mineralization of dental pulp cells. However, gene expression associated with this phenomenon has not yet been reported. This is important for future dental therapeutic application. Objective Our study aimed to investigate the effect of high glucose levels on mineralization of human dental pulp-derived cells (hDPCs) and identify the genes involved. Methodology hDPCs were cultured in mineralizing medium containing 25 or 5.5 mM D-glucose. On days 1 and 14, RNA was extracted and expression microarray performed. Then, differentially expressed genes (DEGs) were selected for further validation using the reverse transcription quantitative polymerase chain reaction (RT-qPCR) method. Cells were fixed and stained with alizarin red on day 21 to detect the formation of mineralized nodules, which was further quantified by acetic acid extraction. Results Comparisons between high-glucose and low-glucose conditions showed that on day 1, there were 72 significantly up-regulated and 75 down-regulated genes in the high-glucose condition. Moreover, 115 significantly up- and 292 down-regulated genes were identified in the high-glucose condition on day 14. DEGs were enriched in different GO terms and pathways, such as biological and cellular processes, metabolic pathways, cytokine-cytokine receptor interaction and AGE-RAGE signaling pathways. RT-qPCR results confirmed the significant expression of pyruvate dehydrogenase kinase 3 (PDK3), cyclin-dependent kinase 8 (CDK8), activating transcription factor 3 (ATF3), fibulin-7 (Fbln-7), hyaluronan synthase 1 (HAS1), interleukin 4 receptor (IL-4R) and apolipoprotein C1 (ApoC1). Conclusions The high-glucose condition significantly inhibited the mineralization of hDPCs. DEGs were identified, and interestingly, HAS1 and Fbln-7 genes may be involved in the glucose inhibitory effect on hDPC mineralization.

Study of rrPDGF-BB gene modified BMSCs in promoting distraction osteogenesis of rat femur / 中华显微外科杂志

Objective:To investigate the therapeutic effect of rat bone marrow mesenchymal stem cells (BMSCs) transfected with recombinant rat platelet-derived growth factor BB (rrPDGF-BB) gene on the distraction osteogenesis.Methods:From October, 2019 to June, 2020, 48 batches of BMSCs were cultured from 48 young SD rats, 24 of which were transfected with rrPDGF-BB gene by lentivirus. Meanwhile, other 72 male adult SD rats were randomly selected to establish the right femoral distraction osteogenesis model. The rats were equally divided into 3 groups. PBS, BMSCs without intervention and BMSCs transfected with rrPDGF-BB gene were injected into the distraction space of each group of rats assigned as Blank group, Negative group and Experimental group, respectively. Results of the experiment were evaluated by means of imaging and immunohistochemistry. P<0.05 indicated a statistically significant difference. Results:The cultured BMSCs grew well. The expression of CD34(0.1%) and CD45(2.8%) in the third generation of BMSCs was low, and that of CD29 (95.1%) was high, which was consistent with the phenotype of BMSCs described in literatures. After transfection, the expression of green fluorescence gradually increased with the extension of transfection time, confirming the success of transfection. After 14 days, all rats reached the expected distance of distraction. The rats were observed at assigned time points in 2, 4 and 8 weeks. The photos of femur specimen showed that continuous callus could be seen in the experimental group, the hardness and colour were close to the normal bone tissue, and the activity of the distraction space was poor, which was lower than that of the blank group. X-ray examination showed that there were more new callus in the experimental group, and the bone marrow cavity was re-canalized earlier than that of the blank group; Micro-CT examination, in sagittal plane, showed that the distraction space of the experimental group healed well, the broken end was connected, and the recanalization of bone marrow cavity was earlier than that of the blank group; Micro-CT parameters of each group showed that trabecular thickness[(0.297±0.005) mm], trabecular number [(1.663±0.032) mm], bone volume fraction[(59.832±2.187)%] and bone mineral density[(0.586±0.014) g/cm 3] of the experimental group were the greatest, while trabecular separation[(0.399±0.051) mm] of the experimental group was the smallest. There was statistical difference between each group( P < 0.05); HE staining and VEGF immunohistochemistry showed that the vessels and chondrocytes formed earlier and were more in the experimental group than that in the blank group. In 8 weeks, the new callus joined into one piece under the microscope in the experimental group, and the bone marrow cavity was re-canalized with a large number of red blood cells. Conclusion:Studies have shown that BMSCs transfected with rrPDGF-BB gene can promote the formation of callus in the distraction area of rats, shorten the mineralisation time of new callus, and promote the maturation of new bone in the area of distraction osteogenesis.

Exosomes derived from lipopolysaccharide-preconditioned dental folic cells regulate osteogenic differentiation of periodontal ligament cell in periodontitis / 口腔疾病防治

Objective@#The purpose of this study was to investigate the effect of different concentrations of exosomes (Exos) secreted from dental folic cells (DFCs) preconditioned with lipopolysaccharide (LPS) on the osteogenic differentiation ability of periodontal cells in periodontitis (p-PDLCs) in patients to provide a basis for the prevention and treatment of periodontal disease.@*Method @#Tissue block and enzyme digestion methods were used to culture DFCs and p-PDLCs. Exosomes were isolated from 250 ng/mL LPS-preconditioned DFCs 24 h later. The characteristics of exosomes were detected by transmission electron microscopy, particle size analysis and Western blotting. The effects of 10 μg/mL and 100 μg/mL exosomes on the osteogenic differentiation of p-PDLCs were detected by RT-PCR and Alizarin red staining.@*Results @# LPS-pretreated DFC-derived exosomes (L-Exos) are vesicle-like structures with a size between 30-100 nm that positively express CD63 and Alix. Compared with the control group, exosomes significantly upregulated Periostin, Col Ⅰ, and Col Ⅲ expression at 100 μg/mL (P < 0.05), while TGF- β1 was significantly upregulated at 10 μg/mL (P < 0.01). At 7 days after osteogenic induction, mineralized nodules were significantly more abundant in the exosome group than in the control group (P < 0.01), and the results were better at a concentration of 100 μg/mL (P < 0.01). @*Conclusion@# 100 μg/mL L-Exos are better than 10 μg/mL L-Exos in enhancing the osteogenic differentiation ability of p-PDLCs.

Biphasic calcium phosphate loaded with advanced platelet rich fibrin can promote the activity of rabbit bone marrow mesenchymal stem cells / 中国组织工程研究

BACKGROUND: Adding growth factor to scaffold material can promote the proliferation and osteogenic differentiation of cultured stem cells in vitro and promote bone tissue regeneration. Advanced platelet rich fibrin (A-PRF) contains a variety of growth factors, which can promote the proliferation activity of a variety of cells and the expression of related functional proteins. OBJECTIVE: To observe the effects of the sole and combined usage regarding A-PRF and biphasic calcium phosphate (BCP) on the growth of bone marrow mesenchymal stem cells. METHODS: The third generation of rabbit bone marrow mesenchymal stem cells was cultured in four groups, including basic medium (blank group), A-PRF condition medium (A-PRF group), BCP (BCP group), A-PRF condition medium and BCP (A-PRF+BCP group). Cell proliferation activity was detected by CCK-8 assay. Cell adhesion was observed based on methylrhodamine-phalloidin fluorescence staining. Intracellular alkaline phosphatase expression and mineralized nodules were quantitatively measured. RESULTS AND CONCLUSION: (1) The absorbance value of proliferation of the A-PRF+BCP group was higher than that of the other three groups at 3, 5, 7, 11 and 14 days after culture. The absorbance value of proliferation of cells cultured in the A-PRF group was higher than that of the BCP group and the blank group at 1, 3 and 5 days after culture. The absorbance value of proliferation of BCP group was higher than that of the A-PRF group and the blank group at 7, 11 and 14 days after culture. (2) Methylrhodamine-phalloidin fluorescence staining showed that bone marrow mesenchymal stem cells in the BCP group and the A-PRF+BCP group adhered to the surface of BCP and the number of cells and microfilaments in the A-PRF+BCP group was higher than that in BCP group. (3) The synthesis of mineralized nodules was A-PRF+BCP group > BCP group > A-PRF group > blank group at 1, 21 and 28 days after surgery. (4) The expression of alkaline phosphatase was A-PRF+BCP group > BCP group > A-PRF group > blank group at 5, 7 and 9 days. There was significant difference between the two groups (P < 0.05). (5) The results showed that BCP exerted a weak influence on promoting cell proliferation in the early stage, but its effect of scaffold was apparent. A-PRF had a significant effect on promoting cell proliferation with considerable influence on promoting cell proliferation and differentiation when combined BCP.

Expert consensus on clinical management of metabolic bone disease of prematurity (2021) / 中国当代儿科杂志

Metabolic bone disease of prematurity (MBDP) is a systemic bone disease with a reduction in bone mineral content due to disorder of calcium and phosphorus metabolism. There is still a lack of in-depth research and systematic understanding of MBDP in China, and there are many irregularities in clinical management of this disease. Based on relevant studies in China and overseas, Grading of Recommendations Assessment, Development and Evaluation was used to develop the expert consensus on the clinical management of MBDP, which provides recommendations from the following five aspects: high-risk factors, screening/diagnosis, prevention, treatment, and post-discharge follow-up of MBDP, so as to provide relevant practitioners with recommendations on the clinical management of MBDP to reduce the incidence rate of MBDP and improve its short- and long-term prognosis.

Self-assembly and mineralization of full-length human amelogenin and its functional fragments / 华西口腔医学杂志

OBJECTIVES@#To investigate the dynamic process of the self-assembly behaviors of a full-length human amelogenin (AM) and its functional fragments tyrosine-rich amelogenin peptide (TRAP) and leucine-rich amelogenin peptide(LRAP) @*METHODS@#The full-length human AM and its functional fragments, TRAP and LRAP, were reassembled and purified @*RESULTS@#When pH=8, the full-length human AM and TRAP assembly started spontaneously and formed "nanospheres" after 15 min.The nanospheres formed by TRAP existed independently, with a uniform size but without obvious internal structures. The full-length AM was assembled hierarchically, which formed "nanospheres" and further extended in all directions, formed a chain structure, and then aggregated into a net. The self-assembly behavior of LRAP was not obvious. Proteins mostly existed in the form of monomers without "nanosphere" formation. Only few oligomers were observed. The full-length AM was induced independently for 3 days to form rod-shaped HA crystals. TRAP and LRAP proteins were added, after 3 days the crystal elongation was obvious in the c axis, but the growth in plane A and plane B was poor.@*CONCLUSIONS@#The self-assembly and mineralization behaviors of full-length human AM, TRAP, and LRAP were consistent with the directional growth mechanism of HA crystals

Mineralización del complejo estilohioideo en una población de Cuenca-Ecuador / Mineralization of the stylohyoid complex in a population from Cuenca-Ecuador

RESUMEN El complejo estilohioideo es una estructura ósea y ligamentosa, formada por varias entidades anatómicas como: la apófisis estiloides, el ligamento estilohioideo y el cuerno menor del hioides. La apófisis estiloides se origina en la porción timpánica del hueso temporal y mide en promedio 25 mm; en ocasiones puede encontrarse aumentada en longitud, situación que puede o no manifestarse con dolor. Objetivo: determinar la prevalencia de mineralización del complejo estilohioideo de pacientes de Ecuador mediante radiografías panorámicas digitales. Material y Métodos: Para ello se analizaron 2025 radiografías panorámicas digitales de pacientes de ambos sexos, de edades entre 12 a 92 años, del período comprendido entre los años 2015-2016. Se consideró como complejo estilohioideo mineralizado, cuando este sobrepasaba los 25mm. Resultados: Se observaron 2025 radiografías panorámicas,de las cuales 1206 (59,6%) radiografías, mostraron algún tipo de mineralización del complejo estilohioideo. De estas 1288 (63,6%) pertenecen al sexo femenino y 737 (36,4%) al sexo masculino. La presentación más frecuente fue bilateral. Además, se encontró que en los adultos mayores la prevalencia alcanzaba el 76%. Conclusiones: En el presente estudio se muestra que existe una alta prevalencia de mineralización del complejo estilohioideo en la población estudiada.

SUMMARY The stylohyoid complex is a bony and ligamentous structure, formed by several anatomical entities such as the styloid process, the stylohyoid ligament and the horn of the hyoid. The styloid process originates in the tympanic portion of the temporal bone and measures an average of 25 mm; sometimes it may be increased in length, a situation that may or may not have pain itself. Objective: To determine the prevalence of mineralization of the stylohyoid complex of patients at the country of Ecuador using digital panoramic radiographs. Material and methods: Analysis of 2025 digital panoramic radiographs of patients of both sexes, between 12 and 92 years of age, from the period 2015-2016. It was considered as mineralized stylohyoid complex, when it exceeded 25mm. Results: Of the 2025 panoramic radiographs, it was concluded that 1206 (59.6%) radiographs showed some type of mineralization of the stylohyoid complex. Of these 1288 (63.6%) belong to the female sex and 737 (36.4%) to the male sex. The most frequent presentation was bilateral. In addition, it was found that in older adults the prevalence reached 76%. Conclusions: In the present study it is shown that there is a high prevalence of mineralization of the stylohyoid complex in the population studied.

Artropatías en el adulto mayor / Arthropathies in the elderly

Introducción: Los pacientes mayores de 65 años son la parte de la población más afectada por las enfermedades reumáticas. El diagnóstico reumatológico en los ancianos se complica por las manifestaciones clínicas que imitan los cambios relacionados con la edad. Objetivo: Sintetizar los aspectos generales del manejo clínico, el diagnóstico y la terapéutica de las principales enfermedades reumáticas inflamatorias y no inflamatorias en este subgrupo de población. Desarrollo: Los principales trastornos musculoesqueléticos no inflamatorios que afectan a los adultos mayores son la osteoartritis, la osteoporosis y el dolor de espalda, mientras que las artritis inflamatorias predominantes comprenden la artritis reumatoide, la artropatía cristalina, la polimialgia reumática y las formas inflamatorias de la osteoartritis. Conclusiones: Para el diagnóstico y la terapéutica de las principales enfermedades reumáticas (inflamatorias y no inflamatorias) en este subgrupo de población, es necesario el enfoque multidisciplinar(AU)

Introduction: It is recognized that patients older than 65 years are the part of the population most affected by rheumatic diseases. The rheumatological diagnosis in the elderly is complicated by clinical manifestations, which mimic the changes related to age. Objective: To synthesize the general aspects of clinical management, diagnosis and therapy of the main rheumatic diseases inflammatory and non-inflammatory in this subgroup of the population. Development: The main non-inflammatory musculoskeletal disorders that affect older adults are osteoarthritis, osteoporosis and back pain, while the predominant inflammatory arthritis include rheumatoid arthritis, crystalline arthropathy, polymyalgia rheumatica and the inflammatory forms of osteoarthritis. Conclusions: It is vital for academics to be involved in the rheumatological aspects of aging and call attention to the imperative that is to promote reflective discussion within community medicine to address the impact of musculoskeletal problems that affect function and mobility of the elderly and immune dysregulation in aging, among other issues(AU)

Negative pressure irrigation presents mineralizing potential in dogs' immature teeth with periapical lesion

Abstract The objective of this in vivo study was to assess the effect of the root canal irrigation by negative and positive apical pressure on the expression of molecules that are an indicative of cell differentiation with mineralizing phenotype in teeth of dogs with incomplete rhizogenesis and induced periapical lesion. A total of 30 teeth (60 roots) were distributed into 3 groups (n=20): EndoVac®, Conventional and Control. After 90 days, the routine histotechnical procedures were performed and the sections were submitted to immunohistochemical technique for the staining of osteopontin (OPN), alkaline phosphatase (ALP) and the RUNX2 transcription factor in the apical and periapical regions of the roots. A semi-quantitative analysis of the positive immunostaining was performed and the intensity of the expression was classified in absent (0), mild (1), moderate (2), or intense (3). Scores data were statistically analyzed by the Kruskal-Wallis non-parametric test and Dunn post-test, and the significance level was set at 5%. RUNX2 immunostaining revealed that in the negative pressure group there was a significantly stronger (p<0.05) immunostaining in comparison to the control group. Regarding the OPN expression, it was not possible to detect a statistically significant difference between the groups (p>0.05). After analyzing ALP immunostaining, a statistically significant difference was observed between the groups (p<0.05), and the negative pressure group showed a markedly stronger mark immunostaining than the control group. The results of the present in vivo study allowed concluding that negative apical pressure irrigation presents mineralizing potential in immature teeth with apical periodontitis.

Resumo O objetivo do presente estudo in vivo foi avaliar o efeito da irrigação do canal radicular por pressão apical negativa e por pressão positiva na expressão de moléculas que são indicativas de diferenciação celular com fenótipo mineralizador em dentes de cães com rizogênese incompleta e lesão periapical. Um total de 30 dentes (60 raízes) foi distribuído em 3 grupos (n=20): EndoVac, Convencional e Controle. Após 30 dias, foram realizados os procedimentos histotécnicos de rotina e os cortes foram submetidos à técnica de imunohistoquímica para marcação de Osteopontina (OPN), Fosfatase Alcalina (ALP) e para o fator de transcrição RUNX2 nas regiões apical e periapical das raízes. Foi realizada uma análise semi-quantitativa da imunomarcação positiva e a intensidade da expressão foi classificada em ausente (0), leve (1), moderada (2) ou intensa (3). Os dados por escores foram analisados estatisticamente pelo teste não-paramétrico de Kruskal-Wallis e pelo pós-teste de Dunn, e o nível de significância adotado foi de 5%. A imunumarcação para RUNX2 revelou que no grupo pessão negativa houve marcação significativamente mais intensa (p<0,05), em comparação ao grupo controle. Com relação à expressão de OPN, não foi possível observer diferença estatisticamente significante entre os grupos (p>0,05). Após análise da imunomarcação para ALP, foi observado diferença estatisticamente significante entre os grupos (p<0,05), e o grupo pressão negativa demonstrou uma marcação siginificativamente mais intensa do que o grupo controle. Os resultados do presente estudo in vivo permitiram concluir que a irrigação por pressão apical negativa apresenta potencial mineralizador em dentes com ápice aberto e lesão periapical.

In vitro remineralization of primary teeth with a mineralization-promoting peptide containing dental varnish

Abstract Mineralization-promoting peptides are attractive candidates for new remineralization systems. In previous studies, peptides have been applied as aqueous solutions, which is not a clinically relevant form. Objective This study aims to investigate the efficiency of a mineralization-promoting peptide, applied in varnish, on remineralizing artificial caries on primary teeth. Methodology 55 primary molars were collected. Specimens were immersed in a demineralizing solution for 7 days and then, divided into 7 groups: Baseline: No-remineralization, Placebo: Blank colophony, F: Colophony 5% fluoride, P: Colophony 10% peptide, P+F: Colophony 5% fluoride and 10% peptide, Embrace: Embrace™ varnish, Durashield: Durashield™ varnish. A mixture of 35% w/v colophony varnishes were prepared in ethanol and applied accordingly. Specimens were immersed in a remineralization solution for 4 weeks and it was evaluated using PLM and SEM. Lesion depth reduction was examined by one-way ANOVA. Results There was no significant difference in mean lesion depths between baseline (147.04 ± 10.18 µm) and placebo groups (139.73 ± 14.92 µm), between F (120.95 ± 12.23 µm) and Durashield (113.47 ± 14.36 µm) groups and between P (81.79 ± 23.15 µm) and Embrace (90.26 ± 17.72 µm) groups. Lesion depth for the P+F group (66.95±10.59 µm) was significantly higher compared to all other groups. All groups contained samples with subsurface demineralized regions. Number of subsurface demineralized regions were higher in fluoride-containing groups. Conclusions We conclude that the mineralization-promoting peptide (MPP3) is effective in this in vitro study and the peptide shows benefits over fluoride as it yields less subsurface demineralized regions.