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ABSTRACT Identifying the presence, size, type and location of voids in an endodontic obturation is of great clinical importance because it enables evaluation of the three-dimensionality of the sealing techniques, which can be related to the success of the endodontic treatment. Aim To analyze by micro-CT the presence of voids in lower single-rooted premolar root canal obturations prepared using the single cone and ultrasound vibration technique. Materials and methods Twenty extracted single-rooted lower premolars were selected, and the root canal prepared surgically and chemically. In GROUP 1 - Without Vibration, the canal was obturated with a single cone and bioceramic, without applying vibration. In GROUP 2 - With Vibration, the gutta-percha cone inside the root canal was held with a cotton plier to which ultrasound vibration was applied for 3 periods of 3 seconds each. A micro-CT scanner was used to acquire and reconstruct images for analysis. Results No significant difference was found between obturation techniques, though there were differences between thirds, with the cervical third having a higher percentage of voids than the middle and apical thirds. Conclusions The results suggest that the volume of closed, open and total voids does not differ between treatments with and without ultrasound vibration. In the cervical third, the highest volume of voids was related to oval geometry in the teeth evaluated.
RESUMEN La presencia de vacíos en la obturación endodóntica, su tamaño y el tipo y localización tiene gran importancia clínica ya que permite evaluar la tridimensionalidad de las técnicas de sellado y relacionarlas con el éxito del tratamiento endodóntico. Objetivo analizar mediante microtomografía la presencia de vacíos en la obturación del conducto radicular de premolares inferiores unirradiculares, utilizando la técnica de cono único y vibración con ultrasonido. Materiales y Método se seleccionaron 20 premolares inferiores unirradiculares a los que se les realizó la preparación quirúrgica y química del conducto radicular. Se realizó la obturación con cono único y biocerámico GRUPO 1- sin vibración. En el GRUPO 2 - con vibración se aplicó vibración por ultrasonido, se tomó del cono de gutapercha colocado en el interior del conducto con pinza de algodón que fue vibrada durante 3 períodos de 3 segundos cada uno. Las mismas fueron adquiridas y reconstruidas en un microtomógrafo para posterior análisis de las imágenes obtenidas. Resultados No se evidenciaron diferencias significativas entre ambas técnicas de obturación comparadas, pero si entre los tercios analizados, siendo el cervical el que mayor porcentaje de vacíos presenta en comparación a los cortes correspondientes al tercio medio y apical. Conclusiones Los resultados sugieren que el volumen de vacíos cerrados, abiertos y total no varía en los tratamientos donde se aplica vibración por ultrasonido. En el tercio cervical, el mayor volumen de vacíos se relaciona con la geometría oval que presentaron las piezas dentarias evaluadas en este estudio.
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ABSTRACT The remaining filling material after retreatment can harbor bacteria and organic tissues that can influence the outcome of the therapy. Aim The aim of this study was to evalúate, by micro-CT, the amount of filling material remaining in the root canal after its removal using WaveOne Gold or ProDesign RT. Material and Method Forty human mandibular canines were instrumented with the ProTaper Next system up to the X2 instrument (25.06) and filled with gutta-percha cones and AHPlus. Teeth were divided into 2 groups (n=20): WaveOne Gold 25.07 (WOG) and ProDesign RT 25.08 (PRT) for filling removal, after which they were scanned in a micro-CT device to quantify the volume of remaining filling material. The data were subjected to log 10 transformation, Student 's t-test was performed to account for multiple observationsper sample, significance was set at 5%. Results Student 's t-test showed that there was no difference between the two systems regarding the volume of remaining filling material in the thirds: apical (p = 0.392), middle (p = 0.065), or cervical (p = 0.918). Conclusión Remaining filling material was present in all groups and both systems were similar in removing root filling material in mandibular canines.
RESUMO A permanencia de material obturador após o retratamento pode abrigar bactérias e tecidos orgánicos que podem influenciar o resultado da terapia. Objetivo O objetivo deste estudo foi avaliar, por micro-CT, a quantidade de material obturador remanescente no canal radicular após a desobturagdo com WaveOne Gold e ProDesign RT. Material e Método Quarenta caninos inferiores humanos foram instrumentados com o sistema ProTaper Next até o instrumento X2 (25.06) e obturados com cones de guta-percha e AHPlus. Os dentes foram divididos em dois grupos (n=20): WaveOne Gold 25.07 (WOG) e ProDesign RT 25.08 (PRT) e escaneados em micro-CT para quantificagdo do volume de material obturador remanescente. Os dados foram submetidos á transformando log10, o teste t de Student foi realizado para contabilizar múltiplas observagoes por amostra, a significáncia foi fixada em 5%. Resultados O teste t de Student mostrou que ndo houve diferenga no volume de material obturador remanescente entre os dois sistemas nos tergos: apical (p = 0,392), médio (p = 0,065) ou cervical (p = 0,918). Conclusao O material obturador remanescente estavapresente em todos os grupos e ambos os sistemas foram semelhantes na remogdo do material obturador radicular nos caninos inferiores.
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BACKGROUND:Low to moderate intensity aerobic exercise can help protect knee cartilage.Long-chain non-coding RNAs are crucial for gene regulation.Among them,HOTAIR can activate numerous transcriptional co-repressors to repress the activation of certain genes. OBJECTIVE:To detect the expression levels of HOX transcript antisense RNA(HOTAIR)and other related factors in chondrocytes of high fat-fed mice and after low to moderate intensity exercise intervention,and to investigate their role in cartilage injury and sports rehabilitation. METHODS:Thirty C57BL/6 male mice were randomly divided into control group(normal feeding),high fat feeding group and high fat feeding plus treadmill exercise group,with 10 mice in each group.The mice in the high fat feeding plus treadmill exercise group were subjected to an 8-week low to middle intensity treadmill exercise,and the mice in the other two groups were caged.During this period,body mass was weighed every week on Sunday.After the 8-week exercise,both lower extremities of mice were taken,and the knee joint was scanned using Micro CT to make a 3D femoral condyle image to obtain relevant parameters.Hematoxylin-eosin and safranin O-fast green staining of the knee joint were performed for Mankin and Osteoarthritis Research Society International(OARSI)scoring.RT-PCR was performed to detect the mRNA levels of cartilage metabolic indicators and lipid metabolism indicators,including type II collagen,matrix metalloproteinase 13,interleukin 1,low-density lipoprotein receptor-related protein 5,HOTAIR and its downstream factor lysine specific demethylase 1. RESULTS AND CONCLUSION:The body mass of high fat-fed mice were higher than that of the control group(P<0.01),and the body mass of the high fat feeding plus treadmill exercise group was lower than that of the high fat feeding group(P<0.05).The connectivity density of high fat-fed mice was higher than that of the control group(P<0.01).Mankin and OARSI scores of the high fat feeding were higher than those of the control group(P<0.01)and high fat feeding plus treadmill exercise group(P<0.05).The mRNA level of type II collagen was higher in the control group than the high fat feeding plus treadmill exercise group(P<0.05)and high fat feeding group(P<0.01)as well as higher in the high fat feeding plus treadmill exercise group than the high fat feeding group(P<0.01).The mRNA levels of matrix metalloproteinase 13,interleukin 1,low-density lipoprotein receptor-related protein 5,HOTAIR and lysine specific demethylase 1 were higher in the high fat feed group than the control group and high fat feeding plus treadmill exercise group(P<0.01).To conclude,high fat feeding can increase the bone substance of the femoral condyle,lead to knee cartilage wear,and cause chondrocyte metabolism disorder.HOTAIR is highly expressed in this process.An 8-week low to middle intensity treadmill exercise can reduce body mass,alleviate knee cartilage wear,improve chondrocyte function and down-regulate HOTAIR expression in mice.
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BACKGROUND:The lower cervical vertebral pedicle is the main stress site of the posterior column of the spine,which is of great significance for the maintenance of the stability of the human center of gravity and the reduction of shock.At present,there are few reports on the characteristics of the internal bone trabeculae,and the characteristics of the joint site of the vertebral pedicle with the articular process and the vertebral body.It is urgent to understand the fine anatomical structure of the vertebral pedicle and the relationship and function of each part. OBJECTIVE:To observe the microanatomical morphology of the vertebral pedicle by Micro-CT scanning of cervical vertebra specimens,and to measure and analyze the microstructure and morphometric parameters of the bone trabecula in the cervical pedicle under normal conditions to evaluate the safety performance of the cervical spine. METHODS:Micro-CT scanning was performed on 31 sets of cervical vertebrae C3-C7.By checking and reconstructing the areas of interest in the bone trabecular within the vertebral pedicle,the morphological characteristics and distribution direction of the bone trabecular within the cervical pedicle were observed,and the bone microstructure parameters were detected,and the differences in the bone microstructure of the C3-C7 vertebral pedicle were analyzed and compared. RESULTS AND CONCLUSION:(1)The Micro-CT images showed that the honeycomb bone trabeculae of the pedicle of the lower cervical spine presented a complex network of microstructures.The trabeculae near the cortical bone were lamellar and relatively compact,extending forward toward the vertebral body and backward toward the articular process lamina.Abatoid bone trabeculae extended into the medullary cavity and transformed into a network structure,and then into rod-shaped bone trabeculae.The rod-shaped bone trabeculae were sparsely distributed in the medullary cavity.(2)Statistical results of morphological parameters of bone trabeculae showed that bone volume fraction values in C4 and C5 were higher than that in C7(P<0.05).The bone surface/bone volume value in C7 was higher than that in C3,C4 and C6(P<0.05).The bone surface density of bone trabeculae in C7 was higher than that in C3,C4,C5 and C6(P<0.05).Trabecular thickness in C7 was higher than that in C3,C4 and C5(P<0.05).Bone surface/bone volume and bone surface density of the left pedicle bone trabecular were greater than those on the right side(P<0.05).(3)The microstructural changes of C3-C7 were summarized,in which the load capacity and stress of the C7 pedicle were poor,and the risk of injury was high in this area.
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BACKGROUND:The calcaneus is located in the lower posterior part of the foot and is heavily stressed.Calcaneus is complex and irregular in shape,surrounded by thin cortical bone and filled with a large number of trabeculae.The study of the microstructure,movement,and distribution of trabeculae is helpful to improve the understanding of calcaneus fracture. OBJECTIVE:The image data of calcaneus were obtained by scanning the calcaneus specimens with micro-computed tomography,and the structure of trabecular bone in calcaneus was analyzed to explore the morphology,distribution and structural characteristics of trabecular bone in calcaneus. METHODS:Dry adult calcaneus specimens were continuously scanned by micro-computed tomography,and the images were obtained after scanning and stored in DICOM format.Image data were imported into Hiscan Analyzer software to display clear and complete images of the sagittal plane,coronal plane,and the horizontal plane of the adult calcaneus.The trabecular movement of bone was observed layer by layer.According to the trabecular movement characteristics,the sagittal plane of the calcaneus was divided into six parts.A 49-mm2 region of interest was selected for each part at the same thickness as 7 mm.The three-dimensional microstructure of calcaneus and trabecular bone was obtained after three-dimensional reconstruction.After binarization,the volume fraction,surface density,trabecular thickness,trabecular space,and trabecular number parameters of the trabecular bone in the region of interest were calculated by software. RESULTS AND CONCLUSION:(1)The cortical layer of the calcaneus was very thin and filled with a large amount of cancellous bone,and the cortical layer of the horn of Gissane was obviously thickened.(2)The trabecular volume fraction in the upper part of the calcaneus was greater than that in the anterior part of the lower part of the calcaneus,the central triangle,the posterior part of the lower part of the calcaneus,and the base of the calcaneus,and the trabecular volume fraction in the tubercle of the calcaneus was greater than that in the anterior part of the lower part of the calcaneus,the central triangle,the posterior part of the lower part of the calcaneus,and the base of the calcaneus.The surface density of the trabecular bone in the tubercle of the calcaneus was higher than that in the front of the lower calcaneus,the middle triangle area,and the bottom of calcaneus,and the surface density of the trabecular bone in the upper part of calcaneal bone,and the lower part of the calcaneus was higher than that in the middle triangle area.The thickness of the trabecular bone in the upper part of the calcaneus was greater than that in the tubercle of the calcaneal bone.The bone trabecular space in the middle triangle was larger than that in the upper part of the calcaneus and calcaneal tubercles.The number of bone trabeculae in the calcaneal tubercles was greater than that in the middle triangle area.(3)These results indicate that the trabeculae of rod bone were mainly distributed in the middle triangle area.The surface density of trabeculae was the smallest,the volume fraction was smaller,and the space between trabeculae was the largest.This part of the bone is relatively loose.The compression resistance is poor when subjected to high impact.The trabecular bone fractures first occur,which is a prone site for fractures.
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Abstract This study aimed to compare the quality of root canal obturation (ratio of area occupied by gutta-percha (G), sealer (S), and presence of voids (V)) in different anatomical irregularities (intercanal communications, lateral irregularities, and accessory canals) located at different thirds of the root canal system of mandibular molar replicas. Sixty-seven 3D printed replicas of an accessed mandibular molar were prepared using ProGlider and ProTaper Gold rotatory systems. Three specimens were randomly selected to be used as controls and did not receive further treatment. The rest were randomly distributed in 4 experimental groups to be obturated using either cold lateral compaction (LC), continuous wave of condensation (CW), and core-carrier obturation (ThermafilPlus (TH) or GuttaCore (GC)) (n=16 per group). AHPlus® sealer was used in all groups. The three controls and a specimen from each experimental group were scanned using micro-computed tomography. The rest of the replicas were sectioned at the sites of anatomical irregularities and examined at 30× magnification. The G, S, and V ratios were calculated dividing the area occupied with each element by the total root canal area and then compared among groups using the Kruskal-Wallis test. Voids were present in all obturation techniques with ratios from 0.01 to 0.15. CW obtained a significantly higher G ratio in the irregularity located in the coronal third (0.882) than LC (0.681), TH (0.773), and GC (0.801) (p<0.05). TH and GC achieved significantly higher G ratios in those located in the apical third (p<0.05). The worst quality of obturation was observed in the loop accessory canal with all obturation techniques. Whitin the limitations of this study, it can be concluded that CW and core-carrier obturation are respectively the most effective techniques for obturating anatomical irregularities located in the coronal and the apical third.
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Abstract Wetting the dentin is critical to atraumatic restorative treatment. The conventional insertion can be challenging when using high-viscosity glass-ionomer cement. This study evaluated the formation of gaps and voids after three insertion methods using micro-CT. Teeth underwent removal of occlusal and proximal caries through the atraumatic restorative treatment technique. Then, they were fixed in an artificial dental arch to simulate the clinical condition and were restored using three insertion methods: conventional, Centrix injection, and double-filling. Previous dentin conditioning procedures, steel matrix and wooden wedge application, and post-insertion procedures (digital compression and surface protection) were the same. The material was inserted using a manual instrument in the conventional technique and was inserted with a syringe in the Centrix injection group. In the double-filling technique, the tooth received a first layer of a flowable ionomer (through modifying the powder/liquid ratio), and a second layer (with standard ratio) was applied before the final set of the first one. A micro-CT unit scanned each tooth before and after restoration. Each cavity was defined as the volume of interest, and the volumes of gaps and voids were calculated. Data were analyzed using one-way ANOVA and Tukey posthoc test (p < .05). Double-filling had improved filling volume with lower values for gap volume, followed by Centrix injection. The conventional technique had the highest gap volume. No statistically significant difference was observed for void volume. Double-filling demonstrated fewer gaps, followed by Centrix injection, which is critical to obtain better adhesive, remineralizing, and antibacterial activities.
Resumo O molhamento da dentina parcialmente desmineralizada no fundo da cavidade dentária é fundamental para o sucesso do tratamento restaurador atraumático. No entanto, o método de inserção convencional pode ser desafiador ao usar cimento de ionômero de vidro de alta viscosidade. Este estudo avaliou a formação de gaps e vazios internos após três métodos de inserção de cimento de ionômero de vidro de alta viscosidade usando micro-CT. Dez terceiros molares foram submetidos à remoção de cárie oclusal através da técnica de tratamento restaurador atraumático e complementação proximal (com ou sem lesão pré-existente). Em seguida, foram fixados em uma arcada dentária artificial para simular a condição clínica. Os dentes foram restaurados usando a técnica de tratamento restaurador atraumático com três métodos de inserção: convencional, injeção Centrix e dupla inserção. Os procedimentos anteriores de condicionamento dentinário, inserção de matriz de aço, aplicação de cunha de madeira e procedimentos pós-inserção do material (como compressão digital e proteção de superfície) foram os mesmos para os três grupos testados. O material foi inserido com instrumento manual na técnica convencional, seguindo a metodologia clássica do tratamento restaurador atraumático. O material foi inserido com um dispositivo desenvolvido especificamente para esse fim na técnica de inserção com seringa tipo Centrix. Na técnica de dupla obturação, o dente recebeu uma primeira camada do cimento de ionômero de vidro mais fluido (obtido através da modificação da relação pó/líquido), e uma segunda camada (com relação pó/líquido padrão) foi aplicada antes da presa final da primeira. Um micro-CT escaneou cada dente antes e depois da restauração. Cada cavidade foi definida como o volume de interesse, e os volumes de gaps e vazios foram calculados. Os dados foram analisados por ANOVA one-way e teste post-hoc de Tukey com nível de significância de 5%. A dupla inserção melhorou significativamente o volume de preenchimento com valores percentuais mais baixos para o volume do gap, seguido pela injeção com seringa tipo Centrix. A técnica convencional apresentou o maior percentual de volume de gap. Nenhuma diferença estatisticamente significativa foi observada para o volume de vazios internos. O grupo de dupla inserção demonstrou menor formação de gaps, seguido pelo grupo de injeção com seringa tipo Centrix, que é fundamental para obter melhores atividades adesivas, remineralizantes e antibacterianas.
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El retratamiento no quirúrgico es la primera opción ante el fracaso del tratamiento endodóntico, por lo que se vuelve importante asegurar el completo retiro del material de relleno del conducto radicular, para mejorar el pronóstico del procedimiento. Los cementos biocerámicos en base a silicatos cálcicos han aparecido en los últimos años, caracterizados principalmente por su bioactividad, lo que adicionalmente se puede traducir en una mayor dificultad para su retiro del conducto radicular. El objetivo de esta revisión es determinar qué técnica de retratamiento es más efectiva en la eliminación de cementos selladores biocerámicos, en base al volumen de material remanente en el conducto radicular, evaluado a través del análisis de imágenes con micro-CT. Se realizó una revisión sistemática mediante la búsqueda de publicaciones en las bases de datos Pubmed, ScienceDirect y SciELO, de los últimos 10 años, en idioma español e inglés. Se incluyeron sólo estudios in vitro de dientes obturados con cemento biocerámico y diferentes técnicas de retratamiento endodóntico, en los que se evalúe la limpieza del conducto post eliminación del relleno mediante micro-CT. De un total de 174 artículos encontrados, 7 fueron seleccionados, analizados y se incluyeron en esta revisión sistemática. Los resultados de los estudios seleccionados no encuentran diferencias significativas en la eliminación de material entre las diferentes técnicas de retratamiento evaluadas. A pesar de la heterogeneidad presente en las metodologías de los artículos analizados, ninguna técnica de retratamiento ni técnicas complementarias lograron dejar completamente limpios los conductos radiculares, por lo que se sugiere realizar nuevos estudios en el futuro que evalúen nuevas técnicas de desobturación radicular.
Non-surgical retreatment is the first option in the case of endodontic treatment failure, so it becomes important to ensure complete removal of the root canal filling material, to improve the prognosis of the procedure. Bioceramic cements based on calcium silicate have appeared in recent years, characterized mainly for their bioactivity, which can additionally translate into greater difficulty in their removal from the root canal. The aim of this review is to determine which retreatment technique is most effective in the removal of bioceramic sealer cements, evaluated through micro-CT image analysis. A systematic review was performed by searching for publications in Pubmed, ScienceDirect and SciELO databases, of the last 10 years in Spanish and English. Only in vitro studies of teeth filled with bioceramic cement and different endodontic retreatment techniques were included, in which the cleaning of the canal after removal of the filling was evaluated by micro- CT. From a total of 174 articles found, 7 were selected, analyzed and included in this systemic review. The results of the included studies did not find significant differences in the removal of material between the different retreatment techniques evaluated. Despite the heterogeneity in the methodologies of the studies, no retreatment technique or complementary techniques were able to completely clean the root canals, it is therefore suggested that new studies be carried out in the future to evaluate new techniques.
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Objective@# The goal of this study was to investigate the effect of the Toll-like receptor-4 (TLR-4) inhibitor TAK-242 on bone resorption in severe periodontitis in rats in order to provide an experimental basis for finding new adjuvant treatments for severe periodontitis.@*Methods @# Eighteen three-week-old male Wistar rats were randomly divided into three groups (n=6). One group was the control group, and the other two groups were modelled with severe periodontitis in bilateral maxillary molars ligated with 5-0 silk thread containing P. gingivalis ATCC33277 (periodontitis and TAK-242 groups, respectively). The TAK-242 group was injected with TAK-242 (2 mg/kg) in DMSO every other day through the tail vein from the first day of silk ligation, and the other two groups were injected with DMSO solvent at the same proportion of body weight for 8 consecutive weeks. At the end of the 8th week, rats in the 3 groups were sacrificed, and maxillary specimens were taken. Three-dimensional reconstruction was achieved after micro-CT scanning to measure the distance between the enamel cementum boundary and alveolar crest at specific sites to assess the amount of bone loss. The parameters related to alveolar bone and bone microstructure were analyzed, and the pathological changes of periodontal tissue were observed by hematoxylin-eosin (HE) staining. Alveolar bone resorption was observed by Methyl Green staining, and the distribution of osteoclasts was observed by anti-tartrate acid phosphatase double staining (TRAP).@*Results@#Micro-CT quantitative analysis showed that alveolar bone resorption in the periodontitis group and TAK-242 group was significantly higher than that in the control group. Compared with the periodontitis group, bone loss of the mesial and distal root resorption sites of maxillary first molars was significantly reduced in the TAK-242 group (P < 0.001), the bone mineral density (P < 0.05) and bone volume/total volume fraction (P < 0.01) were significantly increased, and the number of trabeculae and the trabeculae thickness (P < 0.01) were relatively increased. The trabecular separation (P < 0.01) and trabecular structure model index were significantly decreased. In the periodontitis group, the bone exhibited a sparse and porous honeycomb structure, with deterioration of the trabecular structure and a shift towards a rod-strength structure. In the TAK-242 group, the bone microstructure was improved, the bone volume was enriched, the distribution of trabeculae was relatively denser and the trabecular structure shared more similarities with the control group. HE staining displayed that the attachment loss and bone absorption were significantly higher in the periodontitis group and TAK-242 group than in the control group. Compared with the periodontitis group, MG staining displayed significantly alleviated bone absorption in the TAK-242 group. TRAP staining showed that osteoclast infiltration decreased in the TAK-242 group compared with the periodontitis group (P < 0.001)@*Conclusions @#The TLR-4 inhibitor TAK-242 can alleviate bone resorption in severe periodontitis and improve the porous, sparse and disorganized inflammatory bone trabecular structure in rats.
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Objective:To observe the effect of fluoride on growth and development of bone microstructure of rats condyle subchondral bone (RCSB).Methods:Forty two 3-week-old SD rats (half male and half female) were fed adaptively for 1 week, and 3 females and 3 males were sacrificed and recorded as 0 month. The remaining rats were randomly divided into control group ( n = 18) and fluoride exposed group ( n = 18) according to their body weight (55 - 70 g), half male and half female. The fluoride exposed group was fed with 150 mg/L sodium fluoride (NaF) aqueous solution, and the control group was fed with tap water. The two groups of experimental animals were sacrificed at 3, 5 and 7 month, respectively, 6 rats in each group, half male and half female. The right mandibular condyle was separated, and Micro CT scanning was performed to detect the microstructure parameters of RCSB. Results:In fluoride exposed group (3 month), bone surface/tissue volume (BS/TV), bone surface/bone volume (BS/BV), trabecular thickness (Tb.Th), trabecular number (Tb.N), structure model index (SMI), connectivity, connectivity density (Conn.D) and total porosity of female rats were significantly different from those of male rats ( t = - 5.10, - 5.58, 4.52, - 4.32, - 4.03, - 2.81, - 6.71, - 3.32, P < 0.05). There was no significant difference in each index between female and male rats in fluoride exposed group (5, 7 month, P > 0.05). Conclusion:In chronic fluorine exposure bone environment, the RCSB bone microarchitecture of male and female rats is different with time, showing the tendency of fluoride injury that the bone changes of female rats are slowed and the bone changes of male rats are active.
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Objective:To investigate the effects of long-term high-fat diet on bone mineral density and intestinal flora in mice.Methods:Sixteen male C57BL/6 mice were randomly divided into control group (NC group) and high-fat group (HF group). After 24 weeks of high-fat feeding, biochemical indicators such as blood glucose and blood lipids were detected, bilateral femurs were taken and bone microstructure was analyzed with micro-computered tomography (micro-CT), and changes of intestinal microbial composition and proportion were revealed using 16S rDNA sequencing technology.Results:Compared with the control group, the serum total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) in HF group were significantly increased. Micro-CT uncovered that the bone mineral density (Tb.BMD), bone volume fraction (BV/TV) and the number of trabecular bone (Tb.N) decreased, yet structural model index (SMI) and the trabecular fraction (Tb.Sp) increased in the HF group mice. The gut microbiota 16S rDNA sequence analysis showed that the proportion of Proteobacter was significantly increased and the proportions of pachycete, warty microbacterius, and actinomycete were reduced in HF group at the phyla level. The proportion of Bacteroidetes S24-7_norank in the NC group was significantly higher than that in the HF group, and the multilevel discriminant analysis of species differences (LEfSe) identified that the difference was significant, yet the proportion of Bacteroides, Pseudo-Prevotella, Desulfovibrio, Altobacter, and Helicobacter in the HF group were higher than those in the NC group, which were significant differences in Altobacter and Helicobacter at genus level.Conclusion:Long-term high-fat feeding can cause the destruction of femoral trabecular structure, decrease in the number of trabeculus bones, and bone mineral density in C57BL/6 mice. It also leads to significant changes in the composition and proportion of the intestinal flora.
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ObjectiveTo study the effect of Jinlida granules on visceral fat accumulation and its induced inflammatory response in prediabetic rats. MethodMale SD rats were randomly divided into normal group, model group, Jinlida low-dose group (1.5 g·kg-1), Jinlida high-dose group (3.0 g·kg-1) and atorvastatin group (10 mg·kg-1). Prediabetic rat model was established using high-carbohydrate, high-fat diet combined with low-dose streptozotocin (STZ) by multiple small-dose intraperitoneal injections. After 8 weeks of modeling and drug intervention for 13 consecutive weeks, body weight, oral glucose tolerance test(OGTT), fasting blood glucose (FBG), fasting insulin (FINS), insulin resistance index (HOMA-IR), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) were measured in each group of rats. The content of visceral fat was quantified by micro-computed tomography (Micro-CT). Hematoxylin-eosin staining (HE) was used to observe the pathological changes of fat cells. The levels of tumor necrosis factor-α (TNF-α) and interleukin- 6 (IL-6) in rat visceral fat and serum were determined by enzyme linked immunosorbent assay (ELISA). The expression of macrophage marker CD68 in visceral fat was detected by immunofluorescence and Western blot. ResultCompared with normal group, model group had increased oral glucose tolerance, FBG, FINS, HOMA-IR, TC, LDL-C (P<0.01), elevated body weight and visceral fat accumulation (P<0.05, P<0.01), enhanced CD68 protein expression and TNF-α and IL-6 levels (P<0.01), decreased HDL-C (P<0.01), and abnormal hypertrophy of adipocytes. Compared with model group, Jinlida high- and low-dose groups lowered oral glucose tolerance, HOMA-IR, TC and LDL-C (P<0.05, P<0.01), body weight and visceral fat accumulation (P<0.05), and CD68 protein expression and TNF-α and IL-6 levels (P<0.05, P<0.01) and lessened hypertrophy of fat cells. ConclusionJinlida can improve the insulin resistance in prediabetic rats by reducing visceral fat accumulation and its induced inflammatory response, which provides a new pharmacological basis for clinical treatment of prediabetes by Jinlida granules.
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SUMMARY: The objective of the study was to provide a detailed anatomical description of the rat's ear anatomy that will prove insightful to different experimental otologic surgical procedures regardless of scope. Three male Wistar rats were enrolled in the study. Candidates were screened for systemic and otologic pathology. External ear canal endoscopy was carried out with a 30˚ rigid endoscope through an image capture system. Middle ear anatomical elements were analyzed under stereomicroscopy. 3D computer tomography image reconstruction was realized with a micro-CT to describe the anatomy. Image data from all three rats were analyzed. Anatomical annotations and surgical exposure recommendations were added for key elements. The most relevant images from all three rats were selected for representation. Detailed visualization of the structural elements of the tympanic cavity were clearly visible: promontory, round window, stapedial artery, stapes, incus, and tympanic membrane were all constant findings. We describe a step wise ventral surgical approach of the middle and inner ear for which we found that the clavotrapezius muscle was a reliable landmark. For the transtympanic approach the endoscopic transcanal access was an easy and reliable method for which a detailed anatomical representation was depicted. Further, anatomical similarities to humans were observed by stereomicroscopy and Micro-CT imaging reiterating that the rat model is suitable for otologic research. The endoscopic approach to the tympanic membrane is comfortable and less expensive than a microscope. The tendon of the clavotrapezius muscle can be a reliable landmark for discovering the tympanic bulla when considering a ventral approach. 3D Micro-CT reconstruction allows intact evaluation of the samples, simultaneously being a diagnostic and also a learning tool.
RESUMEN: El objetivo de este trabajo fue proporcionar una descripción anatómica detallada de la anatomía del órgano vestíbulococlear de la rata que resultará útil para diferentes procedimientos quirúrgicos otológicos experimentales, independientemente del alcance. En el estudio se usaron tres ratas Wistar macho. Los ejemplares fueron evaluados por patología sistémica y otológica. La endoscopía del meato acústico externo se realizó con un endoscopio rígido de 30˚ a través de un sistema de captura de imágenes. Los elementos anatómicos del oído medio se analizaron bajo estereomicroscopía. La reconstrucción de la imagen de tomografía computarizada en 3D se realizó con un micro-CT para describir la anatomía. Se analizaron los datos de imagen de las tres ratas. Se agregaron anotaciones anatómicas y recomendaciones de exposición quirúrgica para elementos clave. Las imágenes más relevantes de las tres ratas fueron seleccionadas para su representación. La visualización detallada de los elementos estructurales de la cavidad timpánica era claramente visible: promontorio timpánico, ventana coclear, arteria estapedial, estapedio, yunque y membrana timpánica eran hallazgos constantes. Describimos un abordaje quirúrgico ventral escalonado del oído medio e interno para el cual encontramos que el músculo clavotrapecio era un punto de referencia confiable. Para el abordaje transtimpánico, el acceso transcanal endoscópico fue un método fácil y confiable para el cual se describió una representación anatómica detallada. Además, se observaron similitudes anatómicas con los humanos mediante estereomicroscopía e imágenes Micro-CT, lo que reitera que el modelo de rata es adecuado para la investigación otológica. El abordaje endoscópico de la membrana timpánica es cómodo y menos costoso que un microscopio. El tendón del músculo clavotrapecio puede ser un punto de referencia fiable para descubrir la bulla timpánica cuando se considera un abordaje ventral. La reconstrucción 3D Micro- CT permite la evaluación intacta de las muestras, siendo simultáneamente una herramienta de diagnóstico y también de aprendizaje.
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Animais , Masculino , Ratos , Orelha/anatomia & histologia , Orelha/cirurgia , Procedimentos Cirúrgicos Otológicos , Ratos Wistar , Imageamento Tridimensional , Orelha/diagnóstico por imagem , Microtomografia por Raio-XRESUMO
Introdução: o desafio no uso do Micro-Ct tem sido estabelecer e padronizar padrões adequados para escaneamento e tratamento das imagens, para que se obtenha o máximo desempenho do equipamento, e permitir a comparação dos achados entre diferentes estudos. Objetivo: o presente estudo tem como objetivo comparar a porcentagem de volume ósseo em regiões com perda óssea periodontal utilizando diferentes metodologias para definição da área a ser analisada (ROI). Material e método: dez ratos foram submetidos à indução de doença periodontal, e, após a eutanásia, as mandíbulas foram escaneadas com cortes de 9 µ e 18 µm de espessura, com passo de rotação de 0.3mm. As imagens foram reconstituídas utilizando o software NRecon, e em seguida, utilizando o software CTAnalyser - CTAn, foram definidas as áreas de interesse (ROI) ao redor dos segundos molares. A primeira área de interesse (ROI1) foi definida em um padrão retangular que se restringiu às regiões interproximais e furca, onde a área total de tecido ósseo foi obtida somando os resultados dos 3 ROIs. A segunda área (ROI2) foi definida no sentido corono/apical ao redor do segundo molar até suas limitações proximais com os dentes vizinhos, onde a porcentagem de tecido ósseo pertencente às raízes foram excluídas das avaliações. As análises foram realizadas com cinco diferentes valores de thresholds (130-50, 130-60, 130-70, 130-80, 130-90 e 130-100). Resultado: a análise entre os diferentes ROIs demonstrou que em ambas as análises foi observada a tendência a menor porcentagem de tecido ósseo quanto maior o contraste de tons de cinza utilizado, no entanto, nos resultados obtidos no ROI2 essa diferença não foi estatisticamente significante. Conclusão: com os resultados obtidos pode se concluir que a utilização de diferentes thresholds para quantificação óssea, em áreas onde houve doença periodontal, pode trazer resultados divergentes; a definição da área de interesse interfere com os resultados obtidos e que a obtenção de uma área de interesse com a remoção das raízes mostrou-se menos susceptível à variação dos parâmetros de escaneamento.
Introduction: the challenge in the use of Micro-Ct has been to establish and standardize adequate standards for scanning and image processing to obtain the maximum performance of the equipment and to allow the comparison of findings between different studies. Objective: this study aims to compare the percentage of bone volume in regions with periodontal bone loss using different methodologies to define the area to be analysed (ROI). Material and method: ten rats were submitted to periodontal disease induction, and, after euthanasia, the mandibles were scanned with slices of 9µ and 18 µm thickness, with a rotation step of 0.3mm. The images were reconstructed using the NRecon software, and then, using the CTAnalyser - CTAn software, the areas of interest (ROI) around the second molars were defined. The first area of interest (ROI1) was defined in a rectangular pattern that was restricted to the interproximal and furcation regions, where the total area of bone tissue was obtained by adding the results of the 3 ROIs. The second area (ROI2) was defined in the coronal/apical direction around the second molar to its proximal limitations with the neighboring teeth, in which the percentage of bone tissue belonging to the roots was excluded from the evaluations. Analyses were performed with five different threshold values (130-50, 130-60, 130-70, 130-80, 130-90, and 130-100). Result: the analysis between the different ROIs showed that, in both analyses, there was a tendency towards a lower percentage of bone tissue the greater the grayscale contrast used. However, in the results obtained in ROI2, this difference was not statistically significant. Conclusion: with the results obtained, it can be concluded that the use of different thresholds for bone quantification, in areas where there was a periodontal disease, can bring divergent results; the definition of the area of interest interferes with the results obtained; and that obtaining an area of interest with the removal of the roots, proved to be less susceptible to the variation of the scanning parameters.
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Animais , Ratos , Doenças Periodontais , Periodontite , Perda do Osso Alveolar , Microtomografia por Raio-X , Mandíbula , Dente Molar , Análise de VariânciaRESUMO
SUMMARY: The aim of the present study was to evaluate the changes of alveolar bone in aged rats. The mandibles of the 4- month and 22-month aged rats were scanned by micro-CT. After the reconstruction of the alveolar bone,the distance between the cemento enamel junction (CEJ) and the alveolar bone crest (ABC) was measured. The micro architectures of the inter-radicular alveolar bone were analyzed. The 22-month rats experienced the reduction in alveolar crest height in the buccal side and the lingual side, and significant increase in alveolar bone loss compared with the 4-month rats. The 22-month rats had a porous microarchitecture, the trabecular arrangement was obviously dissociated with the expanded inter-bone spaces of marrow, and the bone histomorphometry analysis showed the decreased bone volume/tissue volume and trabecular thickness in the 22-month rats. These results suggest that alveolar bone loss and alveolar trabecular bone deterioration might contribute to the weakening of molar support in the elderly.
RESUMEN: El objetivo del presente estudio fue evaluar los cambios del hueso alveolar en ratas envejecidas. Las mandíbulas de las ratas de 4 y 22 meses se escanearon mediante micro-TC. Después de la reconstrucción del hueso alveolar, se midió la distancia entre la unión cementoesmalte (CEJ) y la cresta ósea alveolar (ABC). Se analizaron las microarquitecturas del hueso alveolar interradicular. Las ratas de 22 meses experimentaron la reducción de la altura de la cresta alveolar. en el lado bucal y lingual, y un aumento significativo en la pérdida de hueso alveolar en comparación con las ratas de 4 meses. Las ratas de 22 meses tenían una microarquitectura porosa, la disposición trabecular estaba obviamente disociada con los espacios interóseos expandidos de la médula y el análisis de histomorfometría ósea mostró una disminución del volumen óseo / volumen tisular y del grosor trabecular en las ratas de 22 meses. Estos resultados sugieren que la pérdida ósea alveolar y el deterioro del hueso trabecular alveolar podrían contribuir al debilitamiento del soporte molar en los ancianos.
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Animais , Masculino , Ratos , Perda do Osso Alveolar/patologia , Perda do Osso Alveolar/diagnóstico por imagem , Envelhecimento , Ratos Wistar , Microtomografia por Raio-XRESUMO
Abstract This study evaluated the effect of the use of glass ionomer cement (GIC) and flowable bulk-fill resin composite (BFRC) for filling pulp chambers and the type of high-speed handpiece light used on dentin removal during access preparation for endodontic retreatment in molar teeth. Twenty maxillary molars were treated endodontically. BFRC (Opus Bulk Fill Flow APS, FGM) was used to fill the pulp chamber and replace coronal dentin (n = 10). In the remaining teeth, the pulp chamber was filled with GIC (Maxion R, FGM). Conventional resin composite (Opallis, FGM) was used to restore the enamel layer in all teeth. The samples in each group were divided into two subgroups, and the root canals were reaccessed using a handpiece with white or ultraviolet light. The teeth were scanned using micro-CT before and after root canal reaccess. The dentin volume removed was calculated and analyzed using 2-way analysis of variance and Tukey's test (α = 0.05). The crown and pulp chamber locations with dentin removal are described using frequency distribution. During the access, fewer pulp chamber walls were affected and a lower volume of dentin was removed from the pulpal floor in the group restored with GIC than in the group restored with BFRC. No effect was observed on the coronal dentin walls with respect to the filling protocols and type of light used. For dentin removal from the pulp chamber, handpieces with white light performed better than those with ultraviolet light, irrespective of the filling protocol used. The use of GIC to fill the pulp chamber and use of white handpiece light reduced dentin removal from the pulpal floor and resulted in fewer affected dentin walls.
Resumo Este estudo avaliou os efeitos do cimento de ionômero de vidro (GIC) e da resina composta fluida bulk fill (BFRC) usados como preenchimento da câmara pulpar; e o tipo de iluminação das turbinas de alta rotação na remoção dentinária após cavidades de acesso para retratamento endodôntico em dentes molares. Vinte molares superiores foram tratados endodonticamente. Dez dentes foram restaurados usando BFRC (Opus Bulk Fill Flow APS, FGM) para preencher a câmara pulpar e dentina coronária; e resina composta convencional (Opallis, FGM) para restaurar a camada de esmalte. Os outros dentes foram restaurados usando GIC (Maxion R, FGM) para preencher a câmara pulpar e resina composta (Opallis, FGM). As amostras foram divididas em dois grupos e os canais radiculares foram novamente acessados com turbina de alta-rotação com iluminação branca ou ultravioleta. Os dentes foram escaneados usando micro-CT antes e após o novo acesso ao canal radicular. O volume de dentina removida foi calculado e os dados foram analisados por ANOVA bidirecional e teste de Tukey (α=0,05). As regiões na coroa e na câmara pulpar que apresentaram dentina removida no acesso dos canais foram descritas por meio de distribuição por frequência. A reabertura do canal radicular com GIC resultou em menos paredes afetadas da câmara pulpar e menor volume de dentina removida no assoalho. Nenhum efeito foi observado nas paredes de dentina coronária considerando aos protocolos de preenchimento. A turbina de alta rotação com iluminação branca reduziu a remoção de dentina da câmara pulpar, independentemente do protocolo de restauração utilizado. O uso de turbina de alta rotação com iluminação branca e GIC para preencher a câmara pulpar reduziram a remoção de dentina do assoalho e afetaram menos paredes dentinárias.
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Objective@# Establish a murine model for hyperuricemia (HU) and periodontitis to explore whether there is correlation between them and provide a basis for periodontal treatment.@*Methods@#Fourteen male KM mice were divided into 2 groups; the HU group (n=7) was fed food supplemented with potassium oxonate and uric acid, the NC group (n=7) was fed standard food, and the induction period was 35 days. On the 25th day, the molars on one side were ligated to induce periodontitis (P side), while the opposite was true for the control (C side). Baseline and terminal serum uric acid (UA) levels were detected, and alveolar bone resorption was analyzed by micro-CT.@*Results@#The serum UA level of HU mice was (112.94 ± 26.82 )mol/L, that of the NC group was (72.21 ± 19.95) μmol/L, and the difference in UA level was statistically significant (P < 0.05). The P side bone volume fractions of the HU and NC groups were( 29.01 ± 11.09)% and (29.56 ± 15.27)%, respectively, which were not significantly different (t=-0.072, P=0.944). The P side bone mineral densities of the HU and NC groups were(0.53 ± 0.16) g/cm3 and (0.52 ± 0.14) g/cm3, respectively, which were not significantly different (t=0.038, P=0.970). Additionally, there was no correlation between HU or serum UA and alveolar bone resorption (P > 0.05). @* Conclusion @#This research established a murine model for HU and periodontitis, but based on micro-CT analysis of alveolar bone, no relationship between HU or UA levels and periodontitis was found.
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Objective:To investigate the therapeutic effect of Guizhi Shaoyao Zhimutang (GSZT) on the osteoporosis (OP) in SD female rats induced by ovariectomy (OVX) combined with glucocorticoid injection and its related mechanisms. Method:The rats were divided into a sham operation group and an experimental group for OVX. One week later, the experimental rats were divided into an OP model group, a calciferol (positive control, 0.1 mg·kg<sup>-1</sup>) group, and low(0.8 g·kg<sup>-1</sup>), medium(1.6 g·kg<sup>-1</sup>), and high-dose (3.2 g·kg<sup>-1</sup>) GSZT groups. Except for those in the sham operation group, the rats received an intramuscular injection of dexamethasone (1 mg·kg<sup>-1</sup>) twice per week for six weeks. After the rats were treated correspondingly for eight weeks, the rats were sacrificed for thighbone sample collection. The computer microtomography (Micro CT) was used to analyze the parameters of bone mineral density (BMD), bone volume (BV), tissue volume (TV), structure model index (SMI), connectivity density (Conn.D), trabecular number (Tb.N), trabecular thickness (Tb.Th), trabecular pattern factor (Tb.Pf), and trabecular separation (Tb.Sp). In addition, hematoxylin-eosin (HE) and Masson staining was used for the histopathological examination of the thighbone. Tartrate-resistant acid phosphatase (TRAP) staining was used to analyze osteoclasts in bone tissues. The enzyme-linked immunosorbent assay (ELISA) was used to determine matrix metalloproteinase-9 (MMP-9), cathepsin K (CTSK), and TRAP5b in bone tissues, and Western blot was carried out to determine receptor activator of NF-kappaB ligand (RANKL), osteoprotegerin (OPG), alkaline phosphatase (ALP) in bone tissues. Result:Compared with normal group, the number of bone trabeculae in cancellous part of OP model rats decreased significantly, the spacing widened, the thickness became thinner, and the continuity was poor. Compared with model group, GZST medium and high-dose groups could improve the changes of femoral bone trabecular cancellous bone. Masson staining showed that compared with the normal group, the growth plate thickness of the distal femur epiphysis was thinner and the area of new bone was smaller in the OP model group, while the reduction of new bone was inhibited in the high dose group of calcitol and GZST. TRAP staining results showed that the number of osteoclasts in OP group was significantly increased compared with the normal group, and the number of osteoclasts in medium-high dose GZST group was reduced. Micro CT results showed that compared with normal group, BMD, BV, Tb.N, Tb.Th and Conn.D of OP rats were decreased, SMI and Tb.Sp were significantly increased(<italic>P</italic><0.01). Compared with model group, medium and high dose of GZST could improve the degree of osteoporosis in OP rats, BV, Tb.N were significantly increased, SMI, Tb.Sp were significantly decreased (<italic>P</italic><0.01). ELISA results revealed that compared with the sham operation group, the OP model group showed decreased ALP content (<italic>P</italic><0.01) and increased MMP-9, TRAP5b, and CTSK (<italic>P</italic><0.01). Compared with the OP model group, the high-dose GSZT group showed increased ALP content (<italic>P</italic><0.01) and decreased MMP-9, TRAP5b, and CTSK (<italic>P</italic><0.01). Western blot results demonstrated that compared with the OP model group, the calciferol group and the high-dose GSZT group showed inhibited expression of the RANKL protein (<italic>P</italic><0.05), and increased OPG expression (<italic>P</italic><0.05). Conclusion:The findings suggest that GZST has a potential therapeutic effect on OP caused by OVX combined with glucocorticoids in rats, and the underlying mechanism is associated with the regulation of RANKL/OPG in bone tissues. This study is expected to lay a preliminary foundation for its clinical application and modern preparation development.
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Objective:To study the effect of Bushen Huatan prescription on helper T cell 17 (Th17)/T regulatory cells (Treg) balance of immune T cell subsets in the prevention and treatment of postmenopausal osteoporosis. Method:Sixty 6-month-old female SD rats were randomly divided into sham operation group, model group, estradiol valerate group (0.184 mg·kg<sup>-1</sup>) and Bushen Huatan prescription low, medium and high groups (4.7, 9.4, 18.8 g·kg<sup>-1</sup>) according to the random number table. All the groups except the sham operation group received ovariectomy to make postmenopausal osteoporosis model. Intragastric administration was started 1 week after operation, and the rats in model group and sham operation group received equal volume of normal saline, once a day for 12 weeks. Microcomputed tomography (Micro CT) was then used to detect bone mass and microstructure of rats, the contents of Forkhead box protein (Foxp3) and retinoic acid related nuclear orphan receptor (ROR<italic>γ</italic>t) in serum were detected by enzyme-linked immunosorbent assay (ELISA), the mRNA expression levels of Foxp3 and ROR<italic>γ</italic>t in bone tissues were detected by Real-time fluorescence quantitative polymerase chain reaction (Real-time PCR) and Western blot was used to detect the protein expression of Foxp3 and ROR<italic>γ</italic>t in bone tissues, the number of Th17 and Treg cells in each group was analyzed and compared by flow cytometry. Result:Compared with the sham operation group, the bone mass and trabeculae of the model group decreased (<italic>P</italic><0.01), the bone microstructure was destroyed, the concentration of Foxp3 in serum decreased, the concentration of ROR<italic>γ</italic>t increased (<italic>P</italic><0.01), the mRNA and protein expression levels of Foxp3 in bone tissues decreased, ROR<italic>γ</italic>t increased, the number of Treg cells in bone tissues decreased, number of Th17 cells increased (<italic>P</italic><0.01), and Th17/Treg ratio increased (<italic>P</italic><0.01) in model group. Compared with the model group, the bone mass in each treatment group increased (<italic>P</italic><0.05, <italic>P</italic><0.01), Foxp3 concentration in serum increased, ROR<italic>γ</italic>t concentration decreased (<italic>P</italic><0.01), the mRNA and protein expression levels of Foxp3 in bone tissues increased significantly (<italic>P</italic><0.05, <italic>P</italic><0.01), but no statistical difference was shown in mRNA expression between low dose group and the model group. In addition, the mRNA and protein expression of ROR<italic>γ</italic>t decreased (<italic>P</italic><0.05, <italic>P</italic><0.01), number of Treg cells increased, number of Th17 cells decreased (<italic>P</italic><0.05, <italic>P</italic><0.01), and Th17/Treg ratio decreased in treatment groups (<italic>P</italic><0.01). Conclusion:Bushen Huatan prescription can increase bone mass, improve bone microstructure, increase the number of Treg cells and decrease the number of Th17 cells in ovariectomized rats. It is concluded that Bushen Huatan prescription may play a role in preventing and treating postmenopausal osteoporosis by regulating Th17/Treg balance.
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Porous titanium alloy scaffold was widely used in treating bone defect caused by traumatic injury and osteomyelitis, which was incapable of self-healing. The implantation of scaffold produced stress shielding thereby forming osteolysis. The objective of this study was to analysis trabecular morphological features of osseointegrated bone. 14 New Zealand rabbits were divided into two groups, surgery group and healthy control group. 7 rabbits in surgery group were selected to perform 3D printed porous titanium alloy scaffold implantation surgery with preload at the defect of femoral condyle for osseointegration. The other 7 rabbits in control group were feed free. After 90 days healing, femoral condyles were extracted to perform micro-CT scanning with hydroxyapatite calibration phantom. Mean bone mineral density (BMD), bone volume fraction (BV/TV), BS/TV (bone surface area ratio), Tb.Th (thickness of trabeculae), Tb.N (number of trabeculae), Tb.Sp (trabecular separation) and DA (degree of anisotropy) were calculated from micro-CT images. The results revealed that osseointegration inside and at the surface of scaffolds worked well from grey values of micro-CT images. After 12 weeks healing, mean bone mineral densities (BMD) in surgery group and healthy control group were calculated as 800±20mg/cm3 and 980±90mg/cm3, respectively. This revealed that the strength of trabeculae in surgery group might lower than that in the healthy group. Trabecular morphological parameters test showed that trabecular morphological parameters at the surface of scaffolds in the surgery group deteriorated significantly. It was found from micro-CT images that ingrowth bone was filled with pores of scaffold. Overall, the effect of osseointegration was promoted through the change of mechanical micro-environment in the scaffold region. Overall, preload could improve osseointegration effect in the long-term after surgery. However, the trabecular morphology in the surgery group was deteriorated, which might bring secondary fracture risk again.
La malla de aleación de titanio poroso se usó ampliamente en el tratamiento de defectos óseos causados por lesiones traumáticas y osteomielitis. El implante de la malla generó una protección contra el estrés, formando así osteolisis. El objetivo de este estudio fue analizar las características morfológicas trabeculares del hueso osteointegrado. Se dividieron 14 conejos (Neozelandeses) en dos grupos, grupo cirugía y grupo control saludable. Se seleccionaron 7 conejos en el grupo de cirugía para realizar una implantación de mallas de aleación de titanio poroso, impresas en 3D con precarga en el defecto del cóndilo femoral para la osteointegración. Los 7 conejos restantes del grupo control se mantuvieron sin alimentación. Después de 90 días de curación, se extrajeron los cóndilos femorales para realizar una exploración por micro-CT con un espectro de calibración de hidroxiapatita. Se calcularon a partir de imágenes de micro-CTDensidad mineral ósea media (DMO), fracción de volumen óseo (BV / TV), BS / TV (relación de área de superficie ósea), Tb.Th (espesor de trabéculas), Tb.N (número de trabéculas), Tb.Sp (trabecular separación) y DA (grado de anisotropía). Los resultados revelaron que la osteointegración dentro y en la superficie de los andamios funcionó bien a partir de los valores grises de las imágenes de micro-CT. Después de 12 semanas de curación, las densidades medias de minerales óseos (DMO) en el grupo cirugía y en el grupo control sano se calcularon como 800 ± 20 mg/cm3 y 980 ± 90 mg/cm3, respectivamente. Esto reveló que la fuerza de las trabéculas en el grupo de cirugía podría ser menor que la del grupo sano. La prueba de parámetros morfológicos trabeculares mostró que en el grupo de cirugía, la superficie de las mallas, se deterioraron significativamente. Se descubrió a partir de imágenes de microCT que el hueso en crecimiento estaba lleno de poros de andamio. En general, el efecto de la osteointegración se promovió mediante el cambio del microambiente mecánico en la región de la malla. En general, la precarga podría mejorar el efecto de osteointegración a largo plazo después de la cirugía. Sin embargo, la morfología trabecular en el grupo de cirugía se deterioró, lo que podría traer un nuevo riesgo de fractura secundaria.