Evaluation of Two Configurations of Hydroxyapatite and Beta-Tricalcium Phosphate in Sinus Grafts with Simultaneous Implant Installation: An Experimental Study in Rabbits.

BACKGROUND: This study aimed to evaluate peri-implant bone formation in rabbits after sinus grafting mediated by hydroxyapatite and beta-tricalcium phosphate (HA + ß-TCP) in granule or paste configurations, concomitant with immediate implant installation. MATERIAL & METHODS: Thirty-four rabbit maxillary sinuses were grafted with HA + ß-TCP, half of which were applied in a granule and half in a paste composition. Implant placement was performed simultaneously. At 7 and 40 days postoperatively, the animals were euthanized, and samples were prepared for tomographic, microtomographic, histological, histometric (hematoxylin and eosin staining, HE), and immunohistochemical (labeling of transcription factor Runx-2 [RUNX2], vascular endothelial growth factor [VEGF], osteocalcin [OCN], and tartrate-resistant acid phosphatase [TRAP]) analysis. Implant removal torque was also measured. RESULTS: On tomography, maintenance of sinus membrane integrity was observed in both the groups. Higher values of morphometric parameters evaluated by micro-CT were found in the "paste group" after seven days. At 40 days, there were no significant differences between the groups in most of the microtomographic parameters evaluated. In histological sections stained with HE, a higher percentage of newly formed bone was observed in the "granule group" after 40 days. Similar positive immunolabeling was observed for both RUNX2 and OCN in both the experimental groups. TRAP immunolabeling was similar in both groups as well. VEGF labeling increased in the "granule group", indicating a higher osteoconductive potential in this biomaterial. Similar removal torque values were observed in both groups. Thus, the two HA + ß-TCP configurations showed similar healing patterns of simultaneously installed implants adjacent to sinus floor elevation. However, significantly higher bone values were observed for the "granule configuration". CONCLUSIONS: The HA + ß-TCP granules and paste presentations showed favorable long-term healing results, with bone formation in similar quantities and quality adjacent to the implants.

The effectiveness of hydroxyapatite-beta tricalcium phosphate incorporated into stem cells from human exfoliated deciduous teeth for reconstruction of rat calvarial bone defects.

OBJECTIVE: To investigate the effects of stem cells from the pulp of human exfoliated deciduous teeth (SHED) on biphasic calcium phosphate granules (BCP) to repair rat calvarial defects as compared to autogenous bone grafting. MATERIALS AND METHODS: A defect with a 6-mm diameter was produced on the calvaria of 50 rats. BCP granules were incorporated into SHED cultures grown for 7 days in conventional (CM) or osteogenic (OM) culture media. The animals were allocated into 5 groups of 10, namely: clot, autogenous bone, BCP, BCP+SHED in CM (BCP-CM), and BCP+SHED in OM (BCP-OM). The presence of newly formed bone and residual biomaterial particles was assessed by histometric analysis after 4 and 8 weeks. RESULTS: The autogenous group showed the largest newly formed bone area at week 8 and in the entire experimental period, with a significant difference in relation to the other groups (P < 0.05). At week 8, BCP-CM and BCP-OM groups showed homogeneous new bone formation (P = 0.13). When considering the entire experimental period, the BCP group had the highest percentage of residual particle area, with no significant difference from the BCP-CM group (P = 0.06) and with a significant difference from the BCP-OM group (P = 0.01). BCP-CM and BCP-OM groups were homogeneous throughout the experimental period (P = 0.59). CONCLUSIONS: BCP incorporated into SHED cultures showed promising outcomes, albeit less pronounced than autogenous grafting, for the repair of rat calvarial defects. CLINICAL RELEVANCE: BCP incorporated into SHED cultures showed to be an alternative in view of the disadvantages to obtain autogenous bone graft.

Oral Myiasis in a Patient With HIV Manifestations and Neurologic Toxoplasmosis Treated by Ivermectin.

Myiasis has been defined as a pathologic condition where dipterous larvae are lodged in mammalian hosts causing an infestation, which feeds on living or dead tissue for at least a certain period inside the host and develops itself as parasites. In humans, the most commonly affected sites are the nose, eyes, skin wounds, sinuses, lungs, ears, gut, gall bladder, vagina, nasal cavities, and rarely the mouth because the oral tissues are rarely exposed to the external environment. The etiology of oral myiasis is usually related to local factors such as poor oral hygiene, periodontal disease and labial incompetence, and systemic factors such as neurologic deficits.

Alveolar bone healing in rats: micro-CT, immunohistochemical and molecular analysis.

INTRODUCTION: Alveolar bone healing after upper incisor extraction in rats is a classical model of preclinical studies. The underlying morphometric, cellular and molecular mechanism, however, remains imprecise in a unique study. OBJECTIVES: The aim of this study was therefore to characterize the alveolar bone healing after upper incisor extraction in rats by micro computed tomographic (Micro-CT), immunohistochemical and real-time polymerase chain reaction (RT-PCR) analysis. MATERIAL AND METHODS: Thirty animals (Rattus norvegicus, Albinus Wistar) were divided into three groups after upper incisors extraction at 7, 14, and 28 days. Micro-CT was evaluated based on the morphometric parameters. Subsequently, the histological analyses and immunostaining of osteoprotegerin (OPG), receptor activator of nuclear kappa B ligand (RANKL) and tartrate resistant acid phosphate (TRAP) was performed. In addition, RT-PCR analyses of OPG, RANKL, the runt-related transcription factor 2 (RUNX2), osteocalcin (OC), osteopontin (OPN), osterix (OST) and receptor activator of nuclear kappa B (RANK) were performed to determine the expression of these proteins in the alveolar bone healing. RESULTS: Micro-CT: The morphometric parameters of bone volume and trabecular thickness progressively increased over time. Consequently, a gradual decrease in trabecular separation, trabecular space and total bone porosity was observed. Immunohistochemical: There were no differences statistically significant between the positive labeling for OPG, RANKL and TRAP in the different periods. RT-PCR: At 28 days, there was a significant increase in OPG expression, while RANKL expression and the RANKL/OPG ratio both decreased over time. CONCLUSION: Micro-CT showed the newly formed bone had favorable morphometric characteristics of quality and quantity. Beyond the RUNX2, OC, OPN, OST, and RANK proteins expressed in the alveolar bone healing, OPG and RANKL activity showed to be essential for activation of basic multicellular units during the alveolar bone healing.

Comparative Evaluation of Cell Viability Immediately After Osteotomy for Implants With Drills and Piezosurgery: Immunohistochemistry Analysis.

OBJECTIVE: To evaluate the effect of reusing drills and piezosurgery tips during implant osteotomy on immediate bone cell viability through immunohistochemical analysis. MATERIALS AND METHODS: Six male rabbits were divided into 2 groups and then divided into 5 subgroups-correspond to drills and tips used 10, 20, 30, 40, and 50 times, respectively. All animals received 10 osteotomies in each tibia, by use of the classic drilling procedure in one group (G1) and the piezosurgery device in the other group (G2). For immunohistochemical technique were utilized the osteoprotegerin, RANKL, osteocalcin, and caspase 3. Control procedures were performed by omitting the primary antibodies (negative control). RESULTS: Bone formation and resorption responses presented in more intense way during the piezosurgery. The expression of osteocalcin had become quite intense in piezosurgery groups, but with reduced immunostaining from the 30th osteotomy. The caspase 3 showed the viability of the osteoblast from the 20th osteotomy with piezosurgery and remained constant until the 50th. CONCLUSION: Piezosurgery provides greater osteoblastic cell viability than the system of conventional drilling. CLINICAL RELEVANCE: This study will provide data so that the authors can recycle the drills and tips for implant placement, thus enabling a better cell viability for osseointegration.

Simplified Access for Reduction and Fixation of a Frontal Bone Fracture.

The frontal bone fractures occur very often in service units in oral and maxillofacial surgery. Bicoronal access is the most common for the surgical treatment of frontal bone fractures. However, patients are surprised when they receive notice that such invasive access will be made. This approach allows adequate visualization of the fracture site, but may be associated with complications, which can be avoided by the use of less invasive techniques. We describe an alternative approach that aims to minimize the complications of a coronal incision.

Respiratory Obstruction Due to Richards Type 4 Fracture.

Facial fractures can be potentially fatal in polytraumatized patients due to retropositioning tissues to upper airway obstruction. In the first aids, this situation can be reversed using a tracheostomy procedure to break out the airways. However, fractures leading to airway obstruction are rare and according to Richards Classification can be classified into 5 types. The purpose of this article is to report a clinical patient with a bilateral condylar and mandibular symphysis fractures that resulted in airway obstruction and severe mandibular rear projection.

Avaliação de duas formas de hidroxiapatita e beta-tricálcio fosfato em enxertos sinusais com concomitante instalação de implantes em coelhos / Evaluation of two formulations of hydroxyapatite and beta-tricalcium phosphate in rabbit sinus grafts with concomitant implant placement

Este trabalho teve por objetivo avaliar o tecido ósseo periimplantar formado após o enxerto sinusal com hidroxiapatita e beta-tricálcio fosfato (HA + ß-TCP), nas apresentações em grânulos e em pasta, concomitante à instalação de implantes em coelhos. Trinta e quatro seios maxilares de coelhos foram enxertados com HA + ß-TCP, sendo metade do grupo grânulos e metade do grupo pasta. Concomitantemente, foi realizada a instalação de implantes. Aos 7 e 40 dias pósoperatórios, realizou-se a eutanásia dos animais, e as amostras foram preparadas para as análises tomográfica, microtomográfica, histológica (coloração por hematoxilina e eosina - HE), imunoistoquímica (marcação de fator de transcrição Runt-2 ­ RUNX2 ­, fator de crescimento endotelial vascular ­ VEGF ­, osteocalcina ­ OCN ­ e fosfatase ácida resistente ao tartarato ­ TRAP) e de torque de remoção dos implantes. Na tomografia, foi observada a manutenção da integridade da membrana sinusal, sem extravasamento de material, nos dois grupos e períodos. Parâmetros morfométricos de volume ósseo, porcentagem do volume ósseo e número de trabéculas foram significativamente superiores para o grupo pasta do que para o grupo grânulos aos 7 dias, enquanto que a porosidade foi maior para o grupo grânulos nesse mesmo período. Aos 40 dias, não houve diferença significativa entre os grupos para a maioria dos parâmetros microtomográficos estudados. Nos cortes histológicos corados por HE, observou-se que em ambos os grupos ocorreu a formação de tecido ósseo junto às espiras do implante aos 40 dias, favorecendo a osseointegração. Imunomarcações positivas semelhantes foram encontradas tanto para o fator de diferenciação osteoblástica RUNX2 quanto para o fator de mineralização OCN no osso neoformado nos dois grupos experimentais. A atividade osteoclástica evidenciada pela TRAP mostrou-se semelhante nos dois grupos, com discreto predomínio para o grupo grânulos. Já a marcação positiva para o VEGF mostrou-se aumentada no grupo grânulos, caracterizando um potencial osteocondutor superior nessa apresentação do biomaterial. Ademais, não houve diferenças nos valores de torque de remoção do implante entre ambos os grupos. Logo, as duas apresentações da HA + ß-TCP mostraram resultados favoráveis à osseointegração a longo prazo, com formação de tecido ósseo em quantidade e qualidade semelhantes junto aos implantes(AU)

This work aimed to evaluate the peri-implant bone tissue after maxillary sinus grafting with hydroxyapatite and beta-tricalcium phosphate (HA + ß-TCP), in granular and paste formulations, concomitant with implant placement in rabbits. Thirty four rabbit maxillary sinuses were grafted with HA + ß-TCP, being half of the granular group and half of the paste group. Concomitantly, the implant placement was performed. At 7 and 40 postoperative days, animals were euthanized, and the samples were prepared for tomographic, microtomographic, histological (hematoxylin and eosin staining), immunohistochemical (Runt-related transcription factor 2 ­ RUNX2, vascular endothelial growth factor ­ VEGF ­, osteocalcin ­ OCN ­ and tartrate-resistant acid phosphatase ­ TRAP ­ staining) and implant torque removal analyses. In computed tomography, the maintenance of sinus membrane integrity, with no material extravasation, was observed in both groups and periods. Morphometric parameters of bone volume, percentage of bone volume and trabecular number were significantly higher for paste than granular group at day 7, while the porosity was higher for granular group in this period. At day 40, there were no significant differences between both groups for the majority of the microtomographic parameters studied. In the HE-stained histological sections, it was observed that bone healing around implant threads occurred for both groups at day 40, enhancing osseointegration. Similar positive immunostainings were observed for both the RUNX2 osteoblastic differentiation factor and the OCN mineralization factor in the neoformed bone in the two experimental groups. The osteoclast activity evidenced by TRAP was similar in both groups, with a slight predominance for the granular group. Positive staining for VEGF growth factor was increased in the granular group, characterizing a superior osteoconductive potential for this biomaterial formulation. Besides, there were no differences in the values of implant removal torque between both groups. Thus, the two formulations o H + ß-TCP showed favorable osseointegration results in the long term, with similar amount and quality of bone tissue formation around the implants(AU)

Alveolar bone healing in rats: micro-CT, immunohistochemical and molecular analysis

Abstract Alveolar bone healing after upper incisor extraction in rats is a classical model of preclinical studies. The underlying morphometric, cellular and molecular mechanism, however, remains imprecise in a unique study. Objectives The aim of this study was therefore to characterize the alveolar bone healing after upper incisor extraction in rats by micro computed tomographic (Micro-CT), immunohistochemical and real-time polymerase chain reaction (RT-PCR) analysis. Material and Methods Thirty animals (Rattus norvegicus, Albinus Wistar) were divided into three groups after upper incisors extraction at 7, 14, and 28 days. Micro-CT was evaluated based on the morphometric parameters. Subsequently, the histological analyses and immunostaining of osteoprotegerin (OPG), receptor activator of nuclear kappa B ligand (RANKL) and tartrate resistant acid phosphate (TRAP) was performed. In addition, RT-PCR analyses of OPG, RANKL, the runt-related transcription factor 2 (RUNX2), osteocalcin (OC), osteopontin (OPN), osterix (OST) and receptor activator of nuclear kappa B (RANK) were performed to determine the expression of these proteins in the alveolar bone healing. Results Micro-CT: The morphometric parameters of bone volume and trabecular thickness progressively increased over time. Consequently, a gradual decrease in trabecular separation, trabecular space and total bone porosity was observed. Immunohistochemical: There were no differences statistically significant between the positive labeling for OPG, RANKL and TRAP in the different periods. RT-PCR: At 28 days, there was a significant increase in OPG expression, while RANKL expression and the RANKL/OPG ratio both decreased over time. Conclusion Micro-CT showed the newly formed bone had favorable morphometric characteristics of quality and quantity. Beyond the RUNX2, OC, OPN, OST, and RANK proteins expressed in the alveolar bone healing, OPG and RANKL activity showed to be essential for activation of basic multicellular units during the alveolar bone healing.

Diagnosis and Management of Cerebrospinal Fluid Leak in a Panfacial Fracture.

Cerebrospinal fluid fistula caused by head trauma is a potentially dangerous problem and precise localization and radical treatment are necessary. We present a case of a patient with Panfacial fracture caused by a motorcycle accident, resulting in a cerebrospinal fluid leakage. The correct diagnosis was realized by computed tomography and auxiliary tests. The successful treatment can be confirmed with the support of radionuclide cisternography examination.

Estágio atual das vacinas anticárie / Current stage of anticaries vaccines

Atualmente, grande interesse tem sido dirigido ao desenvolvimento de vacinas anticárie que atuem na imunização dos indivíduos contra o Streptococcus mutans, agente etiológico principal da cárie dentária. Algumas estratégias para a imunização da mucosa bucal incluem a administração direta de vacinas contendo imunoglobulina A secretora (S-IgA), responsável pela defesa imune específica contra as bactérias cariogênicas, e a utilização de adesinas de superfície, proteínas de ligação ao glucano ou glicosiltransferase como antígenos-chave, para que haja maior indução da produção de S-IgA pelo organismo humano. Acredita-se, portanto, que uma vacina eficaz e segura contra a cárie poderá estar disponível em breve, de forma que, se não eliminar completamente a doença, ao menos minimizará seu impacto endêmico na população

Análise dos restos epiteliais de Malassez em ratos normais e ratos com lesäo periapical / An analysis of the epithelial rests of Malassez both in normal rats and rats with periapical lesion

O objetivo deste estudo foi analisar a prevalência, distribuiçäo e possíveis alteraçöes dos restos epiteliais de Malassez em ratos normais e ratos com lesäo periapical. A análise histológica revelou que os restos epiteliais foram mais freqüentes em ratos jovens, sendo mais comuns na regiäo cervical e regiäo de furca respectivamente. Em nenhum caso foi observado cisto periapical e a via de drenagem dos abscessos periapicais foi através do ligamento periodontal