ABSTRACT
O selamento dentinário imediato é um procedimento essencial na Odontologia, que envolve a aplicação de agentes de selamento na interface entre a dentina e o material restaurador imediatamente após a remoção da cárie e do preparo da cavidade dentária. Este processo busca selar os túbulos dentinários expostos, proporcionando proteção à polpa dentária. O presente caso foi realizado em um paciente do sexo masculino, 56 anos que se queixou de desconforto no elemento dentário 17. Após avaliação clínica e radiográfica, foi constatado uma ampla restauração desadaptada na porção mesio - oclusal do referido dente, sendo que o elemento em questão não possui tratamento endodôntico. Após planejamento e assinatura do TCLE, os seguintes passos foram realizados: remoção da lesão cariosa do dente 17, seguido da realização do levantamento marginal mesial e a realização do selamento dentinário imediato. Moldagem com silicone de adição do dente em questão e do antagonista, assim como registro da mordida. Foi confeccionada uma restauração semidireta em resina composta sob o modelo de gesso obtido. A cimentação da restauração foi feita na consulta seguinte, cumprindo os requisitos fundamentais para restaurar forma, função e estética, resultando na melhoria da qualidade de vida do paciente(AU)
Immediate dentin sealing is an essential procedure in dentistry, involving the application of sealing agents at the interface between dentin and the restorative material immediately after caries removal and cavity preparation. This process aims to seal exposed dentinal tubules, providing protection to the dental pulp. The present case involved a 56-year-old male patient who complained of discomfort in tooth number 17. After clinical and radiographic evaluation, a wide, maladapted restoration in the mesio-occlusal portion of the tooth was identified, with no endodontic treatment in the affected element. Following planning and informed consent, the following steps were taken: removal of the carious lesion from tooth number 17, followed by the execution of mesial marginal elevation and immediate dentin sealing. Silicone addition molding of the affected tooth and antagonist, along with bite registration, was performed. A semi-direct restoration in composite resin was fabricated based on the obtained gypsum model. The restoration was cemented in the subsequent appointment, meeting the essential requirements to restore form, function, and aesthetics, resulting in an improvement in the patient's quality of life(AU)
Subject(s)
Humans , Male , Middle Aged , Dental Cavity Preparation , Dental Restoration, Permanent , Dental CementsABSTRACT
Sabe-se que para uma restauração ser considerada um sucesso clínico é preciso que haja uma concomitância saudável entre a estrutura dentária, o material restaurador e as estruturas biológicas periodontais. As restaurações transcirúrgicas caracterizam-se como procedimentos alternativos para possibilitar a restauração de dentes com cárie dentária extensa, restaurações subgengivais desadaptadas e fraturas. O presente estudo teve como objetivo realizar um relato de caso de um procedimento cirúrgico-restaurador, através de uma técnica de restauração transcirúrgica. Este estudo tem como justificativa relatar um caso clínico, colaborando com maiores informações sobre a escolha da técnica a ser empregada, mostrando em quais situações devemos escolher uma restauração transcirúrgica e quais seus benefícios. Também, salientar se devemos fazer a recuperação do espaço biológico do periodonto ou não(AU)
It is known that for a restoration to be considered a clinical success, there must be a healthy concomitance between the tooth structure, the restorative material and the periodontal biological structures. Transsurgical restorations are characterized as alternative procedures to enable the restoration of teeth with extensive dental caries, maladapted subgingival restorations and fractures. The present study aims to carry out a case report of a surgical-restorative procedure, using a transsurgical restoration technique. This study is justified by reporting a clinical case, providing more information on the choice of technique to be used, showing in which situations we should choose a transsurgical restoration and what its benefits are. Also, highlight whether we should recover the biological space of the periodontium or not(AU)
Subject(s)
Humans , Male , Middle Aged , Oral Surgical Procedures , Dental Restoration, PermanentABSTRACT
A escolha da técnica restauradora desempenha papel fundamental na eficácia e duração de um tratamento reabilitador. O objetivo deste relato de caso foi descrever a utilização da técnica semidireta para a confecção de uma restauração em resina composta em um primeiro molar inferior. A paciente apresentava uma restauração insatisfatória no dente 36, que necessitava ser substituída devido à infiltração por cárie. Optou-se pela técnica semidireta devido à amplitude da cavidade, que envolvia estruturas de suporte, e pela combinação das vantagens das abordagens direta e indireta. O procedimento envolveu a remoção de tecido cariado, a aplicação de hidróxido de cálcio pasta, seguida da aplicação de uma fina camada de ionômero de vidro e, posteriormente, resina fluída para realizar o selamento dentinário. O preparo foi realizado seguindo os princípios necessários. O elemento em questão foi moldado com silicone de adição e o arco antagonista, com alginato. Ambos modelos foram vertidos com silicone para modelos semirrígidos e montados em oclusor de peças de brinquedo. A restauração semidireta foi confeccionada em resina composta Filtek Z350 XT, respeitando a anatomia do dente 36. Pigmentos foram utilizados para aprimorar detalhes estéticos. Após acabamento e polimento, a peça foi condicionada e cimentada com cimento dual Relyx Ultimate. Pode-se concluir que a abordagem restauradora por meio da técnica semidireta construída em modelo semirrígido é uma opção terapêutica conservadora e vantajosa para dentes com extensa destruição coronária. Essa técnica possibilita a restauração de forma eficaz, garantindo tanto a estética quanto a função adequada do dente afetado(AU)
The choice of restorative technique plays a fundamental role in the effectiveness and duration of rehabilitation treatment. The objective of this case report was to describe the use of the semi-direct technique to create a composite resin restoration in a lower first molar. The patient had an unsatisfactory restoration on tooth 36, which needed to be replaced due to cavity infiltration. The semi-direct technique was chosen due to the amplitude of the cavity, which involved support structures, and the combination of advantages of the direct and indirect approaches. The procedure involved the removal of carious tissue, and the application of calcium hydroxide paste, followed by the application of a thin layer of glass ionomer and, subsequently, fluid resin to seal the dentin. The preparation was carried out following the necessary principles. The element in question was molded with addition silicone and the antagonist arch was molded with alginate. Both models were poured with silicone for semi-rigid models and mounted on toy parts occluders. The semi-direct restoration was made in Filtek Z350 XT composite resin, respecting the anatomy of tooth 36. Pigments were used to improve aesthetic details. After finishing and polishing, the piece was conditioned and cemented with Relyx Ultimate dual cement. It can be concluded that the restorative approach using the semi-direct technique built on a semi-rigid model is a conservative and advantageous therapeutic option for teeth with extensive coronal destruction. This technique allows for effective restoration, ensuring both the aesthetics and adequate function of the affected tooth(AU)
Subject(s)
Humans , Female , Adult , Dental Cavity Preparation , Dental Restoration Repair , Cementation , Tooth Preparation , Dental Restoration, PermanentABSTRACT
ABSTRACT Glass ceramics are widely used to manufacture esthetic veneers, inlays, onlays, and crowns. Although the clinical survival rates ofglass-ceramic restorations arefavorable,fractures or chips are common. Certain cases can be repaired with direct composite. Aim The aim of this study was to investigate the interaction effect of different designs and surface treatments on the load-to-failure of lithium disilicate glass-ceramic repaired with nanofilled composite. Materials and Method Lithium-disilicate glass-ceramic slabs (IPS e.max Press, Ivoclar Vivadent) with three different designs of the top surface (flat, single plateau, or doubleplateau) (n=U) received 'no treatment', '5% HF etching', or "AI2O3 sandblasting". HF-etched and sandblasted slabs also received silane and universal one-step adhesive application. All slabs were incrementally repaired with nanofilled composite (Filtek Z350, 3M ESPE) up to6 mm above the highest ceramic top plateau. Specimens were stored in artificial saliva at 37 °C for 21 days and then subjected to 1,000 thermocycles between 5 and 55 °C. The interface composite-ceramic of each specimen was tensile tested until failure in a universal testing machine and the mode of failure was determined under a stereomicroscope. The ceramic surface morphology of one representative tested specimen from each subgroup (design/surface treatment) was observed through scanning electron microscopy (SEM). Results Regardless of ceramic design, the absence of surface treatment resulted in significantly lower load-to-failure values. No significant differences in load-to-failure values were observed between HF-etched and sandblasted specimens for the flat design; however, HF etching resulted in significantly higher load-to-failure values than sandblasting for both single plateau and double plateau designs. The majority (60%) of HF-etched specimens with single plateau or double plateau presented mixed failures. SEM photomicrographs showed that HF-etched specimens had smoother surfaces than sandblasted specimens. Conclusion The surface treatment of a defective lithium disilicate glass-ceramic restoration has more influence than its macroscopic design on the retention of the composite repair. HF etching seems to provide higher bond strength to the composite repair.
RESUMO Embora fraturas e lascamento de restauragoes vitrocerámicas sejam comuns, alguns casos podem ser reparados com compósito direto. Objetivo investigar o efeito da interagao de diferentes formas e tratamentos de superficie na carga de ruptura de uma vitrocerámica reforgada com dissilicato de litio reparada com compósito nanoparticulado. Materials e Método A superficie superior de espécimes de vitroceramica (IPS e.max Press, Ivoclar Vivadent) foi preparada com tres formas (plana, plato único, ou duplo) e recebeu (n=11): 'nenhum tratamento', 'condicionamento com ácido hidrofluoridrico 5%', ou 'jateamento com AfOf. Ambos espécimes condicionados e jateados receberam silano e adesivo universal. Todos os espécimes foram reparados incrementalmente com compósito (Filtek Z350, 3M ESPE) até6 mm acima do plato cerámico mais alto, armazenados em saliva artificial á 37 °C por 21 dias, e submetidos á 1.000 termociclos (5 e 55 °C). A interface compósito-cerámica de cada amostra foi testada á tragao até sua falha em máquina universal e o modo de falha foi determinado com estereomicroscópio. A morfologia da superficie de uma amostra representativa de forma/tratamento de superficie foi observada através de microscopia eletronica de varredura (MEV). Resultados Independentemente da forma ceramica, a ausencia de tratamento superficial resultou em valores de carga de ruptura significativamente menores. Nao foi observada differenga significativa entre os espécimes planos condicionados ou jateados; no entanto, o condicionamento resultou em valores significativamente maiores que o jateamento para espécimes com plato único e duplo. A maioria (60%) dos espécimes condicionados e com plato único ou duplo apresentou falhas mistas. Imagens SEM demonstraram rugosidade superficial mais regular dos espécimes condicionados que os jateados. Conclusoes O tratamento superficial de uma restauragao defeituosa de vitrocerámica reforgada por dissilicato de litio tem maior influencia na retengao do reparo de compósito do que sua forma macroscópica; ainda, o condicionamento com ácido hidrofluoridrico parece proporcionar maior resistencia de uniao ao reparo com compósito.
ABSTRACT
The choice of retaining material that will replace the lost properties of the tooth, in which it is fragile and with loss of dentin structure, is important. The success of the treatment will depend on the qualities presented in it. Therefore, the objective of this work, through a literature review, is to present the advantages and disadvantages observed in the use of fiberglass post intraradicular retainer. This paper reviews the most relevant articles on the specificities presented in the fiberglass post retaining material, published in the period (2003 to 2020). The bibliographic search was performed in PubMed, Lilacs, Scielo, Google Scholar databases. In view of the selected articles on the subject, it is possible to observe the authors' acceptance of the application of the use of retainers, highlighting that in the treatment of cases with extensive coronary destruction, the aim is to have the functional and retentive capacity returned, in addition to the tension resistance. Therefore, theThe use of fiberglass posts in weakened teeth is effective as the material of choice. In cases that require reconstruction and return of tissue integrity, it has sufficient advantages for its selection. Despite the disadvantages it has, these do not outweigh the benefits to the point of making its use unfeasible. However, knowing when, where and how to treat is always important in any procedure for a satisfactory final outcome.
A escolha do material retentor que irá substituir as propriedades perdidas do dente, no qual este se apresenta de forma fragilizada e com perca de estrutura dentinária é importante. O sucesso do tratamento irá depender das qualidades apresentadas no mesmo. Sendo assim, o objetivo deste trabalho por meio de uma revisão de literatura é apresentar as vantagens e desvantagens observadas no uso do retentor intrarradicular de pino de fibra de vidro. Este trabalho revisa os artigos mais relevantes sobre as especificidades apresentadas no material retentor de pino de fibra de vidro, publicadas no período (2003 até 2020). A busca bibliográfica foi realizada nos bancos de dados PubMed, Lilacs, Scielo, Google Scholar. Diante dos artigos selecionados referentes ao tema, pode-se observar a aceitação dos autores sobre a aplicação do uso de retentores, destacando-se que no tratamento de casos com destruição coronária extensa o intuito é dispor da devolução da capacidade funcional, retentiva, além da resistência a tensão. Portanto, a utilização de pinos de fibra de vidro em dentes fragilizados apresenta efetividade como material de escolha. Em casos que necessitam de reconstrução e devolução de sua integridade tecidual, possui consigo vantagens suficientes para sua seleção. Apesar das desvantagens que possui, essas não se sobrepõem aos benefícios a ponto de tornarem inviáveis ao seu uso. Entretanto, saber quando, onde e como tratar é sempre importante em qualquer procedimento para um desfecho final satisfatório.
Subject(s)
Dental Materials , Dental Pins , Dental Restoration, Permanent , Flexural StrengthABSTRACT
Oral diseases concern almost every individual and are a serious health risk to the popula-tion.The restorative treatment of tooth and jaw defects is an important means to achieve oral function and support the appearance of the contour.Based on the principle of"learning from the nature",Deng Xu-liang's group of Peking University School and Hospital of Stomatology has proposed a new concept of"microstructural biomimetic design and tissue adaptation of tooth/jaw materials"to address the worldwide problems of difficulty in treating dentine hypersensitivity,poor prognosis of restoration of tooth defects,and vertical bone augmentation of alveolar bone after tooth loss.The group has broken through the bottle-neck of multi-stage biomimetic technology from the design of microscopic features to the enhancement of macroscopic effects,and invented key technologies such as crystalline/amorphous multi-level assembly,ion-transportation blocking,and multi-physical properties of the micro-environment reconstruction,etc.The group also pioneered the cationic-hydrogel desensitizer,digital stump and core integrated restora-tions,and developed new crown and bridge restorative materials,gradient functionalisation guided tissue regeneration membrane,and electrically responsive alveolar bone augmentation restorative membranes,etc.These products have established new clinical strategies for tooth/jaw defect repair and achieved inno-vative results.In conclusion,the research results of our group have strongly supported the theoretical im-provement of stomatology,developed the technical system of oral hard tissue restoration,innovated the clinical treatment strategy,and led the progress of the stomatology industry.
ABSTRACT
Objective@#To investigate the clinical effects of sinus elevation surgery and implant restorationdue to insufficient bone massafter tooth extraction in patients with odontogenic maxillary sinusitis (OMS) and to provide a reference for use in clinical practice.@*Methods@#This study was reviewed and approved by the Ethics Committee, and informed consent was obtained from the patients. Forty-five teeth were extracted from patients with OMS in the maxillary posterior area (the study group). Sinus elevation and implantation were performed due to insufficient bone height in the implant area 6-8 months after tooth extraction in the study group. Forty-eight teeth were extracted from patients without "OMS" in the maxillary posterior area (the control group), and sinus elevation and implantation were performed due to insufficient bone height in the implant area 6-8 months after tooth extraction inthe control group. In the study group, 13 cases of discontinuous maxillary sinus floor bone and residual alveolar bone height of the maxillary sinus floor less than 4 mm were addressed with lateral wall sinus elevation, and the other 32 cases were addressed with crest-approach sinus elevation. In the control group, 8 cases of residual alveolar bone height less than 4 mm in the maxillary sinus floor were addressed with lateral wall sinus,and the other 40 cases were addressed with crest approach sinus elevation. Restorations were placed 6 to 8 months after surgery. The patients were followed up 21 days, 3 months, and 8 months after implantation and every 6 months after the placement of the restorations. The sinus bone gain (SBG), apical bone height (ABL) and marginal bone loss (MBL) were statistically analyzed 24 months after the restoration.@*Results@#The average preoperative mucosal thickness in the 45 patients in the study group was (1.556 ± 0.693) mm, which was significantly larger than that in the control group (1.229 ± 0.425) mm (P<0.001). There were no perforations in either group. Twenty-four months after restoration, there was no significant difference in the SBG, ABH or MBL between the two groups (P>0.05).@*Conclusion@#After the extraction of teeth from patients with OMS, the inflammation of the maxillary sinus decreased, and the bone height and density in the edentulous area were restored to a certain degree. The effects of sinus floor lifting surgery and implant restoration do not differ between patients with and without OMS.
ABSTRACT
Objective@#To explore the treatment options for congenitally missing teeth in patients with ectodermal dysplasia and provide a clinical reference.@*Methods@#A patient with ectodermal dysplasia with a concave midface, anterior protrusion of the chin, and underdevelopment of the lower third of the face presented with congenital loss of multiple maxillary teeth, malocclusion of the remaining teeth, congenital loss of mandibular dentition, small dental arches, and upper and lower alveolar bone hypoplasia. The patient was treated by means of a removable partial maxillary prosthesis, implants in the anterior region of the lower mandible designed with the assistance of digital guides, and bar-clamped implant-overlay prostheses. A literature review of the protocol for the treatment of this condition was also conducted.@*Results@#In addition to good retention and stability after denture wear, an excellent occlusal relationship, improvement of the patient's facial appearance, including upper and lower lip fullness, more equal balancing of the lower and middle 1/3 of the face, and improved masticatory function were achieved. The results of the literature review showed that patients with ectodermal dysplasia who are congenitally edentulous usually have a complex intraoral situation that makes restoration difficult, and common restorative modalities for these patients include fixed bridges, removable partial dentures, complete dentures, overdentures, and implant prostheses, which need to be selected according to the actual intraoral situation of each patient. Currently, there is no consensus on the treatment of congenitally missing teeth in patients with ectodermal dysplasia, and some scholars have suggested that fixed restorations be recommended for patients with fewer missing teeth, while the option of removable or implant-covered denture restorations should be given to patients with more missing teeth, with removeable prostheses for underage patients that are replaced with permanent fixed prostheses when the jaws have stabilized.@*Conclusion@#In patients with ectodermal dysplasia with congenital tooth loss, all factors should be taken into account, and an individualized restorative plan should be developed.
ABSTRACT
@#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.
ABSTRACT
Objective To investigate the impact of midazolam on neuronal injury induced by oxygen glucose depri-vation/reoxygenation(OGD/R)in mice.Methods An injury model of neuronal cell line HT22 was established by OGD/R induction.HT22 cells were divided into OGD/R group,low-dose group,medium-dose group and high-dose group,midazolam+KG-501(CREB inhibitor)group and control group.ELISA was applied to detect TNF-α and IL-6 levels;Commercialy available reagent kits were applied to detect superoxide dismutase(SOD),catalase(CAT),and malondialdehyde(MDA)levels;MTT and Edu experiments were applied to detect cell prolifera-tion;flow cytometry was applied to detect cell apoptosis rate;RT-qPCR method was applied to detect the ex-pression levels of CREB mRNA and PGC-1α mRNA;Western blot was applied to detect the expression levels of Ki-67,Bcl-2,Bax,CREB,and PGC-1α proteins.Results Compared with the control group,the A490 value(24,48 hours),proliferation rate,SOD and CAT activity,CREB mRNA and PGC-1α mRNA expres-sion,Ki-67,Bcl-2,CREB,and PGC-1α protein level in the OGD/R group were all significantly reduced(P<0.05);The apoptosis rate,TNF-α,IL-6,MDA,and Bax protein expression were significanty increased(P<0.05).Compared with the OGD/R group,the A490 values(24,48 hours),proliferation rate,SOD,CAT activity,CREB mRNA and PGC-1α mRNA expression,and Ki-67,Bcl-2,CREB,and PGC-1α protein expression were significantly increased in low,medium,and high dose midazolam groups;The apoptosis rate,TNF-α,IL-6,MDA,and Bax protein expression were obviously reduced(P<0.05).Compared with the high-dose midazolam group,A490 value(24,48 hours),proliferation rate,activity of SOD and CAT,CREB mRNA and PGC-1α mRNA expression as well as Ki-67,Bcl-2,CREB,and PGC-1α protein expression were all sig-nificantlu reduced in the high-dose midazolam+KG-501 group while the apoptosis rate,TNF-α,IL-6,MDA,and Bax protein expression were obviously increased(P<0.05).Conclusions Midazolam might alleviate nerve cell injury potentially through the mechaninsms of promoting OGD/R-induced proliferation and reducing cell apoptosis in HT22 cells.
ABSTRACT
Objective@#To evaluate the impact of ultra-high-molecular-weight polyethylene (UHMWPE)-Ribbond fibers, when combined with different restorative materials, on fracture resistance and marginal adaptation of isolated primary molar defects, to provide a reference for clinical practice.@*Methods@#This study was approved by the Ethics Review Committee. A total of 72 extracted primary molars with complete crowns were collected, and 66 primary molars were randomly assigned as experimental groups for the fracture resistance and microleakage tests. The molars were divided into six groups (n = 11) based on the type of restorative materials and the application of Ribbond fibers: Group A1, 3M Filtek Z250 + Ribbond; Group A2, 3M Filtek Z250; Group B1, Beautifil II LS + Ribbond; Group B2, Beautifil II LS; Group C1, 3M Filtek Bulk Fill + Ribbond; and Group C2, 3M Filtek Bulk Fill. Groups A1, B1 and C1 received the fiber-reinforcing technique, whereas Groups A2, B2 and C2 received the direct restorative technique; the remainings were in Group D (blank control group), which did not receive treatment for the fracture resistance test. The fracture resistance test was divided into six experimental groups and one blank control group (n = 6). Primary molar teeth in each experimental group were prepared with Class II cavities and filled. The fracture load of all samples was detected, and the fracture mode was analyzed after thermal cycling. The microleakage test was divided into six experimental groups, with five in each group. Class I cavities with a diameter of 3 mm and depth of 2.5 mm were prepared within the mesial and distal marginal ridges on the occlusal surface and filled for primary molars in each group. Marginal microleakage was assessed after thermal cycling.@*Results@#The fracture resistance test results showed that the fracture resistance in groups that received the fiber-reinforcing technique was greater than that in groups that received the direct restorative technique: Group A1>Group A2, Group B1>Group B2, Group C1>Group C2 (P<0.05). The application of Ribbond fibers increased fracture resistance to all tested restorative materials by 37.08% to 39.34%. The proportion of tooth frac-ture decreased significantly in groups A1, C1 compared with A2, C2, with a significant increase in the occurrence rate of “Repairable” (P<0.05). The fracture resistance in Group A1 was significantly greater than that in Group B1 and Group C1 (P<0.05). The marginal microleakage test results showed that the microleakage depth in groups that received the fiber-reinforcing technique was smaller than that in groups that received the direct restorative technique: Group A1<Group A2, Group B1<Group B2, Group C1<Group C2 (P<0.05). The microleakage depth in groups that received the fiber-reinforcing technique decreased by 53.90% to 66.96% compared to that in groups that received the direct restorative technique. The microleakage depth in Group B1 was significantly less than that in Group A1 and Group C1.@*Conclusion@#The application of Ribbond fibers combined with various restorative materials could enhance fracture resistance and diminish the microleakage depth to improve marginal adaptation.
ABSTRACT
Objective:To assess the impact of reducing the mesh density on the overall volume and trueness of single-crown restora-tions.Methods:15 single-crown restorations were included,and their mesh density in 3D software was simplified by 75%,50%,25%,10%and 5%respectively.The overal volume,file size and mesh edge length of the restorations with different reduction levels were compared.Deviation analysis was conducted by curving clipping the area of the shoulder,tissue surface(except for the shoulder)and occlusal surface of the restorations and compared with those of the corresponding regions in the non-simplified restorations.Trueness was assessed using the root mean square(RMS)values for the volume and trueness of different areas.Results:Reducing the mesh den-sity did not significantly affect the overal volume of the single-crown restorations(P>0.05),but it had a significant impact on the file size(P<0.001),mesh edge length(P<0.001)and the trueness of the shoulder(P<0.001),tissue surface(except for the shoulder)(P<0.001)and occlusal surface(P<0.001)areas.Conclusion:Reducing the mesh density had little impact on the overall volume of the restorations but significantly affected their trueness.
ABSTRACT
BACKGROUND:In implant restoration in the aesthetic area,zirconium dioxide is gradually becoming the most commonly used upper restorative material and has achieved better clinical results.Resin-ceramic composite,a new type of dental restorative material,begins to try to be used as an upper restorative material in implant restoration,but there is less research on the application of this material in implant restoration. OBJECTIVE:To compare the biomechanical differences between resin ceramic crowns and zirconia all-ceramic crown implant restorations in three occlusal relationships for restoring maxillary central incisors. METHODS:The cone-beam CT image data of a patient with single-crown implant restoration of maxillary central incisor were selected,and the maxillary bone model was extracted by using Mimics 21.0 software,and the model was imported into Solidworks 2020 software.The crown,adhesive,abutment,central screw,and implant were modeled,and the model of single-crown implant restoration of maxillary central incisor was assembled.After giving the model material property parameters(resin-ceramic composite and zirconia for the upper restoration materials)in ANSYS Workbench 2021 R1 software,three occlusal relationships(edge-to-edge occlusion,normal overjet and deep overbite)were simulated and loaded to analyze the stress distribution of the resin-ceramic crown and zirconia all-ceramic crown implant restoration models. RESULTS AND CONCLUSION:(1)The stress concentration areas in the implant restoration models of the resin-ceramic crown group and the zirconia all-ceramic crown group in different occlusal relationships were distributed in the upper restoration loading point,the abutment-implant connection,the implant neck and the surrounding bone tissue.As the occlusal relationship changed from the edge-to-edge to normal and deep overbite,the peak equivalent forces of the restorative abutment,central screw,implant,and bone tissue in both the resin-ceramic and zirconia all-ceramic crown groups gradually decreased.The highest peak equivalent forces were observed for the upper restorations in deep overbite.The zirconia all-ceramic crown group had the highest peak equivalent force in the adhesive layer in the edge-to-edge relationship,and the resin-ceramic crown group had the highest peak equivalent force in the adhesive layer in the deep overbite.(2)In the edge-to-edge occlusion,the peak equivalent force of the adhesive layer and central screw in the resin-ceramic crown group was slightly smaller than that in the zirconia all-ceramic crown group,and there was no significant difference between the two groups in the peak equivalent force at the upper restoration,restoration abutment,implant,and bone tissue.The peak stresses in the upper restoration,adhesive layer,and central screw of the resin-ceramic crown group were slightly less than those of the zirconia all-ceramic crown group at normal fit,and there were no significant differences between the two groups in the peak equivalent forces at the restoration abutment,implant,and bone tissue.In deep overbite,the peak adhesive,abutment,and central screw stresses were greater in the resin-ceramic crown group than in the zirconia all-ceramic crown group,with no significant differences in the upper restorations,implants,or bone tissue.(3)The results showed that the upper restorative material had no significant effect on the stress distribution of the implant and bone tissue,and had some effects on the stress distribution of the upper restoration,adhesive,restoration abutment,and central screw,but the difference was not significant.The occlusal relationship has a significant influence on the stress distribution in all structures and bone tissue of the implant restoration.The resin-ceramic crowns have a buffering effect on the stresses in the case of edge-to-edge and normal occlusion.
ABSTRACT
BACKGROUND:The threaded conical implant has a good ability to control micro movements and is conducive to immediate loading.However,the effects of double-threaded conical cylindrical implants and conical cylindrical implants on stress distribution and initial stability of implant-bone interface after immediate loading have not been reported. OBJECTIVE:To investigate the impact of double-threaded conical cylindrical implants and conical cylindrical implants on the biological distribution of the implant and the surrounding bone interface during immediate loading in the mandibular molar region. METHODS:(1)Three-dimensional finite element analysis:Conical beam CT scans of the mandible and first molar of a volunteer were used to develop a basal model of the mandible.The double-threaded conical cylindrical implants and conical cylindrical implants were assembled with the mandibular models,and an immediate-load(or delayed implantation)implant model(a total of four models)for the first mandibular molar was established.Loads in four directions(100 N):axial,lingual and buccal 45°,mesial and distal,and buccal and lingual,were applied to the central fossa of each model's crown.Three-dimensional finite element method was used to analyze the implant displacement and the stress distribution at the implant-bone interface.(2)In vitro experiment:With the assistance of the oral implant robot,the double-threaded conical cylindrical implants and conical cylindrical implants were implanted on the same artificial bone pieces,separately,and the immediate load model of immediate implant implantation(or delayed implantation)was established in vitro(a total of four groups of models).Osstell resonance frequency analyzer and SmartPeg sensor were used to measure the implant stability coefficient in four vertical directions:front,rear,left,and right measurements,evaluate the initial stability,and verify the finite element analysis results. RESULTS AND CONCLUSION:(1)The displacement difference between double-threaded conical cylindrical implants and conical cylindrical implants was small when the immediate loading of delayed implantation was applied,but the maximum stress value of conical cylindrical implant-bone interface was greater than that of double-threaded conical cylindrical implant-bone interface.When the immediate loading of immediate implantation was applied,the maximum stress value and the maximum displacement of bone around the implant appeared when the load was applied in mesiodistal direction.The stress value of the conical cylindrical implant reached 298.84 MPa and the maximum displacement was 0.31 mm,both of which were larger than that of the double-threaded conical cylindrical implant.(2)The results of in vitro experiments showed that the stability coefficient of the double-threaded conical cylindrical implant was greater than that of the conical cylindrical implant.(3)Compared with the conical cylindrical implant,the double-threaded conical cylindrical implant has higher initial stability under immediate loading,suggesting that the use of double-threaded conical cylindrical implant should be given priority in clinical immediate loading.
ABSTRACT
Objective:To screen the independent influencing factors of restoration of spontaneous circulation (ROSC) in patients after cardiopulmonary resuscitation (CPR) and establish a predictive model, and explore its clinical value.Methods:A retrospective case control study was conducted. The clinical data of cardiac arrest patients admitted to the emergency department of Tangdu Hospital of Air Force Military Medical University and received CPR from January to July 2023 were analyzed, including general information, blood biochemical indicators, main cause of cardiac arrest, whether it was defibrillation rhythm, duration from admission to CPR, and whether ROSC was achieved. The clinical data between the patients whether achieved ROSC or not were compared. The binary multivariate Logistic regression analysis was used to screen the independent influencing factors of ROSC in in-hospital CPR patients. According to the above influencing factors, the ROSC prediction model was established, and the receiver operator characteristic curve (ROC curve) was drawn to evaluate the predictive value of the model for ROSC.Results:A total of 235 patients who received CPR in the emergency department were enrolled, including 153 cases (65.11%) of in-hospital CPR and 82 cases (34.89%) of out-of-hospital CPR. The ROSC ratio was 30.21% (71/235). Among all patients, the majority were aged 61-80 years [40.43% (95/235)], and cardiogenic disease was the main cause of cardiac arrest [32.77% (77/235)]. Among 153 patients with in-hospital CPR, 89 were non-ROSC and 64 were ROSC with ROSC rate of 41.83%. Compared with the non-ROSC group, the patients in the ROSC group had lower blood lactic acid (Lac), N-terminal pro-brain natriuretic peptide (NT-proBNP), Lac/albumin (Alb) ratio (LAR), and ratio of non-defibrillation rhythm [Lac (mmol/L): 5.50 (2.33, 9.65) vs. 7.10 (3.50, 13.35), NT-proBNP (μg/L): 0.87 (0.20, 8.68) vs. 3.00 (0.58, 20.17), LAR: 0.14 (0.07, 0.29) vs. 0.19 (0.10, 0.43), non-defibrillation rhythm ratio: 68.75% (44/64) vs. 93.26% (83/89)], higher actual base excess (ABE) and Alb [ABE (mmol/L): -3.95 (-12.75, 0.23) vs. -7.50 (-13.50, -3.35), Alb (g/L): 38.13±7.03 vs. 34.09±7.81], and shorter duration from admission to CPR [hours: 3.25 (1.00, 14.00) vs. 8.00 (2.00, 27.50)], the differences were statistically significant (all P < 0.05). Binary multivariate Logistic regression analysis showed that LAR [odds ratio ( OR) = 0.037, 95% confidence interval (95% CI) was 0.005-0.287], non-defibrillation rhythm ( OR = 0.145, 95% CI was 0.049-0.426), and duration from admission to CPR ( OR = 0.984, 95% CI was 0.972-0.997) were independent influencing factors for ROSC in hospitalized CPR patients (all P < 0.05). Based on the above influencing factors, a ROSC prediction model was constructed through regression analysis results. The ROC curve analysis showed that the area under the ROC curve (AUC) for predicting ROSC in in-hospital CPR patients was 0.757 (95% CI was 0.680-0.834), Yoden index was 0.429, sensitivity was 76.6%, and specificity was 66.3%. Conclusions:LAR, non-defibrillation rhythm and duration from admission to CPR were independent influencing factors for ROSC in patients with in-hospital CPR. The ROSC prediction model established based on the above influencing factors has a good predictive value for ROSC of CPR patients in hospital, and can guide clinicians to evaluate the prognosis of patients through relevant indicators as early as possible.
ABSTRACT
Abstract Resin composites containing surface pre-reacted glass (S-PRG) have been introduced to reduce demineralization and improve remineralization of the tooth structure. However, water diffusion within the material is necessary for its action, which can impair its overall physicomechanical properties over time, including color stability. This study aimed to evaluate the color stability and related degree of conversion (DC) of four resin composites. Discs (6 x 4 mm, n = 5/group) of microhybrid (MH), nanofilled (NF), nanohybrid (NH), and S-PRG-based nanohybrid (S-PRG-NH) composites with two opacities (A2/A2E and A2O/A2D) were prepared. Color (CIELab and CIEDE2000) was evaluated with a spectrophotometer after aging in grape juice (2 x 10 min/10mL/7days). The DC was analyzed by using Fourier transform infrared spectroscopy before and after light-curing. Data were statistically analyzed by using two-way analysis of variance and post-hoc least significant difference tests (p<0.05). In the color stability analysis, the interaction between filler type and opacity was significant (CIELab, p = 0.0015; CIEDE2000, p = 0.0026). NH presented the highest color stability, which did not differ from that of MH. The greatest color alteration was observed for S-PRG-NH. S-PRG fillers also influenced DC (p < 0.05). The nanohybrid resin composite presented favorable overall performance, which is likely related to its more stable organic content. Notwithstanding the benefits of using S-PRG-based nanohybrid resins, mostly in aesthetic procedures, professionals should consider the susceptibility of such resins to color alteration, probably due to the water-based bioactive mechanism of action.
ABSTRACT
Abstract Epiphytes are considered indicators of forest ecological integrity, but the factors that explain their abundance are still not well understood. We here evaluated tree colonization by epiphytes in old-growth monospecific reforestation stands of Astronium urundeuva (M.Allemão) Engl. (Anacardiaceae) and Eucalyptus saligna Sm. (Myrtaceae), in comparison to a neighbor seasonal tropical forest fragment under similar environmental conditions. In each forest type, we identified and measured all trees (planted and colonizers) from 5-cm stem diameter in five 200 m² plots and quantified all vascular epiphytes per tree. Tree species were categorized by bark roughness, canopy deciduousness and growth rate. The abundance of epiphytes and the frequency of host trees were higher in the A. urundeuva plantation than in the native forest, with the E. saligna stand in an intermediate position. Also, we found that host traits influenced the abundance of epiphytes in their trunks. Host trees had average stem perimeter and height both higher than non-hosts, which indicates that colonization is more likely to occur in older trees. The average abundance of epiphytes per tree was higher in species with rough bark, but no relationship was found with canopy deciduousness or tree growth rate. We evidenced, therefore, that forest plantations, even if monospecific, can provide habitat for epiphytes. However, at community level, colonization success, either in native or restored forest, depends on the relative abundance of species whose bark type favors epiphytes establishment.
Resumo Epífitas são consideradas indicadores de integridade ecológica em florestas, mas os fatores que explicam sua abundância ainda não são bem compreendidos. Neste estudo, avaliamos a colonização por epífitas em antigos talhões monoespecíficos de Astronium urundeuva (M.Allemão) Engl. (Anacardiaceae) e Eucalyptus saligna Sm. (Myrtaceae), em comparação com um fragmento vizinho de floresta estacional semidecidual sob condições ambientais semelhantes. Em cada tipologia florestal, identificamos e medimos todas as árvores (plantadas e que colonizaram os locais) a partir de 5 cm de diâmetro à altura padrão, em cinco parcelas de 200 m². Nelas, também quantificamos todas as epífitas vasculares por árvore. Em busca de uma explicação funcional para as diferenças entre espécies, utilizamos rugosidade da casca, deciduidade da copa e taxa de crescimento como atributos potencialmente relevantes. A abundância das epífitas e a frequência de forófitos foi maior no talhão de A. urundeuva do que na floresta nativa, com o talhão de E. saligna ocupando uma posição intermediária. Encontramos evidências, também, de que os atributos dos forófitos influenciaram a abundância de epífitas em seus troncos. Os forófitos apresentaram maior perímetro médio e altura que as árvores não hospedeiras, o que indica que a colonização é mais provável de ocorrer em árvores mais velhas. A abundância média de epífitas por árvore foi maior em espécies com casca rugosa, mas nem a deciduidade da copa, nem a velocidade de crescimento exerceram efeito neste aspecto. Evidenciamos, portanto que, plantações florestais, ainda que monoespecíficas, podem prover habitat para epífitas. Contudo, em nível de comunidade, o sucesso da colonização, seja em florestas nativas ou restauradas, depende da abundância relativa de espécies cujo tipo de casca favorece o estabelecimento de epífitas.
ABSTRACT
L'anorexie est une pathologie du vide de sens, qui presente une défaillance au niveau des processus de la pensée, avec des implications directes au niveau de la construction identitaire. Le Rorschach a été utilise comme instrument d'évaluation du fonctionnement mental et comme méthode d'analyse des transformations psychiques. Martha est une adolescente de dix-sept ans, avec deux hospitalisations, avec un diagnostic d'anorexie. L'analyse du Rorschach à mettre en évidence deux mouvements psychiques: la présence d'une forte tension pulsionnelle, mobilisée face à l'atteinte ressentie dans la relation Moi-Autre; la dévitalisation du Moi, par un fort mouvement d'annulation du Moi. La compréhension de ces mouvements a permis une intervention thérapeutique dans le but de restaurer son Être, de consolider son identité et de permettre un ensemble de transformations psychiques qui permettent la subjectivation et la croissance mentale.
Resumos A anorexia é uma patologia do vazio do sentido, que apresenta uma falha ao nível dos processos do pensamento, com implicações diretas ao nível da construção da identidade. O Rorschach foi usado como um instrumento para aceder ao funcionamento mental e como um método de análise das transformações psíquicas. Martha é uma adolescente de dezessete anos, com duas internações, com um diagnóstico de anorexia. A análise de Rorschach permitiu destacar dois movimentos psíquicos: a presença de uma forte tensão pulsional, mobilizada perante o ataque sentido na relação Eu-Outro; a desvitalização do Eu, através de um movimento de uma forte anulação do próprio eu. A compreensão desses movimentos permitiu uma intervenção terapêutica com o objetivo de restaurar o seu Ser, consolidar sua identidade e permitir um conjunto de transformações psíquicas que possibilitam a subjetivação e o crescimento mental.
Anorexia is a pathology of the emptiness of meaning, which presents a failure at the level of thought processes, with direct implications in self-identity. Rorschach test was used as an instrument to assess mental functioning and as a method to analyze the psychic transformations. Martha is a 17-year-old adolescent, with two previous hospitalizations, diagnosed with anorexia. Through Rorschach test, it was possible to highlight two movements: the presence of a strong instinctual drive, mobilized in the face of the perceived attack in the Self-Other relationship; the devitalization of the Self, through a strong annulment of the self. The understanding of such movements enabled a therapeutic intervention aimed at restoring her Being, consolidating her identity and enabling a set of psychic transformations that allow for subjectivation and mental growth.
La anorexia es una patología del vacío de sentido, que presenta una falla al nivel de los procesos del pensamiento, con implicaciones directas en la construcción de la identidad. El Rorschach se utilizó como instrumento para evaluar el funcionamiento mental y como método de análisis de las transformaciones psíquicas. Martha es una adolescente de 17 anos, con dos hospitalizaciones y diagnóstico de anorexia. El análisis del Rorschach reveló dos movimientos psíquicos: la presencia de una fuerte tensión instintiva, movilizada frente al ataque sentido en la relación Yo-Otro; la desvitalización del Yo, mediante un fuerte movimiento de anulación del Yo. La comprensión de estos movimientos permitió aplicar una intervención terapéutica con el objetivo de restaurar el Ser de la paciente, consolidar su identidad y permitir un conjunto de transformaciones psíquicas que permitan la subjetivación y el crecimiento psíquico.
ABSTRACT
BACKGROUND: The monthly regeneration of human endometrial tissue is maintained by the presence of human endometrial mesenchymal stromal/stem cells (eMSC), a cell population co-expressing the perivascular markers CD140b and CD146. Endometrial regeneration is impaired in the presence of intrauterine adhesions, leading to infertility, recurrent pregnancy loss and placental abnormalities. Several types of somatic stem cells have been used to repair the damaged endometrium in animal models, reporting successful pregnancy. However, the ability of endometrial stem cells to repair the damaged endometrium remains unknown. METHODS: Electrocoagulation was applied to the left uterine horn of NOD/SCID mice causing endometrial injury. Human eMSC or PBS was then injected into the left injured horn while the right normal horn served as controls. Mice were sacrificed at different timepoints (Day 3, 7 and 14) and the endometrial morphological changes as well as the degree of endometrial injury and repair were observed by histological staining. Gene expression of various inflammatory markers was assessed using qPCR. The functionality of the repaired endometrium was evaluated by fertility test. RESULTS: Human eMSC successfully incorporated into the injured uterine horn, which displayed significant morphological restoration. Also, endometrium in the eMSC group showed better cell proliferation and glands formation than the PBS group. Although the number of blood vessels were similar between the two groups, gene expression of VEGF-α significantly increased in the eMSC group. Moreover, eMSC had a positive impact on the regeneration of both stromal and epithelial components of the mouse endometrium, indicated by significantly higher vimentin and CK19 protein expression. Reduced endometrial fibrosis and down-regulation of fibrosis markers were also observed in the eMSC group. The eMSC group had a significantly higher gene expression of anti-inflammatory factor Il-10 and lower mRNA level of pro-inflammatory factors Ifng and Il-2, indicating the role of eMSC in regulation of inflammatory reactions. The eMSC group showed higher implantation sites than the PBS group, suggesting better endometrial receptivity with the presence of newly emerged endometrial lining. CONCLUSIONS: Our findings suggest eMSC improves regeneration of injured endometrium in mice.
Subject(s)
Humans , Animals , Female , Pregnancy , Mice , Uterine Diseases/metabolism , Uterine Diseases/pathology , Uterine Diseases/therapy , Mesenchymal Stem Cells , Placenta/pathology , Fibrosis , Mice, SCID , Mice, Inbred NOD , Endometrium/metabolism , Endometrium/pathologyABSTRACT
Introducción: Las áreas impactadas por minería en bosques tropicales requieren de la aplicación de estrategias de restauración ecológica, pero este proceso, muchas veces involucra el uso de especies vegetales exóticas, desconociendo los efectos sobre la regeneración ecológica de los sitios donde se introducen. Objetivo: Evaluar el efecto de las plantaciones de Acacia mangium (planta exótica) sobre la rehabilitación ecológica temprana (suelo y vegetación) de áreas impactadas por minería de oro a cielo abierto en la selva pluvial tropical del Chocó, Colombia. Métodos: Se seleccionaron 16 áreas mineras como unidades de muestreo (ocho reforestadas con A. mangium y ocho en sucesión natural) en dos localidades. En cada unidad de muestreo se estableció una parcela de 2 × 50 m (cuatro parcelas por escenario de muestreo y localidad), donde se analizó la fertilidad del suelo (parámetros físicos y químicos) y se cuantificó el número de individuos de cada especie de planta vascular. Resultados: Se registraron 73 especies (69 géneros, 45 familias). La densidad de individuos fue mayor en áreas de sucesión natural que en aquellas reforestadas con A. mangium; por el contrario, la riqueza y diversidad de especies fueron superiores bajo las plantaciones de A. mangium. La similitud florística fue baja entre escenarios sucesionales (especies compartidas 35.6 %). El suelo mostró mejores condiciones (especialmente, N-NHO3) en áreas con A. mangium que en áreas en regeneración natural. Conclusiones: Las plantaciones de A. mangium parecen facilitar la rehabilitación temprana de la fertilidad del suelo y la vegetación en las minas abandonadas; por lo tanto, esta especie puede jugar un papel importante para la implementación de estrategias de restauración ecológica de áreas impactadas por minería de oro a cielo abierto en el Chocó y otros sistemas forestales tropicales con condiciones ambientales y de perturbación similares.
Introduction: Mining-impacted areas in tropical forests require the application of ecological restoration strategies, but this process often involves use of exotic plant species ignoring the effects on the ecological regeneration of the sites where they are introduced. Objective: To evaluate the effect of Acacia mangium plantations (exotic plant) on early ecological rehabilitation (soil and vegetation) of areas impacted by open-pit gold mining in the tropical rain forest of Chocó, Colombia. Methods: 16 mining areas were selected as sampling units (eight reforested with A. mangium and eight in natural succession) in two locations. In each sampling unit, a 2 × 50 m plot was established (four plots per sampling scenario and locality), where soil fertility (physical and chemical parameters) was analyzed and the number of individuals of each vascular plant species was quantified. Results: 73 species (69 genera, 45 families) were recorded. The density of individuals was higher in areas of natural succession than in those reforested with A. mangium; conversely, species richness and diversity were higher under the A. mangium plantations. Floristic similarity was low between successional scenarios (shared species 35.6 %). The soil showed better conditions (especially N-NHO3) in mining areas with A. mangium than in those in natural regeneration. Conclusions: A. mangium plantations appears to facilitate the early rehabilitation of soil fertility and vegetation in abandoned mines; therefore, this species can play an important role in the implementation of ecological restoration strategies in areas impacted by open-pit gold mining in the Chocó and other tropical forest systems with similar environmental and disturbance conditions.