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OBJECTIVE: This in vitro study aimed to evaluate the effectiveness of a printed surgical guide for root sectioning in the socket-shield technique. MATERIALS AND METHODS: A typodont model of the maxilla with augmented filler was used for the upper right central incisor, and CBCT images were obtained. Two types of vertical root sectioning guides were tested: one with a buccal sleeve (Group A, n = 10) and another with a buccal orientation slit (Group B, n = 10). Control group (n = 10) performed freehand cuts on printed models. After crown cutting with diamond burs, root sectioning was conducted using an ultrasonic tip with the guides. Mean and standard deviation were calculated for the remaining root length, width, and volume. Data were analyzed using the Kruskal-Wallis test and Dunn's post hoc test. RESULTS: Statistical analysis showed significant differences in root width between the control group (2.0 mm) and both Groups A (2.655 mm; p < 0.0001) and B (2.460 mm; p < 0.0001). Group B (5.585 mm) also showed a significant difference in root remnant compared with the control (13.880 mm; p < 0.0043). Groups A and B did not differ significantly from each other. CONCLUSIONS: The socket shield technique is safe and effective, this study aimed to add improvements through the introduction of surgical guides, facilitating the root section, which is the critical phase so that the parameters that are requisite for success are achieved in terms of width, length, and volume of the root remnant. Both guided techniques effectively facilitated root sectioning, maintaining satisfactory root thickness and length. CLINICAL SIGNIFICANCE: Sectioning the root is challenging for the correct angulation to remove the palatal portion in the socket shield technique. Therefore, modifying this technique with the use of the presented guides, it is possible to prevent damage to the soft tissues and to plan the surgery with the help of cone beam computed tomography (CBCT) scans to remove the root apex and maintain the root remnant with a thickness greater than 1.5 mm, making the socket-shield technique more predictable.

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O objetivo dessa revisão foi descrever o estado de arte da técnica de preservação radicular (TPR), abordando suas indicações, contraindicações, vantagens, desvantagens e sobretudo os resultados alcançados seja do ponto de vista estético e funcional. Para isso, foi realizada uma pesquisa bibliográfica no PUBMED com as palavras-chave "socket-shield technique", "socket preservation", "bonepreservation", "immediateimplant", "dental implant" e esthetic. Além do mais, foram feitas pesquisa e seleção manual de trabalhos na lista de referências dos trabalhos encontrados mais o acréscimo de dois capítulos de livro de Implantodontia, totalizando 66 publicações para a confecção desta monografia. Com base nessa revisão de literatura, as conclusões foram de que deve-se selecionar criteriosamente cada caso, levando-se em conta possíveis limitações inerentes a técnica; a TPR é uma técnica sensível que requer uma execução atraumática e cuidadosa, com o intuito de não lesionar as fibras do ligamento periodontal que mantém o remanescente radicular em posição; a determinação do remanescente ósseo e da saúde dos tecidos periodontais são fundamentais para o planejamento da TPR; o uso de alternativas complementares, como a tomografia computadorizada Cone Bean(TCCB), na elaboração de guia cirúrgicos têm sido consideradas com o objetivo de reduzir possíveis riscos e complicações inerentes a técnica; a TPR tem apresentado resultados clínicos e radiográficos satisfatórios a curto prazo, quanto a manutenção dos tecidos duros e moles no local do implante; a TPR tem apresentado bons resultados estéticos quando comparada as técnicas convencionais ou ao implante imediato; ensaios clínicos randomizados são requeridos para a obtenção de maior evidência clínica quanto ao sucesso da terapia; acompanhamentos mais longos são precisos para determinar o prognóstico clínico a longo prazo.

The aim of this review is to describe the socket-shield technique (SST), discussing its indications, contraindications, advantages and disadvantages. Also, this study explores its functional and esthetics results. For this study, a bibliographic research was carried out in PUBMED database with "socket-shield technique", "socket preservation", "bone preservation", "immediate implant", "dental implant" and esthetic. Furthermore, research and manual selection were realized in the reference list of the selected articles, adding two chapters of Implantology's books. A total of 66 publications were added for the elaboration of this monograph. Based on this literature review, it can be concluded that each case must be carefully selected due to possible limitations from the technique; SST is a sensitive technique that requires an atraumatic procedure, in order to not injure fibers of periodontal ligament that keep the root's position; determination of the remaining bone and periodontal health are fundamental for the SST's planning; the use of alternative methods, such as cone beam computed tomography, in the surgical procedure guide, may reduce possible risks and complications inherent to SST; SST presented satisfactory short-term clinical and radiographic results due to the preservation of hard and soft tissues; SST showed good aesthetic results when compared to defined conventional techniques and immediate implantation; randomized clinical trials are required for further clinical evidence; longer follow-ups are needed to determine long-term clinical results.

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BACKGROUND: Decompressive craniectomy may be used as a primary or secondary treatment for intracranial hypertension and is clearly associated with reduced mortality. The removed bone flap is usually preserved in the abdominal subcutaneous tissue or in the bone bank. The aim of this study was to describe an option for preserving the bone flap after decompressive craniectomy using bone flap preservation in the skull subcutaneous tissue in subgaleal space over the pericranium contralateral to the craniectomy site. METHODS: This was a multicenter retrospective study including patients with severe traumatic brain injury from 2014 to 2016. There were 23 patients who had their bone fragments preserved below the scalp in the subcutaneous tissue for analysis. The following results were analyzed: surgical site infection, bone flap resorption during the period of preservation, and patient discomfort. RESULTS: Five patients died of systemic infectious complications, and the remaining patients underwent cranioplasty a mean 118 days after craniectomy. There were no surgical wound infections, macroscopically evident bone absorption, or site discomfort in any of the patients during a period of 18 months. CONCLUSIONS: This variant of the bone flap preservation technique has been shown to be satisfactory as an option for routine use.

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Palaeodemographic studies of animals using frequency distributions of radiocarbon dates are increasingly used in studies of Quaternary extinction but are complicated by taphonomic bias, or the loss of material through time. Current taphonomic models are based on the temporal frequency distributions of sediments, but bone is potentially lost at greater rates because not all sedimentary contexts preserve bone. We test the hypotheses that (i) the loss of bone over time is greater than that of sediment and (ii) this rate of loss varies geographically at large scales. We compiled radiocarbon dates on Pleistocene-aged bone from eastern Beringia (EB), the contiguous United States (CUSA) and South America (SA), from which we developed models of taphonomic loss. We find that bone is lost at greater rates than terrestrial sediment in general, but only for CUSA and SA. Bone in EB is lost at approximately the same rate as terrestrial sediments, which demonstrates the excellent preservation environments of arctic regions, presumably due to preservative effects of permafrost. These differences between bone and sediment preservation as well as between arctic and non-arctic regions should be taken into account by any research addressing past faunal population dynamics based on temporal frequency distributions.

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Introducción: Los tallos no cementados recubiertos con hidroxiapatita de fijación metafisaria han logrado excelentes resultados a largo plazo. La segunda generación de tallos cortos de fijación cervicometafisaria ha surgido a principios de la década de 1990, con el objetivo de preservar capital óseo femoral. Sin embargo, la preservación ósea femoral teóricamente propuesta no ha sido comprobada. El objetivo de este trabajo es determinar radiográficamente la preservación del capital óseo femoral cuando se utilizó un tallo corto de fijación cervicometafisaria, comparando las radiografías posoperatorias con la programación del tallo que se debería haber utilizado en caso de ser un diseño convencional con fijación metafisaria. Materiales y Métodos: Los primeros 50 tallos cortos de fijación cervicometafisaria (MiniHip TM, Corin, Cirencester, Reino Unido) fueron analizados por dos observadores independientes, con radiografías de frente, en cuanto a nivel de resección cervical y longitud del tallo, comparándolos con las filminas de un tallo convencional de fijación metafisodiafisaria (MetaFix TM, Corin, Cirencester, Reino Unido). Resultados: Según el análisis radiográfico, los tallos cortos de fijación cervicometafisaria ocuparon una longitud femoral promedio de 79 mm (rango 68-102). Los tallos convencionales de fijación metafisaria hubiesen ocupado, en promedio, 73 mm más que los tallos cortos (rango 47-94). Esta distribución se observó en el corte de cuello (promedio 10 mm más distal) y en la longitud del implante (promedio 66 mm mayor longitud) (p <0,001). Esta diferencia permite preservar un 42% el capital óseo femoral. Conclusión: La preservación ósea relacionada con el uso de tallos cortos de fijación cervicometafisaria podría traer beneficios a largo plazo en pacientes jóvenes con alta demanda funcional.

Background: Uncemented hydroxyapatite-coated stems with methaphyseal fixation have demonstrated excellent long-term results. Second generation of short stems has been developed in the 90’s with the purpose to preserve femoral bone at the femoral neck and diaphysis. However, the amount of bone that would be theoretically saved has not been well-established. To radiographically determine femoral bone preservation in a series of patients operated on with a short, neck preserving stem, we compared these results with the length of a templated conventional length, uncemented hydroxyapatite-coated stem. Methods: The first 50 short hydroxyapatite-coated uncemented stems (MiniHip TM, Corin, Cirencester, UK) were radiographically analyzed by two independent observers measuring the level of neck cut and the stem length. Then, these results were compared with the level of neck cut and stem length when a conventional, metaphysodiaphyseal stem (MetaFix TM, Corin, Cirencester, UK) was implanted using templates. Results: According to the radiographic results, short stems measured an average length of 79 mm (range 68-102). Conventional stems would have required 78 mm (range 47-94) more bone for fixation than short stems. This difference was observed in the neck cut (average 10 mm more distal with a conventional stems), as well as in the diaphysis (average 66 mm more distal with a conventional stems) (p <0.001). Conclusion: Femoral bone preservation may be related to long-term benefits especially in young patients.

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Se presenta la Osteotecnia en peróxido de hidrógeno y ácido acético como una herramienta para la conservacón de material óseo para fines docentes en colegios y universidades o de exhibición en museos o instituciones afines. Esta técnica de conservación de material óseo permite además rescatar piezas y estructuras óseas de difícil adquisición. Es un método rápido y muy baja toxicidad, fácil de aplicar y de un costo relativamente bajo en comparación con otros descritos en la literatura.

An Osteotechnique is presented on hidrogen peroxide and acetic acid as a tool for the conservation of bone material with teaching purposes on high schools and colleges, museum exhibitions or similar institutions. This bone preservation technique allowds to rescue pieces and bone structures that are difficult to adquire. It`s a simple and low toxicity method, easy to apply and with relatively low cost compared to other techniques described on the literature.

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Devido ao crescente uso dos aloenxertos nas cirurgias ortopédicas, há a necessidade do conhecimento de suas características biomecânicas ao longo do tempo de preservação. O presente trabalho consistiu na análise da força de resistência à micro-tração de amostras de ossos corticais de coelho preservadas em diversos meios por até 180 dias e a fresco. Os resultados revelaram que a resistência e o tempo de preservação apresentaram uma relação inversamente proporcional, significando que, quanto maior o tempo de preservação, menor a resistência física avaliada no ensaio biomecânico de resistência à micro-tração. Dos meios utilizados, a glicerina apresentou menores valores quanto ao teste de resistência, demonstrando, após 30 dias de preservação, apenas 24,58 por cento da força presente no osso a fresco e, aos 180 dias, 1,76 por cento. As amostras submetidas à autoclavagem também demonstraram baixos valores ao final do experimento, quando permaneceram com apenas 12,31 por cento da força presente no osso a fresco. Os ossos preservados em plasma homólogo, líquido de dakin e aqueles criopreservados apresentaram os melhores índices de resistência ao final do experimento, permanecendo, respectivamente, com 82,47; 70,34 e 66,72 por cento da força máxima quando comparados com a resistência dos ossos frescos. Concluiu-se que a escolha do método e o tempo de preservação interferiu diretamente na biomecânica dos ossos corticais, promovendo a diminuição da capacidade de resistência à tração ao longo do período de preservação.

Due to the increasing use of cortical bone allografts in orthopedic surgeries, de knowledge of its biomechanics characteristics during preservation time is needed. The present study consisted in the analyses of the resistance power to the micro-traction of samples of rabbit cortical bones preserved in several means for up to 180 days and fresh. The results showed that the resistance and the preservation time presented an inversely proportional relation, meaning that, the longer the time of preservation, the shorter the physical resistance evaluated in the biomechanical rehearsal of resistance to the micro-traction. The glycerin has presented lower values in relation to the resistance test, showing, after 30 days, only 24.58 percent of the present power in the fresh bone, and by 180 days, 1.76 percent. The samples submitted to autoclavation also showed low values by the end of the experiment, while they remained with just 12.31 percent of the power present in the fresh bone. The bones preserved in homologous plasma, Dakin liquid and the ones cryopreserved showed the best levels of resistance at the end of the experiment, remaining, respectively with 82.47, 70.34 and 66.72 percent of the maximum power, while compared with the resistance of the fresh bones. The conclusion is that the choice of methodology and time of preservation interfered directly in the biomechanics of the cortical bones, promoting decrease of the resistance capacity to the traction along the period of preservation.

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