Research progress on applications and mechanisms of osteogenesis effect of magnetic fields in oral field / 口腔疾病防治

@#Magnetic fields are safe and used in noninvasive physical therapies. Numerous studies have confirmed that magnetic fields have good osteogenic effects and certain value for clinical application in accelerating orthodontic tooth movement, promoting bone-implant integration, promoting fracture healing and improving the effects of distraction osteogenesis. Magnetic fields are expected to become applied as effective auxiliary methods for treating oral diseases. To support the clinical application of magnetic fields, this article reviews the applications of magnetic fields in the oral cavity, the biological effects on bone cells and the molecular mechanisms through which magnetic fields regulate bone metabolism. The biological effects of magnetic fields on bone cells include promoting osteogenesis by osteoblasts and mesenchymal stem cells and inhibiting bone resorption by osteoclasts. At the molecular level, bone cells sense and respond to magnetic stimulation, and through various mechanisms, such as displacement currents, Lorentz forces, and free radical pair effects, stimuli are transformed into biologically recognizable electrical signals that activate complex downstream signaling pathways, such as the P2 purinergic receptor signaling pathway, adenosine receptor signaling pathway, transforming growth factor-β receptor signaling pathway, mammalian target of rapamycin (mTOR) pathway, and Notch pathway. In addition, magnetic parameters, which are the factors affecting the osteogenic effects of magnetic fields, are discussed. However, the mechanisms of the osteogenic effects of magnetic fields are unclear, and further studies of these mechanisms could provide effective strategies for bone regeneration and periodontal tissue regeneration. In addition, considering the target of magnetic field therapies, combination with other drugs could lead to new strategies for the treatment of oral diseases.

Preparation of an amino hybrid mesoporous silica-based nanotopography protective coating on a titanium implant surface and evaluation of its osteogenic effect / 口腔疾病防治

Objective@#To deposit degradable amino-hybrid mesoporous silica (AHMS) in situ on the surface of titanium nanotube (TNT) and explore its protective effect on nanomorphology and osteogenesis.@*Methods@#TNT and TNT@AHMS were sequentially prepared via an anodizing method: the oil-water two-phase method (experimental group) and the acid-etched titanium method [control group (Ti)]. The parameters for synthesis were explored by changing the silicon source dosage ratio (3∶1, 1∶1, 1∶3); the surface morphology was observed by scanning electron microscope(SEM), hydrophilicity was detected by Water Contact Angle Tester, elemental composition was detected by X-ray photoelectron spectroscopy (XPS); nanoindentation test and ultrasonic oscillator were used to observe the morphological holding effect as mechanical strength of TNT@AHMS in vitro; simulated immersion experiments in vitro was used to observe the degradation behavior of the material. the MC3T3-E1 cell line was used to observe the effect of cell adhesion, proliferation and differentiation on the material; and an SD rat femoral implant model and micro-CT were used to verify the protective effect and osseointegration effect of AHMS on TNT morphology.@*Results@#The morphologies of TNT and TNT@AHMS were successfully prepared, and the silicon source ratio was 1:3. SEM showed that the titanium nanotubes were uniformly covered with AHMS coating, and the mesoporous pore size was about 4 nm. After AHMS was incorporated, the surface of the material was hydrophilic (12.78°), the presence of amino groups (NH2-) was detected, the material was completely degraded within 12 h in vitro, and the active morphology of the TNT was re-exposed with a cumulative silicon release of 10 ppm. Nanoindentation test showed that TNT@AHMS exhibited more ideal surface mechanical strength. SEM revealed that TNT maintains its own morphology under the protection of AHMS, and the TNT group suffered severe exfoliation. In addition, the early adhesion and proliferation rates, ALP activity, and bone volume fraction of cells on the TNT@AHMS surface 4 weeks after implantation were significantly higher than those in the TNT group.@*Conclusion@#By depositing AHMS on the surface of TNT, the nanotopography can be protected. It not only prevents the active base topography from exerting subsequent biological effects but also further endows the material with the ability to promote bone regeneration, laying a foundation for the future development of nanotopography-modified titanium implants.

Effect of different thread configurations on hydrophilic implant stability. A split-mouth RCT

Abstract This split-mouth randomized controlled trial aimed to evaluate the primary and secondary stability of hybrid implants with different thread configurations and hydrophilic surfaces. Twenty patients with a partially edentulous maxilla were selected. These patients received two types of implants with the same hydrophilic surface: CTP group: Cylindrical-Tapered implant with perforating threads; CTH: Cylindrical-Tapered implant with hybrid threads configuration (perforating and condensing threads). The primary and secondary stability parameters were measured by insertion torque and resonance frequency analysis at the time of implant placement and 7, 28, 56, and 90 days after the surgical procedure. The paired t-test was used to compare the data on the implant's stability between the groups. The statistical analysis was performed with a confidence level set at 95%. It was found that the implants in the CTH group presented higher primary stability values ​​at the time of implant placement, due to the higher ISQ (63.61 ± 9.44 vs. 40.59 ±7.46) and insertion torque (36.92 ± 16.50 Ncm vs. 28.00 ± 14.40 Ncm), than the implants in the CTP group. The CTH group presented higher ISQ values ​​in all follow-up periods: 7 days (68.67 ± 7.60 vs. 41.55 ± 9.07), 28 days (68.61 ± 5.98 vs. 47.90 ±13.10), 56 days (74.09 ± 3.96 vs. 55.85 ± 13.18), and 90 days (75.45 ± 4.02 vs. 63.47 ± 6.92) after implant placement. Hybrid implants with perforating and condensing threads demonstrated greater stability than hybrid implants with only perforating threads.

Resumo O objetivo deste estudo controlado randomizado de boca dividida foi avaliar a estabilidade primária e secundária de implantes híbridos com diferentes configurações de rosca e superfícies hidrofílicas. Vinte pacientes com maxila parcialmente edêntula foram selecionados. Esses pacientes receberam dois tipos de implantes com a mesma superfície hidrofílica: Grupo CTP: Implante cilíndrico-cônico com roscas perfurantes; Grupo CTH: Implante cilíndrico-cônico com roscas perfurantes e condensadoras. Os parâmetros de estabilidade primária e secundária foram medidos por análise de torque de inserção e frequência de ressonância no momento da colocação do implante e 7, 28, 56 e 90 dias após o procedimento cirúrgico. O teste t-pareado foi utilizado para comparação dos dados de estabilidade entre os grupos. A análise estatística foi executada levando-se em consideração um nível de confiança de 95%. Constatou-se que os implantes do grupo CTH apresentaram maiores valores de estabilidade primária no momento da colocação do implante, devido ao maior ISQ (63.61 ± 9.44 vs. 40.59 ±7.46) e torque de inserção (36.92 ± 16.50 Ncm vs. 28.00 ± 14.40 Ncm), do que os implantes do grupo CTP. Implantes do grupo CTH apresentaram valores de ISQ superiores em todos os períodos de acompanhamento: 7 dias (68.67 ± 7.60 vs. 41.55 ± 9.07), 28 dias (68.61 ± 5.98 vs. 47.90 ±13.10), 56 dias (74.09 ± 3.96 vs. 55.85 ± 13.18) e 90 dias (75.45 ± 4.02 vs. 63.47 ± 6.92). Os implantes híbridos com roscas perfurantes e condensantes demonstraram maior estabilidade do que os implantes híbridos com apenas roscas perfurantes.

Abordajes de una molestia periimplantar

Los implantes dentales se han convertido en un componente rutinario de la práctica dental diaria. A la vez, pueden producir molestias, destrucción desenfrenada de la salud bucal o reemplazo quirúrgico y costoso de un implante fallido. La detección temprana de la pérdida ósea marginal es vital para la planificación del tratamiento y el pronóstico de los implantes. Estos están diseñados para adaptarse mejor a los diversos tipos de hueso y fallan debido a muchas razones. Entender los desafíos y las expectativas del paciente a través de la honestidad, es una parte importante del tratamiento, cuyo éxito no solo dependerá de los integrantes del equipo implantológico o de técnica, sino también del cuidado del paciente al realizar su higiene diaria. Por esa razón, se realizó una búsqueda bibliográfica en las bases de datos MEDLINE y PubMed sobre molestias periimplantar, consultándose 30 referencias de los últimos cinco años.

Dental implants have become a routine component of daily dental practice. At the same time, they can cause discomfort, rampant destruction of oral health, or expensive surgical replacement of a failed implant. Early detection of marginal bone loss is vital for treatment planning and implant prognosis. These are designed to best fit various bone types and fail due to many reasons. Understanding the patient's challenges and expectations through honesty is an important part of the treatment, whose success will not only depend on the members of the implantology or technical team, but also on the patient's care when performing their daily hygiene. For this reason, a bibliographic search was carried out in the MEDLINE and PubMed databases on peri-implant discomfort, consulting 30 bibliographical references from the last 5 years.

Poly ether keton keton polymer deposition on laser surface structured commercial pure titanium using magnetron sputtering / Deposição de polímero de poliéter cetona cetona em titânio comercial puro com superfície estruturada a laser usando pulverização catódica por magnetro

Objective: This study aimed to evaluate the effect of coating titanium (Ti) dental implant with polyether ketone ketone (PEKK) polymer using magnetron sputtering on osseointegration, trying to overcome some of the problems associated with Ti alloys. Material and Methods: Implants were prepared from grade (II) commercially pure titanium (CP Ti), then laser was used to induce roughness on the surface of Ti. PEKK was deposited on the surface of Ti implants by radiofrequency (RF) magnetron sputtering technique. The implants were divided in to three groups: without coating (Ls), with PEKK coating using argon (Ar) as sputtering gas (Ls-PEKK-Ar), and with PEKK coating using nitrogen (N) as sputtering gas (Ls-PEKK-N). All the implants were implanted in the femoral bones of rabbits. After three different healing periods (2, 6, and 12 weeks) the rabbits were sacrificed for a mechanical examination (removal torque) and for histological examination. Results: The results revealed a significant increase in the removal torque mean values when using PEKK coating on Ti implants, with the highest value recorded by Ls-PEKK-N group. Histologically, the study demonstrated the progression of osteogenesis during all the research periods. It was observed that the Ls-PEKK-N group had the highest percentage of new bone formation in all healing periods. Conclusion: The use of PEKK as coating material on the surface of Ti implants by RF- magnetron sputtering results in an increase in the torque required to remove implants and enhance bony tissue formation around the implants especially when using nitrogen as a sputtering gas (AU)

Objetivo: Este estudo teve como objetivo avaliar o efeito do revestimento de implante dentário de titânio (Ti) com polímero de poliéter cetona cetona (PEKK) usando pulverização catódica por magnetron na osseointegração, tentando superar alguns dos problemas associados às ligas de Ti. Material e Métodos: Os implantes foram preparados a partir de titânio comercialmente puro grau (II) (CP Ti), em seguida o laser foi utilizado para induzir rugosidade na superfície do Ti. PEKK foi depositado na superfície de implantes de Ti pela técnica de pulverização catódica por radiofrequência (RF). Os implantes foram divididos em três grupos: sem revestimento (Ls), com revestimento de PEKK utilizando argônio (Ar) como gás de pulverização catódica (Ls-PEKK-Ar) e com revestimento de PEKK utilizando nitrogênio (N) como gás de pulverização catódica (Ls-PEKK -N). Todos os implantes foram implantados em ossos femorais de coelhos. Após três períodos de cicatrização diferentes (2, 6 e 12 semanas), os coelhos foram sacrificados para exame mecânico (torque de remoção) e exame histológico. Resultados: Os resultados revelaram um aumento significativo nos valores médios do torque de remoção quando se utilizou o revestimento de PEKK em implantes de Ti, sendo o maior valor registrado pelo grupo Ls-PEKK-N. Histologicamente, o estudo demonstrou a progressão da osteogênese durante todos os períodos da pesquisa Observou-se que o grupo Ls-PEKK-N apresentou maior percentual de neoformação óssea em todos os períodos de cicatrização. Conclusão: O uso de PEKK como material de revestimento na superfície de implantes de Ti por pulverização catódica RF-magnetron resulta em um aumento no torque necessário para remover os implantes e melhorar a formação de tecido ósseo ao redor dos implantes, especialmente quando se utiliza nitrogênio como gás de pulverização catódica(AU)

The effects of repeated high acceleration on implant osseointegration in SD rats / 实用口腔医学杂志

Objective:To investigate the effects of repeated high acceleration(+Gz)on implant osseointegration in SD rats.Methods:18 SD rats were divided into+Gz and control groups randomly(n=9),and 1 implant was placed in each femur of the rat's lower limb.24 hours postoperatively,the experimental rats were exposed to+Gz of 4 to 9 G with 1 G/s environment 3 times a week,while the con-trol rats were fed normally.3 rats from each of the 2 groups were sacrificed at 2,4 and 8 weeks after implantation.Micro-CT,sequential fluorescence double labeling,and histological examination were perfomed for the analysis of implant osseointegration.Results:The bone volume fraction(BV/TV),trabecular number(Tb.N),mineral apposition rate(MAR),implant-bone contact rate(BIC)and bone area in implant thread(BA)of the+Gz group were significantly lower than those of the control group at 2 weeks(P＜0.05),and so as to MAR,BA at 4 weeks(P＜0.05),while there was no significant difference of the parameters at 8 weeks after implantation.Conclusion:In SD rats early exposure to+Gz environment postoperatively may have a negative effect on initial osseointegration by slowing bone forma-tion.However,it will not lead to poorer bone mass when sustained over a long period.

Application of metal-organic frameworks in implant surface modification / 中国组织工程研究

BACKGROUND:In recent years,metal-organic frameworks have been widely used in the biomedical field because of their unique properties,and metal-organic frameworks can be applied to implant surface modification for improving their biological properties and the surgery's success rate. OBJECTIVE:To introduce metal-organic frameworks commonly used in implant surface modification and the preparation and action mechanism of surgical implants modified by metal-organic frameworks. METHODS:The articles concerning metal-organic frameworks used in implant surface modification published from 2010 to 2023 were searched on PubMed,Web of Science and CNKI.Finally,64 articles were included for review. RESULTS AND CONCLUSION:(1)Metal-organic frameworks have the properties of high porosity,large specific surface area,and diverse spatial structure.As bioactive material,metal-organic frameworks have attracted much attention in tissue engineering and regenerative medicine.(2)The metal-organic frameworks commonly used in the field of implant surface modification include three types.Zeolitic imidazolate frameworks are commonly used as carriers,carrying various drugs and biomolecules.The MIL series are suitable for drug carriers and nanoenzymes.Bio-metal-organic frameworks have many applications because of their diverse structure and are characterized by excellent biosafety.(3)The preparation of implant materials modified by metal-organic frameworks can be mainly divided into two types:one is to incorporate metal-organic frameworks into pretreated implants;the other is to synthesize metal-organic frameworks in situ on pretreated implants.(4)Metal-organic frameworks on the implant surface could release their components,load drugs,catalyze active reactions,or combine with other materials,giving implants antibacterial and anti-inflammatory characteristics and promoting osseointegration.The preparation method of metal-organic framework coatings needs further improvement,and the metabolism and distribution of metal-organic framework coatings should be deeply explored,and its clinical application should be actively promoted.

Design and finite element analysis of experimental device for simulating interface micro motion of bone trabecular prosthesis / 医疗卫生装备

Objective To design an experimental device for simulating the interface micro motion of bone trabecular prosthesis and carry out the finite element analysis.Methods The experimental device was composed of a screw-in cylinder with threads,a flexible hinge,a micro-motion rod,a trabecular prosthesis,a connecting rod and a fixation post.A model of the experimental device was constructed with SolidWorks software,and then imported into ABAQUS software to establish a finite element model.An axial displacement load was applied to the femur to analyze the effects of the position of the flexible hinge,the gap between the prosthesis and the femur and the length of the connecting rod on the micro motion.Results The interface micro motion produced by the experimental device increased with the distance of the flexible hinge from the lower end of the screwed-in cylinder;the gap between the prosthesis and the femur did not affect the interface micro motion when the gap was not lower than 20 μm;the interface micro motion rose with the length of the connecting rod.Conclusion The experimental device can accurately simulate the micro motion of different bone trabecular prosthesis interfaces,and can be used for studying the effect of the interface micro motion on osseointegration.[Chinese Medical Equipment Journal,2024,45(1):25-30]

Clinical development of osseointegrated prostheses / 中华创伤骨科杂志

Osseointegrated prostheses provide a rehabilitation option for amputees. Due to their greater mobility, better satisfaction, and higher use than traditional socket prostheses, they have been employed in transhumeral, transradial, transfemoral, transtibial, and other hand and finger amputations. They are perceived by their users as part of their own body (high embodiment) because they have enhanced motor-sensory capability of the stump. An osseointegrated robotic limb also can be equipped with sensory-motor integration and targeted muscle reinnervation. This article reviews the problems of prosthetic adaptation, the technological development, surgical protocols, complications, and prognosis in osseointegrated prostheses, and discusses their future application and development.

Fluoride-modified implant surfaces improves osseointegration in the tibias of rats with induced diabetes

Abstract This study evaluated the influence of a fluoride-modified titanium surface on osseointegration in rats with induced diabetes. One hundred and eighty rats were randomly allocated into 3 groups with 60 animals each: Control group (C): Animals without diabetes; Diabetes Group (D): Animals with uncontrolled induced diabetes; Controlled Diabetes Group (CD): Animals with diabetes induced controlled by the insulin administration. Diabetes was induced by streptozotocin injection. Each animal received 2 implants in the proximal tibial metaphysis, one with the machined surface (M) and the other one with a fluoride-modified titanium surface (F), after 4 weeks of induction of diabetes. The animals were submitted to euthanasia 2, 4, and 6 weeks after the implant placement (n = 20 animals/group). The osseointegration was evaluated by the implant removal torque test and the histometric analysis of the non-decalcified histological sections: 1) Contact bone/implant (%BIC); 2) Bone tissue area between implant threads (%BBT). Implants with F surface showed a higher removal torque than implants with surface M in all groups. There was no difference in %BIC between the groups regardless of the surface used. The F surface showed a tendency to present higher %BBT values for the 3 evaluation periods in the D group. The fluoride-modified implant surface has no impact on the %BIC and %BBT. However, the fluoride-modified implant surface increases the locking of the implants with the bone. The hyperglycemia was associated with lower removal torque values despite the surfaces of the implant used.

Resumo Este estudo avaliou a influência de uma superfície de titânio modificada com flúor na osseointegração em ratos com diabetes induzida. Cento e oitenta ratos foram distribuídos aleatoriamente em 3 grupos com 60 animais cada: Grupo controle (C): Animais sem diabetes; Grupo Diabetes (D): Animais com diabetes induzida descompensada; Grupo Diabetes Controlado (CD): Animais com diabetes induzido controlado pela administração de insulina. O diabetes foi induzido por injeção de estreptozotocina. Cada animal recebeu 2 implantes na metáfise proximal da tíbia, um com superfície usinada (M) e outro com superfície de titânio modificado com flúor (F), após 4 semanas de indução do diabetes. Os animais foram submetidos à eutanásia 2, 4 e 6 semanas após a colocação do implante (n = 20 animais/grupo). A osseointegração foi avaliada pelo teste de torque de remoção do implante e pela análise histométrica dos cortes histológicos não descalcificados: 1) Contato osso-implante (%BIC); 2) Área de tecido ósseo entre as roscas do implante (%BBT). Os implantes com superfície F apresentaram maior torque de remoção do que os implantes com superfície M em todos os grupos. Não houve diferença no %BIC entre os grupos independente da superfície utilizada. A superfície F mostrou tendência a apresentar maiores valores de %BBT para os 3 períodos de avaliação no grupo D. As superfícies de implantes modificadas com flúor não influenciaram nos dados de %BIC e %BBT. Entretanto, essas superfícies aumentaram o travamento dos implantes no tecido ósseo. A hiperglicemia foi associada a menores torques de remoção dos implantes independentemente do tipo de superfície de implante utilizada.

Evaluation of hydrophilic surface osseointegration in low-density bone: Preclinical study in rabbits

Abstract The aim of this study was to evaluate the osseointegration of a hydrophilic surface (blasting + acid etching + immersion in isotonic solution) in comparison with that of a control surface (blasting + acid etching) using an experimental model of low-density bone. To perform the study, 24 rabbits were submitted to the installation of 4 implants in the iliac bone bilaterally: 2 implants with a control surface and 2 implants with a hydrophilic surface. The rabbits were euthanized at 2, 4, and 8 weeks after implant installation. After euthanasia, one implant from each surface was used to perform the removal torque analysis, and the other implant was used for the execution of non-decalcified histological sections and evaluation of the bone implant contact (% BIC) as well as the fraction of bone tissue area between the implant threads (% BBT). The implants with a hydrophilic surface presented higher %BIC (42.92 ± 2.85% vs. 29.49 ± 10.27%) and % BBT (34.32 ± 8.52% vs. 23.20 ± 6.75%) (p < 0.05) in the 2-week period. Furthermore, the hydrophilic surface presented higher removal torque in the 8-week period (76.13 ± 16.00 Ncm2 vs. 52.77 ± 13.49 Ncm2) (p<0.05). Implants with a hydrophilic surface exhibited acceleration in the process of osseointegration, culminating in greater secondary stability in low-density bone than in implants with a control surface.

Resumo O objetivo deste estudo foi avaliar a osseointegração de uma superfície hidrofílica (jateamento + ataque ácido + imersão em solução isotônica) em comparação com uma superfície controle (jateamento + ataque ácido) usando um modelo experimental de osso de baixa densidade. Para realizar o estudo, 24 coelhos foram submetidos a instalação de 4 implantes bilateralmente no osso ilíaco: 2 implantes com superfície controle e 2 implantes com superfície hidrofílica. Os coelhos foram eutanasiados com 2, 4 e 8 semanas após a instalação dos implantes. Após a eutanásia, um implante de cada superfície foi usado para avaliar o torque de remoção, e o outro implante foi utilizado para execução de cortes histológicos não descalcificados e avaliação de contato osso implante (% BIC) bem como a fração da área tecido ósseo entre as roscas do implante (% BBT). Os implantes com superfície hidrofílica apresentaram maior %BIC (42.92 ± 2.85% vs. 29.49 ± 10.27%) e % BBT (34.32 ± 8.52% vs. 23.20 ± 6.75%) (p < 0.05) no período de 2 semanas. Além disso, a superfície hidrofílica apresentou maior torque de remoção no período de 8 semana (76.13 ± 16.00 Ncm2 vs. 52.77 ± 13.49 Ncm2) (p<0.05). Implantes com a superfície hidrofílica apresentaram aceleração no processo de osseointregração, culminando em melhor estabilidade secundária no osso de baixa densidade em relação a implantes com superfície controle.

RADIOGRAPHIC EVALUATION OF THE SUCCESS OF IMPLANT-SUPPORTED TOTAL PROSTHESES ON CONICAL EXTERNAL HEXAGON IMPLANTS AND 6-MONTH FOLLOW-UP AFTER INSTALLATION OF THE PROSTHESES

The development of dental implants has revolutionized the rehabilitation possibilities for partially or totally edentulous patients. The long-term success of the dental implant depends on osseointegration and this is achieved by the combination of two essential stabilities: primary and secondary. Implant-supported prostheses are a great evolution for these treatments, positively interfering in the quality of life of the population, as they generate function and aesthetics for the patient. Thus, the present study aimed to radiographically evaluate complete dentures supported by an external hexagon conical implant in the anterior region of the mandible. More specifically, to evaluate the feasibility of using these implants in cortical bone of the mandible, to verify the success rate regarding the significance of peri-implant bone loss and to compare peri-implant bone loss between patients.

Osseointegration and Success in Hip Arthroplasty Acetabular Revision Using Structured Homologous Graft Average 9.6 Years Follow-up / Osteointegração e sucesso em revisão acetabular de artroplastia total de quadril com enxerto estrutural homólogo seguimento médio de 9, 6 anos

Abstract Objective To evaluate the clinical and radiographic results and survival of the acetabular revision surgery of total hip arthroplasty with cemented implant without the use of reinforcement ring, associated with structural homologous bone grafting. Methods A total of 40 patients (44 hips) operated from 1995 to 2015 were retrospectively analyzed. Radiographs were evaluated according to the classification of the acetabular bone defect, graft shape, and the presence of osseointegration. Cases were considered as failures when the migration of the implant was > 5 mm in any direction, and/or the progression of radiolucency lines around the acetabular component were > 2 mm. We verified the association of radiographic findings with cases of failure using statistical tests and analyzed survival using the Kaplan-Meier curve. Results Of the 44 hips, 45.5% of the acetabular defects were Paprosky type 3A and 50% were 3B. In 65% of the hips, the graft configuration was classified as Prieto type 1 and in 31% as type 2. No radiographic evidence of osseointegration was observed in 13.6% of the cases. We observed 9 (20.5%) reconstruction failures. A correlation was observed between reconstruction failure and the absence of radiographic signs of graft osseointegration. Conclusion We observed good clinic and radiographic results, with survival of 79.54% in a mean follow-up of 9.65 years. Also, there was an association between absence of radiographic signs of osseointegration of the structural graft and failure in this series of patients with large bone defects. The failures did not correlate with the severity of the acetabular bone defect, thickness, or graft configuration.

Resumo Objetivo Avaliarosresultadosclínicos, radiográficos e a sobrevida da cirurgia de revisão acetabular de artroplastia total de quadril com implante cimentado sem uso de anel de reforço, associado à enxertia óssea homóloga estrutural. Métodos Um total de 40 pacientes (44 quadris) operados de 1995 a 2015 foram analisados retrospectivamente. As radiografias foram avaliadas de acordo com a classificação do defeito ósseo acetabular, o formato do enxerto e à presença de osteointegração. Foram considerados casos de insucesso a migração do implante > 5 mm em qualquer direção e/ou a progressão de linhas de radioluscência em torno do componente acetabular > 2mm. Verificamos a associação dos achados radiográficos com os casos de falha utilizando testes estatísticos e analisamos a sobrevida utilizando a curva de Kaplan-Meier. Resultados Dos 44 quadris, 45,5% dos defeitos acetabulares eram Paprosky tipo 3A e 50%, 3B. Em 65% dos quadris, a configuração do enxerto foi classificada como tipo 1 de Prieto e em 31% como tipo 2. Não foi observada evidência radiográfica de osteointe-gração em 13,6% dos casos. Observamos 9 (20,5%) falhas de reconstrução. Foi observada correlação entre falha da reconstrução com a ausência de sinais radiográficos de osteointegração do enxerto. Conclusão Observamos bons resultados clínicos e radiográficos, com sobrevida de 79,54% em seguimento médio de 9,65 anos. Também houve associação entre ausência de sinais radiográficos de osteointegração do enxerto estrutural e falha nesta série de pacientes com grandes defeitos ósseos. As falhas não se correlacionaram com a severidade do defeito ósseo acetabular, espessura ou configuraçãodoenxerto.

Osseointegration of implants with superhydrophilic surfaces in rats with high serum levels of nicotine

Abstract This study aimed to evaluate the effect of nicotine administration on the osseointegration of a superhydrophilic implants surface on rat tibiae. Thirty-two rats were used and divided into 2 groups according to the administration or not of nicotine: HH - Installation of implants with superhydrophilic surfaces in healthy animals; and HN - Installation of implants with superhydrophilic surfaces in animals subjected to nicotine administration. The animals were euthanized 15 and 45 days after implant placement (n = 8). Osseointegration was assessed by means of biomechanical analyses (removal torque), microcomputed tomography (volume of bone around the implants- %BV/TV), and histomorphometry (bone-implant contact -%BIC and the bone area between implant threads -%BBT). The animals subject to the nicotine administration presented lower removal torque than the control animals at the 45-day period (21.88 ± 2.80 Ncm vs. 17.88 ± 2.10 Ncm). The implants placed in the control rats presented higher %BIC (54.26 ± 6.59% vs. 39.25 ± 4.46%) and %BBT (50.57 ± 5.28% vs. 32.25 ± 5.24%) than the implants placed in nicotine animals at 15-day period. The nicotine administration reduces the osseointegration at 15 days, however, the superhydrophilic surface equalized the osseointegration in nicotine-exposed animals compared with healthy animals after 45 days of implant placement.

Resumo O objetivo deste estudo foi avaliar o efeito da administração de nicotina na osseointegração de implantes com superfície modificada por jateamento de oxidos e ataque ácido instalados em tíbia de ratos. Foram utilizados 32 ratos que foram divididos em 2 grupos de acordo com a administração ou não de nicotina: HH - Instalação de implantes com superfícies superhidrofílicas em animais sadios; e HN - Instalação de implantes com superfícies superhidrofílicas em animais submetidos à administração de nicotina. Os animais foram eutanasiados 15 e 45 dias após a colocação do implante (n = 8). A osseointegração foi avaliada por meio de análises biomecânicas (torque de remoção), microtomografia (volume de osso ao redor dos implantes - %BV/TV) e histomorfometrica (contato osso-implante -%BIC e área óssea entre roscas do implante -%BBT). Os animais submetidos à administração de nicotina apresentaram menor torque de remoção do que os animais controle no período de 45 dias (21,88 ± 2,80 Ncm vs. 17,88 ± 2,10 Ncm). Os implantes colocados nos ratos controle apresentaram maiores %BIC (54,26 ± 6,59% vs. 39,25 ± 4,46%) e %BBT (50,57 ± 5,28% vs. 32,25 ± 5,24%) do que os implantes colocados nos animais submetidos a administração de nicotina no período de 15 dias. A administração de nicotina prejudicou a osseointegração no período de 15 dias. Entretanto, a superfície superhidrofílica equalizou a osseointegração em animais expostos à nicotina em comparação com animais saudáveis após 45 dias da colocação do implante.

Niveles bajos de vitamina D y su efecto en la oseointegración: revisión sistemática / Low levels of vitamin D and effect on osseointegration: a systematic review

Introducción: la vitamina D es una hormona que se sintetiza por células de la piel mediante la luz ultravioleta (UV) y se obtiene a través de la dieta. La relación que se establece entre la deficiencia de vitamina D y el fracaso en injertos óseos o implantes se basa en las alteraciones inmunológicas e inflamatorias debido al vínculo que existe con la inmunidad innata y adaptativa. Objetivo: identificar los factores que se presentan en el periodonto cuando existen niveles bajos de vitamina D y se realizan tratamientos periodontales como injertos óseos e implantes. Material y métodos: se realizó la búsqueda primaria de artículos en bases de datos PubMed y Google Académico (en español e inglés), de acuerdo con las palabras claves: deficiencia, vitamina D, implantología y oseointegración. Resultados: la vitamina D afecta y predispone al rechazo de injertos, ausencia de oseointegración en implantes debido a la inmunomodulación. Conclusión: el éxito del tratamiento se vuelve predecible cuando se encuentran niveles óptimos de vitamina D en conjunto con técnicas de abordaje quirúrgico correctas que permitan generar una integración ideal de los tejidos periodontales (AU)

Introduction: vitamin D is a hormone that is synthesized by skin cells using UV light and consumed through the diet. The relationship established between vitamin D deficiency and the failure of bone grafts or implants is based on immunological and inflammatory alterations due to the intimate link with innate and adaptive immunity. Objective: to identify the factors that occur in the periodontium when there are low levels of vitamin D and periodontal treatments such as bone grafts and implants are performed. Material and methods: a search for articles was carried out in PubMed and Google Scholar (Spanish and English). Results: vitamin D affects and predisposes to graft rejection, absence of osseointegration in implants due to immunomodulation. Conclusion: the success of the treatment becomes predictable when optimal levels of vitamin D are found together with the correct surgical approach techniques that allow the generation of an ideal integration of the periodontal tissues.(AU)

Advances in surface treatment of dental implants: a literature review

Amplamente utilizados para substituir dentes perdidos, os implantes dentários nos últimos anos vêm apresentando tecnologias como superfícies com micro e nanotopografia e ajustes nas composições químicas, dentre outros, para melhorar a osseointegração e reduzir o prazo de tratamento, permitindo, assim, carga funcional imediata ou precoce em pacientes com densidade óssea reduzida. Vários métodos são aplicados com intuito de modificar a superfície do implante, como jateamento com areia, corrosão ácida, oxidação anódica, tratamento com flúor, usinagem, pulverização de plasma de titânio e revestimento de fosfato de cálcio; esses métodos podem aumentar notavelmente a área de superfície quando operada a técnica adequadada de modificação, quer por procedimento de adição ou subtração. Tais modificações promovem superfícies rugosas, as quais aumentam a porcentagem de contato osso-implante (BIC) durante o processo de cicatrização óssea inicial. Os principais benefícios da modificação da superfície são melhorar a molhabilidade (hidrofilicidade), adesão e fixação de células a implantes e proliferação celular. Dentre os tratamentos de superfície de implantes dentários destaca-se o jateamento de areia com granulação grossa e ataque-ácido com HCL/H2SO4 (SLA) em altas temperaturas, o revestimento de superfície do implante com hidroxiapatita, oxidação anódica e o duplo ataque ácido. O objetivo deste trabalho é realizar uma revisão de literatura discutindo a importância e eficácia desses métodos para a osseointegração e, por conseguinte, para a redução do período de tratamento.

Widely used to replace lost teeth, dental implants have been presenting technologies such as surfaces with micro and nano topography and adjustments in chemical compositions, among others, to improve osseointegration and reduce treatment time, thus allowing immediate or early functional load in patients with reduced bone density. Several methods are applied to modify the implant surface, such as sandblasting, acid corrosion, anodic oxidation, fluoride treatment, machining, titanium plasma spraying, and calcium phosphate coating; these methods can notably increase the surface area when the appropriate modification technique is operated, either by the addition or subtraction procedure. Such modifications promote rough surfaces, which increase the percentage of bone-implant contact (BIC) during the initial bone healing process. The main benefits of surface modification are to improve wettability (hydrophilicity), adhesion and attachment of cells to implants, and cell proliferation. Among the surface treatments for dental implants, sandblasting with large grit and acid-etching with HCL/H2SO4 (SLA) stands out at high temperatures. The surface coating of the implant with hydroxyapatite, anodic oxidation, and double acid-etching. This work aims to conduct a literature review discussing the importance and effectiveness of these methods for osseointegration and, therefore, for reducing the treatment period.

Estimation du succès fonctionnel et esthétique des implants dentaires / Estimation of the functional and aesthetic success of dental implants

Les implants dentaires ont révolutionné la réhabilitation orale partielle et totale. Des taux de succès allant de 80% à 100% à travers le monde (Buser, 2019) Le succès du traitement implantaire doit répondre à deux objectifs pour être validé. Le premier est le concept d'ostéointégration et le second sur l'aspect esthétique des tissus autour de l'implant. notre objectif était d'estimer le taux de succès fonctionnel, en se basant sur les critères de succès d'Albrektsson et coll (Albrektsson,1986 ) ainsi qu'une évaluation esthétique par le PES (Belser, 2009) sur un échantillon de 50 patients dont 107 implants posés au secteur antérieur où le profil esthétique joue un rôle important. Le taux de succès fonctionnel était estimé à 94% voire 03 échecs sur 50 patients, avec une différence significative entre le succès implantaire et le degré d'hygiène bucco dentaire (p=0.00001) ; ainsi que le degré d'inflammation (p=0.0000) et la maladie parodontale p=0.04. On a eu 100% de succès chez les patients à qui on a procédé à un enfouissement total de l'implant. Enfin le succès esthétique était bon chez 42(84%) patients pour un score de 8 à10, et favorable chez les 5(10 %) restants pour un score de 5 à 7

Dental implants have revolutionized partial and total oral rehabilitation. Success rates ranging from 80% to 100% worldwide (Buser, 2019) The success of the implant treatment must meet two objectives to be validated. The first is the concept of osseointegration and the second on the aesthetic appearance of the tissues around the implant. Our objective was to estimate the functional success rate, based on the success criteria of Albrektsson et al (Albrektsson, 1986) as well as an aesthetic evaluation by the PES (Belser, 2009) on a sample of 50 patients including 107 implants placed in the anterior sector where the aesthetic profile plays an important role. The functional success rate was estimated at 94% or even 03 failures out of 50 patients, with a significant difference between the implant success and the degree of oral hygiene (p=0.00001); as well as the degree of inflammation (p=0.00001) and finally the periodontal disease (p=0.04). We have had 100% success in patients who have undergone total burying of the implant Finally, aesthetic success was good in 42 (84%) patients for a score of 8 to 10, and favorable in the remaining 5 (10%) for a score of 5 to 7.

Clinical application of β-tricalcium phosphate artificial bone material for alveolar cleft repair / 口腔疾病防治

Objective@# To investigate the osteogenic effect of β-tricalcium phosphate (β-TCP) and bone morphogenetic protein-2 (BMP-2) in the repair of the alveolar cleft.@*Methods @# Fifty-nine patients with unilateral alveolar cleft who visited Capital Medical University School of Stomatology from January 2016 to May 2021 were included. They were divided into three groups according to the different bone repair materials: autologous bone, β-TCP and BMP-2 +β-TCP. The preoperative and postoperative CBCT data of the patients were imported into Mimics 21.0 software. The preoperative volume of the bone defect and the new volume of bone formation were calculated by the three-dimensional reconstruction method. The osteogenesis rate was calculated to evaluate the osteogenesis effect@*Results@#The wounds in the three groups healed well after the operation, without implant material discharge, infection, dehiscence, rejection or other symptoms. Twelve months after the operation, CBCT scanning and three⁃dimensional reconstruction images of the three groups of patients showed the formation of new bone bridges in the alveolar ridge fissure area. The image density of the new bone tissue was not significantly different from that of normal bone tissue, and the continuity of the maxilla was re⁃ stored to varying degrees. The bone rate of autogenous bone was 65.00% ± 16.66%, β⁃ TCP group and BMP⁃2+ β⁃ The bone composition rate of TCP was 69.82% ± 17.60%, 71.35% ± 17.51%, respectively, and there was no significant dif⁃ ference compared with the autogenous bone group (P = 0.382, P = 0.244). The β⁃TCP and BMP⁃2+ β⁃TCP groups had no significant differences in bone rate (P = 0.789). @*Conclusion@#β⁃TCP could be used to replace autologous bone for alveolar cleft repair. The addition of BMP⁃2 to β⁃TCP did not significantly improve the osteogenesis rate.

Research progress on surface modification of titanium implants by strontium ions / 口腔疾病防治

@#Traditional titanium implants do not completely meet the clinical requirements because they are bioinert. The surface of titanium implants, modified by strontium ions, can enhance osseointegration and reduce peri-implantitis. In this paper, the biological properties of titanium implant surfaces modified by strontium ions were reviewed. Strontium ions can be coated on the implant surface by hydrothermal treatment, electrochemical deposition, phosphate chemical conversion, flame-spraying, supramolecular self-assembly, magnetron sputtering, laser deposition and alkali etching. Implant surfaces modified by strontium ions can not only promote osteogenesis and early osseointegration but also inhibit bacterial growth and reduce postoperative infections. Even better osseointegration and antibacterial effects can be achieved when strontium ions are incorporated with other elements, such as silver, zinc, gallium, and calcium. However, most of the studies on the use of strontium ion-modified titanium implants are animal experiments and in vitro experiments, and the observation time is short compared with the actual service life of the implants. Thus, the conclusions obtained may be different from the actual clinical application, and the long-term effects need to be studied. In addition, the osteogenic effects of various modification methods also need to be compared. Future research can focus on the following points: ① to find efficient modification methods that can be widely used in the clinic; ②to study how to control the concentration of strontium ions near the implant to exert their biological function and reduce their toxic side effects; and ③ to conduct long-term follow-up clinical trials to observe their osteogenic and antibacterial effects.

Re-osseointegration of peri-implantitis affected and failed implants / 口腔医学

@#Peri-implantitis and implant failure are common issues in the implant dentistry. The contaminated implant can be treated with mechanical, chemical and assisted methods for the formation of re-osseointegration. Re-osseointegration is achievable with valid bone regeneration strategies. The survival rate of implant into the site of previous failure is lower than that of the initial implant. For the hopeless and failed implant, it is necessary to remove the implant with corresponding technique.