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AIM: To evaluate the tissue reaction of a tricalcium silicate-based repair material associated with 30% calcium tungstate (TCS + CaWO4 ) in comparison to Bio-C Repair (Bio-C; Angelus) and to MTA Repair HP (MTA HP; Angelus). METHODOLOGY: Polyethylene tubes filled with one of the materials or left empty (control group, CG) were implanted into the subcutaneous tissues of rats for 7, 15, 30 and 60 days (n = 32/group). The capsule thickness, number of inflammatory cells, collagen content, interleukin-6 (IL-6), osteocalcin (OCN), von Kossa reaction and analysis under polarized light were evaluated. The data were subjected to generalized linear models for repeated measures, except the OCN. OCN data were submitted to Kruskal-Wallis and Dunn's post hoc test and Friedman followed by Nemenyi's test at significance level of 5%. RESULTS: At all time points, significant differences in the number of inflammatory cells were not observed between TCS + CaWO4 and Bio-C, whereas, at 15, 30 and 60 days, no significant difference was detected between TCS + CaWO4 and MTA HP. At all periods, significant differences were not detected in the number of fibroblasts in TCS + CaWO4 versus MTA HP, and, at 60 days, no significant difference was demonstrated between these groups and CG. Significant differences in the immunoexpression of IL-6 were not detected amongst bioceramic materials at all periods. From 7 to 60 days, significant reduction in the number of inflammatory cells, number of IL-6-immunopositive cells and in the capsule thickness was accompanied by significant increase in the collagen in all groups. OCN-immunolabelled cells, von Kossa-positive structures and amorphous calcite deposits were observed around all materials, whereas, in the CG, these structures were not seen. CONCLUSIONS: These findings indicate that the experimental material (TCS + CaWO4 ) is biocompatible and has a bioactive potential, similar to the MTA HP and Bio-C Repair, and suggest its use as a root repair material.
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Interleucina-6 , Materiais Restauradores do Canal Radicular , Ratos , Animais , Óxidos/farmacologia , Óxidos/química , Materiais Restauradores do Canal Radicular/química , Compostos de Alumínio/farmacologia , Compostos de Alumínio/química , Compostos de Cálcio/farmacologia , Compostos de Cálcio/química , Cimentos de Ionômeros de Vidro , Silicatos/farmacologia , Silicatos/química , Cimentos Dentários , Colágeno , Combinação de Medicamentos , Teste de Materiais , Materiais Biocompatíveis/farmacologiaRESUMO
As the biocompatibility and bioactive potential of repair materials are desired characteristics in dentistry, the tissue response of Bio-C Pulpo, a bioceramic material launched on the marked by Angelus (Brazil), was compared with Biodentine (Septodont, France) and White MTA (WMTA; Angelus, Brazil). In 32 rats, 148 polyethylene tubes filled with Bio-C Pulpo, Biodentine or WMTA, and empty (CG, control group) were implanted into subcutaneous tissues for 7, 15, 30, and 60 days. The capsule thickness, numerical density of inflammatory cells (IC) and fibroblasts (Fb), amount of collagen, immunohistochemistry detection of interleukin-6 (IL-6) and osteocalcin (OCN), von Kossa and analysis under polarized light were performed. Data were subjected to two-way ANOVA followed by Tukey's test (p ≤ 0.05). At 7 and 15 days, the capsules around Bio-C Pulpo were thicker than in WMTA while, at 30 and 60 days, significant differences were not observed among the groups. Although at 7, 15, and 30 days, a greater number of IL-6-immunostained cells was found in Bio-C Pulpo and Biodentine than in WMTA, no significant difference was detected among the groups at 60 days. In all groups, the number of Fb and collagen content increased significantly over time. The capsules around materials exhibited von Kossa-positive and birefringent structures, and OCN-immunostained cells whereas, in the CG, these structures were not observed. Bio-C Pulpo, similarly to Biodentine and WMTA, is biocompatible, allows the connective tissue repair and presents bioactive potential in connective tissue of rats.
Assuntos
Materiais Restauradores do Canal Radicular , Tela Subcutânea , Compostos de Alumínio , Animais , Materiais Biocompatíveis/farmacologia , Carbonato de Cálcio , Compostos de Cálcio , Colágeno/metabolismo , Colágeno/farmacologia , Combinação de Medicamentos , Interleucina-6 , Teste de Materiais , Osteocalcina , Óxidos , Ratos , Silicatos , Tela Subcutânea/metabolismoRESUMO
Prosthetic failure secondary to bearing fracture remains a potential complication in ceramic-on-ceramic total hip arthroplasty. We report the unusual presentation of a ceramic component fracture of a total hip arthroplasty performed 17 years ago that mimicked a periprosthetic joint infection. This case was managed based on the current guidelines and algorithms recommended for periprosthetic joint infection management. Histologic examination of periprosthetic tissue revealed an adverse inflammatory soft-tissue reaction to the ceramic fragments released from the fracture site. Our case highlights a misleading, inflammatory acute response usually associated with an infectious process corresponding to an adverse soft-tissue reaction. High clinical suspicion and a systematic approach are essential to address these deceiving clinical scenarios.
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BACKGROUND: Adverse local tissue reaction (ALTR) is a recognized complication of total hip arthroplasty (THA) with metal-on-polyethylene (MoP) bearing surface implants. Specific models of THA implants have been identified as having a higher incidence of ALTR. The purpose of this study is to determine if serum metal levels, patient symptoms, implant factors, and imaging findings can be predictive of ALTR within this high-risk population. METHODS: We retrospectively reviewed an observational cohort of 474 patients who underwent MoP THA and were at increased risk of having ALTR. Patients were stratified based on the presence or absence of ALTR. Patient symptoms, serum metal ions, implant head offset, and imaging findings were compared. RESULTS: Patients with ALTR were more likely to be symptomatic (52.9% vs 9.9%, P < .0001). The presence of ALTR was associated with significantly higher serum cobalt and chromium levels (6.2 ppb vs 3.6 ppb, P < .0001; 2.3 ppb vs 1.2 ppb, P < .0001). Head offsets greater than 4 mm were associated with a higher prevalence of ALTR (53% vs 38%, P = .05). On metal artifact reduction sequence magnetic resonance imaging, patients with ALTR had larger effusions (4.7 cm vs 2.1 cm, P < .001) and a higher incidence of trochanteric bursitis (47% vs 16%, P < .001). CONCLUSIONS: In high-risk MoP implants, serum cobalt and chromium levels are elevated, even in patients without ALTR. A larger femoral head offset is a risk factor for the development of ALTR. Our study suggests that patients presenting with painful THA and elevated metal ions require risk stratification based on patient symptoms, metal artifact reduction sequence magnetic resonance imaging findings, and implant factors.
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BACKGROUND: Diagnosis of adverse local tissue reaction (ALTR) in metal-on-polyethylene (MoP) total hip arthroplasty (THA) secondary to head-neck taper corrosion is challenging. The purpose of this study is to compare differences between asymptomatic and symptomatic ALTR in an observational cohort, including presentation, metal ion differences, and metal artifact reduction sequence (MARS) magnetic resonance imaging (MRI) findings. METHODS: We performed a retrospective review of an observational cohort of 492 MoP THA patients at increased risk of developing ALTR. Ninety-four patients underwent revision arthroplasty for ALTR. Patients were stratified into symptomatic and asymptomatic ALTR groups. Presentation, metal ion levels, and imaging findings were compared. RESULTS: For patients with confirmed ALTR, 41% were asymptomatic. There was a statistically significant difference in the serum chromium levels between symptomatic and asymptomatic ALTR patients (2.2 µg/L vs 3.1 µg/L, P = .05). There was no statistically significant difference between the serum cobalt levels or MRI findings in these 2 groups. We observed that extracapsular disease associated with ALTR could be misinterpreted as trochanteric bursitis. CONCLUSION: Almost half of the MoP THA ALTR cases identified were asymptomatic. Cobalt levels could not differentiate between symptomatic and asymptomatic pseudotumor formation. Symptomatic and asymptomatic MoP ALTRs have similar MARS MRI characteristics. Our findings suggest that it is essential to risk stratify patients who could potentially have ALTR based on implant type, symptoms, ion levels, and MARS MRI.
Assuntos
Artroplastia de Quadril , Prótese de Quadril , Artroplastia de Quadril/efeitos adversos , Cromo , Cobalto/efeitos adversos , Corrosão , Prótese de Quadril/efeitos adversos , Humanos , Desenho de Prótese , Falha de Prótese , Reoperação , Estudos RetrospectivosRESUMO
BACKGROUND: We compared the revision risk between metal-on-polyethylene (MOP) and ceramic-on-polyethylene (COP) total hip arthroplasty patients and evaluated temporal changes in short-term revision risks for MOP patients. METHODS: Primary MOP (n = 9480) and COP (n = 3620) total hip arthroplasties were evaluated from the Medicare data set (October 2005 to December 2015) for revision risk, with up to 10 years of follow-up using multivariate analysis. Temporal change in the short-term revision risk for MOP was evaluated (log-rank and Wilcoxon tests). RESULTS: Revision incidence was 3.8% for COP and 4.3% for MOP. MOP short-term revision risk did not change over time (P ≥ .844 at 1 year and .627 at 2 years). Dislocation was the most common reason for revision (MOP: 23.5%; COP: 24.8%). Overall adjusted revision risks were not different between MOP and COP up to 10 years of follow-up (P ≥ .181). CONCLUSIONS: Concerns with corrosion for metal heads do not appear to result in significantly elevated revision risk for MOP at up to 10 years. Corrosion does not appear as a primary reason for revision compared to other mechanisms.
Assuntos
Artroplastia de Quadril , Prótese de Quadril , Idoso , Artroplastia de Quadril/efeitos adversos , Cerâmica , Corrosão , Seguimentos , Prótese de Quadril/efeitos adversos , Humanos , Medicare , Polietileno , Desenho de Prótese , Falha de Prótese , Reoperação , Fatores de Risco , Estados UnidosRESUMO
The authors describe a case of a large diameter head metal-on-metal total hip replacement that evolved with an inflammatory pseudotumor formation. The diagnosis was established by magnetic resonance imaging (MRI) with suppression of the metal artifact. The treatment consisted on the resection of the abnormal tissue and on the revision to a ceramic on cross-linked polyethylene hip replacement. To this date, no similar case has been reported, in Portuguese language, in the PubMed, Scielo, and Lilacs databases.
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Abstract The authors describe a case of a large diameter head metal-on-metal total hip replacement that evolved with an inflammatory pseudotumor formation. The diagnosis was established bymagnetic resonance imaging (MRI) with suppression of themetal artifact. The treatment consisted on the resection of the abnormal tissue and on the revision to a ceramic on cross-linked polyethylene hip replacement. To this date, no similar case has been reported, in Portuguese language, in the PubMed, Scielo, and Lilacs databases.
Resumo Os autores descrevem caso de artroplastia total do quadril (ATQ) com par tribológico metal-metal e cabeça de grande diâmetro que evoluiu com formação de pseudotumor inflamatório. O diagnóstico foi estabelecido por ressonânciamagnética comsupressão de artefato metálico. O tratamento consistiu na ressecção do tecido anormal e revisão com par tribológico cerâmica-polietileno reticulado. Nenhum caso semelhante em língua portuguesa encontra-se descrito nas bases de dados PubMed, Scielo e Lilacs até a presente data.
Assuntos
Humanos , Masculino , Pessoa de Meia-Idade , Artroplastia de Quadril , Granuloma de Células PlasmáticasRESUMO
This study aimed to evaluate the tissue reaction of ethylene-vinyl acetate (EVA) in 4 different compositions and processing: EVA foamed at high pressure with ultrasound (EVACU); EVA with 15% starch foamed at high pressure with ultrasound (EVAMCU); EVA with 15% starch foamed at high pressure without ultrasound and EVA foamed at high pressure without ultrasound as future use as a porous scaffold. Scanning electron microscopy images showed the influence of starch, reducing the diameter of pores. The number of open pores was also reduced with the addition of starch. The ultrasound applied during the manufacturing of composites does not affect these characteristics. Eighteen rats were used to test the tissue reaction of materials and PTFE (polytetrafluoroethylene), proven biocompatible material. After 7, 15, and 60 days of surgery, the materials were removed and processed for microscopic evaluation and counting of the inflammatory infiltrate. The data shows inflammatory reaction similar to PTFE. However, in the quantitative analysis at 60 days, the EVACU and EVAMCU showed less quantity of mononuclear cells (p < 0.05). Thus, the results suggest that the use of ultrasound in the production method (EVA) seems to have improved cell behavior regarding the reduction of infiltration over the period, with tissue response equivalent to the PTFE. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 107B: 400-407, 2019.
Assuntos
Materiais Biocompatíveis , Reação a Corpo Estranho , Teste de Materiais , Polivinil , Animais , Materiais Biocompatíveis/efeitos adversos , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Etilenos/efeitos adversos , Etilenos/química , Etilenos/farmacologia , Reação a Corpo Estranho/induzido quimicamente , Reação a Corpo Estranho/metabolismo , Reação a Corpo Estranho/patologia , Masculino , Politetrafluoretileno/efeitos adversos , Politetrafluoretileno/química , Politetrafluoretileno/farmacologia , Polivinil/efeitos adversos , Polivinil/química , Polivinil/farmacologia , Ratos , Ratos Wistar , Amido/efeitos adversos , Amido/química , Amido/farmacologia , Compostos de Vinila/efeitos adversos , Compostos de Vinila/química , Compostos de Vinila/farmacologiaRESUMO
We report a patient with frontal fibrosing alopecia (FFA), in whom autologous hair transplantation was successfully performed despite evidence of active disease. Since the underlying pathology of FFA is usually lichen planopilaris, reservations, and caveats have been expressed with respect to the risk of köbnerization phenomena following hair transplantation surgery. An important question that arises is how the lichenoid tissue reaction pattern is generated around the hair follicles in FFA. Follicles with some form of damage or malfunction might express cytokine profiles that attract inflammatory cells to assist in damage repair or in the initiation of apoptosis-mediated organ deletion. Alternatively, an as yet unknown antigenic stimulus from the damaged or malfunctioning hair follicle might initiate a lichenoid tissue reaction in the immunogenetically susceptible individual. Therefore, it might be expected that the transplantation of whole healthy hair follicles might less give rise to an inflammatory reaction than the disease itself, as revealed in our case report of successful hair transplantation in FFA.
RESUMO
BACKGROUND: This study investigated the influence of femoral head impaction force, number of head strikes, the energy sequence of head strikes, and head offset on the strength of the taper-trunnion junction. METHODS: Thirty titanium-alloy trunnions were mated with 36-mm zero-offset cobalt-chromium femoral heads of corresponding taper angle. A drop tower impacted the head with 2.5J or 8.25J, resulting in 6 kN or 14 kN impaction force, respectively, in a single strike or combinations of 6 kN + 14 kN or 14 kN + 14 kN. In addition, ten 36-mm heads with -5 and +5 offset were impacted with sequential 14 kN + 14 kN strikes. Heads were subsequently disassembled using a screw-driven mechanical testing frame, and peak distraction force was recorded. RESULTS: Femoral head pull-off force was 45% the strike force, and heads struck with a single 14 kN impact showed a pull-off force twice that of the 6 kN group. Two head strikes with the same force did not improve pull-off force for either 6 kN (P = .90) or 14 kN (P = .90). If the forces of the 2 impactions varied, but either impact measured 14 kN, a 51% higher pull-off force was found compared to impactions of either 6 kN or 6 kN + 6 kN. Femoral head offset did not significantly change the pull-off force among -5, 0, and +5 heads (P = .37). CONCLUSION: Femoral head impaction force influenced femoral head trunnion-taper stability, whereas offset did not affect pull-off force. Multiple head strikes did not add additional stability, as long as a single strike achieved 14 kN force at the mallet-head impactor interface. Insufficient impaction force may lead to inadequate engagement of the trunnion-taper junction.
Assuntos
Artroplastia de Quadril/instrumentação , Cabeça do Fêmur/cirurgia , Prótese de Quadril , Desenho de Prótese , Ligas , Artroplastia de Quadril/métodos , Cromo , Cobalto , Humanos , Fenômenos Mecânicos , Falha de Prótese , TitânioRESUMO
Objective: To evaluate the response of rat subcutaneous tissue in implanted polyethylene tubes that were filled with GMTA Angelus and Portland cements containing different arsenic concentrations. Material and Methods: Atomic absorption spectrophotometry was utilized to obtain the values of the arsenic concentration in the materials. Thirty-six rats were divided into 3 groups of 12 animals for each experimental period. Each animal received two implants of polyethylene tubes filled with different test cements and the lateral of the tubes was used as a control group. After 15, 30 and 60 days of implantation, the animals were killed and the specimens were prepared for descriptive and morphometric analysis considering: inflammatory cells, collagen fibers, fibroblasts, blood vessels and other components. The results were analyzed utilizing the Kuskal-Wallis test and the Dunn's Multiple test for comparison (p<0.05). Results: The materials showed, according to atomic absorption spectrophotometry, the following doses of arsenic: GMTA Angelus: 5.01 mg/kg, WPC Irajazinho: 0.69 mg/kg, GPC Minetti: 18.46 mg/kg and GPC Votoran: 10.76 mg/kg. In a 60-day periods, all specimens displayed a neoformation of connective tissue with a structure of fibrocellular aspect (capsule). Control groups and MTA Angelus produced the lower amount of inflammatory reaction and GPC Minetti, the highest reaction. Conclusions: There was no direct relationship between the concentration of arsenic present in the composition of the materials and the intensity of the inflammatory reactions. Higher values, as 18.46 mg/kg of arsenic in the cement, produce characteristics of severe inflammation reaction at the 60-day period. The best results were found in MTA angelus. .
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Animais , Masculino , Arsênio/toxicidade , Bismuto/toxicidade , Compostos de Cálcio/toxicidade , Cimentos Dentários/toxicidade , Óxidos/toxicidade , Silicatos/toxicidade , Tela Subcutânea/efeitos dos fármacos , Arsênio/administração & dosagem , Bismuto/química , Vasos Sanguíneos/efeitos dos fármacos , Colágeno/efeitos dos fármacos , Cimentos Dentários/química , Fibroblastos/efeitos dos fármacos , Teste de Materiais , Óxidos/química , Polietileno/química , Ratos Wistar , Valores de Referência , Espectrofotometria Atômica , Fatores de TempoRESUMO
INTRODUCTION: The aim of this study was to evaluate the biocompatibility of a new calcium aluminate cement (EndoBinder) in subcutaneous tissue of rats in comparison with mineral trioxide aggregate and calcium hydroxide hard-setting cement. METHODS: Polyethylene tubes (1.5 × 10 mm) containing the dental cements were implanted into dorsal subcutaneous tissue of 30 rats. After experimental periods of 7, 30, and 90 days, biopsies were performed for tissue response analysis under optical light microscope. The mRNA extraction was performed for molecular evaluation of the inflammatory process in the peri-implant tissue, which was submitted to quantitative real-time polymerase chain reaction analysis for inflammatory mediators and cytokines TNF-α, Ptges2, Il-1ß, Il-4, and Il-10. RESULTS: On the basis of the score used to grade the tissue reaction (0-3), EndoBinder (0) presented no inflammatory reaction after the 90-day period, a similar result to mineral trioxide aggregate and calcium hydroxide. The thickness of inflammatory capsules (µm) also presented significant decrease during the course of periods (P < .05). As regards expression of inflammatory mediators, Ptges2 and Il-10 were detected only at 7 and 30 days, with no statistically significant difference among the experimental groups (P > .05). CONCLUSIONS: EndoBinder induced limited inflammatory reaction. It was considered biocompatible when tested in subcutaneous tissue of rats.
Assuntos
Compostos de Alumínio/farmacologia , Materiais Biocompatíveis/farmacologia , Compostos de Cálcio/farmacologia , Citocinas/efeitos dos fármacos , Mediadores da Inflamação/análise , Materiais Restauradores do Canal Radicular/farmacologia , Tela Subcutânea/efeitos dos fármacos , Animais , Hidróxido de Cálcio/farmacologia , Combinação de Medicamentos , Interleucina-10/análise , Interleucina-1beta/efeitos dos fármacos , Oxirredutases Intramoleculares/efeitos dos fármacos , Masculino , Teste de Materiais , Óxidos/farmacologia , Prostaglandina-E Sintases , Ratos , Silicatos/farmacologia , Tela Subcutânea/imunologia , Tela Subcutânea/patologia , Fatores de Tempo , Fator de Necrose Tumoral alfa/efeitos dos fármacosRESUMO
Cytotoxicity and subcutaneous tissue reaction of innovative blends composed by polyvinylidene fluoride and polyvinylidene fluoride-trifluoroethylene associated with natural polymers (natural rubber and native starch) forming membranes were evaluated, aiming its applications associated with bone regeneration. Cytotoxicity was evaluated in mouse fibroblasts culture cells (NIH3T3) using trypan blue staining. Tissue response was in vivo evaluated by subcutaneous implantation of materials in rats, taking into account the presence of necrosis and connective tissue capsule around implanted materials after 7, 14, 21, 28, 35, 60, and 100 days of surgery. The pattern of inflammation was evaluated by histomorphometry of the inflammatory cells. Chemical and morphological changes of implanted materials after 60 and 100 days were evaluated by Fourier transform infrared (FTIR) absorption spectroscopy and scanning electron microscopy (SEM) images. Cytotoxicity tests indicated a good tolerance of the cells to the biomaterial. The in vivo tissue response of all studied materials showed normal inflammatory pattern, characterized by a reduction of polymorphonuclear leukocytes and an increase in mononuclear leukocytes over the time (p < 0.05 Kruskal-Wallis). On day 60, microscopic analysis showed regression of the chronic inflammatory process around all materials. FTIR showed no changes in chemical composition of materials due to implantation, whereas SEM demonstrated the delivery of starch in the medium. Therefore, the results of the tests performed in vitro and in vivo show that the innovative blends can further be used as biomaterials.
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Fibroblastos/metabolismo , Hidrocarbonetos Fluorados/farmacologia , Leucócitos Mononucleares/metabolismo , Teste de Materiais , Polivinil/farmacologia , Amido/farmacologia , Compostos de Vinila/farmacologia , Animais , Regeneração Óssea/efeitos dos fármacos , Fibroblastos/patologia , Hidrocarbonetos Fluorados/efeitos adversos , Inflamação/induzido quimicamente , Inflamação/metabolismo , Inflamação/patologia , Leucócitos Mononucleares/patologia , Masculino , Camundongos , Células NIH 3T3 , Polivinil/efeitos adversos , Ratos , Ratos Wistar , Amido/efeitos adversos , Compostos de Vinila/efeitos adversosRESUMO
The aim of this study was to evaluate the tissue compatibility of a silorane-based resin system (FiltekTM Silorane) and a methacrylate-based nanoparticle resin (FiltekTM Supreme XT) after implantation in the subcutaneous connective tissue of isogenic mice. One hundred and thirty five male isogenic BALB/c mice were randomly assigned to 12 experimental and 3 control groups, according to the implanted material and the experimental period of 7, 21 and 63 days. At the end of each period, the animals were killed and the tubes with the surrounding tissues were removed and processed for microscopic analysis. Samples were subjected to a descriptive and a semi-quantitative analyses using a 4-point scoring system (0-3) to evaluate the collagen fiber formation and inflammatory infiltrate. Data were statistically analyzed using the Kruskal Wallis test (?=0.05). The results showed that there was no significant difference between the experimental and control groups considering the three evaluation periods (p>0.05). The silorane-based and the methacrylate-based nanoparticle resins presented similar tissue response to that of the empty tube (control group) after subcutaneous implantation in isogenic mice.
O objetivo do presente estudo foi avaliar a compatibilidade tecidual de um sistema resinoso à base de silorane (FiltekTM Silorane) e de uma resina nanoparticulada à base de metacrilato (FiltekTM Supreme XT), após implantação no tecido conjuntivo subcutâneo de camundongos isogênicos. Um total de 135 camundongos isogênicos BALB/c machos foram randomicamente divididos em 12 grupos experimentais e em 3 grupos controles, de acordo com o material implantado e com o período experimental (7, 21 e 63 dias). Ao final de cada período, os animais foram mortos, sendo os tubos removidos com o tecido circundante e processados para análise microscópica. As lâminas foram submetidas a análise descritiva e análise semi-quantitativa empregando um sistema de escores de 4 pontos (0-3), a fim de avaliar a formação de fibras colágenas e o infiltrado inflamatório. Os dados obtidos foram submetidos à análise estatística por meio do teste de Kruskal Wallis (?=0,05). Os resultados mostraram que não houve diferença estatisticamente significante entre os grupos experimentais e controles, considerando os três períodos de avaliação (p>0,05). As resinas à base de silorane e à base de metacrilato apresentaram resposta tecidual semelhante à do tubo vazio (controle), após implantação no tecido conjuntivo de camundongos isogênicos.
Assuntos
Animais , Masculino , Camundongos , Resinas Compostas/toxicidade , Siloxanas/toxicidade , Tela Subcutânea/efeitos dos fármacos , Resinas Compostas/química , Reação a Corpo Estranho , Colágenos Fibrilares/biossíntese , Implantes Experimentais , Teste de Materiais , Camundongos Endogâmicos BALB C , Metacrilatos/toxicidade , Distribuição AleatóriaRESUMO
The aim of this study was to morphometrically analyze the tissue response to a customized pin obtained from devitalized bovine cortical bone (DBCB-pin) implanted in the subcutaneous tissue of rats, as well as to assess its microstructural aspect by scanning electron microscopy (SEM). The pins were implanted in the subcutaneous tissue of 20 rats, which were killed at 7, 14, 28 and 60 days (5 rats/period) after implantation. In the subcutaneous tissue, DBCB-pin promoted the formation of a fibrous capsule. At 7 days, capsule showed thickness of 70 ± 3.2 µm with higher density of newly formed capillaries and smaller density of collagen fibers. Between 14 and 60 days, more organized fibrous capsule exhibited smaller thickness (53 ± 5.5 µm) with higher density of fibroblasts and collagen fibers. In this period, a small and slow bioresorption of the DBCB-pin by macrophages and rare multinucleated giant cells without tissue damage was observed. The thickness of DBCB-pin resorbed was in mean only of 9.3 µm. During all experimental periods not occurred presence of immune reaction cells as lymphocytes and plasma cells. It was concluded that the pin derived from cortical bovine bone was well tolerated by subcutaneous tissue of rats and slowly resorbed could be an alternative material for membrane fixation in the guided tissue regeneration procedures.
O objetivo deste estudo foi analisar morfometricamente a resposta tecidual a um pino obtido a partir de osso bovino desvitalizado cortical (DBCB pinos) implantado no tecido subcutâneo de ratos, bem como para avaliar o seu aspecto microestrutural por microscopia eletrônica de varredura (MEV). Os pinos foram implantados no tecido subcutâneo de 20 ratos, que foram sacrificados aos 7, 14, 28 e 60 dias (5 animais / período) após a implantação. No tecido subcutâneo, o pino DBCB promoveu a formação de uma cápsula fibrosa. Aos 7 dias, a cápsula apresentou espessura de 70 ± 3,2 μm com maior densidade de capilares neoformados e menor densidade de fibras colágenas. Entre 14 e 60 dias, a cápsula fibrosa apresentava-se mais organizada e exibiram menor espessura (53 ± 5,5 μm) com maior densidade de fibroblastos e fibras colágenas. Nesse período, foi observada uma bioreabsorção pequena e lenta dos pinos DBCB por macrófagos e raras células gigantes multinucleadas, sem dano tecidual. A espessura dos pinos DBCB reabsorvidos foi em média de apenas 9,3 µm. Durante todos os períodos experimentais não ocorreu presença de células como linfócitos e células plasmáticas. Concluiu-se que o pino derivado de osso bovino cortical foi bem tolerado pelo tecido subcutâneo de ratos e reabsorvido lentamente, sendo um potencial material alternativo para fixação da membrana nos procedimentos de regeneração tecidual guiada.
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Animais , Bovinos , Masculino , Ratos , Implantes Absorvíveis , Materiais Biocompatíveis , Pinos Dentários , Regeneração Tecidual Guiada Periodontal/instrumentação , Osso e Ossos , Implantes Experimentais , Membranas Artificiais , Ratos Wistar , Tela Subcutânea/cirurgiaRESUMO
Thirty male Wistar rats were implanted under the skin with surgical nylon or fishing line maintained in formalin or fishing line autoclaved once or twice. Two different types of 3cm length suture material were implanted in each animal parallel and equidistant sites from the vertebral column. The animals were sacrificed at five, 15 and 90 days postoperative for histopathological examination. The greatest tissue reaction was observed in those animals implanted with fishing line maintained in formalin and the smallest reaction in those implanted with surgical nylon. Animals implanted with once and twice autoclaved fishing line showed similar and intermediary reaction.
Foram empregados 30 ratos, machos, linhagem Wistar. Implantou-se sob a pele segmentos de 3cm de comprimento de "linha de pesca " mantida em formalina, "linha de pesca " autoclavada uma vez, "linha de pesca " autoclavada duas vezes e fio de náilon cirúrgico. Cada animal recebeu dois tipos de material de sutura, em locais paralelos e eqüidistantes da coluna vertebral. Foram sacrificados com cinco, 15 e 90 dias de pós-operatório para que se procedesse o exame histopatológico. Pelo grau de reação tecidual pode-se concluir que: a maior reação ocorreu com a "linha de pesca mantida em formalina e a menor com o fio de náilon cirúrgico; as "linhas de pesca " autoclavadas uma e duas vezes se comportaram de forma semelhante e apresentaram um reação intermediária.
RESUMO
Thirty male Wistar rats were implanted under the skin with surgical nylon or fishing line maintained in formalin or fishing line autoclaved once or twice. Two different types of 3cm length suture material were implanted in each animal parallel and equidistant sites from the vertebral column. The animals were sacrificed at five, 15 and 90 days postoperative for histopathological examination. The greatest tissue reaction was observed in those animals implanted with fishing line maintained in formalin and the smallest reaction in those implanted with surgical nylon. Animals implanted with once and twice autoclaved fishing line showed similar and intermediary reaction.
Foram empregados 30 ratos, machos, linhagem Wistar. Implantou-se sob a pele segmentos de 3cm de comprimento de "linha de pesca " mantida em formalina, "linha de pesca " autoclavada uma vez, "linha de pesca " autoclavada duas vezes e fio de náilon cirúrgico. Cada animal recebeu dois tipos de material de sutura, em locais paralelos e eqüidistantes da coluna vertebral. Foram sacrificados com cinco, 15 e 90 dias de pós-operatório para que se procedesse o exame histopatológico. Pelo grau de reação tecidual pode-se concluir que: a maior reação ocorreu com a "linha de pesca mantida em formalina e a menor com o fio de náilon cirúrgico; as "linhas de pesca " autoclavadas uma e duas vezes se comportaram de forma semelhante e apresentaram um reação intermediária.