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1.
Acta Cir Bras ; 35(11): e351101, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33331451

RESUMO

PURPOSE: To evaluate bone formation through ultrastructural analysis around titanium implants in severe alloxanic uncontrolled diabetic rats, and controlled with insulin, in comparison with nondiabetic rats. METHODS: Thirty-six male Wistar rats, weighing between 200 and 300 g, divided into three experimental groups: normal control group (G1), a diabetic group without treatment (G2), and a diabetic group treated with insulin (G3). The animals received titanium implants in the right femur, and osseointegration was evaluated at 7, 14, and 21 days after surgery, through ultrastructural analysis using scanning electron microscopy. RESULTS: The ultrastructural analysis showed a dense bone structure in the G1, few empty spaces and a small number of proteoglycans; G2 presented bone matrix with a loose aspect, irregular arrangement, thin trabeculae, empty spaces and a large number of proteoglycans; G3 obtained similar results to G1, however with a higher number of proteoglycans. CONCLUSION: Severe diabetes caused ultrastructural changes in bone formation, and insulin therapy allowed an improvement in osseointegration, but it was not possible to reach the results obtained in the control group.


Assuntos
Implantes Dentários , Diabetes Mellitus Experimental , Animais , Insulina , Masculino , Osseointegração , Osteogênese , Ratos , Ratos Wistar , Tíbia , Titânio
2.
Swiss Dent J ; 130(11): 887-892, 2020 11 09.
Artigo em Alemão | MEDLINE | ID: mdl-33161691

RESUMO

The aim of this case report was to introduce the clinical use of a prosthetic soft tissue level implant and a completely digitized workflow for the production of an individualized suprastructure fixated on prosthetic implants for orthodontic anchorage rein­forcement. A prosthetic soft tissue level implant was placed in the palatal region for orthodontic anchorage reinforcement. Based on an intraoral optical scan taken after implant osseointegration, the orthodontic suprastructure was manufactured entirely by means of computer­aided design and manufacturing (CAD/CAM). The individualized suprastructure was subsequently loaded in direct manner. The prosthetic implant was then re­moved in a non­invasive manner, similar to palatal implants.The analysis included clinical and laboratory fabrication steps. The placement of prosthetic implant in the palatal region proved to be a painless, easy and fast procedure, and provided absolute anchorage during the entire intended orthodontic treatment. Its non­invasive removal did not cause any adverse patient reactions. The digitally constructed suprastructure did not require any chairside adaptation at delivery and was suc­cessfully used for the intended orthodontic treatment.The reported case presents the successful placement, loading and removal of a prosthetic soft tissue level implant for ortho­dontic anchorage use in the palatal region. The described digital and model­free workflow provides a feasible and streamlined treatment modality for the fabrication of individualized ortho­dontic suprastructures by means of CAD/CAM for the use as or­thodontic anchorage reinforcement. This proof of principle should be substantiated with further larger­scaled investigations.


Assuntos
Implantes Dentários , Desenho Assistido por Computador , Humanos , Osseointegração , Fluxo de Trabalho
3.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 55(11): 908-914, 2020 Nov 09.
Artigo em Chinês | MEDLINE | ID: mdl-33171567

RESUMO

Objective: To evaluate the effects of fluorinated porcine hydroxyapatite (FPHA) on guided bone regeneration of peri-implant buccal bone defects in canine mandible. Methods: Six male beagle dogs were randomly divided into two groups with different time points (4 weeks and 12 weeks after implants placement), with 3 dogs in each group. Bilateral mandibular second premolars, first molars, and second molars in each dog were extracted. The wounds were allowed to heal for 12 weeks. For each dog, four implant beds were prepared in each side and standardized peri-implant buccal bone defect was created at each implant site. After implants placement, the defect sites were randomly allocated in a split-mouth design to blank control group, deproteinized bovine bone mineral (DBBM), the porcine hydroxyapatite (PHA), FPHA and covered with collagen membranes. The animals were sacrificed 4 or 12 weeks after the surgery. Biopsies of the implant sites were obtained for micro-CT evaluation [bone volume fraction (BV/TV) and bone trabecular separation degree (Tb.Sp)] and histological analysis. Results: Micro-CT results showed that 4 weeks after implants placement, PHA, FPHA and DBBM successfully maintained the contour of alveolar ridge at the buccal aspect of the implants, while the contour of alveolar ridge collapsed in the blank control group. BV/TV in the FPHA group [(24.77±2.20) %] was significantly higher than that in the PHA group [(16.89±1.70)%] and DBBM group [(15.68±3.15)%] (P<0.05). Tb.Sp in the FPHA group (0.70±0.07) was significantly lower than that in the DBBM group (1.03±0.19) (P<0.05). Twelve weeks after implants placement, the alveolar ridge contour of the grafted sites in PHA, FPHA and DBBM group remained stable. The alveolar ridge of the blank control group was still collapsed. There was no significant difference in BV/TV and Tb.Sp between PHA group, FPHA group and DBBM group. The histomorphological analysis showed that 4 weeks after implants placement, in the central area of the defect, the amount and maturity of new bone (NB) around the material particles in FPHA group was higher than that in PHA group and DBBM group. Osseointegration could be observed between the NB and implant surface in all the four groups. Twelve weeks after implants placement, the material particles were surrounded by a large number of mature NB in PHA, FPHA and DBBM group. Conclusions: The incorporation of fluoride ion into PHA could effectively promote the repair of peri-implant bone defects in the early stage of guided bone regeneration.


Assuntos
Substitutos Ósseos , Implantes Dentários , Animais , Regeneração Óssea , Bovinos , Implantação Dentária Endo-Óssea , Cães , Durapatita , Masculino , Mandíbula/cirurgia , Membranas Artificiais , Osseointegração , Suínos
4.
Int J Periodontics Restorative Dent ; 40(6): e211-e227, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33151185

RESUMO

For decades, the histologic evidence about osseointegration and the bone-implant interface has been discussed in the literature. In this review, the effectiveness of dental implants retrieved for different causes was evaluated. A literature search was performed in databases for papers about implants retrieved from humans published by the Implant Retrieval Center of the University of Chieti-Pescara, Italy. Sixty-eight articles were selected into categories based on topics. The data indicated high level of bone-to-implant contact, lamellar bone close to the surface, roughness related to an increased bone response, organized and remodeled bone after loading, and peri-implant interfaces subjected to a continuous dynamic function.


Assuntos
Implantes Dentários , Osso e Ossos , Implantação Dentária Endo-Óssea , Humanos , Itália , Osseointegração , Estudos Retrospectivos , Propriedades de Superfície
5.
Artigo em Inglês | MEDLINE | ID: mdl-33151200

RESUMO

This study evaluated the effect of the antimicrobial photodynamic therapy (aPDT) on the osseointegration of immediate implants in a healing situation with greater challenges. The mandibular premolars of eight beagle dogs were submitted to ligature-induced periodontal disease. After 3 months, teeth were extracted and immediate implants were placed in the sockets previously decontaminated by mechanical debridement (MD) or MD+aPDT. Following 12 weeks, the dogs were euthanized and the specimens were analyzed. Histologic and histomorphometric analyses demonstrated significantly better results for the immediate implants decontaminated by debridement associated with aPDT. The sites treated with MD+aPDT led to osseointegration of the immediate implants without evidence of inflammation; conversely, evidence of peri-implantitis was observed where aPDT was not used.


Assuntos
Anti-Infecciosos , Implantes Dentários , Periodontite , Fotoquimioterapia , Animais , Cães , Osseointegração
6.
Int J Nanomedicine ; 15: 7185-7198, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33061375

RESUMO

Background: Next generation of coating materials on the surface of implants is designed with a paradigm shift from an inert material to an osteoimmunomodulatory material. Regulating immune response to biomedical implants through influencing the polarization of macrophage has been proven to be an effective strategy. Methods: Through anodization and hydrothermal treatment, magnesium ion incorporated TiO2 nanotube array (MgN) coating was fabricated on the surface of titanium and it is hypothesized that it has osteoimmunomodulatory properties. To verify this assumption, systematic studies were carried out by in vitro and in vivo experiments. Results: Mg ion release behavior results showed that MgN coating was successfully fabricated on the surface of titanium using anodization and hydrothermal technology. Scanning electron microscopy (SEM) images showed the morphology of the MgN coating on the titanium. The expression of inflammation-related genes (IL-6, IL-1ß, TNF-α) was downregulated in MgN group compared with TiO2 nanotube (NT) and blank Ti groups, but anti-inflammatory genes (IL-10 and IL-1ra) were remarkably upregulated in the MgN group. The in vitro and in vivo results demonstrated that MgN coating influenced macrophage polarization toward the M2 phenotype compared with NT and blank-Ti groups, which enhanced osteogenic differentiation of rat bone mesenchymal stem cells rBMSCs in conditioned media (CM) generated by macrophages. Conclusion: MgN coating on the titanium endowed the surface with immune-regulatory features and exerted an advantageous effect on osteogenesis, thereby providing excellent strategies for the surface modification of biomedical implants.


Assuntos
Inflamação/patologia , Macrófagos/patologia , Magnésio/farmacologia , Nanoestruturas/química , Osseointegração/efeitos dos fármacos , Titânio/farmacologia , Animais , Biomarcadores/metabolismo , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Forma Celular/efeitos dos fármacos , Meios de Cultivo Condicionados/farmacologia , Macrófagos/efeitos dos fármacos , Camundongos , Osteogênese/efeitos dos fármacos , Células RAW 264.7 , Ratos Wistar , Propriedades de Superfície
7.
Hua Xi Kou Qiang Yi Xue Za Zhi ; 38(5): 566-570, 2020 Oct 01.
Artigo em Chinês | MEDLINE | ID: mdl-33085243

RESUMO

The application of cold atmospheric plasma to titanium surface modification has recently become a research focus in the area of material modification. Previous studies found that cold atmospheric plasma can affect the colonization of bacteria and biological behaviors of osteoblasts by changing the surface characteristics of titanium in vitro. In vivo studies reveal that cold atmospheric plasma can promote the process of osseointegration of titanium implants. This review focuses on research on the effects of the surface modification of titanium implants with cold atmospheric plasma on osseointegration.


Assuntos
Implantes Dentários , Gases em Plasma , Osseointegração , Osteoblastos , Titânio
8.
PLoS One ; 15(9): e0237463, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32970688

RESUMO

Titanium is essentially absent from biological systems yet reliably integrates into bone. To achieve osseointegration, titanium must activate biological processes without entering cells, defining it as a bio-activating material. Nanostructuring bulk titanium reduces grain size, increases strength, and improves other quantifiable physical properties, including cytocompatibility. The biological processes activated by increasing grain boundary availability were detected with total RNA-sequencing in mouse pre-osteoblasts grown for 72 hours on nanometrically smooth substrates of either coarse grain or nanostructured ultrafine grain titanium. The average grain boundary length under cells on the conventional coarse grain substrates is 273.0 µm, compared to 70,881.5 µm for cells adhered to the nanostructured ultrafine grain substrates; a 260-fold difference. Cells on both substrates exhibit similar expression profiles for genes whose products are critical for mechanosensation and transduction of cues that trigger osteoconduction. Biological process Gene Ontology term enrichment analysis of differentially expressed genes reveals that cell cycle, chromatin modification, telomere maintenance, and RNA metabolism processes are upregulated on ultrafine grain titanium. Processes related to immune response, including apoptosis, are downregulated. Tumor-suppressor genes are upregulated while tumor-promoting genes are downregulated. Upregulation of genes involved in chromatin remodeling and downregulation of genes under the control of the peripheral circadian clock implicate both processes in the transduction of mechanosensory information. Non-coding RNAs may also play a role in the response. Merging transcriptomics with well-established mechanobiology principles generates a unified model to explain the bio-activating properties of titanium. The modulation of processes is accomplished through chromatin remodeling in which the nucleus responds like a rheostat to grain boundary concentration. This convergence of biological and materials science reveals a pathway toward understanding the biotic-abiotic interface and will inform the development of effective bio-activating and bio-inactivating materials.


Assuntos
Materiais Biocompatíveis/química , Regeneração Óssea , Nanoestruturas/química , Osteoblastos/citologia , Titânio/química , Animais , Linhagem Celular , Teste de Materiais , Mecanotransdução Celular , Camundongos , Osseointegração , Osteoblastos/metabolismo , Análise de Sequência de RNA , Propriedades de Superfície , Transcriptoma
9.
J Am Acad Orthop Surg ; 28(22): e988-e994, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32868701

RESUMO

Biomechanical function, specifically implantation technique and immediate surgical fixation, of orthopaedic implants is the primary consideration during the development of orthopaedic implants. Biologic and material characteristics are additional factors to include in the design process because of the direct impact on short- and long-term implant performance. The body's initial interaction with implant materials can affect protein- and cell-based function, thereby either promoting or impeding osseointegration. An understanding and inclusion of the biologic response, material surface morphology, and material surface chemistry in implant design is crucial because these factors ultimately determine implant function and patient outcomes. Highlighting the biologic- and material-related advantages and inadequacies of current and potential implant materials as well as applications may guide further research and development of implant materials and designs.


Assuntos
Interface Osso-Implante , Teste de Materiais , Osseointegração , Próteses e Implantes , Desenho de Prótese , Coluna Vertebral/cirurgia , Artroplastia , Fenômenos Biomecânicos , Humanos , Propriedades de Superfície
10.
Int J Oral Maxillofac Implants ; 35(5): 955-964, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32991646

RESUMO

PURPOSE: To assess the effects of drilling protocol and bone density on the primary stability of implants with different macrogeometries currently used in clinical practice. MATERIALS AND METHODS: This in vitro study compared the designs of two implants: Biomimetic Coral, a parallel-walled design with a slightly expanded platform and a symmetric progressive thread; and tapered Biomimetic Ocean, a reverse coronal design with an asymmetric progressive thread. The drilling alternatives were grouped according to the standard sequence for each type, plus an extra drill for hard bone, using laminated blocks with different densities. The insertion torques and implant stability quotient (ISQ) values were obtained with a surgical motor and resonance frequency analysis (RFA), respectively. RESULTS: A total of 120 implants (n = 60 Ocean, n = 60 Coral) were inserted and analyzed without registering any deviation from the protocol. The Coral implants presented significantly higher insertion torque values (P < .001), consistent with optimal osseointegration, for the standard drill, the dense bone drill, and the screw tap. Insertion torque was not affected by the drilling sequence (P = .124), and the effect of interaction between the implant design and drilling sequence was not significant (P = .940). Statistically significant differences were observed in insertion torque values due to the type of implant but not due to the bone density. The ISQ values were significantly higher (P < .001) for the Coral design. In both the Ocean and Coral implants, ISQ was affected by the drilling sequence (P < .001), as the ISQ values were higher in the standard sequence with screw tap drilling than in the standard sequence with a dense bone drill. A positive correlation was found between the insertion torque and ISQ values. CONCLUSION: The macrogeometry of the implant and the drilling sequence have a significant effect on both primary stability values (ISQ and insertion torque). The values for the Coral implant were statistically higher but still within the range required to achieve proper osseointegration. These results support the drilling sequence recommended by the manufacturer for this type of implant, using larger-diameter drills and screw taps in sites with harder or cortical bone.


Assuntos
Implantação Dentária Endo-Óssea , Implantes Dentários , Densidade Óssea , Osseointegração , Análise de Frequência de Ressonância
11.
Int J Oral Maxillofac Implants ; 35(5): 1013-1020, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32991653

RESUMO

PURPOSE: The hydrophilic implant surface (INICELL) is a chemical alteration of a sandblasted and thermally acid-etched surface that should lead to long-term osseointegration. This study investigated 3-year results after early loading of implants with a hydrophilic, moderately rough surface in occlusal contact. MATERIALS AND METHODS: This prospective case series study was conducted in subjects with partially edentulous mandibles. Implants were placed on day 21 and loaded with a provisional reconstruction after at least 21 days of healing (baseline, day 0) if their implant stability quotient (ISQ) was ≥ 70 (mean of three measurements) and were replaced by definitive porcelain-fused-to-metal prostheses at the 6-month follow-up visit. Follow-up examinations were planned 1, 3, 6, 12, and 36 months after baseline. RESULTS: A total of 20 implants were placed in 15 patients (mean age: 51 years, range: 32 to 67 years). After 36 months, all implants were osseointegrated, and no suppuration was recorded. Small changes of bone level were observed between 3 months and 36 months. At 36 months, the median values of the 20 implants were 0.25 (range: 0 to 0.5, SD: 0.17), 0.25 (range: 0 to 1, SD: 0.27), and 4 (range: 2 to 7.25, SD: 1.17) for the mean modified Plaque Index (mPI), mean modified Sulcus Bleeding Index (mSBI), and mean probing pocket depth, respectively. The pairwise analysis between 3 and 36 months showed an improvement in the mean mPI (P = .0126) and mean mSBI (P = .0059). After 36 months, all patients (n = 15) were fully satisfied with a mean of 9.43 (range: 8 to 10, SD: 0.678) at the visual analog scale. CONCLUSION: Early functional loading of implants with a hydrophilic, moderately rough outer surface in occlusal contact 21 days after healing appears to be a safe and feasible treatment option when placed in the posterior mandible of partially edentulous patients.


Assuntos
Implantes Dentários , Titânio , Adulto , Idoso , Humanos , Mandíbula , Pessoa de Meia-Idade , Osseointegração , Estudos Prospectivos
12.
Braz Dent J ; 31(4): 368-373, 2020 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-32901711

RESUMO

The aim of this study was to clinically and radiographically compare extra short and standards implants. Forty-two implants were installed in 10 selected patients. They received prosthetic loading only after the conventional waiting time for osseointegration and the prostheses were made ferulized. Radiographic shots were performed to evaluate vertical and horizontal bone losses at times T1 (prosthetic installation), T2 (6 months follow-up) and T3 (12 months follow-up). Biological parameters such as bone level around the implants (CBL) were evaluated, CBL alteration (CBLC), total crown length (TCL) and implant/crown ratio (ICR) were digitally calculated. All implants included in the study were submitted to the analysis of the implant stability quotient (ISQ) at the time of implant installation (T0) and at 12 months of prosthetic function (T3). Data were statistically tested. The ICR was higher in the test group than in the control group (p<0.0001). The CBL measurements at the beginning of the study were 0.21±0.19 mm and 0.32±0.38 mm and at 12 months 0.65±0.24 mm and 0.87±0.34 mm, respectively in the test and control groups. CBLCs and CBL were similar at all times (p>0.05). No correlation was found between CBLC and ICR parameters, as well as between ISQ and implant length. We may conclude that standards and extra short implants can provide similar clinical results in prosthetic rehabilitation of the atrophic jaw over 12 months of follow-up.


Assuntos
Implantação Dentária Endo-Óssea , Implantes Dentários , Coroas , Planejamento de Prótese Dentária , Humanos , Osseointegração
13.
Int J Periodontics Restorative Dent ; 40(5): e189-e196, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32925993

RESUMO

Dental implants are intended to provide long-term reliable dental restorations. Limited data exist on the comparison between different implant surfaces. This study aims to clarify whether there is a difference between airborne particle- abraded and acid-etched (SLA implants) and only acid-etched surfaces (Osseotite) in healthy and periodontally compromised patients. After comprehensive evaluation of all 109 patients, including nonsurgical and surgical therapy for the treatment of periodontal disease, 109 implants were placed according to the manufacturer's guidelines. Each treatment site was examined radiographically 3 to 6 months after the final coronal restorations were placed. Patients were enrolled in the follow-up maintenance program, and radiologic evaluations were carried out at 5 and 10 years. Data recorded from 91 patients who completed the final 10-year follow-up were included in the analysis (SLA: n = 50; Osseotite: n = 41). At 10 years, the difference between bone-to-implant distances (DIBs) for SLA and Osseotite was significantly different (P = .001; 95% confidence interval: 0.55, 1.89 mm). Mean ± SD DIB for SLA implants was 2.1 ± 1.1 mm and 0.9 ± 2.1 mm for Osseotite implants. The overall survival rates of SLA and Osseotite implant surfaces were high during the observation period. History of previous periodontal disease plays an important role in the incidence of complications, regardless of the surface type.


Assuntos
Implantes Dentários , Implantação Dentária Endo-Óssea , Planejamento de Prótese Dentária , Falha de Restauração Dentária , Humanos , Osseointegração , Estudos Prospectivos , Propriedades de Superfície , Titânio
14.
Artigo em Inglês | MEDLINE | ID: mdl-32925994

RESUMO

The goal of the present study was to evaluate human histologic healing of dental implants with a unique triangular neck design that is narrower than the implant body. Four patients in need of full-mouth reconstruction were recruited and received several implants to support a full-arch prosthesis. In each patient, two additional customized reduced-diameter implants were placed, designated to be harvested after 6 months of submerged healing. The eight harvested implants were all placed in healed edentulous maxillary or mandibular ridges. These implants were Ø 3.5 × 8 mm in size, and the final osteotomy drill allowed for the creation of a gap up to 0.2 mm in size between the coronal aspect of the triangular implant neck and the surrounding bone. At the end of the healing period, the implants were retrieved with the surrounding bone. Microcomputed tomography (µCT) was performed before processing the biopsy samples for undecalcified histologic exampination. Bone-to-implant contact (BIC) was measured from the µCT data and from buccolingual/buccopalatal and mesiodistal central histologic sections. All implant gaps were filled by mature remodeled bone. The mean BICs of the BL/BP and MD sections were 64.45% ± 6.86% and 65.39% ± 10.44%, respectively, with no statistically significant difference. The mean 360-degree 3D BIC measured all over the implant surface was 68.58% ± 3.76%. The difference between the BIC measured on the µCT and on the histologic sections was not statistically significant. The positive histologic results of the study confirmed the efficacy of this uniquely designed dental implant.


Assuntos
Implantes Dentários , Osseointegração , Implantação Dentária Endo-Óssea , Planejamento de Prótese Dentária , Humanos , Mandíbula/cirurgia , Microtomografia por Raio-X
15.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 55(9): 691-695, 2020 Sep 09.
Artigo em Chinês | MEDLINE | ID: mdl-32878408

RESUMO

Zirconia material has a color closer to human natural teeth, and has excellent mechanical properties and good biocompatibility, therefore it is expected to become an ideal material for dental implants. In order to improve the osteogenic properties of zirconia implants, a variety of surface treatment techniques emerge in two categories: non-coating method and coating method. Different surface treatment technologies have their advantages and disadvantages. In this paper, the recent progress of zirconia surface treatment technology is reviewed.


Assuntos
Implantes Dentários , Osseointegração , Humanos , Propriedades de Superfície , Titânio , Zircônio
16.
Rev. cuba. estomatol ; 57(3): e2083, jul.-set. 2020. graf
Artigo em Inglês | LILACS, CUMED | ID: biblio-1126528

RESUMO

ABSTRACT Introduction: The placement of dental implants is based on the creation of optimal conditions in the remnant bone. In some cases, it is indispensable to perform bone regeneration procedures and use barrier membranes to create such optimal conditions capable of favorably supporting the dental implant. Objective: Describe alternatives of barrier membranes in cases of guided bone regeneration. Case report: A female 53-year-old patient presents with a gingival fistula attached to tooth 14. Root fracture is diagnosed and extraction is conducted. Next, alveolar biomodification is performed to carry out guided bone regeneration and placement of a fibrin-rich plasma membrane. When healing is complete dental implants will be placed. Conclusions: The use of barrier membrane alternatives has shown to be effective in cases of guided bone regeneration(AU)


RESUMEN Introducción: Para la colocación de implantes dentales se deben establecer condiciones óptimas de hueso remanente, por lo cual existen casos en los que se hace indispensable realizar procesos de regeneración ósea y la utilización de membranas de barrera para generar esas condiciones óptimas que puedan soportar favorablemente el implante dental. Objetivo: Describir alternativas de membranas de barrera en casos de regeneración ósea guiada. Reporte de caso: Paciente femenino de 53 años de edad que acude a consulta por presentar fístula en encía adherida de órgano dentario 14, se diagnostica como fractura radicular y se procede a la extracción, posteriormente se realiza una biomodificación del alveolo para realizar regeneración ósea guiada y colocación de membrana de plasma rica en fibrina, se espera cicatrización para la colocación de implantes dentales. Conclusiones: El uso de alternativas de membranas de barrera muestra resultados efectivos en casos de regeneración ósea guiada(AU)


Assuntos
Humanos , Feminino , Pessoa de Meia-Idade , Regeneração Óssea/fisiologia , Implantes Dentários/efeitos adversos , Osseointegração/fisiologia
17.
Av. odontoestomatol ; 36(2): 107-115, mayo-ago. 2020. ilus
Artigo em Espanhol | IBECS | ID: ibc-194692

RESUMO

La evolución en los diseños de los sistemas de implantes y en la configuración de los pilares protésicos ha desarrollado el concepto de plataforma reducida que comprende la colocación de un pilar más estrecho que la plataforma del implante para aumentar su distancia de la interfase hueso-implante. La plataforma reducida es considerada un factor importante para preservar la estabilidad del hueso crestal y de los tejidos blandos y asegurar el éxito de los implantes dentales a largo plazo. La plataforma reducida reduce las fuerzas oclusales y la contaminación bacteriana en la interfase entre el hueso crestal y el implante. Los estudios experimentales en animales y clínicos en pacientes muestran su eficacia para prevenir la pérdida ósea y de los tejidos blandos periimplantarios


The evolution of designs of implant systems and abutments configurations has developed the concept of platform-switching that involves the connection of a narrower abutment to the platform implant to allow horizontal distance of the interface bone-implant. Platform-switching is considered an important factor to preserve the stability of crestal bone and soft tissue ensuring the success of dental implants in the long-term follow-up. Platform-switching reduces the forces of occlusal loading and bacterial contamination in the interface between the crestal bone and the implant. Experimental studies in animals and clinical studies in patients showed that implants with platform-switching have demonstrated the effectiveness to prevent peri-implant bone loss and subsequent soft tissue los


Assuntos
Animais , Cães , Implantes Dentários/veterinária , Implantação Dentária Endo-Óssea/métodos , Implantação Dentária Endo-Óssea/veterinária , Projeto do Implante Dentário-Pivô/métodos , Projeto do Implante Dentário-Pivô/veterinária , Osseointegração
18.
PLoS One ; 15(8): e0237179, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32760149

RESUMO

Percutaneous osseointegrated (OI) implants are increasingly viable as an alternative to socket suspension of prosthetic limbs. Upper extremity prostheses have also become more complex to better replicate hand and arm function and attempt to recreate pre-amputation functional levels. With more functionality comes heavier devices that put more stress on the bone-implant interface, which could be an issue for implant stability. This study quantified transhumeral loading at defined amputation levels using four simulated prosthetic limb-types: (1) body powered hook, (2) myoelectric hook, (3) myoelectric hand, and (4) advanced prosthetic limb. Computational models were constructed to replicate the weight distribution of each prosthesis type, then applied to motion capture data collected during Advanced Activities of Daily Living (AADLs). For activities that did not include a handheld weight, the body powered prosthesis bending moments were 13-33% (range of means for each activity across amputation levels) of the intact arm moments (reference 100%), torsional moments were 12-15%, and axial pullout forces were 30-40% of the intact case (p≤0.001). The myoelectric hook and hand bending moments were 60-99%, torsional moments were 44-97%, and axial pullout forces were 62-101% of the intact case. The advanced prosthesis bending moments were 177-201%, torsional moments were 164-326%, and axial pullout forces were 133-185% of the intact case (p≤0.001). The addition of a handheld weight for briefcase carry and jug lift activities reduced the overall impact of the prosthetic model itself, where the body powered forces and moments were much closer to those of the intact model, and more complex prostheses further increased forces and moments beyond the intact arm levels. These results reveal a ranked order in loading magnitude according to complexity of the prosthetic device, and highlight the importance of considering the patient's desired terminal device when planning post-operative percutaneous OI rehabilitation and training.


Assuntos
Membros Artificiais/normas , Osseointegração , Torção Mecânica , Suporte de Carga , Membros Artificiais/efeitos adversos , Membros Artificiais/classificação , Fenômenos Biomecânicos , Interface Osso-Implante/fisiologia , Interface Osso-Implante/fisiopatologia , Humanos , Úmero/fisiologia , Úmero/fisiopatologia
19.
Int J Nanomedicine ; 15: 5061-5072, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32764936

RESUMO

Purpose: Zirconia is one of the most promising implant materials due to its favorable physical, mechanical and biological properties. However, until now, we know little about the mechanism of osseointegration on zirconia. The purpose of this study is to evaluate the effect of Syndecan (Sdc) on osteoblastic cell (MC3T3-E1) adhesion and proliferation onto zirconia materials. Materials and Methods: The mirror-polished disks 15 mm in diameter and 1.5 mm in thick of commercial pure titanium (CpTi), 3mol% yttria-stabilized tetragonal zirconia polycrystalline (3Y-TZP) and nano-zirconia (NanoZr) are used in this study. MC3T3-E1 cells were seeded onto specimen surfaces and subjected to RNA interference (RNAi) for Syndecan-1, Syndecan-2, Syndecan-3, and Syndecan-4. At 48h post-transfection, the cell morphology, actin cytoskeleton, and focal adhesion were observed using scanning electron microscopy or laser scanning confocal fluorescence microscopy. At 24h and 48h post-transfection, cell counting kit-8 (CCK-8) assay was used to investigate cell proliferation. Results: The cell morphology of MC3T3-E1 cells on CpTi, 3Y-TZP, and NanoZr changed into abnormal shape after gene silencing of Syndecan. Among the Syndecan family, Sdc-2 is responsible for NanoZr-specific morphology regulation, via maintenance of cytoskeletal conformation without affecting cellular attachment. According to CCK-8 assay, Sdc-2 affects the osteoblastic cell proliferation onto NanoZr. Conclusion: Within the limitation of this study, we suggest that Syndecan affects osteoblastic cell adhesion on CpTi, 3Y-TZP, and NanoZr. Sdc-2 might be an important heparin-sensitive cell membrane regulator in osteoblastic cell adhesion, specifically on NanoZr, through the organization of actin cytoskeleton and affects osteoblastic cell proliferation.


Assuntos
Osseointegração/fisiologia , Osteoblastos/citologia , Osteoblastos/fisiologia , Sindecanas/metabolismo , Citoesqueleto de Actina/efeitos dos fármacos , Animais , Adesão Celular/fisiologia , Membrana Celular/efeitos dos fármacos , Proliferação de Células/fisiologia , Células Cultivadas , Camundongos , Microscopia Eletrônica de Varredura , Osseointegração/genética , Propriedades de Superfície , Sindecana-2/genética , Sindecana-2/metabolismo , Sindecanas/genética , Titânio/química , Ítrio/química , Zircônio/química
20.
Ultrasonics ; 108: 106223, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32771811

RESUMO

Quantitative ultrasound can be used to characterize the evolution of the bone-implant interface (BII), which is a complex system due to the implant surface roughness and to partial contact between bone and the implant. The determination of the constitutive law of the BII would be of interest in the context of implant acoustical modeling in order to take into account the imperfect characteristics of the BII. The aim of the present study is to propose an analytical effective model describing the interaction between an ultrasonic wave and a rough BII. To do so, a spring model was considered to determine the equivalent stiffness K of the BII. The stiffness contributions related (i) to the partial contact between the bone and the implant and (ii) to the presence of soft tissues at the BII during the process of osseointegration were assessed independently. K was found to be comprised between 1013 and 1017 N/m3 depending on the roughness and osseointegration of the BII. Analytical values of the reflection and transmission coefficients at the BII were derived from values of K. A good agreement with numerical results obtained through finite element simulation was obtained. This model may be used for future finite element bone-implant models to replace the BII conditions.


Assuntos
Interface Osso-Implante , Osseointegração , Ondas Ultrassônicas , Módulo de Elasticidade , Análise de Elementos Finitos , Modelos Teóricos , Propriedades de Superfície , Resistência à Tração , Titânio
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