摘要
Los vidrios bioactivos (VBa) son materiales biocerámicos que tienen una extensa aplicación en medicina y odontología. A causa de su contenido de calcio y fosfato son muy simi- lares a la hidroxiapatita del tejido óseo. Su biocompatibili- dad y bioactividad los hacen materiales muy útiles para ser aplicados en diferentes áreas de la práctica dental, tales como periodoncia, cirugía, odontología restauradora y endodoncia. En endodoncia los VBa están indicados para realizar protec- ciones pulpares directas, pulpotomías, desinfecciones y obtu- raciones del sistema de conductos radiculares. El objetivo del presente trabajo fue realizar una revisión de las propiedades biológicas de los VBa en relación a sus aplicaciones en en- dodoncia (AU)
Bioactive glasses (BGs) are bioceramic materials with extensive clinical applications in medicine and dentistry. Be- cause of their phosphate and calcium contents, they are like the hydroxyapatiteof bone tissue. Their biocompatibility and bioactivity make them very useful biomaterials in different areas of dental practice, such as periodontics, oral surgery, restorative dentistry, and endodontics. In endodontics, bioac- tive glasses are indicated for direct pulp capping, pulpoto- mies, disinfections and fillings of the root canal system. The aim of this work was to carry out a review of the biological properties of BGs in relation to its application in endodontics (AU)
Subject(s)
Humans , Animals , Root Canal Filling Materials/chemistry , Biocompatible Materials/chemistry , Durapatite/chemistry , Narration , Dental Pulp Capping/instrumentation , Chemical Phenomena , Glass/chemistry摘要
BACKGROUND:Osteochondral defect of the joint is a difficult problem faced by orthopedic surgeons,and traditional repair methods are difficult to obtain satisfactory curative effects.Hydroxyapatite-polyvinyl alcohol-based composite hydrogel material is a direction of current research. OBJECTIVE:To prepare hydroxyapatite-polyvinyl alcohol/collagen-chitosan-gelatin composite hydrogel material and characterize its physical characteristics,to verify its histocompatibility and cell adhesion and proliferation ability after implantation in vivo,and explore its repair effect on rabbit osteochondral defects. METHODS:The cylindrical porous poly(lactic acid)scaffold was prepared by 3D printing technology(the pore sizes were 1.2,1.4,1.6 and 1.8 mm,respectively).The poly(lactic acid)scaffold was injected with polyvinyl alcohol and hydroxyapatite mixed emulsion.After freezing thawing and dichloromethane dissolution,hydroxyapatite-polyvinyl alcohol hydrogel was prepared.Then,the collagen-chitosan-gelatin mixture was injected into the hydroxyapatite-polyvinyl alcohol hydrogel and crosslinked with genipin.Finally,the hydroxyapatite-polyvinyl alcohol/collagen-chitosan-gelatin composite hydrogel was prepared by alcohol cleaning and freeze-drying.The physical characteristics of the four groups of hydrogels were characterized,and the hydrogels with the best performance were screened for follow-up experiments.Hydroxyapatite-polyvinyl alcohol hydrogel and collagen-chitosan-gelatin composite hydrogel were implanted subcutaneously in SD rats.Hematoxylin-eosin staining and Masson staining were used to observe the adhesion growth of cells on the material surface.Osteochondral defect(diameter:5 mm,depth:6 mm)models were made in the femoral trochlea of bilateral knee joints of 15 rabbits.The composite hydrogel was implanted on the left side(experimental group),while no material was implanted on the right side(control group).Micro-CT and histology were used to evaluate the repair effect of osteochondral defects. RESULTS AND CONCLUSION:(1)Based on the results of porosity,water content,mechanical testing and scanning electron microscopy,it was concluded that the hydroxyapatite-polyvinyl alcohol/collagen-chitosan-gelatin composite hydrogel with a pore size of 1.2 mm was more consistent with the general characteristics of natural cartilage,which was used for subsequent experiments.(2)Hematoxylin-eosin staining and Masson staining exhibited that with the extension of subcutaneous implantation time of the materials,the adhesion of cells around the two materials increased significantly,and the proliferation of cells after the implantation of collagen-chitosan-gelatin was better,a large number of cells could be seen growing into the formed network structure,and the network structure was gradually degraded.(3)In the rabbit osteochondral defect experiment,8 weeks after surgery,Micro-CT examination demonstrated that the material implanted in the experimental group had good integration with the surrounding bone-cartilage,with some bone growth on the surface and inside,while the cartilage and subcartilage in the control group still had obvious defects,without effective repair.Hematoxylin-eosin staining and toluidine blue staining displayed that the composite hydrogel in the experimental group integrated with the surrounding articular cartilage 4-8 weeks after implantation.With the extension of time,new cartilage gradually formed on the surface of the material.At 12 weeks,most of the defect was covered by new cartilage,and good bone growth was also observed in the subcartilage.In the control group,the deep bone defects were mostly repaired and the superficial cartilage and subchondral bone defects were also repaired to a certain extent,but they were mainly replaced by fibrous tissue and part of fibrocartilage 12 weeks after surgery.(4)In conclusion,hydroxyapatite-polyvinyl alcohol/collagen-chitosan-gelatin composite hydrogel material can mimic the structure and function of natural cartilage,and can effectively repair osteochondral defects in animal experiments.
摘要
BACKGROUND:Hydroxyapatite is the main inorganic component of bone tissue.The polymer has the structure and function of a biomimetic extracellular matrix.The composites of hydroxyapatite and polymer have been widely studied. OBJECTIVE:To summarize the research status of hydroxyapatite composite polymer materials for bone tissue repair. METHODS:The articles collected in PubMed,Web of Science,CNKI and WanFang databases were searched from January 2010 to April 2023.The Chinese and English search terms were"hydroxyapatite,polymer,composites,degradability,bone defect,bone repair".Finally,75 articles were included for review. RESULTS AND CONCLUSION:Polymers often used in composite with hydroxyapatite for bone tissue repair include natural polymers(collagen,chitosan,alginate,serine protein,cellulose,hyaluronic acid,and polyhydroxybutyrate)and synthetic polymers[polylactic acid,polylactic acid-hydroxyacetic acid copolymer,poly(has-lactide),poly(amino acid)and poly(vinyl alcohol)].The mechanical properties and osteoinductivity of hydroxyapatite/polymer composites were improved compared with pure hydroxyapatite.Hydroxyapatite composite with polymers can be made into porous scaffolds,hydrogels,and coatings for bone repair.Hydroxyapatite/polymer composites can accelerate bone reconstruction with a slow release of loaded drugs and cytokines due to their bionic extracellular matrix structure and function.Based on the diversity of causes of bone defects and the fact that bone repair is a complex continuous process involving multiple biological factors and proteins,repair materials with mechanical properties matching bone tissue,degradation processes synchronized with bone repair,and efficient osteogenesis and vascularization need to be further investigated.
摘要
BACKGROUND:Nano-zirconium dioxide has good application potential in the field of bone tissue repair.Studying the effect of nano-zirconium dioxide on osteogenic differentiation will help to promote the clinical application of nano-zirconium dioxide in the treatment of bone defects. OBJECTIVE:To explore the effect of nano-zirconium dioxide on the osteogenic differentiation of ectomesenchymal stem cells in the nasal mucosa. METHODS:Ectomesenchymal stem cells derived from rat nasal mucosa were isolated and cultured,and the biotoxicity of nano-zirconium dioxide to the cells was detected by CCK-8 assay.The biosafety concentration was selected according to the cytotoxicity,and the cells were randomly divided into a control group,a nano-zirconium dioxide group,and a nano-hydroxyapatite group.Osteogenic differentiation of cells was directionally induced in each group.On day 7 of induced differentiation,alkaline phosphatase staining was performed.qRT-PCR and western blot assay were used to detect the expression of early osteogenic markers(Runx2 and Osx).On day 21 of induced differentiation,alizarin red staining was conducted.qRT-PCR and western blot assay were utilized to determine the expression levels of late osteogenic markers(OPN and OCN). RESULTS AND CONCLUSION:(1)The median lethal concentration of nano-zirconium dioxide on ectomesenchymal stem cells in nasal mucosa was 0.6 mg/mL.In the experiment,the mass concentration of 200 μg/mL was selected for intervention.Zirconium dioxide had no significant effect on the proliferation of the cells.(2)Compared with the control group,the alkaline phosphatase staining of the cells in the nano-zirconium dioxide group was more obvious and the level of cell mineralization was higher,but there was no significant difference compared with the nano-hydroxyapatite.(3)Compared with the control group,the expression of bone-related genes and proteins increased significantly,but there was no significant difference compared with nano-hydroxyapatite.(4)The results show that nano-zirconium dioxide has good biological safety and can promote the osteogenic differentiation of ectomesenchymal stem cells in the nasal mucosa.This promoting effect is equivalent to that of nano-hydroxyapatite.
摘要
BACKGROUND:Artificially synthesized hydroxyapatite ceramic granules are widely used in clinical practice to repair large-volume bone defects.However,the osteogenic effect of hydroxyapatite ceramic granules prepared by high-temperature sintering is limited by their low degradability and bioactivity. OBJECTIVE:To prepare biomimetically precipitated nanocrystalline calcium phosphate granules by a novel low-temperature deposition technique,and to characterize their physicochemical properties and cytocompatibility. METHODS:Biomimetically precipitated nanocrystalline calcium phosphate granules were prepared using a modified supersaturated calcium phosphate mineralization solution and a repeated settling and decantation washing method.Hydroxyapatite bioceramic granules were used as the control.The morphology and phase composition of the granules were characterized by scanning electron microscopy,X-ray diffraction,and Fourier transform infrared spectroscopy.The specific surface area,porosity distribution,hardness and hydrophilicity of the granules were characterized by BET-N2 method,hardness test,and contact angle test.The adsorption properties of the granules for bovine serum albumin and fetal bovine serum protein were determined by bicinchoninic acid assay.The two kinds of granules or granule extracts were co-cultured with human umbilical cord mesenchymal stem cells,and the cell proliferation was detected by MTT assay. RESULTS AND CONCLUSION:(1)Scanning electron microscopy showed that the surface of the two kinds of particles was slightly rough and accompanied by tiny particles,the surface of the hydroxyapatite bioceramic particles was dense and smooth,and the biomimetically precipitated nanocrystalline calcium phosphate granules were mainly composed of needle/plate crystals with non-uniform nanometer size,and formed a nanopore structure between the crystals.X-ray diffraction and Fourier transform infrared spectroscopy exhibited that compared with hydroxyapatite bioceramic granules,biomimetically precipitated nanocrystalline calcium phosphate granules had smaller crystalline particles,lower crystallinity,and more binding water and carbonic acid groups.Compared with hydroxyapatite bioceramic granules,biomimetically precipitated nanocrystalline calcium phosphate granules had higher specific surface area,better hydrophilicity,lower hardness,and higher protein adsorption capacity.(2)The results of MTT assay showed that the two kinds of granule extracts had no cytotoxicity,human umbilical cord mesenchymal stem cells survived well on the surface of the two kinds of granules,and the biomimetically precipitated nanocrystalline calcium phosphate granules had stronger cell proliferation activity.(3)These findings indicate that compared with hydroxyapatite bioceramic granules,biomimetically precipitated nanocrystalline calcium phosphate granules have better physicochemical properties and cytocompatibility.
摘要
BACKGROUND:A large number of studies have confirmed that tissue engineering scaffolds can almost completely repair osteochondral defects.However,when osteochondral defects are complicated with infection,even after thorough debridement in the early stage,the repair effect of simple osteochondral tissue engineering scaffolds is often unsatisfactory. OBJECTIVE:To prepare fibroin/chitosan/nano-hydroxyapatite scaffold loaded with vancomycin hydrochloride sustained release microspheres,and to investigate the repair effect on infected osteochondral defect in distal femur of rabbit. METHODS:(1)Vancomycin hydrochloride sustained release microspheres were prepared by emulsified solvent evaporation method.The sustained-release microspheres of different weights(7.5,10,and 12.5 mg)were mixed with fibroin protein-chitosan nanohydroxyapatite solution,and the scaffolds of fibroin protein/chitosan/nano-hydroxyapatite were prepared by chemical crosslinking method.The porosity,water absorption and expansion rate,hot water loss rate of the scaffolds,and drug sustained-release in vitro were characterized.(2)Forty-five New Zealand white rabbits were randomly divided into blank group,control group,and experimental group,with 15 rabbits in each group.The osteochondral defect and infection model of the distal femur of the right hind limb was established in both groups.The blank group was not treated,and the control group was implanted with fibroin protein-chitosan-nano-hydroxyapatite scaffold.Vancomycin hydrochloride sustained-release microspheres(10 mg)of fibroin/chitosan/nano-hydroxyapatite scaffold were implanted in the defect of the experimental group.The levels of C-reactive protein and leukocytes in blood samples were detected 1 week after operation.At 4,8 and 12 weeks after operation,the tissue of the operative area was taken for gross observation and pathological observation. RESULTS AND CONCLUSION:(1)With the increase of sustained-release microspheres content,the porosity of scaffolds decreased,and there was significant difference among groups(P＜0.05).There were no significant differences in the pore size,water absorption expansion rate and hot water loss rate among the three groups(P＞0.05).Vancomycin hydrochloride was released sustainably in vitro for more than 30 days in all three groups of scaffolds.(2)The levels of C-reactive protein and leukocytes in blood samples of the experimental group were lower than those of the blank group and control group(P＜0.05).The repair of gross cartilage in the experimental group was significantly better than that in the blank group and the control group.Hematoxylin-eosin,Masson,Alcian blue and type Ⅱ collagen immunohistochemical stainings showed that the osteochondral repair effect of the experimental group was significantly better than that of the blank group and the control group at each time point.(3)The results showed that fibroin/chitosan/nano-hydroxyapatite scaffolds loaded with vancomycin hydrochloride sustained-release microspheres could effectively promote the repair of open osteochondral defects.
摘要
BACKGROUND:Polylactic acid has good biocompatibility and biodegradability,and has become a new orthopedic fixation material.However,the lack of cell recognition signal of this material is not conducive to cell adhesion and osteogenic differentiation,which limits its application in biomaterials. OBJECTIVE:3D-printed polylactic acid-nano-hydroxyapatite(nHA)/chitosan(CS)scaffold to evaluate its drug sustained-release and biological properties. METHODS:The porous polylactic acid scaffold(recorded as PLA scaffold)with interporous pores was printed by fused deposition modeling technique,and the scaffold was soaked in dopamine solution to prepare polylactic acid-dopamine scaffold(recorded as PLA-DA scaffold).Nano-hydroxyapatite was immersed in chitosan solution,and then the PLA-DA scaffold was immersed in it to prepare polylactic acid-nano-hydroxyapatite/chitosan scaffold(recorded as PLA-nHA/CS scaffold).The micro-morphology,porosity,water contact angle,and compressive strength of the three scaffolds were characterized.PLA-nHA/CS scaffold loaded with doxycycline(recorded as PLA-nHA/CS-DOX scaffold)was prepared by freeze-drying method,and its drug release was characterized.PLA,PLA-DA,PLA-nHA/CS,and PLA-nHA/CS-DOX scaffolds were co-cultured with MC3T3-E1 cells,separately,to detect cell proliferation and osteogenic differentiation.Staphylococcus aureus suspensions of different concentrations were co-cultured with four groups of scaffolds.The antibacterial performance of scaffolds was detected by inhibition zone test. RESULTS AND CONCLUSION:(1)Under scanning electron microscopy,the surfaces of PLA and PLA-DA scaffolders were dense and smooth,and nHA particles were observed on PLA-nHA/CS scaffolders.The porosity of PLA,PLA-DA and PLA-nHA/CS scaffolds decreased gradually,and the compressive strength increased gradually.The elastic modulus of PLA-nHA/CS scaffolds met the requirements of cancelous bone.The water contact angle of PLA-DA and PLA-nHA/CS brackets was smaller than that of PLA scaffolds.The PLA-nHA/CS scaffold sustainably released drugs in vitro for 8 days.(2)CCK-8 assay showed that the proliferation of MC3T3-E1 cells was not significantly affected by the four groups of scaffolds.The activity of alkaline phosphatase in PLA-DA group,PLA-nHA/CS group,and PLA-nHA/CS-DOX group was higher than that in PLA group.Alizarin red staining showed that compared with PLA group,the cells in PLA-nHA/CS group and PLA-nHA/CS-DOX group showed higher mineralized water level.(3)Inhibition zone test exhibited that PLA and PLA-DA scaffolds had no antibacterial properties.PLA-nHA/CS scaffolds had certain antibacterial properties.PLA-nHA/CS-DOX scaffolds had super antibacterial properties.(4)The results showed that the PLA-nHA/CS-DOX scaffold had good drug release performance,cell compatibility,osteogenic properties,and antibacterial properties.
摘要
@#As the main means of mastication, teeth can withstand countless functional contacts. The mechanical properties of teeth are closely related to their tissue structure. Enamel and dentin have a high hardness and modulus of elasticity, and their graded structure allows them to withstand bite forces without being susceptible to fracture. When tooth tissue is defective, full crown restoration is often needed to restore the normal shape and function of the tooth. Metal materials, ceramic materials, and polyetheretherketone (PEEK) materials are commonly used for crown restoration. Metal materials have certain disadvantages in terms of aesthetics and are relatively rarely used in clinical practice. Ceramic materials with different compositions exhibit differences in performance and aesthetics, but their elastic modulus and hardness are much higher than those of dental tissue, resulting in mismatching mechanical properties. In contrast, the elastic modulus of PEEK is lower than that of tooth tissue and similar to that of bone tissue, but its properties can be improved by fiber reinforcement. Notably, when the mechanical properties of a restoration material and tooth tissue are not fully matched, the interface between them often forms a potential weak link, which ultimately affects the stability and long-term effect of the restoration. This article introduces the mechanical properties and corresponding structural characteristics of enamel and dentin. On this basis, the advantages and limitations of existing restoration materials are analyzed, and the possibility of biomimetic design of full crowns is further explored.
摘要
Abstract This study aimed to evaluate the osteogenic potential of hydroxyapatite (HA), Alginate (Alg), and Gelatine (Gel) composite in a critical-size defect model in rats. Twenty-four male rats were divided into three groups: a negative control with no treatment (Control group), a positive control treated with deproteinized bovine bone mineral (DBBM group), and the experimental group treated with the new HA-Alg-Gel composite (HA-Alg-Gel group). A critical size defect (8.5mm) was made in the rat's calvaria, and the bone formation was evaluated by in vivo microcomputed tomography analysis (µCT) after 1, 15, 45, and 90 days. After 90 days, the animals were euthanized and histological and histomorphometric analyses were performed. A higher proportion of mineralized tissue/biomaterial was observed in the DBBM group when compared to the HA-Alg-Gel and Control groups in the µCT analysis during all analysis periods. However, no differences were observed in the mineralized tissue/biomaterial proportion observed on day 1 (immediate postoperative) in comparison to later periods of analysis in all groups. In the histomorphometric analysis, the HA-Alg-Gel and Control groups showed higher bone formation than the DBBM group. Moreover, in histological analysis, five samples of the HA-Alg-Gal group exhibited formed bone spicules adjacent to the graft granules against only two of eight samples in the DBBM group. Both graft materials ensured the maintenance of defect bone thickness, while a tissue thickness reduction was observed in the control group. In conclusion, this study demonstrated the osteoconductive potential of HA-Alg-Gel bone graft by supporting new bone formation around its particles.
Resumo Este estudo teve como objetivo avaliar o potencial osteogênico de um compósito de hidroxiapatita (HA), alginato (Alg) e gelatina (Gel) em um modelo de defeito de tamanho crítico em ratos. Vinte e quatro ratos machos foram divididos em três grupos: um controle negativo sem tratamento (grupo controle), um controle positivo tratado com osso bovino desproteinizado (grupo DBBM) e o grupo experimental tratado com o novo compósito HA-Alg-Gel (grupo HA-Alg-Gel). Um defeito de tamanho crítico (8,5mm) foi feito na calvária dos ratos, e a formação óssea foi avaliada por análise de microtomografia computadorizada in vivo (µCT) após 1, 15, 45 e 90 dias. Após 90 dias, os animais foram eutanasiados e análises histológicas e histomorfométricas foram realizadas. Uma maior proporção de tecido mineralizado/biomaterial foi observada no grupo DBBM quando comparado aos grupos HA-Alg-Gel e controle na análise de µCT durante todos os períodos de análise. Entretanto, não foram observadas diferenças na proporção tecido mineralizado/biomaterial no dia 1 (pós-operatório imediato) em relação aos períodos posteriores de análise em todos os grupos. Na análise histomorfométrica, os grupos HA-Alg-Gel e controle apresentaram maior formação óssea do que o grupo DBBM. Além disso, na análise histológica, cinco amostras do grupo HA-Alg-Gal exibiram espículas ósseas formadas adjacentes aos grânulos do enxerto contra apenas duas das oito amostras do grupo DBBM. Ambos os materiais de enxerto garantiram a manutenção da espessura óssea do defeito, enquanto uma redução da espessura do tecido foi observada no grupo controle. Em conclusão, este estudo demonstrou o potencial osteocondutor do enxerto ósseo de HA-Alg-Gel, promovendo a formação de osso novo ao redor das suas partículas.
摘要
A utilização da tecnologia CAD/CAM (computer aided design/computer aided manufacturing) e 3D (tridimensional) para reconstruções alveolares na implantodontia permite o planejamento pré-operatório detalhado, o design do resultado desejado do enxerto e a avaliação virtual do resultado em relação à reconstrução protética. Este trabalho objetiva detalhar a técnica cirúrgica de enxerto ósseo sintético confeccionado por meio dessa tecnologia, seguido da instalação de implantes osseointegráveis e reabilitação protética em um defeito ósseo na mandíbula. Paciente masculino, 22 anos, compareceu à clínica por avulsão dos elementos 32, 31, 41 e 42 com significativa perda óssea vertical de rebordo alveolar. Devido à extensa perda óssea, realizou-se enxerto em bloco prototipado impresso. O escaneamento intraoral e os arquivos de imagem gerados foram enviados ao centro de planejamento virtual. Primeiramente, foi realizada a cirurgia para instalação do enxerto em bloco. Após o período de cicatrização, foi realizada cirurgia para instalação de dois implantes osseointegráveis. Esperado o período de três meses a partir da instalação dos implantes, foi realizada a confecção de próteses provisórias fixas sobre implantes a fim de realizar o condicionamento dos tecidos moles peri-implantares e o carregamento progressivo dos implantes. O aumento do rebordo alveolar através do uso de enxerto em bloco impresso personalizado apresentou-se como uma técnica com inúmeras vantagens, por não necessitar de sítio doador, reduzir tempo cirúrgico e apresentar perfeita adaptação do bloco ao defeito ósseo, resultando em menor morbidade pós-operatória. Essa técnica é uma indicação para casos de defeitos ósseos severos, visando a otimizar o resultado e a propiciar menor desconforto ao paciente.
The use of the technology CAD/CAM (computer aided design/computer aided manufacturing) and 3D (three dimensional) to alveolar reconstructions in implant dentistry allows detailed preoperative planning, the design of the desired grafting result, and the virtual evaluation of the result in relation to the prosthetic reconstruction. This paper aims to details the synthetic bone graft made through this technology, followed by the installation of osseointegrated implants and prosthetic rehabilitation in a bone imperfection in the jaw. A 22-year-old man attended the clinic due to a tooth avulsion of the four lower incisors with significant vertical bone loss of alveolar ridge. Because of the extensive bone loss, it was made a prototyped printed block graft. The intraoral scan and the generated image files were sent to the virtual planning center. First, it was necessary a surgery to install the block graft. After the healing process, it was made a surgery to put two osseointegrated implants. Three months later, temporary fixed prostheses on implants were made to conditioning the peri-implant soft tissues and the progressive loading of the implants. The increase of the alveolar ridge using personalized printed block graft was presented as a technique with numerous advantages, since it does not require a donor site, reduces the surgical time and presents perfect adaptation of the block to the bone imperfection, resulting in a less postoperative morbidity. This technique is indicated to cases of severe bone imperfections, aims to optimize results, and provide less discomfort to the patient.
摘要
Abstract This in vitro study evaluated the effect of an experimental varnish containing 20% nano-hydroxyapatite (nHAP) associated with 5% stannous chloride (SnCl2) against erosive-abrasive wear on bovine dentin. Samples of bovine cervical dentin were pre-eroded (0.3% citric acid, pH 2.6 for 10 minutes) and randomized into 4 groups (n=10): Control group - experimental varnish without active ingredient (CG); experimental varnish containing 20% nHAP (nHG); experimental varnish containing 5% SnCl2 (24.800 ppm Sn2+) (SnG); experimental varnish containing 20% nHAP associated with 5% SnCl2 (18.300 ppm Sn2+) (nHSnG). After applying the materials, the erosive-abrasive challenges were performed for five days. Erosive dentin loss and analysis of the pattern of dentinal obliteration were performed by 3D confocal laser microscopy. A one-way ANOVA/Bonferroni test was performed to analyze the data (α=0.05). The SnG and nHSnG experimental groups presented more effectiveness in preventing erosive wear when compared to the other groups (p<0.05). There was no statistically significant difference between the SnG and nHSnG groups (p = 0.731) in tooth structure dentin loss. Regarding the amount of open dentinal tubules, the highest amount of obstructed dentinal tubules was demonstrated in SnG and nHSnG (p < 0.05) when compared to the others. Between SnG and nHSnG there was no significant difference (p = 0.952) in the amount of closed dentinal tubules in the dentin. Experimental varnishes containing 5% SnCl2 associated or not with 20% nHAP showed to be a promising strategy in preventing erosive-abrasive wear of dentin. In addition, nHSnG was able to obliterate dentinal tubules.
Resumo Este estudo in vitro avaliou o efeito de um verniz experimental contendo 20% de nano-hidroxiapatita (nHAP) associado a 5% de cloreto estanoso (SnCl2) contra o desgaste erosivo-abrasivo da dentina bovina. As amostras de dentina cervical bovina foram pré-erodificadas (0,3% de ácido cítrico, pH 2,6 durante 10 minutos) e aleatorizadas em 4 grupos (n=10): Grupo controle - verniz experimental sem ingrediente ativo (GC); verniz experimental contendo 20% nHAP (GnH); verniz experimental contendo 5% SnCl2 (24.800 ppm Sn2+) (GSn); verniz experimental contendo 20% nHAP associado a 5% SnCl2 (18.300 ppm Sn2+) (GnHSn). Após a aplicação dos materiais, os desafios erosivo-abrasivos foram realizados durante cinco dias. Perda de dentina erosiva e análise do padrão de obliteração dentinária foram realizadas por microscopia laser confocal 3D. Foi realizado o teste ANOVA/Bonferroni unidireccional para analisar os dados (α=0,05). Os grupos experimentais GSn e GnHSn apresentaram maior eficácia na prevenção do desgaste erosivo quando comparados com os outros grupos (p<0,05). Não houve diferença estatisticamente significativa entre os grupos GSn e GnHSn (p = 0,731) na perda de dentina da estrutura dentária. Relativamente à quantidade de túbulos dentinários abertos, a maior quantidade de túbulos dentinários obstruídos foi demonstrada em GSn e GnHSn (p < 0,05) quando comparada com os outros grupos. Entre GSn e GnHSn, não houve diferença significativa (p = 0,952) na quantidade de túbulos dentinários fechados na dentina. Os vernizes experimentais contendo 5% de SnCl2 associados ou não a 20% de nHAP mostraram ser uma estratégia promissora na prevenção do desgaste erosivo-abrasivo da dentina. Além disso, o GnHSn conseguiu obliterar os túbulos dentinários.
摘要
Objective: This study aimed to evaluate the properties of suckermouth catfish bone extract, which allows it to be adopted as a raw material for bone graft following its graft in an artificial defect of a rat model. Material and Methods: Hydroxyapatite (HA) from suckermouth catfish bone extract was characterized using Fourier-transform infrared spectroscopy (FTIR), and its toxicity was evaluated by Brine Shrimp Lethality Test (BSLT). This material was grafted on artificial defects in rats' femoral bones, which were observed immunologically by Enzyme-linked immunosorbent assay (ELISA) after one week and four weeks, and radiographically in the second week, and histologically in the second and fourth weeks. Results: FTIR shows that this material consists of phosphate, hydroxyl, and carbonate groups, while the BSLT results show that this material is not toxic. Observations by ELISA showed an increase in the expression of Tumor necrosis factor alpha (TNF-α) in defects with HA in the fourth week. Radiographically the defect did not show closure in the second week. In contrast, histological analysis showed a better bone healing process in the defect, which was applied with the HA of the suckermouth catfish bone. Conclusion: The HA extracted from the suckermouth catfish bone has beneficial properties as an alternative to bone graft raw material and, more investigated needed to support this biomaterial to be used in the treatment of bone loss (AU)
Objetivo: Avaliar as propriedades do extrato de osso de bagre, que permitem sua adoção como material bruto para enxerto ósseo, em um defeito ósseo artificial em ratos. Material e Métodos: A hidroxiapatita (HA) do extrato de osso de bagre foi caracterizada usando espectroscopia infravermelha por transformada de Fourier (FTIR), e sua toxicidade foi avaliada pelo Teste de Letalidade do Camarão de Sal (BSLT). Esse material foi enxertado em defeitos artificiais nos ossos femorais de ratos. Análise imunológica por meio do ensaio imunoenzimático (ELISA) foi realizada uma e quatro semanas após a colocação dos enxertos. Análises radiográficas foram feitas na segunda semana e histológica na segunda e quarta semanas. Resultados: A FTIR mostrou que esse material é composto por grupos de fosfato, hidroxila e carbonato, enquanto os resultados do BSLT mostraram que esse material não é tóxico. As observações pelo ELISA mostraram um aumento na expressão do fator de necrose tumoral alfa (TNF-α) nos defeitos com HA na quarta semana. Radiograficamente, o defeito não apresentou fechamento na segunda semana. Em contraste, a análise histológica mostrou um melhor processo de cicatrização óssea no defeito que foi aplicado com a HA do osso de bagre. Conclusão: A HA extraída do osso de bagre possui propriedades benéficas como alternativa ao material bruto para enxerto ósseo, sendo necessárias mais investigações para apoiar esse biomaterial a ser usado no tratamento da perda óssea.(AU)
Subject(s)
Animals , Rats , Wound Healing , Bone Transplantation , Spectroscopy, Fourier Transform Infrared , Durapatite摘要
OBJECTIVE@#To investigate the preparation and properties of the novel silica (SiO 2)/hydroxyapatite (HAP) whiskers porous ceramics scaffold.@*METHODS@#The HAP whiskers were modified by the SiO 2 microspheres using the Stöber method. Three types of SiO 2/HAP whiskers were fabricated under different factors (for the No.1 samples, the content of tetraethoxysilane, stirring time, calcination temperature, and soaking time were 10 mL, 12 hours, 560℃, and 0.5 hours, respectively; and in the No.2 samples, those were 15 mL, 24 hours, 650℃, and 2 hours, respectively; while those in the No.3 samples were 20 mL, 48 hours, 750℃, and 4 hours, respectively). The phase and morphology of the self-made HAP whisker and 3 types of SiO 2/HAP whiskers were detected by the X-ray diffraction analysis and scanning electron microscopy. Taken the self-made HAP whisker and 3 types of SiO 2/HAP whiskers as raw materials, various porous ceramic materials were prepared using the mechanical foaming method combined with extrusion molding method, and the low-temperature heat treatment. The pore structure of porous ceramics was observed by scanning electron microscopy. Its porosity and pore size distribution were measured. And further the axial compressive strength was measured, and the biodegradability was detected by simulated body fluid. Cell counting kit 8 method was used to conduct cytotoxicity experiments on the extract of porous ceramics.@*RESULTS@#The SiO 2 microspheres modified HAP whiskers and its porous ceramic materials were prepared successfully, respectively. In the SiO 2/HAP whiskers, the amorphous SiO 2 microspheres with a diameter of 200 nm, uniform distribution and good adhesion were attached to the surface of the whiskers, and the number of microspheres was controllable. The apparent porosity of the porous ceramic scaffold was about 78%, and its pore structure was composed of neatly arranged longitudinal through-holes and a large number of micro/nano through-holes. Compared with HAP whisker porous ceramic, the axial compressive strength of the SiO 2/HAP whisker porous ceramics could reach 1.0 MPa, which increased the strength by nearly 4 times. Among them, the axial compressive strength of the No.2 SiO 2/HAP whisker porous ceramic was the highest. The SiO 2 microspheres attached to the surface of the whiskers could provide sites for the deposition of apatite. With the content of SiO 2 microspheres increased, the deposition rate of apatite accelerated. The cytotoxicity level of the prepared porous ceramics ranged from 0 to 1, without cytotoxicity.@*CONCLUSION@#SiO 2/HAP whisker porous ceramics have good biological activity, high porosity, three-dimensional complex pore structure, good axial compressive strength, and no cytotoxicity, which make it a promising scaffold material for bone tissue engineering.
Subject(s)
Animals , Durapatite , Porosity , Vibrissae , Apatites , Ceramics , Silicon Dioxide摘要
@#Introduction: Tooth extraction before denture placement could result in trauma and damage to up to 50% of the alveolar bone, inducing bone resorption, and affecting the patient’s quality of life. Hydroxyapatite Gypsum Puger (HAGP) can be used as an alternative to bone graft material which degrades slowly, affecting the proliferation and activity of cells that are responsible for bone tissue engineering. This study aimed to analyze the regeneration mechanism of alveolar bone by administering the HAGP scaffold and observing the Stro-1, Runx-2, Osterix, and ALP expression. Methods: Laboratory experimental research was conducted and we used 150-355µm HAGP scaffold particles, applied in vivo inside alveolar sockets of the rats for 7, 14, and 28 days, followed by immunohistochemical examination of Stro-1, Runx-2, Osterix, and ALP expressions. Results: The HAGP scaffold group showed that the Stro-1 expression was significantly higher than the K(-) group, and the Runx-2 expression increased on day 7 and decreased on day 28 in the HAGP and K(-) groups. Osterix expression increased from day 7, 14, to day 28. The high expression of Osterix on day 28 means it took over the Runx-2 function. In ALP there was a significant increase on day 7. ALP expression was a sign of early osteoblast differentiation and production by cells, this extracellular matrix mineralization is an indicator of the osteogenic process. Conclusion: Alveolar bone regeneration mechanism in rats revealed that the expression of Stro-1, Runx-2, Osterix, and ALP was higher in the HAGP scaffold group compared to the control group on days 7,14, and 28.
摘要
Abstract Objective This study aimed to evaluate the influence of sterilization on the compressive and flexural mechanical strength of hydroxyapatite-based biocomponents obtained through freeze-dried bovine bone, and its association with chitosan. Methods Freeze-dried bovine bone was processed into 100 μm particles and mixed with 50% of its weight in chitosan. The mixture was packed in metallic molds for preparing the specimens, and sterilized at 127°C using an autoclave for subsequent experimentation. The specimens were subjected to compression and flexion tests following norm 5833 of the International Organization for Standardization (ISO), with 6 × 12 mm cylindrical blocks (for compression tests) and 75 × 10 × 3.3 mm plates (for flexion tests) as samples. The samples were divided into four groups of 20 specimens each, with 10 for compression and 10 for flexion tests. Three groups were sterilized (autoclave, gamma rays, and ethylene oxide), whereas the fourth group (control) was not. The mechanical tests obtained from the different sterilization processes were compared using analysis of variance (ANOVA, p< 0.05), followed by the Tukey multiple comparison test of means, with a 95% confidence interval. Results The specimens presented mean compressive strengths of 10.25 MPa for the control group and 3.67 MPa, 9.65 MPa, and 9.16 MPa after ethylene oxide, gamma ray, and autoclave sterilization, respectively. Flexion test results showed an average resistance of 0.40 MPa in the control group, and 0.15 MPa, 0.17 MPa, and 0.30 MPa after ethylene oxide, gamma ray, and autoclave sterilization, respectively. There were statistically significant differences observed in the maximum compression of the ethylene oxide-sterilized group compared with that of the control group (p= 0.0002), gamma ray-sterilized (p= 0.0003), and the autoclaved (p= 0.0006) groups. There was a statistically significant difference in maximum flexion of the specimens sterilized by gamma rays when compared with the control group (p= 0.0245). However, low flexural strengths were observed in all specimens. Conclusion The autoclave sterilization group did not result in statistically significant differences in either compression or flexion strength tests. Thus, the autoclave proved to be the best sterilization option for the hydroxyapatite-based biocomponents in this study.
Resumo Objetivo O objetivo deste estudo foi avaliar a influência da esterilização na resistência mecânica à compressão e flexão de biocomponentes à base de hidroxiapatita obtida a partir de osso bovino liofilizado e sua associação com quitosana. Métodos O osso bovino liofilizado foi processado em partículas de 100 μm e misturado à quitosana em proporção de 50% de seu peso. A mistura foi acondicionada em moldes metálicos para preparo dos espécimes e esterilizada a 127°C em autoclave para posterior experimentação. Os espécimes foram submetidos a ensaios de compressão e flexão seguindo a norma 5833 da International Organization for Standardization (ISO); os espécimes eram blocos cilíndricos de 6 × 12 mm (para ensaios de compressão) e placas de 75 × 10 × 3,3 mm (para ensaios de flexão). As amostras foram divididas em quatro grupos de 20 espécimes cada, sendo 10 para ensaios de compressão e 10 para ensaios de flexão. Três grupos foram esterilizados (por autoclavagem, raios gama e óxido de etileno), enquanto o quarto grupo (controle) não foi. Os testes mecânicos obtidos nos diferentes processos de esterilização foram comparados por análise de variância (ANOVA, p< 0,05) seguido pelo teste de comparação múltipla de médias de Tukey, com intervalo de confiança de 95%. Resultados Os espécimes apresentaram resistências médias à compressão de 10,25 MPa para o grupo de controle e 3,67 MPa, 9,65 MPa e 9,16 MPa após esterilização com óxido de etileno, raios gama e autoclavagem, respectivamente. Os resultados do teste de flexão mostraram uma resistência média de 0,40 MPa no grupo de controle, e 0,15 MPa, 0,17 MPa e 0,30 MPa após esterilização com óxido de etileno, raios gama e autoclavagem, respectivamente. A compressão máxima observada no grupo esterilizado com óxido de etileno foi estatisticamente diferente à obtida no grupo de controle (p= 0,0002), esterilizado com raios gama (p= 0,0003) e autoclavado (p= 0,0006). A flexão máxima dos espécimes esterilizados com raios gama foi estatisticamente diferente à observada no grupo de controle (p= 0,0245). No entanto, a resistência à flexão foi baixa em todos os espécimes. Conclusão A esterilização em autoclave não foi associada a diferenças estatisticamente significativas nos testes de compressão ou flexão. Assim, a autoclave foi a melhor opção de esterilização para os biocomponentes à base de hidroxiapatita neste estudo.
Subject(s)
Animals , Biocompatible Materials , Sterilization , Bone Transplantation , Durapatite , Chitosan , Mechanical Tests摘要
Abstract Bone healing after a fracture has many intercalated steps that depend on the host, type of injury, and often the orthopedist. The diamond concept since 2007 has outlined 4 main facets that have to be considered as a model by the treating surgeon at the time of injury and when nonunion develops: osteogenic cells, osteoconductive scaffolds, osteoinduction, and the biomechanical environment. All of these foment fracture healing in optimal circumstances. Yet, this work proposes other facets, such as osteoimmunology and vascularity, to be considered as well in the model. These are as important as the original four, though their correlation to the original work has been less noted until more recent literature. The mindset of the orthopedist must thoroughly analyze all these facets and many more when dealing with nonunion. This work presents, probably the most sig nificant ones, parting from the original 4-corner diamond model and expanding it to a more representative hexagon integrated model. Metaphorically, just like the strongest inorganic constituent of the bone: hydroxyapatite.
Resumen Hay múltiples pasos intercalados en la consolidación de la fractura que dependen del paciente, el tipo de fractura y frecuentemente del ortopedista. Desde su introducción en el año 2007, el concepto del diamante ha delineado 4 facetas o aristas principales que se han de tener en cuenta por el ortopedista en el momento de la lesión y cuando la no-unión de fractura ocurre: células osteogénicas, matrices osteocunductivas, osteoinducción, y el ambiente biomecánico. Otras facetas para tener en cuenta, no menos importantes, son la osteoimmunología y la vascularidad. Estas son tan importantes como las 4 facetas originales, pero la correlación entre las mismas ha sido poco notada o integrada hasta ahora. El ortopedista tratante debe analizar todas ellas en profundidad, especialmente cuando se trata de una no-unión. Este trabajo presenta las más significantes, partiendo del modelo original del diamante de 4 facetas hacia uno más representativo e integrado como el hexágono. Metafóricamente, como el elemento inorgánico más abundante y fuerte en el hueso: la hidroxiapatita.
摘要
ABSTRACT The purpose of tissue engineering (regenerative medicine) is to develop materials that replace human tissue, having as main characteristics' biodegradability, biocompatibility, no toxicity, osteoconductivity, which lead to cell maturation and proliferation. Due to the importance of the development of this type of materials, several researchers have used biopolymers and calcium phosphate salts (hydroxyapatite) as composites to be used in this area as drug releases, scaffolds, implants, among others. Different biopolymers can be suitable for this type of application, in this work we have described the most widely used biopolymers for biomedical purposes, such as alginate, collagen, gellan gum, chitosan, and polylactic acid, in addition to a detailed description of hydroxyapatite, biopolymers, as well as biopolymer/hydroxyapatite composites, to highlight their potential and the most relevant characteristics of these materials.
摘要
In the last few decades, hydroxyapatite (HA) has become one of the most highly prized biominerals in the biomedical industry for orthopedic and dental applications. The focus of this research was to synthesize biomimetic HA from Tridax procumbens (TP) leaf extract and investigate their antibiofilm properties. The HA was made using the sol-gel method and the HA-TP biocomposite was made by precipitation method. The d.nm size of HA and HA-TP biocomposite was determined as 193.28 and 258.14 d.nm, respectively. The zeta potential of HA and HA-TP biocomposite was determined as ?21.2 and ?18.3 mV, respectively, and found highly stable. The FTIR study revealed that phytochemicals of TP were successfully impregnated into HA-TP biocomposite. The HA and HA-TP biocomposite were found spherical and agglomerated from SEM analysis. In HR-TEM analysis, the average diameter of the HA and HA-TP biocomposite were 16.57 – 64.22 nm and 51.71 – 138.68 nm, respectively. According to the EDX analysis, HA is primarily composed of calcium, oxygen, and phosphate, whereas, HA-TP biocomposite is primarily composed of calcium, phosphate, oxygen, and carbon. In the antioxidant assay, the IC50 value (concentration required to scavenge 50% of free radicals) of HA-TP biocomposite was determined as 156.69 ± 14.02 and 180.21 ± 12.84 µg/mL in DPPH and ABTS free radical scavenging assays, respectively. The MIC (minimum inhibitory concentration) and MBC (minimum bactericidal concentration) of as-synthesized HA-TP biocomposite against Staphylococcus aureus – ATCC 13565 and Escherichia coli – MTCC 41 were observed as 181.09 ± 21.47 and 317.30 ± 41.03, and 157.59 ± 32.18 and 264.03 ± 21.58 µg/mL, respectively. The as-synthesized HA-TP biocomposite has detrimentally affected the biofilm formation of both the tested bacteria S. aureus – ATCC 13565 and E. coli – MTCC 41. The study concluded that the as-synthesized HA-TP biocomposite could be highly helpful in the biomedical field for alleviating oxidative-stress-related disorders and inhibiting microbial biofilm formation.
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Aims and Objective: The present study aimed to evaluate 2 bone graft materials, that is, biphasic hydroxyapatite and ??tricalcium phosphate, in the treatment of periodontal vertical bony defects. In term of attachment level, probing depth and radiographic bone level changes. Also, a new digital method of radiographic assessment was used for measurement of vertical bone defect. Material and Methods: Ten subjects with periodontitis and having two or more vertical bony defects were enrolled in the study. Patients were classified randomly into 2 groups. Group I consisted of the experimental site where defect was filled with biphasic hydroxyapatite and ??tricalcium phosphate graft and Group II consisted of control site where only the open flap debridement (OFD) was carried out. Clinical parameters were evaluated at baseline, 3 and 6 months; Radiographs were taken at baseline and 6 months after surgery. Results: Overall, by the end of 6 months, biphasic hydroxyapatite and ??tricalcium phosphate and OFD treatment groups exhibited a significant reduction in probing depth almost by 75% and gain in clinical attachment level at follow?up. In the biphasic hydroxyapatite and ??tricalcium phosphate group, radiographic bone level gain appeared to be greater than in the OFD group. Conclusion: In the present study, biphasic hydroxyapatite and ??tricalcium phosphate have shown promising results and have showed reduction in probing depth, a resolution of osseous defects and gain in clinical attachment level when compared to open flap debridement.
摘要
Calcific tendinitis is a pathology characterized by the deposits of periarticular hydroxyapatite. Its pathophysiology is not completely known. It is clinically characterized by important inflammatory changes with incapacitating pain. It most commonly affects the shoulder joint and it rarely affects the hand and wrist. Given the unusual nature of this localization, we present the clinical case of a woman who developed calcific tendinitis of the third metacarpophalangeal muscle. We present the clinical evolution of the case, the treatments carried out, and a review of the literature related to this unusual localization of calcific tendinitis.