RESUMO Objetivo: o objetivo do presente estudo foi verificar e comparar a precisão de modelos digitais de uma arcada dentária completa obtidos utilizando-se dois tipos de scanners e três metodologias de digitalização. Métodos: um modelo de resina feito com impressão 3D foi digitalizado em um scanner de referência (Zfx Evolution - Zimmer Biomet, Palm Beach Gardens, FL) para se obter uma referência em 3D; o mesmo modelo de resina foi, então, digitalizado com dois scanners intrabucais diferentes (Zfx IntraScan e Carestream 3600 - CS 3600®, Carestream, Rochester, NY, EUA) utilizando: Técnica A (do dente #27 ao dente #17); Técnica B (do dente #11 ao dente #17 e, em seguida, do dente #21 ao dente #27); e Técnica C (do dente #22 ao dente #17 e, em seguida, do dente #12 ao dente #27 - osoftware MeshLab v. 1.3.3 foi, então, usado para mesclar as duas leituras). Em seguida, as imagens digitalizadas foram sobrepostas à imagem de referência, utilizando-se um software, e as discrepâncias volumétricas foram calculadas. Resultados: a média dos resultados para o scanner Zfx Intrascan foram: Técnica A = 302,47 ± 37,42 µm; Técnica B = 180,45 ± 29,86 µm; Técnica C = 147,34 ± 28,23 µm. A média dos resultados para o scanner Carestream 3600 foram: Técnica A= 303,59 ± 40,20 µm; Técnica B = 181,53 ± 29,61 µm; Técnica C = 142,28 ± 35,33 µm. A Técnica C, utilizada em ambos os scanners, produziu as menores discrepâncias volumétricas, quando comparada às outras técnicas. Conclusões: a técnica de digitalização teve um efeito estatisticamente significativo sobre a qualidade do modelo digital (p< 0,0001), enquanto o tipo de scanner usado não apresentou qualquer influência significativa (p= 0,91).

ABSTRACT Objective: The aim of the study was to verify and compare the accuracy of full-arch digital impressions obtained using two intraoral scanners and three scanning methodologies. Methods: A resin model created with dental 3-D printing was scanned by a reference scanner (Zfx Evolution - Zimmer Biomet, Palm Beach Gardens, FL) in order to obtain a 3D reference; the same resin model was then scanned with two different intraoral scanners (Zfx IntraScan and Carestream 3600 - CS 3600®, Carestream, Rochester, NY, USA) using: Technique A (from tooth #27 up to tooth #17); Technique B (from tooth #11 up to tooth #17 and then from tooth #21 up to tooth #27) and Technique C (from tooth #22 up to tooth #17, and then from tooth #12 up to tooth #27 - the MeshLab software v. 1.3.3 was then used to match the two scans). The scans obtained were superimposed over the reference scan by means of a software, and the volumetric discrepancies were calculated. Results: The mean results for the Zfx Intrascan scanner were: Technique A = 302.47 ± 37.42 µm; Technique B = 180.45 ± 29.86 µm; Technique C = 147.34 ± 28.23 µm. The mean results for the Carestream 3600 scanner were: Technique A = 303.59 ± 40.20 µm; Technique B = 181.53 ± 29.61 µm; Technique C = 142.28 ± 35.33 µm. Technique C, used by both scanners, produced less volumetric discrepancies compared to the other techniques. Conclusions: The scanning technique had a statistically significant effect on the quality of the scan (p< 0.0001), whereas the scanner did not present any significant influence (p= 0.91).

Resumo Objetivo: Avaliar a viabilidade da quantificação do tecido adiposo visceral (TAV) pela tomografia computadorizada (TC) e ressonância magnética (RM) usando um software freeware, e também calcular a reprodutibilidade intraobservador e interobservador. Materiais e Métodos: Foi quantificado o TAV em pacientes submetidos a TC e RM de abdome em nossa instituição, entre 2010 e 2015, com um intervalo máximo de três meses entre os dois exames. Selecionou-se um corte adquirido ao nível da cicatriz umbilical. A segmentação foi realizada com o algoritmo de crescimento de região do freeware utilizado. As reprodutibilidades intraobservador e interobservador foram avaliadas, assim como a acurácia da RM em relação à TC. Resultados: Trinta e um pacientes (14 homens e 17 mulheres; média de idade: 57 ± 15 anos) realizaram TC e RM (intervalo médio entre os exames: 28 ± 12 dias). A reprodutibilidade interobservador foi 82% para TC (viés = 1,52 cm2; p = 0,488), 86% para RM ponderada em T1 (viés = −4,36 cm2; p = 0,006) e 88% para RM ponderada em T2 (viés = −0,52 cm2; p = 0,735). A reprodutibilidade intraobservador foi 90% para TC (viés = 0,14 cm2; p = 0,912), 92% para RM ponderada em T1 (viés = −3,4 cm2; p = 0,035) e 90% para RM ponderada em T2 (viés = −0,30 cm2, p = 0,887). A reprodutibilidade entre a RM ponderada em T1 e a RM ponderada em T2 foi 87% (viés = −0,11 cm2; p = 0,957). Em comparação com a TC, a acurácia da RM ponderada em T1 e T2 foi 89% e 91%, respectivamente. Conclusão: O programa utilizado pode ser usado para quantificar o TAV na TC, na RM ponderada em T1 e na RM ponderada em T2. No geral, a acurácia da RM (em comparação com a TC) parece ser alta, assim como a reprodutibilidade intraobservador e interobservador. No entanto, a quantificação do TAV parece ser menos reprodutível nas sequências ponderadas em T1.

Abstract Objective: To evaluate the feasibility of quantifying visceral adipose tissue (VAT) on computed tomography (CT) and magnetic resonance imaging (MRI) scans, using freeware, as well as calculating intraobserver and interobserver reproducibility. Materials and Methods: We quantified VAT in patients who underwent abdominal CT and MRI at our institution between 2010 and 2015, with a maximum of three months between the two examinations. A slice acquired at the level of the umbilicus was selected. Segmentation was performed with the region growing algorithm of the freeware employed. Intraobserver and interobserver reproducibility were evaluated, as was the accuracy of MRI in relation to that of CT. Results: Thirty-one patients (14 males and 17 females; mean age of 57 ± 15 years) underwent CT and MRI (mean interval between the examinations, 28 ± 12 days). The interobserver reproducibility was 82% for CT (bias = 1.52 cm2; p = 0.488), 86% for T1-weighted MRI (bias = −4.36 cm2; p = 0.006), and 88% for T2-weighted MRI (bias = −0.52 cm2; p = 0.735). The intraobserver reproducibility was 90% for CT (bias = 0.14 cm2; p = 0.912), 92% for T1-weighted MRI (bias = −3,4 cm2; p = 0.035), and 90% for T2-weighted MRI (bias = −0.30 cm2; p = 0.887). The reproducibility between T1-weighted MRI and T2-weighted MRI was 87% (bias = −0.11 cm2; p = 0.957). In comparison with the accuracy of CT, that of T1-weighted and T2-weighted MRI was 89% and 91%, respectively. Conclusion: The program employed can be used in order to quantify VAT on CT, T1-weighted MRI, and T2-weighted MRI scans. Overall, the accuracy of MRI (in comparison with that of CT) appears to be high, as do intraobserver and interobserver reproducibility. However, the quantification of VAT seems to be less reproducible in T1-weighted sequences.

ABSTRACT Purpose To describe and analyze our experience with Anderson-Hynes transperitoneal laparoscopic pyeloplasty (LP) in the treatment of recurrent ureteropelvic junction obstruction (UPJO). Materials and methods 38 consecutive patients who underwent transperitoneal laparoscopic redo-pyeloplasty between January 2007 and January 2015 at our department were included in the analysis. 36 patients were previously treated with dismembered pyeloplasty and 2 patients underwent a retrograde endopyelotomy. All patients were symptomatic and all patients had a T1/2>20 minutes at pre-operative DTPA (diethylene-triamine-pentaacetate) renal scan. All data were collected in a prospectively maintained database and retrospectively analyzed. Intraoperative and postoperative complications have been reported according to the Satava and the Clavien-Dindo system. Treatment success was evaluated by a 12 month-postoperative renal scan. Total success was defined as T1/2≤10 minutes while relative success was defined as T1/2between 10 to 20 minutes. Post-operative hydronephrosis and flank pain were also evaluated. Results Mean operating time was 103.16±30 minutes. The mean blood loss was 122.37±73.25mL. The mean postoperative hospital stay was 4.47±0.86 days. No intraoperative complications occurred. 6 out of 38 patients (15.8%) experienced postoperative complications. The success rate was 97.4% for flank pain and 97.4% for hydronephrosis. Post-operative renal scan showed radiological failure in one out of 38 (2.6%) patients, relative success in 2 out of 38 (5.3%) patients and total success in 35 out of 38 (92.1%) of patients. Conclusion Laparoscopic redo-pyeloplasty is a feasible procedure for the treatment of recurrent ureteropelvic junction obstruction (UPJO), with a low rate of post-operative complications and a high success rate in high laparoscopic volume centers.

Magnesium represents a very attractive material for biodegradable stents since the process of its natural and gradual dissolution into the human body by a corrosion process would prevent restenosis risks and would allow the progressive transmission of the mechanical load to the surrounding tissues after several months of service. The objective of the present work is to develop a frame of mechanical and microstructural data about several commercially available Mg alloys in view of their use for biodegradable stents. The AZ31, AZ61, AZ80, ZM21, ZK61 and WE43 alloys in the form of extruded bars were thus investigated to compare their mechanical properties and corrosion resistance. Further high-temperature characterization was carried out by compression tests at high temperature (temperature range: 260-450°C, strain rate range: 5•10-4 ÷ 3•10-2 s-1) in order to assess the optimal processing window for stent precursors manufacturing (small tubes 1÷2 mm in diameter) by hot extrusion. The experimental results made available by this investigation were adopted to support the development of a finite element (FE) framework combining a shape optimization procedure and a detailed model for Mg alloy mechanical and corrosion damage behavior.

OBJECTIVE: Narrow diameter implants (NDI) (i.e. diameter <3.75 mm) are a potential solution for specific clinical situations, such as reduced interradicular bone, thin alveolar crest and replacement of teeth with small cervical diameter. NDI have been available in clinical practice since the 1990s, but only few studies have analyzed their clinical outcome and no study have investigated NDI inserted in fresh-frozen bone (FFB) grafts. Thus, a retrospective study on a series of NDI placed in homologue FFB was designed to evaluate their clinical outcome. MATERIAL AND METHODS: In the period between December 2003 and December 2006, 36 patients (22 females and 14 males, mean age 53 years) with FFB grafts were selected and 94 different NDI were inserted. The mean follow-up was 25 months. To evaluate the effect of several host-, surgery-, and implant-related factors, marginal bone loss (MBL) was considered an indicator of success rate (SCR). The Kaplan Meier algorithm and Cox regression were used. RESULTS: Only 5 out of 94 implants were lost (i.e. survival rate - SVR 95.7%) and no differences were detected among the studied variables. On the contrary, the Cox regression showed that the graft site (i.e. maxilla) reduced MBL. CONCLUSIONS: NDI inserted in FFB have a high SVR and SCR similar to those reported in previous studies on regular and NDI inserted in non-grafted jaws. Homologue FFB is a valuable material in the insertion of NDI.

OBJETIVO: estudo prospectivo para avaliar a utilização da cifoplastia e vertebroplastia como técnicas complementares para o tratamento das fraturas osteoporóticas tipo compressão. MÉTODOS: após um mês de tratamento conservador, os pacientes com fratura osteoporótica do tipo compressão e com dor intratável, foram submetidos à cifoplastia ou vertebroplastia de acordo com algoritmo que considera o tempo da fratura e a quantidade do colapso do corpo vertebral. Biópsia óssea foi obtida no intra-operatório para excluir os pacientes com tumor ou osteomalácia. RESULTADOS: cento e trinta e quatro pacientes foram incluídos de acordo com os critérios do estudo. A média de idade foi 67,7 anos. O seguimento médio foi 33 meses. Dez pacientes não foram seguidos e 154 atingiram um seguimento mínimo de dois; 118 pacientes (69,5%) foram submetidos à vertebroplastia e 36 (30,5%) à cifoplastia. Ocorreram complicações em cinco pacientse tratados por verebroplastia, sendo que um paciente apresentou neuropatia intercostal transitória e quatro pacientes fratura por compressão, tendo ocorrido na vértebra adjacente em dois pacientes. Não foi observada diferença nos escores da avaliação da dor e do questionário de Oswestry. CONCLUSÃO: após um seguimento médio de três anos foram observados resultados satisfatórios com a utilização da vertebroplastia ou cifoplastia para o tratamento das fraturas osteoporóticas por compressão. Ambas as técnicas mostraram bons resultados, de acordo com a sua indicação específica.

OBJECTIVE: in a prospective study, we aimed to evaluate the potential use of kyphoplasty (KP) and vertebroplasty (VP) as complementary techniques in the treatment of painful osteoporotic vertebral compression fractures (VCFs). METHODS: after one month of conservative treatment for VCFs, patients with intractable pain were offered treatment with KP or VP according to a treatment algorithm that considers time from fracture (Ät) and amount of Vertebral Body Collapse (VBC). Bone biopsy was obtained intraoperatively to exclude patients affected by malignancy or osteomalacia. RESULTS: hundred and sixty-four patients were included according to the above criteria. Mean age was 67.6 years. Mean followup was 33 months. Ten patients (6.1%) were lost to follow-up and 154 reached the minimum two years follow-up. 118 (69.5%) underwent VP and 36 (30.5%) underwent KP. Complications affected five patients treated with VP, whose one suffered a transient intercostal neuropathy and four a subsequent VCF (two at adjacent level). Results in terms of VAS and Oswestry scores were not different among treatment groups. CONCLUSION: in conclusion, at an average follow-up of almost 3 years from surgical treatment of osteoporotic VCFs, VP and KP show similar good clinical outcomes and appear to be complementary techniques with specific different indications.

OBJETIVO: estudio prospectivo para evaluar la utilización de la cifoplastia y vertebroplastia como técnicas complementarias para el tratamiento de las fracturas osteoporóticas tipo compresión. MÉTODOS: después de 1 mes de tratamiento conservador, los pacientes con fractura osteoporótica del tipo compresión y de haber presentado un dolor intratable, los pacientes fueron sometidos a la cifoplastia o vertebroplastia de acuerdo con el algoritmo que considera el tiempo de la fractura y la cantidad del colapso del cuerpo vertebral. Biopsia ósea fue obtenida en el intraoperatorio para excluir los pacientes con tumor u osteomalacia. RESULTADOS: ciento treinta y cuatro pacientes fueron incluidos de acuerdo con los criterios del estudio. El promedio de edad fue 67.7 años. El seguimiento promedio fue de 33 meses. Diez pacientes no fueron seguidos y 154 llegaron a un seguimiento mínimo de dos. 118 pacientes (69.5%) fueron sometidos a la vertebroplastia y 36 (30.5%) a la cifoplastia. Complicaciones ocurrieron en cinco pacientes tratados por vertebroplastia, siendo que un paciente presentó neuropatía intercostal transitoria y cuatro pacientes una fractura por compresión en la vértebra adyacente. No fue observada diferencia entre los índices de la evaluación del dolor y del cuestionario de Oswestry. CONCLUSIÓN: después del seguimiento promedio de tres años fueron observados resultados satisfactorios con la utilización de la vertebroplastia o cifoplastia para el tratamiento de las fracturas osteoporóticas por compresión. Ambas técnicas mostraron buenos resultados de acuerdo con su indicación específica.