Analysis of the Chemical Composition, Morphological Characterization, and Porosimetry of Allograft and Comparison with Xenograft for Dental Applications / Análisis de la Composición Química, Caracterización Morfológica y Porosimetría de Aloinjerto y Comparación con Xenoinjerto para Aplicaciones Odontológicas

SUMMARY: Tissue engineering aims to fabricate a scaffold that exhibits a suitable surface topography for a desired cellular response. Therefore, a study analyzing the characteristics of bone grafts is important for future research directions. This work aims to analyze the physical-chemical characteristics of commercially available bone grafts of human and bovine origin for dental use, using morphological analysis of the surface and chemical composition by variable pressure scanning electron microscope (VP-SEM) and energy-dispersive x-ray (EDX) spectrometry. In addition, pore diameter and surface area were analyzed by degassing method using a porosimeter, and particle size by laser diffraction. The analyzed allograft and xenograft particles differ in morphological characteristics and chemical composition. The allograft particles present a cuboidal and prismatic geometric morphology with angled edges and the absence of macropores. On the contrary, the xenograft particles present an irregular morphology with macropores in their structure. There is a statistically significant difference in C, P, and Ca between the xenograft and allografts (p < 0,05). The analyzed composition of allografts showed mainly the presence of C and O. In contrast, the composition of the xenograft was mainly Ca. These differences could influence the osteogenic properties of allografts and xenografts. This analysis provides basic information to understand the physicochemical properties of allografts and xenografts that facilitate cell-graft interaction.

La ingeniería de tejidos tiene como objetivo fabricar un andamio que muestre una topografía de superficie adecuada para una respuesta celular deseada. Por tanto, un estudio que analice las características de los injertos óseos es importante para futuros enfoques de investigación. Este trabajo tiene como objetivo analizar las características físico-químicas de injertos óseos de origen humano y bovino disponibles comercialmente para uso odontológico, mediante análisis morfológico de la superficie y composición química mediante microscopio electrónico de barrido de presión variable (VP-SEM) y x-dispersivo de energía. espectrometría de rayos (EDX). Además, el diámetro de los poros y el área superficial se analizaron mediante el método de desgasificación utilizando un porosímetro y el tamaño de las partículas mediante difracción láser. Las partículas de aloinjerto y xenoinjerto analizadas difieren en características morfológicas y composición química. Las partículas del aloinjerto presentan una morfología geométrica cúbica y prismática con bordes angulados y ausencia de macroporos. Por el contrario, las partículas de xenoinjerto presentan una morfología irregular con macroporos en su estructura. Existe una diferencia estadísticamente significativa en C, P y Ca entre el xenoinjerto y los aloinjertos (p < 0,05). La composición analizada de los aloinjertos mostró principalmente la presencia de C y O. Por el contrario, la composición del xenoinjerto fue principalmente Ca. Estas diferencias podrían influir en las propiedades osteogénicas de los aloinjertos y xenoinjertos. Este análisis proporciona información básica para comprender las propiedades fisicoquímicas de aloinjertos y xenoinjertos que facilitan la interacción célula-injerto.

Split crest con colocación simultánea de implantes en sector anterior: reporte de un caso / Split crest with simultaneous placement of implants in the anterior sector: a case report

La pérdida ósea en el sector anterior, ya sea por un defecto horizontal, vertical o combinado, actualmente es un desafío, no sólo por la integración del implante, sino por la estética involucrada. Entre las técnicas de regeneración ósea que permiten solucionar estos defectos, cabe destacar la técnica de expansión de crestas. Se presenta el caso de una paciente de 58 años con reborde atrófico, que se sometió a la expansión de crestas con colocación simultánea de implantes en sector anterior, con xenoinjerto previo a técnica de expansión de crestas con piezoeléctrico, colocación simultánea de implantes Narrow Connection SLActive Straumann. Se logró ganancia ósea y estabilidad primaria de los implantes, sin complicaciones. En escenarios seleccionados, la técnica de expansión de crestas de manera predecible permite ganancia de hueso horizontal adecuada, el éxito de los implantes con tasa de supervivencia y mínimas complicaciones intra y postoperatorias (AU)

Bone loss in the anterior sector, both a horizontal, vertical or combined defect is a challenge today; not only for the integration of the implant but also the aesthetic involved. There are techniques of bone regeneration that help us to solve this type of defects, among them we should highlight the crest expansion technique. We present the case of a 58-year-old patient with atrophic flange, who underwent the expansion of crests with simultaneous placement of implants in the anterior sector, with xenograft prior to the piezoelectric crest expansion technique, Simultaneous placement of Narrow Connection SLActive Straumann implants, bone gain and primary stability of the implants were obtained, without complications. In selected scenarios, the crest expansion technique could be considered a predictable approach that demonstrates a high implant survival rate, adequate horizontal bone gain, and minimal intra- and postoperative complications (AU)

The expression of matrix metalloproteinase-13 (MMP-13) on xenograft and PRF in bone regeneration / Efeito da combinação de xenoenxerto e PRP na expressão de metaloproteinase de matriz -13 (MMP-13) durante regeneração óssea

Objective: inflammation may play a role in bone loss by altering the boné remodelling process, favouring bone resorption by osteoclasts over bone synthesis by osteoblasts. Matrix metalloproteinase 13 (MMP-13) has the ability to activate osteoclasts, leading to bone resorption. Regenerative treatments have been widely used in periodontology. When combined with Platelet-rich fibrin (PRF), xenografts will give better results in bone regeneration. The aim of this study was to evaluate the effect of xenograft combined with PRF on MMP-13 expression in a bone defect using an experimentally created bone defect. Material and Methods: eighteen New Zealand rabbits were assigned to three groups. Each group consisted of six New Zealand rabbits. A critical bone defect with a diameter size of 5 mm was created in the right tibia of each rabbit in group 1 (application: xenograft), group 2 (application: PRF), and group 3 (application: xenograft and PRF). The PRF was produced from 5 ml of blood taken from each rabbit's ears. After 30 days, the rabbits were euthanized. The tissue samples were evaluated by immunohistochemical staining. Results: group 3 showed the lowest mean expression of MMP-13 (4.50) compared to group 1 (20.50) and group 2 (11.70). Group 3 showed a significant difference in the MMP-13 expression compared to group 1 and group 2 (P = 0.000) (P < 0.05). Conclusion: this research showed that the combination of xenograft and PRF had the lowest expression of MMP-13. The application of a xenograft and PRF has better osteogenesis ability in bone regeneration.(AU)

Objetivo: inflamação pode interferir na perda óssea através de alterações no processo de remodelação, favorecendo a reabsorção óssea pelos osteoclastos ao invés da síntese pelos osteoblastos. A metaloproteinases de matriz 13 (MMP-13) ativa osteoclastos causando reabsorção óssea. Tratamentos regenerativos têm sido amplamente usados na periodontia. Quando combinamos Plasma rico em plaquetas (PRP) e xenoenxerto levam a melhores resultados de regeneração óssea. O objetivo deste estudo foi avaliar os efeitos de xenoenxerto combinado com PRP na expressão de MMP-13 em defeitos ósseos experimentais. Material e Métodos: dezoitos coelhos Nova Zelândia foram distribuídos em 3 grupos de 6 coelhos cada. Um defeito ósseo de 5 mm de diâmetro foi feito na tíbia direita dos animais do grupo 1 (xenoenxerto), grupo 2 (PRP) e grupo 3 (Xenoenxerto+PRP). O PRP foi obtido pela coleta de 5mL de sangue das orelhas dos coelhos. Após 30 dias, os coelhos foram eutanasiados. As amostras foram submetidas a coloração imuno-histoquímica. Resultados: o grupo 3 apresentou a menor expressão de MMP-13 (4.50) quando comparado ao grupo 1 (20.50) e ao grupo 2 (11.70). O grupo 3 mostrou diferença estatística significante em relação a expressão de MMP-13 quando comparado aos grupos 1 e 2 (p=0.000) (p< 0.05). Conclusão: esta pesquisa mostra que a combinação de xenoenxerto e PRP teve a menor expressão de MMP-13. A combinação de xenoenxerto e PRP têm maior habilidade de osteogênese na regeneração óssea (AU)

Socket regeneration after immediate loading implants with tissue and bone graft: 1-year clinical follow-up

Evaluation of ridge alteration after 1 year follow up after immediate loading implant placement. Methods: Ten patients were included in the study, in whom the ridge volume, height, and thickness were evaluated from region of interest (ROI) of tomographic images of the operated areas (test group) and compared to the opposite tooth (control group). Results: After one year, there was no implant loss and all patients were satisfied with the treatment. In the test group there was a statistically significant increase in ridge height (2.89±1.05 mm) when compared to the control group. No significant difference in relation to ridge volume and thickness was observed. In the intragroup evaluation, a significant gain in ridge height (2.65±3.08 mm) was observed when compared to baseline. Conclusion: The placement of an immediate implant, temporary crown, and tissue regeneration in sockets with buccal defects promotes the regeneration of the buccal wall while preventing the reduction of bone volume and thickness

Funcionalização de matriz colágena estável em volume utilizando Fibrina Rica em Plaquetas injetável (i-PRF) para o tratamento de Recessão Gengival unitária / Volume-stable collagen matrix (VCMX) biofunctionalized wit injectable platelet-rich fibrin (i-PRF) for the treatment of single gingival recession: randomized clinical trial

Substitutos de enxerto de tecido conjuntivo têm sido amplamente utilizados para superar as limitações dos enxertos autógenos no tratamento de defeitos dos tecidos moles periodontais e peri-implantares. No entanto, o desempenho clínico desses biomateriais ainda é inferior. A biofuncionalização de matrizes colágenas usando fibrina rica em plaquetas injetável (i-PRF) foi proposta como uma estratégia para aprimorar a bioatividade e, portanto, a eficácia clínica desses substitutos mucosos. Desta forma, o objetivo deste estudo foi avaliar a eficácia do uso da matriz colágena estável em volume (FG) biofuncionalizada com i-PRF no tratamento de recessões gengivais unitárias (RGs) do ponto de vista clínico, estético e de parâmetros centrados no paciente. Para tal, foram selecionados 66 pacientes portadores de RGs unitárias RT1, os quais foram alocados aleatoriamente em um dos seguintes grupos: grupo CAF (n=22), retalho posicionado coronariamente (CAF); grupo CAF+FG (n=22), CAF associado à FG; e grupo CAF+FG+i-PRF (n=22), CAF associado à FG biofuncionalizada com i-PRF. Após 6 meses, os três grupos apresentaram taxas de recobrimento radicular significativas [CAF: 69,1% (2,02 ± 1,06 mm); CAF+FG: 67,44% (1,7 ± 0,81 mm) e CAF+FG+i-PRF: 64,92% (1,64 ± 0,80 mm), sem diferença entre os grupos (p=0,33). Os grupos que receberam os biomateriais forneceram um maior ganho em espessura de tecido queratinizado (ETQ) (CAF: 0,12 ± 0,2 mm; CAF+FG: 0,43 ± 0,24 mm; CAF+FG+i-PRF: 0,48 ± 0,25 mm; p=0,000). Não foram observadas diferenças significativas em termos de altura de tecido queratinizado em nenhum dos grupos e tempos avaliados (p>0,05). Todos os grupos apresentaram redução significativa da hipersensibilidade dentinária e melhorias nas condições estéticas (p>0,05). Também não foram observadas diferenças em termos de dor e morbidade pósoperatórias (p>0,05). Dentro das limitações do presente estudo, conclui-se que as três abordagens forneceram resultados semelhantes e satisfatórios após 6 meses de acompanhamento. A adição da FG, biofuncionalizada ou não com i-PRF, proporcionou benefícios adicionais em termos de ganho de ETQ. (AU)

Soft tissue graft substitutes have been widely used to overcome the limitations of autogenous grafts in the treatment of periodontal and peri-implant soft tissue defects. However, the clinical performance of these biomaterials is still inferior. The biofunctionalization of collagen matrices using injectable platelet-rich fibrin (i-PRF) has been proposed as a strategy to enhance the bioactivity and, therefore, the clinical efficacy of these biomaterials. Thus, the aim of this study was to evaluate the effectiveness of using biofunctionalized volume-stable collagen matrix (VCMX) with i-PRF in the treatment of single gingival recessions (GRs) from clinical, esthetic, and patient-centered parameters. For this purpose, 66 patients with single RT GRs were selected and randomly allocated to one of the following groups: CAF group (n=22), coronally advanced flap (CAF); CAF+VCMX group (n=22), CAF combined with VCMX; and CAF+ VCMX +iPRF group (n=22), CAF combined with biofunctionalized VCMX with i-PRF. After 6 months, all three groups exhibited significant root coverage rates [CAF: 69.1% (2.02 ± 1.06 mm); CAF+FG: 67.44% (1.7 ± 0.81 mm); and CAF+FG+iPRF: 64.92% (1.64 ± 0.80 mm), with no difference between the groups (p=0.33). The groups that received the biomaterials showed a greater gain in keratinized tissue thickness (KTT) (CAF: 0.12 ± 0.2 mm; CAF+FG: 0.43 ± 0.24 mm; CAF+FG+i-PRF: 0.48 ± 0.25 mm; p=0.000). No significant differences were observed in terms of keratinized tissue height in any of the groups and assessed time points (p>0.05). All groups showed a significant reduction in dentin hypersensitivity and improvements in esthetic conditions (p>0.05). No differences were also observed in terms of post-operative pain and morbidity (p>0.05). Within the limitations of this study, it is concluded that all three approaches provided similar and satisfactory results after 6 months of follow-up. The addition of VCMX, whether biofunctionalized or not with i-PRF, provided additional benefits in terms of keratinized tissue thickness gain. (AU)

Comparison of the effectiveness and safety between autologous bone grafts and xenografts for the treatment of alveolar bone defects: overview of systematic reviews using frisbee methodology / Comparación sobre la efectividad y seguridad entre los injertos óseos autólogos y xenoinjertos para el tratamiento de defectos óseos alveolares: overview de revisiones sistemáticas con metodología frisbee

Introduction: Due to the extensive number of studies developed on periodontal pathologies and the clinical need generated to correct bonvze defects, we have carried out an Overview of systematic reviews using the FRISBEE methodology. Material and Methods: Through this study we expect to bridge the knowledge gap generated regarding the clinical question on the effectiveness of autologous bone substitutes and xenografts in maxillary and mandibular bone defects. Results: For this study, we carried out a systematic search in Epistemonikos and PubMed, we included 3 systematic reviews and 5 primary studies included in these reviews to extract their data. We analyzed data using RevMan 5.4. and GRADEpro. Assessed outcomes included: bone gain [MD 0.06 mm lower (0.26 lower to 0.14 higher)] and bone resorption [MD 0.03 mm higher (0.12 lower to 0.18 higher)], where no significant differences were found between the study groups. The certainty of the evidence was moderate for both outcomes. Bone length and bone density outcomes were not measured or reported in the included studies. Conclusion: We concluded that there are no significant clinical differences between the application of autologous bone grafts and xenografts for bone defects correction for the assessed outcomes, therefore, these biomaterials should be applied at the discretion of the clinician and according to the needs and preferences of patients.

Introducción: Debido al extenso número de estudios desarrollados sobre patologías periodontales y a la necesidad clínica generada para corregir defectos óseos, hemos realizado un Overview de revisiones sistemáticas tipo FRISBEE para acortar la brecha de conocimiento generada respecto a la pregunta clínica sobre la efectividad de sustitutos óseos tipo autólogo y xenoinjertos en defectos óseos a nivel maxilar y mandibular. Material y Métodos: Para este estudio realizamos una búsqueda sistemática en Epistemonikos y PubMed, de los cuales incluimos 3 revisiones sistemáticas y 5 estudios primarios incluidos en estas revisiones para extraer sus datos. Los datos fueron analizados a través de RevMan 5.4. Y GRADEpro. Resultados: Los estudios analizaron los desenlaces propuestos: ganancia ósea posterior a la aplicación del injerto óseo [MD 0.06 mm menos (0.26 menos a 0.14 más)] y reabsorción ósea posterior a la aplicación del injerto óseo [MD 0.03 mm más (0.12 menos a 0.18 más)], donde no se encontraron diferencias significativas entre los grupos de estudio. La certeza de la evidencia fue moderada para ambos desenlaces. Los desenlaces longitud ósea y densidad ósea no fueron medidos o reportados en los estudios incluidos. Conclusión: Se concluyó que no hay diferencias que sean clínicamente significativas entre la aplicación de injertos óseos autólogos y xenoinjertos para la corrección de defectos óseos para los desenlaces analizados, por lo que, la aplicación de estos biomateriales queda a criterio del clínico, y de acuerdo a las necesidades y preferencias de los pacientes.

Biología del tejido óseo y cambios morfológicos en su regeneración / Biology of bone tissue and morphological changes in its regeneration

Introducción: La regeneración ósea permite la reintegración y conformación de tejidos posteriores a la extracción o corrección de un defecto óseo. Es considerada una técnica de estimulación para la formación de hueso nuevo, donde se favorece la construcción y la preservación del coágulo con el fin de evitar la infiltración en la zona de reparación, de componentes celulares (células epiteliales y conjuntivas). Objetivos: Describir los cambios a nivel morfológico durante el proceso de regeneración ósea y mencionar distintas técnicas de preservación ósea y los factores necesarios para su realización. Presentación de caso: Paciente femenina con periodontitis apical asintomática en órganos dentarios 34 y 37, que se sometió a preservación alveolar mediante la práctica de exodoncia atraumática y regeneración ósea con xenoinjerto, colocación de membrana colágeno e implante posextractivo inmediato. Principales comentarios: La colocación inmediata de implantes posexodoncia permite una buena preservación del alveolo, siempre y cuando las condiciones clínicas del paciente así lo permitan, por ejemplo, la ausencia de procesos infecciosos agudizados como en el presente caso. La regeneración ósea, en el defecto producido por el proceso inflamatorio periapical, implicó una correcta detoxificación de la zona a través del curetaje y la aplicación de antibióticos. La respuesta inmunológica exagerada ante injertos óseos no es frecuente; sin embargo, en este caso llevó a una pérdida parcial del sustituto óseo sin comprometer el pronóstico de los implantes(AU)

Introduction: Bone regeneration allows the reintegration and conformation of tissues after the extraction or correction of a bone defect. It is considered a stimulation technique for the formation of new bone, where the construction and preservation of the clot is favored in order to avoid infiltration in the repair area of cellular components (epithelial and conjunctiva cells). Objective: Describe the changes at the morphological level during the bone regeneration process and mention different bone preservation techniques and the necessary factors for their implementation. Case presentation: Female patient with asymptomatic apical periodontitis in dental organs 34 and 37, who underwent alveolar preservation through the practice of atraumatic exodontics and bone regeneration with xenograft, collagen membrane placement and immediate post-extraction implant. Main comments: The immediate placement of post-exodontic implants allows a good preservation of the alveolus, as long as the clinical conditions of the patient allow it, for example, the absence of exacerbated infectious processes as in the present case. Bone regeneration, in the defect produced by the periapical inflammatory process, involved a correct detoxification of the area through curettage and the application of antibiotics. Exaggerated immune response to bone grafts is not common; however, in this case it led to a partial loss of bone substitute without compromising the prognosis of the implants(AU)

Hematological Changes after Caprine Demineralized Bone Matrix Implantation in Ulnar Critical Defect of Rabbit Model / Alterações hematológicas após implante de matriz óssea desmineralizada caprina em modelo de defeito ulnar crítico em coelhos

Abstract Objective Several animal models have been used in fracture healing and bone graft studies, but hematological responses are seldom reported. Therefore, the present study reported the hematological changes observed in rabbits that underwent xenografting of caprine demineralized bone matrix (CDBM). Method Twenty-four (24) male rabbits (2.5 0.5kg) were acquired for the purpose of this study and were randomly assigned to three groups: autologous bone graft (ABG), unfilled (NC), and caprine demineralized bone matrix (CDBM). Blood samples were collected through cardiac puncture under xylazine-ketamine anesthesia on day 0 (baseline), and on days 28 and 56 postsurgery and were analyzed manually within 2hours of collection. Statistical analysis was performed using a two-way analysis of variance (ANOVA) with repeated measures, and a p-value< 0.05 was considered significant. Result There was an overall significant difference in the values of total white blood cell count (p» 0.0043), neutrophil count (p< 0.0001), monocyte count (p» 0.0184), red blood cell count (p» 0.003), hemoglobin concentration (p< 0.0001) and packed cell volume (p< 0.0001) across the days and the treatment groups. There was, however, no overall significant difference in lymphocyte count (p» 0.4923), basophil count (p» 0.4183), and eosinophil count (0.4806) within days. Conclusion Response to CDBM grafting in rabbits could, therefore, be said to be characterized by marked leukocytosis with neutrophilia, lymphocytosis, and monocytosis by day 28 of postgrafting. This could form the basis with which hematology can be used to monitor body response of bone graft animal models.

Resumo Objetivo Diversos modelos animais têm sido usados em estudos sobre enxertos ósseos e o tratamento de fraturas, mas as respostas hematológicas são raramente relatadas. Este estudo descreveu as alterações hematológicas observadas em coelhos submetidos a xenoenxertos de matriz óssea desmineralizada caprina (MODC). Métodos Vinte e quatro (24) coelhos machos (2,5 0,5 kg) foram adquiridos para este estudo e divididos aleatoriamente em três grupos: enxerto ósseo autólogo (EOA); controle negativo sem preenchimento (SP) e matriz óssea desmineralizada caprina (MODC). Amostras de sangue foram coletadas por punção cardíaca sob anestesia com xilazina-quetamina no dia 0 (para estabelecimento dos valores basais) e aos dias 28 e 56 após a cirurgia; essas amostras foram submetidas à análise manual em até 2 horas após a coleta. A análise estatística foi composta por análise de variância (ANOVA) de dois fatores com medidas repetidas, e o valor de p< 0,05 foi considerado significativo. Resultados Houve uma diferença geral significativa nos números de leucócitos totais (p» 0,0043), neutrófilos (p< 0,0001), monócitos (p» 0,0184) e hemácias (p» 0,003), na concentração de hemoglobina (p< 0,0001) e no hematócrito (p< 0,0001) ao longo dos dias e entre os grupos de tratamento. No entanto, não houve diferença global significativa no número de linfócitos (p» 0,4923), basófilos (p» 0,4183) e eosinófilos (p» 0,4806) entre os dias. Conclusão A resposta ao enxerto de MODC em coelhos é, portanto, caracterizada por leucocitose intensa com neutrofilia, linfocitose e monocitose no 28° dia após o procedimento. Esses dados podem basear a utilização da hematologia no monitoramento da resposta corporal em modelos animais de enxerto ósseo.

Manejo de defectos tipo recesiones múltiples luego de la terapia de ortodoncia: un caso reportado basado en la evidencia científica / The management of multiple recession like defects after orthodontic therapy: report of a case based on scientific evidence

Por qué en este caso hay nueva in- formación? - Este caso demostró métodos basado en la evidencia para el manejo de severas recesiones gingivales luego de la terapia or- todóntica. - La modificación del grosor gin- gival lleva a resultados estables a largo plazo estéticos y funcio- nales. - Este caso demostró beneficios clínicos usando injertos tomados desde el mismo sitio donador en diferentes momentos de tiempo. Cuales son las claves de éxito para manejar este caso? - Sólidos conocimientos de la anatomía periodontal - Identificación de las caracterís- ticas de RC relacionadas con las causas de la terapia ortodóntica. - ITCSE su toma del paladar. - Uso de colgajos sin tensión. - Incremento del grosor gingival para promover resultados a largo plazo. Cuales son las limitaciones prima- rias del éxito en este caso? - Necesidad de tomas de paladar en ambos lados - Anatomía de las RG y la fina en- cía que puede limitar la extensión del colgajo - Experiencia clínica (AU)

Elevación unilateral de piso de seno maxilar con ventana lateral utilizando xenoinjerto: reporte de caso / Unilateral elevation of maxillary sinus floor with lateral window using xenografts: report of a case

En maxilares atróficos la elevación de piso de seno es una práctica de alta predictibilidad. El adve- nimiento de materiales osteoconductores que generan andamiaje para la formación ósea propor- cionaron un aumento en la tasa de éxito de los implantes endoóseos. El presente artículo reporta un caso clínico en el cual se llevo a cabo un aumento del nivel de altura del piso de seno unila- teralmente por medio de la técnica de Cadwell- Luck modificada por Tatum, técnica con ventana lateral, donde se utilizó xenoinjerto óseo (OstiumMAX, implante de matriz ósea bovina, Laboratorio Bioxen) y membrana reabsorbible de colágeno( Laboratorio Bioxen) en el primer tiempo quirúrgi- co y seis meses después, en el segundo acto quirúrgico se colocaron tres implantes endoóseos (Sistema de implante dental TRP, Laboratorio Tormicron S.R.L.). Los resultados obtenidos fueron controlados en forma mediata y a distancia a través de radiografías panorámicas y tomografías computadas tipo Cone Beam, donde se midió la altura ósea generada post injerto. Pudo consta- tarse el éxito del procedimiento, basándonos en criterios clínico radiograficos de oseointegración (AU)

Valuation of angiogenesis in bovine xenografts implanted in intracorporal sites of rabbits as models of in-vivo bioreactors / Avaliação da angiogênese em xenoenxertos bovinos implantados em sítios intracorpóreos de coelhos como modelos de biorreatores in vivo

The aim of this study was to evaluate neovascularization of bovine xenografts implanted in intracorporeal sites of rabbits (bioreactors). 30 rabbits were used, divided into 6 groups, according to the evaluation time (7, 15, 30, 45, and 60 days); each animal received xenogenic implants in 3 different intracorporeal sites (A1 - omentum bag; A2 - intermuscular space of quadriceps femoris; A3 - subperiosteal of ilium bone). Histological assessments graded the presence of angiogenesis, the number of inflammatory cells, newly formed bone tissue, and the presence of giant cells. Histological analyses showed intense angiogenesis in all implanted xenografts. Presence of inflammatory infiltrate and giant cells at the A1 implant site and presence of bone neoformation at the A3 implant site were noted. Degeneration of implants and formation of a fibrous capsule were noted. When comparing the interaction of the site with the days of evaluation, statistical analysis showed a significant difference (p≤0.05) in any time of neovascularization analysis. The vascular endothelial growth factor (VEGF) and inflammatory cells of the omentum in its structure, may have contributed to the greater presence of neovessels and inflammatory cells, a fact that may indicate functionality as a possible bone substitute.(AU)

O objetivo deste estudo foi avaliar a neovascularização de xenoenxertos bovinos implantados em sítios intracorpóreos de coelhos (biorreatores). Foram utilizados 30 coelhos, os quais foram divididos em seis grupos, de acordo com o tempo de avaliação (sete, 15, 30, 45 e 60 dias); cada animal recebeu implantes xenogênicos em três diferentes sítios intracorpóreos (A1 - bolsa de omento; A2 - espaço intermuscular do quadríceps femoral; A3 - subperiosteal do osso ílio). Avaliações histológicas classificaram a presença de angiogênese, o número de células inflamatórias, de tecido ósseo neoformado e a presença de células gigantes. As análises histológicas mostraram intensa angiogênese em todos os xenoenxertos implantados. Observou-se presença de infiltrado inflamatório e células gigantes no local do implante A1 e presença de neoformação óssea no local do implante A3. Ao mesmo tempo, a degeneração dos implantes e a formação de uma cápsula fibrosa foram observadas. Ao comparar a interação do local com os dias de avaliação, a análise estatística mostrou diferença significativa (P≤0,05) em qualquer momento da análise de neovascularização. O fator de crescimento endotelial vascular (VEGF) e as células inflamatórias do omento em sua estrutura podem ter contribuído para a maior presença de neovasos e células inflamatórias, fato que pode indicar funcionalidade como possível substituto ósseo.(AU)

Cambios Dimensionales en Técnicas de Preservación Alveolar Bartee y Bio-Col con Xenoinjerto Inteross® / Dimensional Changes in Bartee and Bio-col Ridge Preservation Technique Using Xenograft InterOss ®

La preservación de las dimensiones y contorno del reborde alveolar posterior a una extracción es de suma importancia para evitar problemas subsecuentes para la colocación de un implante dental. El objetivo de este estudio fue comparar los cambios dimensionales mediante el análisis en tomografía computarizada de haz cónico (CBCT) en sitios pre y post preservados con técnica Bartee y Bio-Col con xenoinjerto a los 6 meses de cicatrización. En un paciente de 62 años, se realizaron 6 preservaciones alveolares en órganos dentarios uniradiculares, con diagnóstico periodontal sin esperanza, grupo A la técnica de preservación alveolar Bartee (n= 3) y grupo B la técnica de preservación alveolar Bio-Col (n= 3). Se utilizó xenoinjerto (InterOss ® Anorganic Cancellous Bone Graft Granules 0,25- 1mm Sigma graft) en ambos grupos. En el grupo A se colocó injerto óseo en la totalidad del alveolo asistido por una membrana no reabsorbible de politetrafluoroetile no denso (Cytoplast ™ Regentex TXT-200 singles, Osteogenics Biomedical Inc, Lubbock, Texas). En el grupo B se colocó el injerto óseo en 3⁄4 del alveolo y el último 1⁄4 del alveolo fue ocupado por apósito de colágeno reabsorbible (CollaPlug ® Zimmer biomet). Se registraron mediciones obtenidas mediante CBCT inicial previa a la realización de preservaciones alveolares y se tomó una segunda CBCT a los 6 meses de cicatrización obteniendo la medición en sentido vertical y horizontal, coincidiendo en el plano de corte. Se observó mediante el análisis dimensional en grupo A y Grupo B obteniendo en sentido vertical un 13,58 % y 20,76 % de reabsorción y en sentido horizontal 13,45 % y 15,72 % respectivamente a los 6 meses de cicatrización, utilizando xenoinjerto por lo que no existe diferencia estadísticamente significativa en cuanto a los cambios dimensionales entre ambas técnicas p>0,05. La preservación alveolar proporciona una estabilidad dimensional contrarrestando el proceso de reabsorción fisiológica, siendo una opción predecible.

Preserving the dimensions and contour of the alveolar ridge after the dental extraction, it´s of utmost importance to avoidsubsequent problems for the placement of a dental implant. The objective of this study was compare the dimensional changes through the analysis in Cone-beam computed tomography (CBCT), in pre and post sites preserved with the Bartee and Bio-Col technique with xenograft at 6 months of healing. In a 62-year-old patient, 6 alveolar preservations were performed in uniradicular dental organs, with a hopeless periodontal diagnosis, group A the Bartee alveolar ridge preservation technique (n = 3) and group B the Bio-Col alveolar ridge preservation technique (n = 3). Xenograft (InterOss ® Anorganic Cancellous Bone Graft Granules 0.25-1mm Sigma graft) was used in both groups. In the group A a bone graft was placed in the entire socket, assisted by a dense non-absorbable polytetrafluoroethylene membrane (Cytoplast ™ Regentex TXT-200 singles, Osteogenics Biomedical Inc, Lubbock, Texas). In the group B the bone graft was placed in 3⁄4 of the socket and the last 1⁄4 of the socket was occupied by an absorbable collagen dressing (CollaPlug ® Zimmer biomet). Measurements obtained by initial CBCT before recording alveolar ridge preservations were recorded, and the second CBCT was taken 6 months after healing obtaining the measurement vertically and horizontally, coinciding in the section plane. It was observed through dimensional analysis in group A and Group B, obtaining 13.58% and 20.76% of reabsorption vertically and 13.45% and 15.72% respectively at 6 months of healing, using xenograft, so there is no statistical difference significant in terms of dimensional changes between both techniques p> 0.05. Alveolar ridge preservation provides dimensional stability by counteracting the physiological resorption process, being a predictable option.

Expression of CD44 in previously grafted alveolar bone / Expresión del marcador óseo CD44 en hueso alveolar previamente injertado

Objetive: To determine the expressions of the bone surface marker CD44 in samples of alveolar bone previously regenerated with allograft, xenograft, and mixed, using the technique of guided bone regeneration. Material and Methods: This exploratory study was approved by the institutional research and ethics committee. By means of intentional sampling and after obtaining informed consent for tissue donation, 20 samples of alveolar bone previously regenerated with guided bone regeneration therapy with particulate bone graft and membrane were taken during implant placement. The samples were stained with hematoxylin-eosin for histological analysis, and by immunohistochemistry for the detection of CD44. Results: Sections with hematoxylin-eosin showed bone tissue with the presence of osteoid matrix and mature bone matrix of usual appearance. Of the CD44+ samples, 80% were allograft and 20% xenograft. The samples with allograft-xenograft were negative. There were no differences in the intensity of CD44 expression between the positive samples. The marker was expressed in osteocytes, stromal cells, mononuclear infiltrate, and some histiocytes. Eighty percent of the CD44+ samples and 100% of the samples in which 60 or more cells were labelled corresponded to allografts (p=0.000). A total of 67% of the samples from the anterior sector, and 40% from the posterior sector were CD44+ (p=0.689). Conclusion: This study shows for the first time that guided bone regeneration using allografts is more efficient for the generation of mature bone determined by the expression of CD44, compared to the use of xenografts and mixed allograft-xenograft, regardless of the regenerated anatomical area.

Objetivo: Determinar la expresión del marcador de membrana óseo CD44 en muestras de hueso alveolar previamente regenerado con aloinjerto, xenoinjerto y mezcla mediante la técnica de regeneración ósea guiada. Material y Métodos: Con aval del Comité de Investigación y Ética, se realizó un estudio exploratorio. Por muestreo intencional y firma de consentimiento informado de donación, se tomaron durante la colocación del implante, 20 muestras de hueso alveolar previamente regenerado con terapia de regeneración ósea guiada con injerto óseo particulado y membrana. Las muestras fueron teñidas con hematoxilina-eosina para el análisis histológico y por inmunohistoquímica para la detección del CD44. Resultados: : Los cortes con hematoxilina-eosina mostraron tejido óseo con presencia de matriz osteoide y matriz ósea madura de aspecto usual. De las muestras CD44+, 80% fueron de aloinjerto y 20% de xenoinjerto. Las muestras con aloinjerto-xeoninjerto fueron negativas. No hubo diferencias en la intensidad de la expresión del CD44 entre las muestras positivas. El marcador se expresó en osteocitos, células estromales, infiltrado mononuclear y algunos histiocitos. El 80% de las muestras CD44+ y el 100% de las muestras con marcación de 60 o más células correspondían a aloinjertos (p=0,000). El 67% de las muestras del sector anterior y el 40% del sector posterior fueron CD44+ (p=0,689). Conclusión: Este estudio muestra por primera vez que la regeneración ósea guiada usando aloinjertos, es más eficiente para la generación de hueso maduro determinado por la expresión de CD44, comparado con el uso de xenoinjertos y mezcla de aloinjerto-xenoinjerto, independientemente del sector anatómico regenerado.

Establishment of a simple and efficient platform for car-t cell generation and expansion: from lentiviral production to in vivo studies

ABSTRACT Introduction: Adoptive transfer of T cells expressing a CD19-specific chimeric antigen receptor (CAR) has shown impressive response rates for the treatment of CD19 + B-cell malignancies in numerous clinical trials. The CAR molecule, which recognizes cell-surface tumor-associated antigen independently of human leukocyte antigen (HLA), is composed by one or more signaling molecules to activate genetically modified T cells for killing, proliferation, and cytokine production. Objectives: In order to make this treatment available for a larger number of patients, we developed a simple and efficient platform to generate and expand CAR-T cells. Methods: Our approach is based on a lentiviral vector composed by a second-generation CAR that signals through a 41BB and CD3-ζ endodomain. Conclusions: In this work, we show a high-level production of the lentiviral vector, which was successfully used to generate CAR-T cells. The CAR-T cells produced were highly cytotoxic and specific against CD19+ cells in vitro and in vivo, being able to fully control disease progression in a xenograft B-cell lymphoma mouse model. Our work demonstrates the feasibility of producing CAR-T cells in an academic context and can serve as a paradigm for similar institutions. Nevertheless, the results presented may contribute favoring the translation of the research to the clinical practice.

Caprine demineralized bone matrix (DBMc) in the repair of non-critical bone defects in rabbit tibias. A new bone xenograft

Abstract Purpose To evaluate the use of demineralized bone matrix of caprine origin in experimental bone defects of the tibia in New Zealand rabbits. Methods Fragments of the tibia diaphysis were collected aseptically from clinically healthy goats. The bones were sectioned into 1 cm fragments and stored at -20°C for subsequent hydrochloric acid (HCL) demineralization. A 70 mg portion of DBMc was used to fill the experimental bone defects. Twenty-four female adult New Zealand rabbits were divided into 2 groups: the MG (matrix group, left tibia) and CG (control group, right tibia). Additionally, they were separated into 4 groups with 6 animals, according to the period of analysis (15, 30, 60 and 90 days postoperatively). Using microCT, volumetric parameters were evaluated: bone volume, relationship between bone volume and total volume, bone surface area, relationship between bone surface area and total volume, number of trabeculae, trabecular thickness and trabecular separation. Results There was a statistically significant difference (P<0.05) between groups considering bone volume (BV) and bone:total volume (BV/TV), on 15, 30 and 90 days postoperatively. Control group showed a statistically significant superiority (P < 0.05) considering the mean of the variables bone surface (BS), number of trabeculae (Tb.N) and between bone surface and total volume (BS/TV) at 15 and 90 days. Conclusions Caprine demineralized bone matrix was safe and tolerable. No signs of material rejection were seen macroscopically. It is an alternative for the treatment of bone defects when autologous graft is not available or in insufficient quantities.

Reparo de defeitos ósseos críticos usando hidroxiapatita sintética ou bovina com ou sem fração mononuclear da medula óssea: análise histomorfométrica e imuno-histoquímica / Repair of critical size bone defects using synthetic or bovine hydroxyapatite with or without bone marrow mononuclear fraction: histomorphometric and immunohistochemical analysis

O presente trabalho teve como objetivo avaliar a regeneração óssea de defeitos ósseos críticos na calvária de ratos com a utilização de enxerto xenógeno Bio-Oss Small ( Bio-Oss® Geistlich Pharma AG, Wolhusen, Suíça) e hidroxiapatita sintética, (Alobone poros Osseocon Biomateriais Ltda., Rio de Janeiro/RJ, Brasil ) puros e enriquecidos com a fração mononuclear medular de célula tronco. Material e métodos: quarenta ratos adultos jovens machos, Sprague Dawley, com doze semanas distribuídos em cinco grupos com oito animais, sendo assim denominados: grupo controle, grupo 1, grupo 2, grupo 3, e grupo 4. Além dos quarenta ratos adultos jovens, mais oito ratos adultos jovens machos, Sprague Dawley, com doze semanas foram utilizados como doadores de medula óssea. Os cinco grupos foram submetidos a defeitos ósseos críticos com trefina de 8 (oito) milímetros de diâmetro, na região temporoparietal. No grupo controle não teve a colocação de biomaterial, no grupo 1 os defeitos críticos foram preenchidos por hidroxiapatita sintética ,0.10 gramas, (Alobone poros Osseocon Biomateriais Ltda., Rio de Janeiro/RJ, Brasil), no grupo 2 foram preenchidos com hidroxiapatita bovina,0,10 gramas, Bio-Oss Small (Bio-Oss® Geistlich Pharma AG, Wolhusen, Suíça), no grupo 3 os defeitos críticos foram preenchidos por hidroxiapatita sintética,0,10 gramas, (Alobone poros Osseocon Biomateriais Ltda, Rio de Janeiro/RJ, Brasil) enriquecida com 300 µl da fração mononuclear medular de células tronco na concentração de 1 x 10 6, obtida dos animais doadores de medula, e no grupo 4 os defeitos críticos foram preenchidos por hidroxiapatita bovina, 0,10 gramas, Bio-Oss Small (Bio-Oss® Geistlich Pharma AG, Wolhusen, Suíça) também enriquecida com 300 µl da fração mononuclear medular de células tronco na concentração de 1 x 10 6, obtida dos animais doadores de medula Após oito semanas, os cinco grupos tiveram todos os animais eutanasiados, por intermédio de overdose anestésica de Pentobarbital (180 mg/ kg intraperitoneal). Os grupos, foram submetidos a análises histomorfométrica, preparados corados com tricrômico de Masson, e técnicas imuno-histoquímica de VEGF e Osteopontina. Não existiu diferença estatisticamente significativa entre os grupos 1, 2, 3 e 4, porém existiu entre o grupo controle e os demais grupos que receberam tratamento para regeneração dos defeitos ósseos críticos.

The present study aimed to evaluate the bone regeneration of critical bone defects in the calvaria of rats using xenogenous grafts, Bio-Oss Small (Bio-Oss® Geistlich Pharma AG, Wolhusen, Switzerland) and synthetic hypooxypatite, (Alobone poros Osseocon Biomateriais Ltda., Rio de Janeiro / RJ, Brazil) pure or enriched with the medullary mononuclear fraction of stem cells, in the material and methods: forty young adult male rats, Sprague Dawley, were used, with twelve weeks distributed in five groups with eight animals, being thus named: control group, group 1, group 2, group 3, and group 4. In addition to the forty young adult rats, eight more animals were used as bone marrow donors. The Five groups were submitted to critical size bone defects with 8 (eight) millimeter diameter trephine, in the temporoparietal region. In the control group there was no biomaterial placement, in group 1 the critical size bone defects were filled with synthetic hydroxyapatite, 0,10 grams, (Alobone poros Osseocon Biomateriais Ltda., Rio de Janeiro / RJ, Brazil), in group 2 they were filled with bovine hydroxyapatite,0,10gramas, Bio-Oss Small (Bio-Oss® Geistlich Pharma AG, Wolhusen, Switzerland), in group 3 the critical size bone defects were filled with synthetic hydroxyapatite,0,10 grams, (Alobone poros Osseocon Biomateriais Ltda., Rio de Janeiro / RJ, Brazil) enriched with 300 µl of BMMF containing 1x106 cells, obtained from bone marrow donors animals, and in group 4 the critical size bone defects were filled with bovine hydroxyapatite, 0,10 grams Bio-Oss Small (Bio-Oss® Geistlich Pharma AG, Wolhusen, Switzerland) enriched with 300 µl of BMMF containing 1x106 cells, obtained from bone marrow donors animals. After eight weeks, all five of animals were euthanized by Pentobarbital anesthetic overdose (180 mg / kg intraperitoneal). The groups were submitted to histomorphometric analysis, using Masson's trichrome Stain, and immunohistochemical techniques of VEGF and Osteopontin. There was no statistically significant difference among groups 1, 2, 3 and 4, but it did exist with the control group and the other groups that received treatment for the regeneration of critical bone defects.

A study of the effects of imidacloprid under laboratory and field conditions on nymphs of Triatoma infestans (Hemiptera: Reduviidae)

The aim of this study was to determine imidacloprid's lethal activity against fifth-instar nymphs of Triatoma infestans. In the first stage of this work, it was assayed the topical application of this insecticide on non-fed and repletion-fed nymphs. Results showed a DL50 three times greater in non-fed bugs than in those fully engorged. The presence of food determined less time for the insecticide's maximum lethal effect: 24 h post topical application in fed nymphs and 72 h in non-fed nymphs. In the study's second stage, we assayed a xenointoxication assay on dogs. The commercial products, Advantage®, Bayer (imidacloprid 10 % p/v) and Power Ultra®, Brouwer (imidacloprid 5.15 %, permethrin 40 % and piperonyl butoxide [PBO] 3%) were evaluated. Following administration of the insecticide, nymphs were fed on dogs 24, 72, 168, 240 and 336 h. Blood intake was similar in nymphs exposed to treated dogs versus controls. Although both commercial products showed low triatomicidal activity, a higher efficacy of the product combining imidacloprid with the synergist piperonyl butoxide and permethrin versus the product with imidacloprid as the only active ingredient was observed, causing in nymphs a mortality rate of 36.3 % and 20.7 %, respectively. Our results suggest that imidacloprid, alone or in combination with permethrin and PBO, is not an alternative for control of T. infestans.

Evaluación de cicatrización en zonas donantes de injerto de piel parcial con uso de xenoinjerto en comparación con sustituto dérmico sintético de celulosa / Evaluation of healing in partial skin graft donor sites using a xenograft compared to a synthetic cellulose skin substitute

Objetivo: Realizar una evaluación de la cicatrización en la zona donante de injerto de piel parcial con uso de sustituto dérmico comparado con xenoinjerto, en pacientes con lesiones diversas que requirieron injerto de piel parcial. Materiales y métodos: Se presenta el reporte de 20 pacientes entre 19 y 65 años de la Unidad de Cirugía Plástica del Hospital María Auxiliadora de Lima Metropolitana-Perú, entre diciembre 2017 y junio 2018, donde se evaluó la cicatrización en zonas donantes de injerto de piel parcial. El estudio es de tipo intervención, analítico, prospectivo y longitudinal. Emplea el diseño doble ciego para controlar posibles sesgos. Para analizar la significancia estadística se usaron pruebas no paramétricas con un nivel de confianza 95 %. Resultados: Con el uso del sustituto dérmico se aprecia una mejor calidad de cicatrización de zonas donantes de epitelización en comparación con el xenoinjerto. Ambas técnicas se evaluaron con la escala de Vancouver que considera cinco aspectos (cicatrización, vascularidad, pigmentación, flexibilidad y altura), de los cuales, la cicatrización tuvo resultados significativos (p<0,05). Al estimar el riesgo de evolución de cicatrización según el modelo de riesgos proporcionales de Cox, se obtuvo un H=0,60 (IC95% 0,46-0,78), lo cual indica que el menor tiempo de cicatrización se encontró en el grupo en que se empleó el sustituto dérmico. Conclusiones: El sustituto dérmico es una alternativa importante que favorece buena calidad de la cicatrización en las zonas donantes. El sustituto dérmico es más eficiente que el xenoinjerto convencional al ser evaluado y comparado en la escala de cicatrización de Vancouver.

Objective: To evaluate healing in partial skin graft donor sites using a skin substitute compared to a xenograft in patients with different diseases requiring partial skin grafting. Materials and methods: This paper presents a report of 20 patients between 19 and 65 years from the Plastic Surgery Unit of the Hospital María Auxiliadora in Lima Metropolitan Area, Peru, between December 2017 and June 2018, where healing was evaluated in partial skin graft donor sites. An interventional, analytical, prospective and longitudinal study was conducted using a double-blind design to control possible biases. For the statistical significance analysis, nonparametric tests with a 95 % confidence interval were used. Results: Using a skin substitute, a better healing quality of donor sites of epithelialization was seen compared with xenografting. Both techniques were evaluated with the Vancouver scale, which considers five aspects (healing, vascularity, pigmentation, flexibility and height), out of which healing showed significant results (p<0.05). Estimation of the risk in the healing process according to the Cox proportional hazards model showed that H = 0.60 (95 % CI 0.46- 0.78), which indicates that the shortest healing time was found in the skin substitute group. Conclusions: Skin substitutes are an important alternative that favors the good quality of healing in donor sites. skin substitutes proved to be more effective than conventional xenografting when evaluated and compared using the Vancouver healing scale.

Application of Bio-Oss in tissue regenerative treatment prior to implant installation: literature review / Aplicação de Bio-Oss em tratamento regenerativo tecidual previamente a instalação de implante: revisão da literatura

Objetivo: Bio-Oss is a xenogene bone graft in which all organic components are removed while retaining their natural mineral architecture. Therefore, the aim of this study was to evaluate, through a literature review, the benefits of using Bio-Oss for tissue regenerative treatment prior to implant placement. Materials and methods: a search was performed in Pubmed (Medline) in order to identify articles published in English between January 1, 2000 and June 31, 2018, where the Bio-Oss graft was used prior to implantation of implants in humans. A total of 40 studies were selected for detailed analysis. From this analysis, 18 articles were identified for inclusion in this review. Results: the articles analyzed in the review showed several beneficial effects of this xenograft, such as: positive osteoconductive properties, recovery of bone heights at sites with severe atrophies, slow xenograft reabsorption suggesting long term stability, survival rates and success of implants placed in grafted sites ranging from 91 to 100% in several studies. Conclusion: the use of bio-oss as a bone substitute is a viable alternative in the placement before dental implants, being used in clinical practice and with proved efficacy in several studies, due to its similarity with the bone and its high level of osteoconductivity (AU)

Objetivo: o Bio-Oss é um substituído ósseo xenógeno em que são removidos todos os componentes orgânicos, mantendo sua arquitetura natural. Assim, este trabalho teve como foco avaliar através de uma revisão de literatura os benefícios do uso do Bio-Oss para tratamento regenerativo tecidual previamente a instalação de implantes. Materiais e métodos: realizouse uma busca no Pubmed (Medline) com intuito de se identificar artigos publicados em inglês entre 1 de janeiro de 2000 e 31 de junho de 2018, em que se utilizava o enxerto Bio-Oss previamente a instalação de implantes em humanos. Foram selecionados 40 estudos completos para uma análise detalhada. A partir dessa análise foram identificados 18 artigos para inclusão nessa revisão. Resultados: os artigos analisados na revisão mostraram diversos efeitos benéficos desse xenoenxerto, como: propriedades osteocondutoras positivas, recuperação de alturas ósseas em locais com atrofias graves, reabsorção lenta do xenoenxerto sugerindo estabilidade a longo prazo, taxas de sobrevivência e sucesso de implantes colocados em locais enxertados variando de 91 a 100% em diversas pesquisas. Conclusão: a utilização do biooss como substituto ósseo é uma alternativa viável na colocação previamente ao implante dentário, sendo utilizado na prática clínica e comprovado em diversos estudos sua eficácia, devido sua similaridade com o osso natural e seu alto grau de osteocondutividade (AU)

Estudio histológico y radiográfico de la preservación alveolar post-exodoncia con sulfato de calcio y xenoinjerto en cobayos / Estudo histológico e radiográfico da preservação alveolar pós-extracção com sulfato de cálcio e xenoinjerto em cobaias / Histological and radiographical study of the alveolar post-extractionpreservation with calcium sulfate and xenoinjerto in guinea pigs

Después de realizar una exodoncia inicia un proceso de remodelación ósea, dejando como consecuencia un volumen óseo disminuido que puede impedir la colocación de un implante dental en óptimas condiciones. Objetivo: Evaluar la preser-vación alveolar post-exodoncia utilizando sulfato de calcio oxenoinjerto en cobayos en comparación con la cicatrización espontánea. Materiales y Métodos: Se utilizaron 30 cobayos machos, de cuatro meses de edad, asignados en tres grupos de 10 cobayos cada uno: G1 Sulfato de calcio, G2 Xenoinjerto (bovino) G3 control negativo (sin sustituto óseo). Se realizó la exodoncia del incisivo central inferior derecho se cureteó y lavó con suero fisiológico, el grupo G1 y G2 se rellenaron con el biomaterial correspondiente, el grupo G3 no recibió ningún biomaterial. La sutura fue punto en X con Vicryl (4/0). Se tomó radiografías estandarizadas en el pos operatorio inmediato y a los 40 dias,se medió la cresta alveolar en mesial, distal y coronal. A los 40 días los cobayos fueron sacrificados, obteniendo el segmento de hueso alveolar para el análisis histológico del alvéolo. Los datos fueron analizados mediante el test de Kruskal Wallis y chi cuadrado con un nivel de significancia del 5%. Resultados: Fue observada la preservación de la cresta alveolar en mesial 2,92 (p= 0,025) y cervical 0,92 (p=0,043). En el análisis histológico los espacios en la región fibrosa en la parte media del alvéolo fue 26,00 para el sulfato de calcio y 23,80 para el xenoinjerto (p = 0,011), en apical 16,20para el sulfato de calcio y 20,60para el xenoinjerto (p= 0,020), espacios vacíos en coronal (p= 0,003), tejido fibroso (p=0,010), regeneración ósea (p= 0,019), áreas hialinas (p= 0,010).Conclusión: Se preservan mejor los alvéolos postextracción usando Sulfato de Calcio y Xenoinjerto en compa-ración con la cicatrización espontánea en cobayos.

After performing an extraction, a process of bone remodeling begins, leaving as a consequence a decreased osseous volume that can prevent the placement of a dental implant in optimal conditions. Objective: To evaluate post-exodontia alveolar preservation using calcium sulfate or xenograft in guinea pigs compared to spontaneous healing. Materials and Methods:30 male guinea pigs, four months old, assigned in three groups of 10 guinea pigs each were used: G1 Calcium sulphate, G2 Xenograft (bovine) G3 Negative control (without bone substitute). Exodontia of the lower right central incisor was curetted and washed with physiological serum, group G1 and G2 were filled with the corresponding biomaterial, group G3 did not receive any biomaterial. The suture was point in X with Vicryl (4/0). Standardized radiographs were taken in the imme-diate postoperative period and after 40 days, the alveolar crest was measured mesially, distally and coronally. At 40 days the guinea pigs were sacrificed, obtaining the segment of alveolar bone for the histological analysis of the alveolus. The data were analyzed through of the Kruskal Wallis test and chi square test with a level of significance of 5%. Results: The preservation of the alveolar crest was observed in mesial 2.92 (p = 0.025) and cervical 0.92 (p = 0.043). In the histological analysis, the spaces in the fibrous region in the middle part of the alveolus were 26.00 for calcium sulphate and 23.80 for xenograft (p = 0.011), apical 16.20 for calcium sulphate and 20 , 60 for the xenograft (p = 0.020), empty coronal spaces (p = 0.003), fibrous tissue (p = 0.010), bone regeneration (p = 0.019), hyaline areas (p = 0.010). Conclusion: Post-extraction alveoli are better preserved using Calcium Sulphate and Xenograft compared to spontaneous wound healing in guinea pigs.

Após a realização de uma extração, inicia-se um processo de remodelação óssea, deixando como conseqüência um volume ósseo diminuído que pode impedir a colocação de um implante dentário em condições ótimas. Objetivo: Avaliar a preservação alveolar pós- pós extração com sulfato de cálcio ou xenoenxerto em cobaias em comparação com a cicatrização espontânea. Materiais e Métodos: Foram utilizadas 30 cobaias machos de quatro meses de idade, distribuídos em três grupos de 10 cobaias cada. G1 Sulfato de cálcio, G2 Xenoenxerto (bovino) G3 Controle negativo (sem substituto ósseo). A exodontia do incisivo central inferior direito foi curetada e lavada com soro fisiológico, o grupo G1 e G2 foram preenchidos com o biomaterial correspondente, o grupo G3 não recebeu nenhum biomaterial. A sutura foi ponto em X com Vicryl (4/0). Radiografias padronizadas foram realizadas no pós-operatório imediato e, após 40 dias, a crista alveolar foi medida mesial, distal e coronária. Aos 40 dias as cobaias foram sacrificadas, obtendo-se o segmento de osso alveolar para a análise histológica do alvéolo. Os dados foram analisados por meio do teste de Kruskal Wallis e teste do qui-quadrado com nível de significância de 5%. Resultados: A preservação da crista alveolar foi observada em mesial 2,92 (p = 0,025) e cervical 0,92 (p = 0,043). espaços análise histológica da região fibroso no meio do alvéolo foi 26,00 para o sulfato de cálcio e de 23,80 para o xenoenxerto (p = 0,011), em apical 16,20 para o sulfato de cálcio e 20 , 60 para o xenoenxerto (p = 0,020), em espaços vazios coronal (p = 0,003), o tecido fibroso (p = 0,010), a regeneração óssea (p = 0,019), as áreas hialinas (p = 0,010). Conclusão: Os alvéolos pós-extração são melhor preservados usando Sulfato de Cálcio e Xenoenxerto em comparação com a cicatrização espontânea em cobaias.