1000 resultados para PIEZOELECTRIC SURGERY


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Purpose: The present article sought to evaluate the effectiveness of a piezoelectric surgical unit for maxillary sinus augmentation surgeries in avoiding perforation of the sinus membrane and other possible procedural complications in patients with anatomical variations of the sinus. Materials and Methods: Twenty-five patients presenting sinus anatomical variations, who were indicated for a total of 40 sinus grafting procedures performed by the lateral window approach with a piezoelectric device, were analyzed. After 6 months of healing, implants were placed. Information collected included clinical and computed tomographic information on anatomical variations in the sinus bone walls, in the size of the sinus, and in the thickness of the sinus membrane. Occurrence of sinus membrane perforation and computed tomographic measurements of the amount of bone height gained with the grafting procedures were also recorded. Results: Only two patients presented a small perforation (less than 5 mm in diameter) of the sinus membrane, which occurred only after osteotomies of the lateral windows and did not compromise the surgical outcome. No implants were lost during a mean follow-up period of 19 months. Conclusion: The use of piezoelectric surgery allowed for the accomplishment of all rehabilitation treatments within the follow-up period of this study. INT J ORAL MAXILLOFAC IMPLANTS 2012;27:1211-1215

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In maxillary Le Fort I type osteotomy the detachment of the nasal mucosa should be done carefully. Piezoelectric surgery contributed much to increase the safety of osteotomies, despite the initial advantage of minimizing the risk of injury in nervous tissue, mainly in bilateral sagittal split osteotomy; we use the piezoelectric device for the initial detachment of the nasal mucosa in the maxillary osteotomy.

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Sinus floor augmentation has been established as a predictable technique to overcome maxillary bone loss. Antral cystic lesions may lead to intrasurgical complications and should be accurately diagnosed. However, antral pseudocysts have recently been described not to be contraindicated for sinus-grafting procedures. The current article sought to report clinical, cone beam computed tomographic, and histologic results of a maxillary sinus floor augmentation, performed with piezoelectric surgery, in the presence of a large antral pseudocyst. Success of graft maturation was confirmed with histologic analysis, which also indicated the absence of inflammatory infiltration in the tissue evaluated. On the basis of our findings, it is possible to perform a predictable treatment based on sinus floor augmentation in the presence of antral pseudocysts. Graft maturation can also be achieved 6 months after sinus-lifting surgeries.

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A presente Tese de Mestrado em Medicina Dentária tem como tema a Piezocirurgia e, sobre ela, pretende-se saber a sua aplicabilidade no consultório do Médico Dentista, nomeadamente na área da Cirurgia oral. A pesquisa bibliográfica foi realizada através de bases de dados, como a Medline, Science Direct e a Pub-Med, entre outras. Limitou-se a pesquisa, temporalmente, entre 2000 e 2016, e nas línguas Portuguesa e Inglesa. Excluiu-se todas as referências a estudos animais e, todas as que, em nada, contribuiríam para o conteúdo especificado. A cirurgia Piezoeléctrica é uma técnica de osteotomia atraumática, quando comparada a técnicas convencionais, e que revoluciona a área da Cirurgia Oral, através do seu corte preciso e altamente selectivo, mas também através do fenómeno de cavitação que a caracteriza, e que garante um campo operatório livre, uma óptima visibilidade, e, consequentemente, uma maior segurança do operador, culminando tudo isto no sucesso do tratamento. A sua maior desvantagem é o tempo de trabalho que requere, contudo este tende a diminuir, e a ser ainda menor que o tempo de trabalho exigido na cirurgia convencional. Inúmeras são as aplicações da Piezocirurgia, mas na área da Medicina Dentária, nomeadamente na Cirurgia Oral, destaca-se o levantamento do seio maxilar, o aumento da crista óssea, a extracção dos terceiros molares impactados e a cirurgia ortognática.

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Background: Piezoelectric instrumentation seems to offer 3 important advantages for cutting bone structures. Be more precise because it is produced by micro-vibrations from the cutting insert. Be safer because the ultrasonic frequency used does not affect soft tissue. Thirdly, the less invasive cutting action produces minor tissue damage and consequently probably a better healing Aim of the Study: The aim of this study is to evaluate the effectiveness of piezoelectric device capability in maxillo-facial surgery, in order to take advantage of these favourable capacity. Material and Methods: Considering the several potential application of the piezoelectric technology in Orthognathic, Oncologic and Extractive surgery, we would like to design protocols in order to verify how this new device can modify the surgical technique, the surgical time, the patients healing and its quality of life. Results: Due to the precise Piezosurgery cut, we can manage the Cad-Cam-Custom Made plates protocol in Oncologic Surgery and in Orthognatic Surgery increasing our percentage of comparison between the 3D preoperative plan and the surgical execution. We also found a better quality of life impaction in Patient who underwent and extractive surgery Conclusion: Piezosurgery device seems to be a strong surgical aid were safe and precise cut are needed and its capability to reduce the discomfort Patients need to be study in deep also in major surgery like Orthognatic and Oncologic surgery.

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This study used scanning electron microscopy (SEM) to evaluate the morphology and adhesion of blood components on root surfaces instrumented by curettes, piezoelectric ultrasonic scaler and Er,Cr:YSGG laser. One hundred samples from 25 teeth were divided into 5 groups: 1) Curettes; 2) Piezoelectric ultrasonic scaler; 3) Curettes plus piezoelectric ultrasonic scaler; 4) Er,Cr:YSGG laser; 5) Curettes plus Er,Cr:YSGG laser. Ten samples from each group were used for analysis of root morphology and the other 10 were used for analysis of adhesion of blood components on root surface. The results were analyzed statistically by the Kruskall-Wallis and Mann-Whitney tests with a significance level of 5%. The group treated with curettes showed smoother surfaces when compared to the groups were instrumented with piezoelectric ultrasonic scaler and the Er,Cr:YSGG laser. The surfaces instrumented with piezoelectric ultrasonic scaler and Er,Cr:YSGG laser, alone or in combination with hand scaling and root planing, did not differ significantly (p>0.05) among themselves. No statistically significant differences (p>0.05) among groups were found as to the adhesion of blood components on root surface. Ultrasonic instrumentation and Er,Cr:YSGG irradiation produced rougher root surfaces than the use of curettes, but there were no differences among treatments with respect to the adhesion of blood components.

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The aim of this study was to evaluate the morphology and adhesion of blood components on root surfaces instrumented with piezoelectric ultrasonic Piezon Master Surgery. Methods 10 teeth were used in this study. The teeth had their proximal divided into four areas that received different treatments: Group 1: untreated control Group 2: scaling with manual instrument; Group 3: scaling with ultrasound; Group 4: Scaling with manual instruments and ultrasound. We obtained 20 samples, 10 of which were used to analyze the morphology and the other 10 were used for analysis of adhesion of blood components. The specimens were analyzed by scanning electron microscopy. Photomicrographs were analyzed by the scores of adhesion of blood components and the index of root morphology. The results were statistically by the Kruskall-Wallis and Mann-Whitney with a significance level of 95%. Results The morphological analysis showed that the Group 1 had a surface unchanged in relation to other groups (Group 1 X Group 2 = 0.0025; Group 1 X Group 3 = 0.0003; Group 1 X Group 4 = 0.0003) and Group 2 presented a smoother surface compared to Group 1 and groups instrumented with ultrasound (Group 2 X Group 3 = 0.0025; Group 2 X Group 4 = 0.0025) there were no statistical differences between the Groups 3 and 4. analysis of adhesion of blood components showed that the Groups 2, 3 and 4 had no statistically significant differences between themselves, but more biocompatible surfaces promoted the surface untreated control (Group 1 X Group 2 = 0.02; Group 1 X Group 3 = 0.04; Group 1 X Group 4 = 0.005). Conclusion The instrumentation with piezoelectric ultrasonic promoted an irregular root surface, but did not negatively affect the adhesion of blood components.

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Primary stability of stems in cementless total hip replacements is recognized to play a critical role for long-term survival and thus for the success of the overall surgical procedure. In Literature, several studies addressed this important issue. Different approaches have been explored aiming to evaluate the extent of stability achieved during surgery. Some of these are in-vitro protocols while other tools are coinceived for the post-operative assessment of prosthesis migration relative to the host bone. In vitro protocols reported in the literature are not exportable to the operating room. Anyway most of them show a good overall accuracy. The RSA, EBRA and the radiographic analysis are currently used to check the healing process of the implanted femur at different follow-ups, evaluating implant migration, occurance of bone resorption or osteolysis at the interface. These methods are important for follow up and clinical study but do not assist the surgeon during implantation. At the time I started my Ph.D Study in Bioengineering, only one study had been undertaken to measure stability intra-operatively. No follow-up was presented to describe further results obtained with that device. In this scenario, it was believed that an instrument that could measure intra-operatively the stability achieved by an implanted stem would consistently improve the rate of success. This instrument should be accurate and should give to the surgeon during implantation a quick answer concerning the stability of the implanted stem. With this aim, an intra-operative device was designed, developed and validated. The device is meant to help the surgeon to decide how much to press-fit the implant. It is essentially made of a torsional load cell, able to measure the extent of torque applied by the surgeon to test primary stability, an angular sensor that measure the relative angular displacement between stem and femur, a rigid connector that enable connecting the device to the stem, and all the electronics for signals conditioning. The device was successfully validated in-vitro, showing a good overall accuracy in discriminating stable from unstable implants. Repeatability tests showed that the device was reliable. A calibration procedure was then performed in order to convert the angular readout into a linear displacement measurement, which is an information clinically relevant and simple to read in real-time by the surgeon. The second study reported in my thesis, concerns the evaluation of the possibility to have predictive information regarding the primary stability of a cementless stem, by measuring the micromotion of the last rasp used by the surgeon to prepare the femoral canal. This information would be really useful to the surgeon, who could check prior to the implantation process if the planned stem size can achieve a sufficient degree of primary stability, under optimal press fitting conditions. An intra-operative tool was developed to this aim. It was derived from a previously validated device, which was adapted for the specific purpose. The device is able to measure the relative micromotion between the femur and the rasp, when a torsional load is applied. An in-vitro protocol was developed and validated on both composite and cadaveric specimens. High correlation was observed between one of the parameters extracted form the acquisitions made on the rasp and the stability of the corresponding stem, when optimally press-fitted by the surgeon. After tuning in-vitro the protocol as in a closed loop, verification was made on two hip patients, confirming the results obtained in-vitro and highlighting the independence of the rasp indicator from the bone quality, anatomy and preserving conditions of the tested specimens, and from the sharpening of the rasp blades. The third study is related to an approach that have been recently explored in the orthopaedic community, but that was already in use in other scientific fields. It is based on the vibration analysis technique. This method has been successfully used to investigate the mechanical properties of the bone and its application to evaluate the extent of fixation of dental implants has been explored, even if its validity in this field is still under discussion. Several studies have been published recently on the stability assessment of hip implants by vibration analysis. The aim of the reported study was to develop and validate a prototype device based on the vibration analysis technique to measure intra-operatively the extent of implant stability. The expected advantages of a vibration-based device are easier clinical use, smaller dimensions and minor overall cost with respect to other devices based on direct micromotion measurement. The prototype developed consists of a piezoelectric exciter connected to the stem and an accelerometer attached to the femur. Preliminary tests were performed on four composite femurs implanted with a conventional stem. The results showed that the input signal was repeatable and the output could be recorded accurately. The fourth study concerns the application of the device based on the vibration analysis technique to several cases, considering both composite and cadaveric specimens. Different degrees of bone quality were tested, as well as different femur anatomies and several levels of press-fitting were considered. The aim of the study was to verify if it is possible to discriminate between stable and quasi-stable implants, because this is the most challenging detection for the surgeon in the operation room. Moreover, it was possible to validate the measurement protocol by comparing the results of the acquisitions made with the vibration-based tool to two reference measurements made by means of a validated technique, and a validated device. The results highlighted that the most sensitive parameter to stability is the shift in resonance frequency of the stem-bone system, showing high correlation with residual micromotion on all the tested specimens. Thus, it seems possible to discriminate between many levels of stability, from the grossly loosened implant, through the quasi-stable implants, to the definitely stable one. Finally, an additional study was performed on a different type of hip prosthesis, which has recently gained great interest thus becoming fairly popular in some countries in the last few years: the hip resurfacing prosthesis. The study was motivated by the following rationale: although bone-prosthesis micromotion is known to influence the stability of total hip replacement, its effect on the outcome of resurfacing implants has not been investigated in-vitro yet, but only clinically. Thus the work was aimed at verifying if it was possible to apply to the resurfacing prosthesis one of the intraoperative devices just validated for the measurement of the micromotion in the resurfacing implants. To do that, a preliminary study was performed in order to evaluate the extent of migration and the typical elastic movement for an epiphyseal prosthesis. An in-vitro procedure was developed to measure micromotions of resurfacing implants. This included a set of in-vitro loading scenarios that covers the range of directions covered by hip resultant forces in the most typical motor-tasks. The applicability of the protocol was assessed on two different commercial designs and on different head sizes. The repeatability and reproducibility were excellent (comparable to the best previously published protocols for standard cemented hip stems). Results showed that the procedure is accurate enough to detect micromotions of the order of few microns. The protocol proposed was thus completely validated. The results of the study demonstrated that the application of an intra-operative device to the resurfacing implants is not necessary, as the typical micromovement associated to this type of prosthesis could be considered negligible and thus not critical for the stabilization process. Concluding, four intra-operative tools have been developed and fully validated during these three years of research activity. The use in the clinical setting was tested for one of the devices, which could be used right now by the surgeon to evaluate the degree of stability achieved through the press-fitting procedure. The tool adapted to be used on the rasp was a good predictor of the stability of the stem. Thus it could be useful for the surgeon while checking if the pre-operative planning was correct. The device based on the vibration technique showed great accuracy, small dimensions, and thus has a great potential to become an instrument appreciated by the surgeon. It still need a clinical evaluation, and must be industrialized as well. The in-vitro tool worked very well, and can be applied for assessing resurfacing implants pre-clinically.

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PURPOSE Extended grafting procedures in atrophic ridges are invasive and time-consuming and increase cost and patient morbidity. Therefore, ridge-splitting techniques have been suggested to enlarge alveolar crests. The aim of this cohort study was to report techniques and radiographic outcomes of implants placed simultaneously with a piezoelectric alveolar ridge-splitting technique (RST). Peri-implant bone-level changes (ΔIBL) of implants placed with (study group, SG) or without RST (control group, CG) were compared. MATERIALS AND METHODS Two cohorts (seven patients in each) were matched regarding implant type, position, and number; superstructure type; age; and gender and received 17 implants each. Crestal implant bone level (IBL) was measured at surgery (T0), loading (T1), and 1 year (T2) and 2 years after loading (T3). For all implants, ΔIBL values were determined from radiographs. Differences in ΔIBL between SG and CG were analyzed statistically (Mann-Whitney U test). Bone width was assessed intraoperatively, and vertical bone mapping was performed at T0, T1, and T3. RESULTS After a mean observation period of 27.4 months after surgery, the implant survival rate was 100%. Mean ΔIBL was -1.68 ± 0.90 mm for SG and -1.04 ± 0.78 mm for CG (P = .022). Increased ΔIBL in SG versus CG occurred mainly until T2. Between T2 and T3, ΔIBL was limited (-0.11 ± 1.20 mm for SG and -0.05 ± 0.16 mm for CG; P = .546). Median bone width increased intraoperatively by 4.7 mm. CONCLUSIONS Within the limitations of this study, it can be suggested that RST is a well-functioning one-stage alternative to extended grafting procedures if the ridge shows adequate height. ΔIBL values indicated that implants with RST may fulfill accepted implant success criteria. However, during healing and the first year of loading, increased IBL alterations must be anticipated.

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