Three-dimensional printed poly (L-lactide) and hydroxyapatite composite for reconstruction of critical bone defect in rabbits

ABSTRACT Purpose To use a 3D printed poly (L-lactide) acid (PLLA) and hydroxyapatite (HA) composite as a bone substitute for reconstruction of a critical bone defect in the radius of rabbits. Methods A 1.5 cm ostectomy was performed in the radial diaphysis of 60 New Zealand white rabbits. The rabbits were divided into three groups according to surgical treatment of the bone defect (group I - control, group II - bone graft, group III - 3D PLLA). Each group was divided into four subgroups with different radiographic and histopathologic evaluation times (T1 - 15 days, T2 - 30 days, T3 - 60 days, T4 - 90 days). Results The implant group had greater clinically lameness (p = 0.02), edema (p = 0.007), pain (p = 0.04) and more complications at the surgical site (p = 0.03). Histologically, this group showed greater congestion (p = 0.04), hemorrhage (p = 0.04) and inflammation. Osteogenesis was microscopically similar between days (p = 0.54) and treatments (p = 0.17), even though radiographically, more effective bone healing occurred in the graft group (II), with more callus and bone bridge formation. Conclusions The customization of a 3D PLLA/HA scaffold was successful. However, in animals receiving the polymer-ceramic composite less bone callus and bone bridge was formed compared to the graft group.

Enucleation of Odontogenic Cyst with Bone Graft / Enucleación de Quiste Odontogénico con Injerto Óseo

ABSTRACT: Periapical cyst originates from an inflammatory reaction in the body that occurs due to a long-term endodontic aggression. It is more prevalent in caucasian male, during the third decade of life, in the anterior portion of the maxilla. They are commonly radiographic findings, due to their asymptomatic aspect. This study reports a Periapical Cyst in the portion corresponding to teeth 21, 22 and 23, which was treated by enucleation of the cyst, apicoectomy and retrograde root filling with Mineral trioxide aggregate (M.T.A) of teeth 21 and 22, filling of the cyst cavity with xenogeneic bone graft GenOx and a collagen membrane Gen-Derm. Observations after three months show good and rapid bone regeneration, periodontal and periapical health of the teeth involved.

RESUMEN: El quiste periapical se origina de una reacción inflamatoria que ocurre debido a una agresión endodóntica a largo plazo. Es más frecuente en el varón caucásico, durante la tercera década de la vida, en la porción anterior del maxilar. Son comúnmente hallazgos radiográficos, debido a su aspecto asintomático. En este estudio informamos acerca de un quiste periapical, en la porción correspondiente a los dientes 21, 22 y 23, que se trató mediante enucleación, apicectomía y relleno de raíz retrógrada con agregado de trióxido mineral (MTA) de los dientes 21 y 22, relleno de la cavidad del quiste con injerto óseo xenogénico Gen-Ox y una membrana de colágeno GenDerm. Las observaciones después de tres meses mostraron una buena y rápida regeneración ósea, con conservación de la salud periodontal y periapical de los dientes involucrados.

Uso de la Fibrina Rica en Plaquetas Inyectable (i-PRF) en Defectos Infra Óseos en Terapia Periodontal no Quirúrgica. Reporte de Dos Casos / Use of Injectable Platelet-Rich Fibrin (i-PRF) in Infra Osseous Defects in Non-Surgical Periodontal Therapy. Report of Two Cases

RESUMEN: Entre los concentrados plaquetarios de segunda generación, ha suscitado creciente interés, el uso de fibrina rica en plaquetas y leucocitos inyectable (i-PRF); que se obtiene a partir de la centrifugación inmediata de sangre venosa del propio individuo, y que aporta concentraciones elevadas de factor de crecimiento vascular endotelial, factor de crecimiento transformante beta, y factor de crecimiento derivado de plaquetas, entre otras proteínas que inician y coordinan el proceso reparativo. Su nula citotoxicidad y consistencia líquida abren un nuevo campo de estudio y experimentación en el ámbito de la Cirugía Oral y de la Periodoncia, como sustancia para irrigar. El objetivo de este manuscrito fue reportar el uso del i-PRF como irrigador subgingival en el tratamiento periodontal convencional de defectos infra óseos con 6 meses de seguimiento. En ambos casos, se verificó un efecto positivo de irrigación, lo que abre el debate al uso de productos farmacéuticos tradicionales como la clorhexidina versus preparados autólogos sin efectos adversos reportados a la fecha.

ABSTRACT: Second generation platelet concentrates include the use of injectable platelet-rich fibrin (i-PRF), which has generated increasing interest because it is derived from immediate centrifugation of venous blood from the patients themselves. It provides high concentrations of vascular endothelial growth factor, transforming growth factor beta, and platelet-derived growth factor, among other proteins that initiate and coordinate the healing process. Its null cytotoxicity and liquid consistency has opened new research lines in the field of oral surgery and periodontics, as an irrigation substance. The aim of this manuscript was to report the use of i-PRF, as a subgingival irrigator in conventional periodontal treatment of infra osseous defects, with six months follow-up. In both cases, a positive effect of irrigation was confirmed. These findings, open the debate as regards the use of traditional pharmaceutical products (such as chlorhexidine), versus autonomous preparations without adverse effects reported to date.

Short-term use of resveratrol in alloplastic graft material applied with calvarial bone defects in rats

Abstract Purpose: The effects of resveratrol administration on calvarial bone defects with alloplastic graft material was investigated for osteoinductive reaction and bone development in rats. Methods: Healthy male rats were randomly divided into 3 groups consisting of 10 rats. Groups were as follows: control (defect) group, defect + graft group, and defect + graft + resveratrol group. A calvarial bone defect was created in all groups, alloplastic bone grafts were applied to the defect in the 2nd and 3rd group, resveratrol (5 mg/kg/day) was added to the drinking water of the animals following graft application for 28 days in the 3rd group. Results: Increase in osteoclasts and necrotic changes were observed histopathologically in the control group. In the 2nd group, reduction of inflammation, congestion of blood vessels, increased osteblastic activity, osteoinductive effect, progression of osteocyte development and increased collagen fibers in connective tissue were observed. In the 3rd group, osteoblasts seemed to secrete bone matrix and accelerate osteoinductive effect with increased osteopregenitor activity and positive osteopontin and osteonectin expressions. Conclusion: Resveratrol treatment was thought to be an alternative and supportive drug for implant application by inducing new bone formation in the calvaral defect region as a result of short-term treatment.

Characterization of bone substitute beta946; -TCP block for maxillofacial reconstruction / Caracterización del bloque beta946; -TCP de sustitución ósea para la reconstrucción maxilofacial

SUMMARY: The aim of this study was to characterize a commercial beta tricalcium phosphate (β-TCP) block allograft for use in maxillofacial reconstruction, evaluating its homogeneity, porosity and mineralization. Two commercial 5 x 5 x10 mm chronOS Vivify β-TCP blocks were used, which were evaluated by a STEM SU-3500 variable pressure scanning electron microscope (SEM-STEM) (Hitachi, Japan). For the semi-quantitative microanalysis of elements, the QUANTAX 100 energy dispersive x-ray spectrometer detector (EDX) (Bruker, Germany) was used. The homogeneity of the structural morphology, macropore and micropore size and component homogeneity were evaluated. The microscopic analysis showed micropores of 164.92 mm (± 35.032 mm) in diameter in the outer area and micropores in the inner area of 54.44 mm (± 17.676 mm). The formation of porosities and irregularities present in the block was heterogeneous between the outer and inner surfaces. The mineral content of the blocks presented homogeneity with the presence of carbon (2.02 %), oxygen (44.33 %), phosphate (16.62 %) and calcium (37.87 %). The β-TCP block can be used in bone reconstruction but the presence of reduced macropore and micropore sizes could limit efficiency in the substitution and bone regeneration phase.

RESUMEN: El objetivo de este estudio fue caracterizar un aloinjerto de bloqueo de fosfato tricálcico (β-TCP) comercial para su uso en la reconstrucción maxilofacial, evaluando su homogeneidad, porosidad y mineralización. Se utilizaron dos bloques comerciales de 5 x 5 x 10 mm de vivify β-TCP de chronOS, que se evaluaron mediante un microscopio electrónico de barrido de presión variable STEM SU-3500 (SEM-STEM) (Hitachi, Japón). Para el microanálisis de elementos semicuantitativo, se utilizó el detector de espectrómetro de rayos X de dispersión de energía QUANTAX 100 (EDX) (Bruker, Alemania). Se evaluó la homogeneidad de la morfología estructural, el tamaño del macroporo y microporo y la homogeneidad de los componentes. El análisis microscópico mostró microporos de 164,92 mm (± 35,032 mm) de diámetro en el área externa y microporos en el área interna de 54,44 mm (± 17,676 mm). La formación de porosidades e irregularidades presentes en el bloque fue heterogénea entre las superficies externas e internas. El contenido mineral de los bloques presentó homogeneidad con la presencia de carbono (2,02 %), oxígeno (44,33 %), fosfato (16,62 %) y calcio (37,87 %). El bloque β-TCP se puede utilizar en la reconstrucción ósea, pero la presencia de macroporos y tamaños de microporos reducidos podría limitar la eficacia en la fase de sustitución y regeneración ósea.

Avaliação do aumento ósseo obtido após cirurgias de enxerto em seio maxilar com um biomaterial aloplástico / Evaluation of bone augmentation obtained after maxillary sinus grafting with alloplastic biomaterial

Objetivos: avaliar o aumento ósseo com um biomaterial aloplástico no seio maxilar. Materiais e métodos: foram selecionados seis pacientes, totalizando nove seios maxilares, que realizaram cirurgia de reconstrução óssea em região posterior de maxila. Todas as cirurgias de elevação do seio maxilar traumáticas utilizaram o biomaterial sintético Straumann Bone Ceramic. Os pacientes realizaram uma tomografia pré-operatória, e uma após seis meses do ato cirúrgico, em que foram obtidas medidas lineares horizontais e verticais na imagem panorâmica da tomografia e medidas lineares horizontais e verticais no corte sagital da tomografia, ambas no centro das imagens. Resultados: identificou-se 100% de sucesso nas cirurgias de elevação de seio maxilar, em que verticalmente obteve-se diferença estatística significante (p < 0,05) e horizontalmente sem significância estatística (p > 0,05). Em média, obteve-se ganho vertical ósseo de 14,73 mm na imagem panorâmica e 16,05 mm no corte sagital, e espessura 20,82 mm na imagem panorâmica e 11,37 mm no corte sagital. Conclusão: o biomaterial sintético Straumann Bone Ceramic demonstrou-se excelente para a reconstrução de seios maxilares.

Objectives: to evaluate bone augmentation using an alloplastic material. Material and methods: six patients (9 maxillary sinuses) underwent surgical bone reconstruction at the posterior maxillary region. All surgeries were performed after atraumatic sinus membrane lifting and packing of Straumann BoneCeramic. Also, CBCTs were made at baseline and 6 months later to generate horizontal and vertical measurements at the panoramic and sagittal view modes both at the center of the images. Results: operative procedures were considered 100% successful. At the vertical dimension, statistical differences were obtained (p<0.05) but no significant differences were seen in the horizontal dimension (p>0.05). Overall, the vertical mean gain was 14.73mm at the panoramic and 16.05mm at the sagittal sections, being the observed thicknesses of 20.82mm and 11.37mm, respectively. Conclusion: the Straumann BoneCeramic biomaterial provided excellent results for maxillary sinus reconstructions.

Horizontal Bone Reconstruction on sites with different amounts of native bone: a retrospective study

Abstract: The lack of guidelines for bone augmentation procedures might compromise decision making in implantology. The objective of this study was to perform a retrospective study to verify the outcomes of horizontal bone reconstruction in implant dentistry with different types of materials and amounts of native bone in the recipient bed to allow for a new guideline for horizontal bone reconstruction. One hundred preoperative CT scans were retrospectively evaluated and categorized in accordance to horizontal bone defects as presence (Group P) or absence (Group A) of cancellous bone in the recipient bed. Different approaches were used to treat the edentulous ridge and the outcomes were defined either as satisfactory or unsatisfactory regarding the possibility of implant placement. The percentage distribution of the patients according to the presence or absence of cancellous bone was 92% for Group P and 8% for Group A. In Group P, 98% of the patients had satisfactory outcomes, and the use of autografts had 100% of satisfactory outcomes in this group. In Group A, 37.5% of the patients had satisfactory outcomes, and the use of autografts also yielded 100% of satisfactory outcomes. The use of allografts and xenografts in Group A had 0% and 33.3% of satisfactory outcomes, respectively. Therefore, it seems reasonable to speculate that the presence of cancellous bone might be predictive and predictable when the decision includes bone substitutes. In cases of absence of cancellous bone in the recipient bed, the use of a vitalized graft seems to be mandatory.

A comparison of different bone graft materials in peri-implant guided bone regeneration

Abstract The aim of this study was to compare the effects of hydroxyapatite (HA), deproteinized bovine bone (DPB), human-derived allogenic bone (HALG), and calcium sulfate (CAP) graft biomaterials used with titanium barriers for bone augmentation to treat peri-implant defects in rat calvarium treated by guided bone regeneration (GBR). Thirty-two female Sprague-Dawley rats were divided into four groups: DPB, HALG, HA, and CAP. One titanium barrier was fixed to each rat's calvarium after the titanium implants had been fixed. In total, 32 titanium implants and barriers were used. Ninety days after the surgical procedure, all the barriers were removed. After decalcification of bone tissue, the titanium implants were removed gently, and new bone regeneration in the peri-implant area was analyzed histologically. Immunohistochemical staining of vascular endothelial growth factor (VEGF) was also performed. There were no statistically significant between-group differences in new bone regeneration or VEGF expression after 3 months. According to the results of the histological and immunohistochemical analyses, none of the grafts used in this study showed superiority with respect to new bone formation.

Bioactive glass added to autogenous bone graft in maxillary sinus augmentation: a prospective histomorphometric, immunohistochemical, and bone graft resorption assessment

Abstract Objective The aim of this study was to compare the bone resorption rate, histomorphometry and immunohistochemical findings of bioactive glass (Biogran; Biomet, Warsaw, IN, USA) mixed with autogenous bone grafts (1:1) and autogenous bone graft isolate in maxillary sinus elevation surgery. Material and Methods A total of 9 maxillary sinuses were grafted with Biogran with autogenous bone graft (group 1) and 12 were mixed with autogenous bone graft (group 2). Postoperative cone beam computed tomography (CBCT) was used to measure the initial graft volume after 15 days (T1), and 6 months later, another CBCT scan was performed to evaluate the final graft volume (T2) and determine the graft resorption rate. The resorption outcomes were 37.9%±18.9% in group 1 and 45.7%±18.5% in group 2 (P=0.82). After 6 months, biopsies were obtained concurrent with the placement of dental implants; these implants were subjected to histomorphometric analysis and immunohistochemical analysis for tartrate-resistant acid phosphatase (TRAP). Results The average bone formation in group 1 was 36.6%±12.9 in the pristine bone region, 33.2%±13.3 in the intermediate region, and 45.8%±13.8 in the apical region; in group 2, the values were 34.4%±14.4, 35.0%±13.9, and 42.0%±16.6 of new bone formation in the pristine bone, intermediate, and apical regions, respectively. Immunostaining for TRAP showed poor clastic activity in both groups, which can indicate that those were in the remodeling phase. Conclusions The similarity between the groups in the formation and maintenance of the graft volume after 6 months suggests that the bioactive glass mixed with autogenous bone (1:1) can be used safely as a bone substitute for the maxillary sinus lift.

Bone repair access of BoneCeramic™ in 5-mm defects: study on rat calvaria

Abstract Objective: The aim of this study was to evaluate the osteoconductive potential of BoneCeramic™ on bone healing in rat calvaria 5-mm defects. Material and Methods: A 5-mm calvaria bone defect was induced in three groups and the defect was not filled with biomaterial [Clot Group (CG)], autogenous bone (AG), or Bone Ceramic Group (BCG). Animals were euthanized after 14 or 28 days and the bone tissue within the central area of the bone defect was evaluated. Results were compared using ANOVA and Tukey test (p<0.05). Immunohistochemistry was performed using primary antibodies against osteocalcin, RUNX-2, TRAP, VEGF proteins, and 3-dimensional images of the defects in μCT were obtained to calculate bone mineral density (BMD). Results: In BCG, the defect was completely filled with biomaterial and new bone formation, which was statistically superior to that in the GC group, at both time-points (p<0.001 for 14 days; p=0.002 for 28 days). TRAP protein showed weak, RUNX-2 showed a greater immunolabeling when compared with other groups, VEGF showed moderate immunostaining, while osteocalcin was present at all time-points analyzed. The μCT images showed filling defect by BCG (BMD= 1337 HU at 28 days). Conclusion: Therefore, the biomaterial tested was found to be favorable to fill bone defects for the reporting period analyzed.

Osteointegration of porous absorbable bone substitutes: A systematic review of the literature

Biomaterials' structural characteristics and the addition of osteoinductors influence the osteointegration capacity of bone substitutes. This study aims to identify the characteristics of porous and resorbable bone substitutes that influence new bone formation. An Internet search for studies reporting new bone formation rates in bone defects filled with porous and resorbable substitutes was performed in duplicate using the PubMed, Web of Science, Scielo, and University of São Paulo Digital Library databases. Metaphyseal or calvarial bone defects 4 to 10 mm in diameter from various animal models were selected. New bone formation rates were collected from the histomorphometry or micro-CT data. The following variables were analyzed: animal model, bone region, defect diameter, follow-up time after implantation, basic substitute material, osteoinductor addition, pore size and porosity. Of 3,266 initially identified articles, 15 articles describing 32 experimental groups met the inclusion criteria. There were no differences between the groups in the experimental model characteristics, except for the follow-up time, which showed a very weak to moderate correlation with the rate of new bone formation. In terms of the biomaterial and structural characteristics, only porosity showed a significant influence on the rate of new bone formation. Higher porosity is related to higher new bone formation rates. The influence of other characteristics could not be identified, possibly due to the large variety of experimental models and methodologies used to estimate new bone formation rates. We suggest the inclusion of standard control groups in future experimental studies to compare biomaterials.

Influence of ß-tricalcium phosphate of different geometric shape on the morphology of regeneration of experimental defect of compact bone tissue / Influencia del fosfato ß-tricálcico de diferentes formas geométricas en la morfología de la regeneración del defecto experimental del tejido óseo compacto

Purpose: to compare the healing process of a defect of compact bone tissue after the implantation of osteoplastic materials based on ß-tricalcium phosphate ("ChronOS™" and "Calc-i-oss®"), which differ by manufacturer, geometrical shape and microscopic structure. Methods: the experiment was performed on 48 white male Wistar rats. In the middle third of the diaphysis of the femur we produced a perforated defect of 2.5 mm diameter in the medullary canal, which in the animals of the first group was filled with the osteoplastic material "ChronOS™" (block, Synthes, Switzerland), and in the animals of the second group with "Calc-i-oss®" (granules, «Degradable Solutions Dental¼, Switzerland). Fragments of the injured bones were studied on the 60th and 120th day by light microscopy with morphometry and by scanning electron microscopy. Results: it was found that regardless the geometric shape and the microscopic structure, both osteoplastic materials show high biocompatibility, osteoconductive properties, good integration with bone tissue of the regenerate, and that the microscopic structure of ß-tricalcium phosphate ("ChronOS™") may significantly affect the microscopic structure of bone tissue of the regenerate, which manifests itself in the specificity of its geometric shape. It was noticed that osteoplastic materials "ChronOS™" and "Calc-i-oss®" almost at the same rate were subjected to resorption and replacement by the bone tissue, the ratio of which was 22.55±1.25 to 77.45±1.25 and 25.72±2.06% to 74.28±2.06% on the 60th day of the experiment, and 17.65±1.09 to 82.35±1.09 and 18.31±1.54% to 81.69±1.54% on the 120th day. (AU)

Objetivo: Comparar el proceso de cicatrización de un defecto del tejido óseo compacto tras la implantación de materiales osteoplásticos a base de fosfato ß-tricálcico («ChronOS™¼ and «Calc-i-oss®¼) que difieren según el fabricante en la forma geométrica y estructura microscópica. El estudio fue realizado en 48 ratas Wistar machos en los cuales se produjo, en el tercio medio de la diáfisis del fémur, un defecto perforado de 2,5 mm de diámetro, el cual fue llenado con el material «ChronOS™¼ (block, Synthes, Switzerland) en un grupo y con «Calc-i-oss®¼ (granules, «Degradable Solutions Dental¼, Switzerland) en el segundo grupo. El sector del defecto fue evaluado en los días 60 y 120 por microscopía óptica y por microscopía electrónica de barrido. Resultados: independientemente de la forma geométrica y la estructura microscópica, ambos materiales osteoplásticos mostraron alta biocompatibilidad, propiedades osteoconductivas y buena integración con el tejido óseo regenerado. La estructura microscópica del fosfato ß-tricálcico («ChronOS™¼) puede afectar significativamente a la estructura microscópica del tejido óseo regenerado, que se manifiesta en su forma geométrica. Adicionalmente, se observó que ambos materiales osteoplásticos «ChronOS™¼ y «Calc-i-oss®¼ mostraron valores similares de resorción y reemplazo por tejido óseo, cuya relación al 60º día del experimento fue de 22,55±1,25 a 77,45±1,25 y 25,72±2,06% a 74,28±2,06%, y a los 120 días de 17,65±1,09 a 82,35±1,09 y de 18,31±1,54% a 81,69±1,54% respectivamente. (AU)

Utilização de PRF líquido como biomaterial auxiliar em enxertos particulados / Use of liquid PRF as auxiliary biomaterial in particulate grafts ­ case report

O PRF líquido pode facilitar o posicionamento e a escultura de enxertos ósseos particulados, além dos possíveis benefícios relacionados ao reparo ósseo e fibromucosa. Para tanto, é necessário que o profissional conheça os aspectos práticos e teóricos envolvidos no seu uso. Um paciente com 45 anos de idade, apresentava perda dos incisivos maxilares e de espessura da crista óssea na região, impossibilitando a colocação de implantes de diâmetro convencional. Para a regeneração óssea, foi utilizado enxerto com substituto ósseo associado a coágulos de PRF, PRF líquido e tela de titânio. Após o reparo ósseo, foram instalados dois implantes na região dos incisivos laterais como pilares de uma prótese parcial fixa de quatro elementos. O PRF líquido pode facilitar procedimentos de enxertia óssea e diminuir o risco de iatrogenia sem, contudo, aumentar significativamente o custo e o tempo do tratamento.

The liquid PRF can facilitate the positioning and carving of particulate bone grafts, in addition to possible benefi ts related to bone and soft tissue repair. Therefore, it is necessary that the professional knows the practical and theoretical aspects involved in its use. A 45-year-old patient presented loss of maxillary incisors and thickness of the bone crest in the region, making it impossible to place implants of conventional diameter. For bone regeneration, graft was used with bone substitute associated with PRF clots, liquid PRF and titanium mesh. After bone repair, two implants were installed in the region of the lateral incisors as pillars of a fixed partial denture of four elements. The liquid PRF can facilitate bone graft procedures and reduce the risk of iatrogenic, without, however, significantly increasing the cost and time of treatment.

Off-label use of rhBMP-2 as bone regeneration strategies in mandibular ameloblastoma unicystic / Utilização off-label das rhBMP-2 como estratégia de regeneração do tecido ósseo em ameloblastoma mandibular

ABSTRACT Jawbone reconstruction after tumor resection is one of the most challenging clinical tasks for maxillofacial surgeons. Osteogenic, osteoinductive, osteoconductive and non-antigenic properties of autogenous bone place this bone as the gold standard for solving problems of bone availability. However, the need for a second surgical site to harvest the bone graft increases significantly both the cost and the morbidity associated with the reconstructive procedures. Bone grafting gained an important tool with the discovery of bone morphogenetic proteins in 1960. Benefit of obtaining functional and real bone matrix without need of second surgical site seems to be the great advantage of use bone morphogenetic proteins. This study analyzed the use of rhBMP-2 in unicystic ameloblastoma of the mandible, detailing its structure, mechanisms of cell signaling and biological efficacy, in addition to present possible advantages and disadvantages of clinical use of rhBMP-2 as bone regeneration strategy.

RESUMO A reconstrução óssea dos maxilares após ressecções tumorais é uma das tarefas mais difíceis para o cirurgião maxilofacial. As propriedades osteogênicas, osteoindutoras, osteocondutoras e não antigênicas do osso autógeno o colocam como o padrão-ouro para a solução de problemas de disponibilidade óssea. Entretanto a coleta do enxerto ósseo necessita de um segundo sítio cirúrgico, aumentando significativamente o custo e a morbidade associados ao procedimento reconstrutivo. A enxertia óssea ganhou uma excelente ferramenta com a descoberta das proteínas ósseas morfogenéticas na década de 1960. O benefício da obtenção de matriz óssea verdadeira e funcional, sem a necessidade de um segundo sítio cirúrgico, parece ser a grande vantagem do uso das proteínas ósseas morfogenéticas. Neste contexto, o objetivo deste estudo foi analisar a utilização da rhBMP-2 na regeneração óssea de ameloblastoma mandibular unicístico, detalhando sua estrutura, seus mecanismos de sinalização celular e sua eficácia biológica, além de apresentar potenciais vantagens e desvantagens da utilização clínica das rhBMP-2, enquanto estratégia regenerativa.

Desenvolvimento, caracterização e desempenho biológico de um novo biomaterial de liberação controlada à base de carbonato de lítio aplicado ao reparo ósseo / Development, characterization and biological performance of a new biomaterial of controlled release based on lithium carbonate applied to bone repair

Neste trabalho desenhou-se bases de desenvolvimento, caracterização e avaliação dos aspectos biológicos relacionados ao Sistema BoneLithium, idealizado a partir da associação de partículas de carbonato de lítio dispersas em matriz gel de carbopol®, com capacidade de atuar como um sistema liberador de fármacos. Metodologicamente este estudo se dividiu em quatro partes: Na primeira delas, o objetivo central foi o desenvolvimento e a caracterização do biomaterial através da manipulação farmacológica. Na segunda etapa, avaliou-se a reação tecidual em subcutâneo de ratos, na terceira a influência das partículas de lítio liberadas pelo Sistema BoneLithium no reparo ósseo através de modelos experimentais utilizando coelhos, e por ultimo, a capacidade de cicatrização de defeitos ósseos criados cirurgicamente em calvária de ratos, tratados com o biomaterial e diferentes opções de enxertos ósseos com o objetivo de comparar a eficiência do Sistema BoneLithium aos protocolos pré-existentes. Experimentalmente, avaliou-se a reação tecidual onde se utilizou 15 ratos machos divididos aleatatoriamente em 5 grupos onde implantouse no subcutâneo tubos de butterfly contendo o biomaterial por períodos de preservação recomendados pela norma ADA 10993 para teste de reação tecidual. Os resultados demonstram que o Sistema BoneLithium apresenta reação tecidual normal. Para a avaliação do comportamento biológico do Sistema BoneLithium foram utilizados coelhos brancos adultos da raça New Zealand nos quais defeitos ósseos bilaterais de 1 cm de diâmetro foram confeccionados cirurgicamente na calvária e foram Tratados com o Sistema Bone Lithium do (lado Direito) e somente o Gel de Carbopol (lado esquerdo)/Coágulo sanguíneo (controle). A Histomorfometria demonstrou comportamento favorável ao reparo ósseo e adicionalmente através de Microtomografia Computadorizada (CT SKYSCAN), foi possível constatar diferenças significativas considerando p> 0.05 (ANOVA, Tukey) para o processo de reparo ósseo. A avaliação da performance do Sistema BoneLithium utilizando ratos Wistar nos quais foram criados defeitos críticos no centro da calvária e tratados com diferentes modalidades de enxertos ósseos (controle, autógeno, osso de banco (Unioss®, Marília Brasil), Bio-Oss® e associações com o Sistema BoneLithium. A histomorfometria mostrou diferenças significativas considerando p> 0.05 (ANOVA, Tukey) para avaliação de tecido conjuntivo pré-osteogênico e tecido ósseo neoformado, e quando avaliado qualitativamente por tomografia computadorizada de feixe cônico (I cat Cone Beam FOV 0.05 Xoran Tecnology, LLC, EUA e E-vol, CDT, Brasil), observaram-se áreas de neoformação óssea compatíveis com hiperdensidade óssea em toda a extensão do defeito quando apuradas em analises de paridade em escala Hounsfield. Dessa forma, conclui-se que no contexto deste estudo é possível concluir que Sistema BoneLithium representa uma alternativa com potencial viabilidade clínica e necessita seguimento de aplicação em novas metodologias.(AU)

In this work, bases for the development, characterization and evaluation of the biological aspects related to the BoneLithium System were designed, based on the association of lithium carbonate particles dispersed in carbopol® gel matrix, capable of acting as a drug-releasing system. Methodologically this study was divided in four parts: In the first one, the central objective was the development and characterization of the biomaterial through the pharmacological manipulation. In the second step, the tissue reaction was evaluated in subcutaneous of rats, in the third the influence of the lithium particles released by BoneLithium System in the bone repair through experimental models using rabbits, and finally, the capacity of healing of bone defects created surgically in Calvaria of rats, treated with the biomaterial and different options of bone grafts with the objective to compare the efficiency of the BoneLithium System to the preexisting protocols. Experimentally, the tissue reaction was evaluated in which 15 male rats were randomly divided into 5 groups, where butterfly tubes containing the biomaterial were implanted in the subcutaneous tubes for preservation periods recommended by the ADA 10993 standard for biocompatibility test. The results demonstrate that the BoneLithium System is tissue reaction positive. To evaluate the biological behavior of the BoneLithium System, adult New Zealand white rabbits were used in which bilateral bone defects of 1 cm in diameter were surgically made on calvaria and treated with the Bone Lithium System (right side) and only Gel Of Carbopol (left side) / blood clot (control). Histomorphometry showed a favorable behavior to bone repair and, in addition, through Computerized Microtomography (CT SKYSCAN), it was possible to verify significant differences considering p> 0.05 (ANOVA, Tukey) for the bone repair process. The evaluation of the performance of the BoneLithium System using Wistar rats in which critical defects were created at the calvarial center and treated with different bone graft modalities (control, autogenous, bone bank (Unioss®, Marília Brazil), Bio-Oss® and associations (ANOVA, Tukey) for evaluation of pre osteogenic connective tissue and neoformed bone tissue, and when assessed qualitatively by cone beam computed tomography (I cat - Cone Beam - FOV 0.05 - Xoran Tecnology, LLC, USA and E-vol, CDT, Brazil), areas of bone neoformation compatible with bone hyperdensity throughout the extent of the defect were ascertained in Hounsfield scale parity analyzes, It is concluded that in the context of this study it is possible to conclude that the BoneLithium System represents an alternative with potential clinical feasibility And requires follow-up of application in new methodologies.(AU)

Effects of platelet-rich fibrin on healing of intra-bony defects treated with anorganic bovine bone mineral

Abstract Anorganic bovine bone mineral (ABBM) is extensively used in the treatment of intra-bony defects. Platelet-rich fibrin (PRF) is a new-generation platelet concentrate with a simplified technique. Although certain studies have reported the use of PRF in the treatment of intra-bony defects, to date, none of them have evaluated its additive effects with ABBM. Therefore, a randomised, split-mouth clinical trial was conducted to compare healing of intra-bony defects treated with an ABBM-PRF combination with healing of those treated with ABBM alone. By using a split-mouth design, 15 paired intra-bony defects were randomly treated with either ABBM alone (control group) or ABBM-PRF combination (test group). Following clinical parameters and radiographical measurements were recorded at baseline and 6 months after treatment: plaque index (PI), gingival index (GI), probing depth (PD), gingival recession (GR), clinical attachment level (CAL), vertical bone loss, depth of defect and defect angle. Preoperative clinical and radiographical measurements were similar for the test and control groups. Statistically significant reductions in GI, PD, CAL, vertical bone loss, depth of intra-bony defect and widening of defect angle were detected after treatment in both groups. With respect to inter-group analysis, gain in CAL was significantly greater in the test group than in the control group, whereas no inter-group differences were observed in any other parameter. The results of this study indicate that both therapies are effective in the treatment of intra-bony defects.

Improving gingival smile by means of guided bone regeneration principles

ABSTRACT Objective: This study evaluated the effectiveness of guided bone regeneration (GBR) carried out with xenogenic bone substitute (Bio-OssTM) and collagen resorbable membrane (Bio-GideTM) to improve gingival smile (GS) in patients with excessive vertical maxillary growth (EVMG). Methods: Twelve healthy women aged between 20 and 49 years old (mean age of 26 years), with 5 mm or more of gingival exposure during fully posed smile (FPS) due to EVMG, were included. Baseline digital photographs were taken with standardized head position at rest and FPS. In eight out of 12 cases, crown lengthening procedure was indicated and the initial incision was made 2 to 4 mm from the gingival margin. In four cases, with no indication for crown lengthening procedure, a sulcular incision was performed. GBR was performed in all cases, using micro screws and/or titanium mesh associated with Bio-OssTM and Bio-GideTM. After 10 days, sutures were removed. Recall appointments were scheduled at 1, 6, and 12 months when standardized photographs were again taken. ImageToolTM software was used to measure the gingival exposure (GE) during FPS from the standardized close-up smile photographs at baseline and 12 months. Results: GE mean at baseline was 275.44 mm2. After 12 months, patients who undergone exclusively GBR procedure, presented GE reduction of 40.7%, ∆ = 112.01 mm2 (statistically significant, p = 0.12), and patients who had crown lengthening associated with the graft had a reduction of 60%, ∆ = 167.01 mm2. Conclusion: Our results using GBR to improve GS in cases of EVMG showed an exceptionally high patient acceptance and satisfaction. One-year follow-up confirmed stable results.

RESUMO Objetivo: o presente estudo avaliou a eficácia da regeneração óssea guiada (ROG) usando enxerto ósseo xenógeno (Bio-Oss(r)) e membrana de colágeno reabsorvível (Bio-Gide(r)) para melhorar a estética do "sorriso gengival" (SG) em pacientes com crescimento maxilar vertical excessivo (CMVE). Métodos: foram incluídas 12 mulheres saudáveis com idades entre 20 e 49 anos (média = 26 anos) com 5mm ou mais de exposição gengival durante o sorriso amplo posado (SAP), em função de CMVE. Foram realizadas fotografias digitais padronizadas (FDP) em repouso e em SAP. Em 8 dos 12 casos, foi indicado o procedimento de aumento da coroa clínica, e a incisão inicial foi realizada de 2 a 4mm da margem gengival. Em 4 casos, para os quais não houve indicação de aumento da coroa clínica, foi realizada uma incisão intrassulcular. A ROG foi realizada, em todos os casos, utilizando-se mini-implantes e/ou malha de titânio, associados a Bio-Oss(r) e Bio-Gide(r). Após 10 dias, as suturas foram removidas. O programa ImageTool(r) foi utilizado para medir a "área gengival exposta" (AGE) durante o SAP, nas imagens padronizadas do sorriso, em close-up, ao início do estudo e após 12 meses. Resultados: a média da AGE no início do estudo foi de 275,44mm2. Após 12 meses, os pacientes submetidos exclusivamente ao procedimento de ROG apresentaram redução na AGE de 40,7%, Δ = 112,01mm2 (estatisticamente significativo, p = 0,12); já nos pacientes em que o aumento de coroa clínica foi associado ao enxerto, a redução foi de 60%, Δ = 167,01mm2. Conclusão: os resultados do uso da ROG para melhorar o SG em casos de CMVE demonstraram aceitação e satisfação extremamente elevadas por parte dos pacientes. O acompanhamento de 1 ano pós-tratamento confirmou a estabilidade dos resultados.

Effects of a buried magnetic field on cranial bone reconstruction in rats

ABSTRACT The understanding of bone repair phenomena is a fundamental part of dentistry and maxillofacial surgery. Objective The present study aimed to evaluate the influence of buried magnetic field stimulation on bone repair in rat calvaria after reconstruction with autogenous bone grafts, synthetic powdered hydroxyapatite, or allogeneic cartilage grafts, with or without exposure to magnetic stimulation. Material and Methods Ninety male Wistar rats were divided into 18 groups of five animals each. Critical bone defects were created in the rats’ calvaria and immediately reconstructed with autogenous bone, powdered synthetic hydroxyapatite or allogeneic cartilage. Magnetic implants were also placed in half the animals. Rats were euthanized for analysis at 15, 30, and 60 postoperative days. Histomorphometric analyses of the quantity of bone repair were performed at all times. Results These analyses showed significant group by postoperative time interactions (p=0.008). Among the rats subjected to autogenous bone reconstruction, those exposed to magnetic stimulation had higher bone fill percentages than those without magnetic implants. Results also showed that the quality of bone repair remained higher in the former group as compared to the latter at 60 postoperative days. Conclusions After 60 postoperative days, bone repair was greater in the group treated with autogenous bone grafts and exposed to a magnetic field, and bone repair was most pronounced in animals treated with autogenous bone grafts, followed by those treated with powdered synthetic hydroxyapatite and allogeneic cartilage grafts.

Respuesta tisular en defectos tratados con matriz ósea de origen bovino o humano / Tissue response in treated defects with bovine or human bone matrix

El objetivo de esta investigación fue comparar la respuesta tisular en defectos tratados con matriz óseo de origen bovino y humano. Se realizó un estudio descriptivo con 12 conejos en los cuales se confeccionaron dos defectos en la calota craneana de acuerdo a procesos convencionales. Cada defecto fue aleatoriamente rellenado con matriz ósea bovina o con matriz ósea humana; se realizaron evaluaciones histológicas a las 7 y 15 semanas de realizada la cirugía (6 animales en cada grupo). A las 7 semanas se identificó un leve infiltrado inflamatorio y claras diferencias entre el hueso periférico y el sitio injertado, mientras que a las 15 semanas se observo la persistencia de algunas partículas injertadas y la presencia de hueso nuevo formado en el defecto; no se logró identificar diferencias en la secuencia de reparación o retrasos en la misma con ninguno de los dos materiales. Se concluye que ambos materiales son útiles en la regeneración ósea en el presente modelo experimental.

The aim of this research was to compare the tissue response in treated defects with bone matrix with bovine or human origin. Was realized a descriptive study with 12 rabbits where was executed two defects in the skull in relation to conventional techniques. Randomized defects were used to put bone matrix with bovine or human origin; histological exam was realized in the week number 7 and 15 with 6 animals each. At 7 weeks was observed a limited inflammatory infiltrate with clear differences between the peripheral bone and the filled bone and in the 15 weeks of analysis was observed the presence of some particulate of the bone graft beside a new bone into the defect; was not observed any differences in the sequence of repair or delayed in the bovine or human material. It´s concluded that both materials are useful in bone regeneration for this experimental model.

Substitutos ósseos sintéticos na Implantodontia / Synthetic bone substitutes for Implant Dentistry ­ a literature review

Objetivo: analisar sistematicamente, na literatura científica, o uso de substitutos ósseos sintéticos na regeneração óssea para Implantodontia. Material e métodos: uma busca foi realizadas nas bases de dados PubMed, Cochrane, LILACS e SciELO, nos últimos quinze anos, combinando as palavras-chave "regeneração óssea", "materiais biocompatíveis", "implantes dentários", e "materiais aloplásticos". Resultados: Dos 199 artigos inicialmente recuperados, apenas 27 foram selecionados, incluindo revisões sistemáticas/ metanálises (n=2), revisões da literatura (n=1), estudos clínicos (n=9) e pré-clínicos (n=12), relato de caso (n=1) e tese (n=1). Nos modelos animais, o vidro bioativo é capaz de provocar formação óssea à distância, inibir a migração apical do epitélio juncional, e gerar maior deposição de cemento na superfície radicular. Partículas esféricas geram melhor dissolução e integração com o novo osso circundante, e bons resultados são vistos nas técnicas de ROG e RTG. Em um estudo clínico randomizado, o vidro bioativo misturado ao osso autógeno para regeneração de defeitos intraósseos reduziu significativamente a profundidade de sondagem, com ganho de nível clínico de inserção, e resolução dos defeitos já aos seis meses. Nos modelos animais, a tríade hidroxiapatita (HA), beta-fosfato tricálcio (ß-TCP), e fosfato de cálcio bifásico (HA+ ß-TCP) tem se mostrado biocompatível, biorreabsorvível e osteocondutora. Um estudo clínico controlado com HA+ ß-TCP/ membrana revelou melhor preservação óssea vertical e horizontal comparado ao coágulo/membrana, nas TCFCs de seis meses. Regenerações ósseas verticais significativas com estes materiais sintéticos são potencializadas pelo uso dos fatores de crescimento. Conclusão: substitutos ósseos sintéticos demonstram uso promissor para regeneração. Entretanto, a evidência clínica deve ser substancialmente aumentada.

Objective: to systematically analyze in the scientifi c literature the use of synthetic bone substitutes for bone regeneration in implant dentistry. Material and methods: a search was conducted at the PubMed, Cochrane, LILACS and SciELO databases considering the last fi fteen years, and combining the keywords "bone regeneration", "biocompatible materials", "dental implants", and "alloplastic materials". Results: of the 199 articles initially retrieved, only 27 were selected, including systematic reviews/meta-analysis (n=2), literature reviews (n=1), clinical (n=9) and pre-clinical (n=12) studies, case report (n=1) and thesis (n=1). In animal models, the bioactive glass can cause bone formation at distance, inhibit apical migration of the junctional epithelium, and generate greater deposition of cementum over the root surface. Spherical particles generate better dissolution and integration with the new surrounding bone, and good results are seen in the ROG and RTG techniques. In a randomized study, the bioactive glass mixed with autogenous bone to regenerate intra-osseous defects signifi cantly reduced probing depths, with clinical attachment level gains, and defect resolution as early as 6 months. In animal models, the triad hydroxyapatite (HA), beta-tricalcium phosphate (ß-TCP), and biphasic calcium phosphate (HA + ß-TCP) has been shown to be biocompatible, bioresorbable, and osteoconductive. A controlled clinical study with (HA + ß-TCP/membrane) showed better vertical and horizontal bone preservation compared to clot / membrane at the 6 month CBCT images. Also, signifi cant vertical bone regeneration with these synthetic materials is enhanced by the use of growth factors. Conclusion: the synthetic bone substitutes are good candidates for regeneration. However, the level of clinical evidence must be substantially increased.