ABSTRACT
El presente estudio busca definir los parámetros de la cámara fotográfica y encuadre de la imagen para generar fotografías estandarizadas a modelos dentales de yeso que permitan realizar mediciones intermaxilares a través de fotogrametría, y que estas distancias sean tan confiables y válidas como el registro físico. Se realizó medición directa de los modelos con compás de Korkhaus y medición indirecta a través de fotogrametría digital, evaluando si existía diferencia estadística entre ambas mediciones. Como resultado, no se observaron diferencias significativas entre el protocolo digital con un objetivo 100 mm y magnificación 1:4 en comparación con las mediciones directas, por lo que se concluye que con los parámetros seleccionados se logra una adecuada precisión en la fotogrametría respecto a la medición directa.
This study aims to compare the different parameters of the photographic camera with the digital image framing to standardize dental model photography, in order to take intermaxillary measurements through photogrammetry, and so that these distances are as reliable and valid as the physical record. Direct measurement of the models was made with a Korkhaus compass, and indirect measurement through digital photogrammetry, evaluating whether there was a statistical difference between both measurements. As a result, no significant differences were observed between the digital protocol with a 100 mm objective and 1:4 magnification and the direct measurements. It is concluded that with the selected parameters, adequate precision is achieved in photogrammetry, when compared to the direct measurement.
Subject(s)
Humans , Male , Female , Calcium Sulfate , Photogrammetry , Models, DentalABSTRACT
OBJECTIVE@#To investigate the clinical efficacy of acrylic cement (PMMA) mixed with calcium sulfate combined with percutaneous kyphoplasty (PKP) in the treatment of osteoporotic fracture (OVCF).@*METHODS@#The clinical data of 191 patients with OVCF treated with PKP from January 2020 to March 2021 were retrospectively analyzed. Among them, 82 patients with 94 vertebral bodies were treated with PMMA mixed with calcium sulfate as the observation group, and 109 patients with 125 vertebral bodies were treated with pure PMMA as the control group. Among the 82 patients in the observation group, there were 16 males and 66 females, with a mean age of (75.35±11.22) years old, including 36 thoracic vertebrae and 58 lumbar vertebrae. In the control group, there were 109 patients, 22 males and 87 females, with an average age of (74.51±9.21) years old, including 63 thoracic vertebrae and 62 lumbar vertebrae. The visual analog scale (VAS) before operation and 1 day, 3 months and 1 year after operation were calculated. The Oswestry disability index (ODI), Cobb's angle, vertebral body height and the probability of postoperative bone cement leakage were used to analyze the efficacy of the two groups.@*RESULTS@#All the patients were followed up for more than one year. Compared with the control group, there was no significant difference in operation time, bleeding volume and bone cement injection volume between the two groups(P>0.05), while the leakage rate of bone cement was significantly lower in the observation group (P<0.05). In addition, there was no significant difference in VAS, ODI, Cobb angle, and vertebral body height between the two groups before operation, and 1 day, 3 months, and 1 year after operation (P>0.05), but each index was improved compared with that before operation (P<0.05).@*CONCLUSION@#PMMA mixed with calcium sulfate has equivalent efficacy in treating OVCF than PMMA alone, but can effectively reduce the probability of cement leakage.
Subject(s)
Female , Male , Humans , Aged , Aged, 80 and over , Middle Aged , Polymethyl Methacrylate , Calcium Sulfate/therapeutic use , Osteoporotic Fractures/surgery , Bone Cements/therapeutic use , Kyphoplasty , Retrospective Studies , Lumbar Vertebrae/surgeryABSTRACT
OBJECTIVE@#To investigate the short-term effectiveness of transverse antecubital incision in the treatment of failed closed reduction of Gartland type Ⅲ supracondylar humeral fractures (SHFs) in children.@*METHODS@#Between July 2020 and April 2022, 20 children with Gartland type Ⅲ SHFs who failed in closed reduction were treated with internal and external condylar crossing Kirschner wire fixation through transverse antecubital incision. There were 9 boys and 11 girls with an average age of 3.1 years (range, 1.1-6.0 years). The causes of injuries were fall in 12 cases and fall from height in 8 cases. The time from admission to operation ranged from 7 to 18 hours, with an average of 12.4 hours. The healing of the incision and the occurrence of complications such as nerve injury and cubitus varus were observed after operation; the elbow flexion and extension range of motion after removing the gypsum, after removing the Kirschner wire, and at last follow-up were recorded and compared, as well as the elbow flexion and extension and forearm rotation range of motion at last follow-up between healthy and affected sides; the Baumann angle was measured on the X-ray film, and the fracture healing was observed. At last follow-up, the effectiveness was evaluated according to the Flynn elbow function evaluation criteria.@*RESULTS@#All incisions healed by first intention, and there was no skin necrosis, scar contracture, ulnar nerve injury, and cubitus varus. Postoperative pain occurred in the radial-dorsal thumb in 2 cases. The gypsum was removed and elbow flexion and extension exercises were started at 2-4 weeks (mean, 2.7 weeks) after operation, and the Kirschner wire was removed at 4-5 weeks (mean, 4.3 weeks). All the 20 patients were followed up 6-16 months, with an average of 12.4 months. The fracture healing time was 4-5 weeks, with an average of 4.5 weeks, and there was no complication such as delayed healing and myositis ossificans. The flexion and extension range of motion of the elbow joint gradually improved after operation, and there were significant differences between the time after removing the gypsum, after removing the Kirschner wire, and at last follow-up ( P<0.017). There was no significant difference in the flexion and extension of the elbow joint and the forearm rotation range of motion between the healthy and affected sides at last follow-up ( P>0.05). There was no significant difference in Baumann angle between the time of immediate after operation, after removing the Kirschner wire, and at last follow-up ( P>0.05). According to Flynn elbow function evaluation standard, 16 cases were excellent and 4 cases were good, the excellent and good rate was 100%.@*CONCLUSION@#The treatment of Gartland type Ⅲ SHFs in children with failed closed reduction by internal and external condylar crossing Kirschner wire fixation through transverse antecubital incision has the advantages of complete soft tissue hinge behind the fracture for easy reduction and wire fixation, small incision, less complications, fast fracture healing, early functional recovery, reliable reduction and fixation, and can obtain satisfactory results.
Subject(s)
Male , Female , Humans , Child , Child, Preschool , Calcium Sulfate , Humerus , Humeral Fractures/surgery , Plastic Surgery Procedures , Fracture Fixation, Internal/methods , Bone Wires , Fracture Healing , Treatment Outcome , Range of Motion, ArticularABSTRACT
OBJECTIVE@#To compare the operation complexity and accuracy of traditional splint impression technique and impression technique with prefabricated rigid connecting bar system for full-arch implants-supported fixed protheses in vitro.@*METHODS@#Standard mandibular edentulous model with six implant analogs was prepared. The implants were placed at the bone level and multiunit abutments screwed into the implants. Two impression techniques were performed: the traditional splint impression technique was used in the control group, and the rigid connecting bar system was used in the test group. In the control group, impression copings were screwed into the multiunit abutments and connected with autopolymerizing acrylic resin. Open tray impression was fabricated with custom tray and polyether. In the test group, cylinders were screwed into the multiunit abutments. Prefabricated rigid bars with suitable length were selected and connected to the cylinders with small amount of autopolymerizing acrylic resin, and open tray impression was obtained. Impression procedures were repeated 6 times in each group. The working time of the two impression methods were recorded and compared. Analogs were screws into the impressions and gypsum casts were poured. The gypsum casts and the standard model were transferred to stereolithography (STL) files with model scanner. Comparative analysis of the STL files of the gypsum casts and the standard model was carried out and the root mean square (RMS) error value of the gypsum casts of the control and test groups compared with the standard model was recorded. The trueness of the two impression techniques was compared.@*RESULTS@#The work time in the test group was significantly lower than that in the control group and the difference was statistically significant [(984.5±63.3) s vs. (1 478.3±156.2) s, P < 0.05]. Compared with the standard model, the RMS error value of the implant abutments in the test group was (16.9±5.5) μm. The RMS value in the control group was (20.2±8.0) μm. The difference between the two groups was not significant (P>0.05).@*CONCLUSION@#The prefabricated rigid connecting bar can save the chair-side work time in implants immediate loading of edentulous jaw and simplify the impression process. The impression accuracy is not significantly different from the traditional impression technology. The impression technique with prefabricated rigid connecting bar system is worthy of clinical application.
Subject(s)
Humans , Acrylic Resins , Calcium Sulfate , Dental Implants , Dental Impression Materials , Dental Impression Technique , Jaw, Edentulous , Models, Dental , Mouth, EdentulousABSTRACT
OBJECTIVE@#To observe clinical effect of calcium sulfate on promoting natural healing of docking sites during bone transport.@*METHODS@#A retrospective study was performed on the patients with posttraumatic chronic osteomyelitis treated by bone transport and calcium sulfate implantation from January 2013 to January 2018. There were 23 males and 4 females, aged from 20 to 61 years old with an average of (44.30±10.00) years, the courses of disease ranged from 3 to 86 months with an average of(13.26±16.47) months. Sixteen patients with posttraumatic chronic osteomyelitis were caused by internal fixation of closed fractures, and 11 patients were caused by open fractures. The length of bone defects after debridement ranged from 4 to 14 cm with an average of(9.11±2.57) cm. Postoperative complications, natural healing rate of the docking sites, external fixation index were observed, Checketts & Otterburn pin-tract infection classification was used to evaluate pin-tract infection, and Paley evaluation criteria was used to evaluate bone and function results.@*RESULTS@#Twenty-seven patients were followed up from 26 to 41 months with an average of (31.32±3.37) months. It did not happened skin embedded between bone stumps in all patients. All patients obtained bone union at (17.78±5.43) months after operation.Among them, 25 patients healed naturally in the docking sites, 2 patients with poor compliance healed after debridement and bone grafting in the docking sites. One patient occurred equines deformity, and no re-fracture or recurrence of infection occurred. According to Checketts & Otterburn pin tract infection classification, 22 patients (41 pin tracts)occurred pin-tract infection with varying degrees. The average external fixation index was (2.02±0.24) months/cm(ranged from 1.6 to 2.4 months/cm). According to Paley evaluation criteria, bony results showed 21 patients obtained excellent results, 5 good, and 1 moderate;functional results showed 19 patients got excellent results, 7 good, and 1 moderate.@*CONCLUSION@#During bone transport, the implantation of calcium sulfate on the bone defect areas could prevent skin embedding between the bone stumps, benefit for the natural healing of the docking sites, and could avoid the second-stage debridement and bone grafting for most patients. However, it should be noted that compliance needs to be increased.
Subject(s)
Animals , Child , Child, Preschool , Female , Humans , Infant , Male , Bone Transplantation , Calcium Sulfate , Fracture Fixation , Horses , Osteomyelitis/surgery , Retrospective Studies , Tibial Fractures , Treatment OutcomeABSTRACT
SUMMARY: A comparative study of the morphology of suboccipital cavernous sinus (SCS) using MRI and cast specimens was performed. The present retrospective study analysed the craniocervical magnetic resonance venography (MRV) imaging data of 61 patients. Three-dimensional reconstruction was performed using Mimics 19.0. The SCS left-right diameter(d1), distance from the midline (d2), supero-inferior diameter(d3), anteroposterior diameter (d4), distance from posterior diameter to skin (d5), and diameter of the SCS at different parts (d6-d8) were measured. Comparison between MRV images and cast specimens, the SCS, marginal sinus, anterior condylar vein, and vertebral artery venous plexus were symmetrical and could be bilaterally displayed, whereas the presence of extra condylar vein and posterior condylar vein exhibited different types. The adjacency between the SCS and its communicating vessels and changes in its communicating vessels corresponded well with the MRV images and cast specimens. Many types of the presence of left and right lateral condylar and posterior condylar veins were found in the cast specimens, which could be divided into the bilateral presence of posterior condylar and lateral condylar veins, unilateral presence of posterior condylar veins, and unilateral presence of lateral condylar vein. A total of 61 cases analysed using MRV images revealed the bilateral presence of posterior condylar and lateral condylar veins (77.1 %), the unilateral presence of posterior condylar vein (18.0 %), and the unilateral presence of lateral condylar vein (9.8 %), of which the bilateral presence of posterior condylar and lateral condylar veins accounted for the largest proportion. MRV images and cast specimens of the SCS showed its normal morphological structure and adjacency, thus providing accurate and complete Three-dimensional imaging anatomical data of the SCS and its communicating vascular structures. This study enriches the Chinese SCS imaging anatomy data and may be valuable in clinical practice.
RESUMEN: Se realizó un estudio comparativo de la morfología del seno cavernoso suboccipital (SCS) mediante resonancia magnética y muestras de yeso. El presente estudio retrospectivo analizó los datos de imágenes de venografía por resonancia magnética (RNM) craneocervical de 61 pacientes. La reconstrucción tridimensional se realizó con Mimics 19.0. Se midió: el diámetro izquierdo-derecho del SCS (d1), la distancia desde la línea mediana (d2), el diámetro superoinferior (d3), el diámetro anteroposterior (d4), la distancia desde el diámetro posterior hasta la piel (d5) y el diámetro del SCS en diferentes partes (d6-d8). En la comparación entre las imágenes RNM y las muestras de yeso, el SCS, el seno marginal, la vena condilar anterior y el plexo venoso de la arteria vertebral eran simétricos y se observaron bilateralmente, mientras que la presencia de la vena extracondilar y la vena condilar posterior presentaba tipos diferentes. La proximidad del SCS y sus vasos comunicantes y los cambios en sus vasos comunicantes se correspondieron bien con las imágenes de RNM y los especímenes moldeados. Se encontraron muchos tipos de venas condilares laterales y condilares posteriores izquierda y derecha en las muestras de yeso, que podrían dividirse en presencia bilateral de venas condilares posteriores y condilares laterales, presencia unilateral de venas condilares posteriores y presencia unilateral de venas condilares laterales. Un total de 61 casos analizados mediante imágenes MRV revelaron la presencia bilateral de venas condilares posteriores y condilares laterales (77,1 %), la presencia unilateral de venas condilares posteriores (18,0 %) y la presencia unilateral de venas condilares laterales (9,8 %) de los cuales la presencia bilateral de las venas condilar posterior y condilar lateral representó la mayor proporción. Las imágenes de RNM y las muestras de yeso del SCS mostraron su estructura morfológica y adyacencia normales, lo que proporcionó datos anatómicos de imágenes tridimensionales precisos y completos del SCS y sus estructuras vasculares comunicantes. Este estudio enriquece los datos de anatomía de imágenes de SCS chino y puede ser valioso en la práctica clínica.
Subject(s)
Humans , Cavernous Sinus/anatomy & histology , Cavernous Sinus/diagnostic imaging , Calcium Sulfate , Magnetic Resonance Imaging , Retrospective Studies , Printing, Three-DimensionalABSTRACT
Resumen Caso reporte de una enfermedad infrecuente, aproximadamente 1% de las artritis sépticas son esternoclavicular, con poca respuesta a antibioterapia intravenosa, requiriendo manejo quirúrgico agresivo, el siguiente caso narra la excelente respuesta con el uso de perlas de sulfato de calcio impregnadas con antibióticos, existiendo en la literatura sólo casos reportes sobre su uso.
Abstract Case report of an infrequent disease, approximately 1% of septic arthritis are sternoclavicular, with little response to intravenous antibiotic therapy, requiring ag gressive surgical management, the following case narrates the excellent response with the use of calcium sulfate pearls impregnated with antibiotics, existing in the literature only cases reports on its use.
Subject(s)
Humans , Female , Middle Aged , Osteomyelitis , Calcium Sulfate , Arthritis, Infectious , DiseaseABSTRACT
Resumen Introducción: La vegetación arbórea de selvas que se desarrolla en ambientes kársticos dominados por carbonato de calcio enfrenta la restricción de agua y nutrientes, lo que condiciona su desarrollo. Objetivo: Analizar la composición, diversidad y estructura de la vegetación arbórea que se desarrolla en afloramientos de calcio (yesales) y sus condiciones edáficas comparándolas con las presentes en vegetación secundaria (VS). Métodos: Se emplearon 17 parcelas de 1 000 m², 14 en yesales y 3 en VS. Se obtuvo una muestra compuesta de suelo por parcela y estimamos pH, conductividad eléctrica (CE-salinidad), % de carbonatos de calcio (CaCO3), materia orgánica (MO), fósforo (P) y nitrógeno (N). La diferencia en la composición de especies se evaluó mediante un análisis de similitud (ANOSIM). Empleamos métodos de rarefacción y extrapolación, estimando la diversidad mediante los números de Hill (q = 0, q = 1 y q = 2). Se utilizó un análisis de regresión linear para evaluar la influencia de las características edáficas en la diversidad, el diámetro y la altura promedios. Resultados: Los suelos en yesales presentaron concentraciones bajas de MO, P y N, valores altos de CE-salinidad y altos porcentajes de CaCO3. Se registraron 6 443 individuos de 54 especies en yesales y 594 individuos de 62 especies en la VS, siendo la composición significativamente diferente. La diversidad, los valores promedio de altura y diámetro fueron menores en yesales respecto de VS, estas diferencias estuvieron relacionadas con las condiciones edáficas. Conclusiones: La vegetación arbórea en yesales tiene una composición semejante a la de selvas subperennifolias de Calakmul. Las tallas pequeñas de los árboles están relacionadas con el alto porcentaje de CaCO3 y los altos valores de CE que condicionan la disponibilidad de MO, N y P. Este estudio apoya la idea de que precarias condiciones edáficas tienen una influencia negativa en la diversidad y la estructura horizontal y vertical de la vegetación arbórea.
Abstract Introduction: Tree vegetation of forests that develops in karst environments dominated by calcium carbonate faces the restriction of water and nutrients, which negatively affects its development. Objective: Analyze the composition, diversity, and structure of tree vegetation that develops in calcium outcrops (yesales) and their edaphic conditions compared to those present in the adjacent secondary vegetation (VS). Methods: Plots of 1 000 m² were used, 14 in yesales and 3 in VS. For soil sampling, we obtained a sample composed of each plot, and estimate pH, electrical conductivity (EC-salinity), % of calcium carbonates (CaCO3), organic matter (OM), phosphorus (P) and nitrogen content (N). The difference in species composition was estimated by similarity analysis (ANOSIM). We used rarefaction and extrapolation methods to standardize sample, and estimate diversity by Hill numbers (q = 0, q = 1 and q = 2). Linear regression was used to determine the relative influence of edaphic characteristics in diversity, average diameter, and height. Results: Soils in yesales presented low concentrations of OM, P, and N, with high values of EC-salinity and high percentages of CaCO3. In yesales, 6 443 individuals were recorded in 54 species and in the secondary vegetation 594 individuals and 62 species, the species composition being significantly different between both conditions. Diversity, average values of height, and diameter were significantly lower in yesales regarding the secondary vegetation, these differences were significantly related to edaphic conditions. Conclusions: Tree vegetation in yesales has a composition like the sub-evergreen forests of Calakmul. Small sizes in the arboreal individuals are related to the high percentage of CaCO3 and the high EC values, which partly condition the low availability of OM, N and P affecting the growth of the trees. This study supports the idea that precarious edaphic conditions have a negative influence on the diversity and horizontal and vertical structure of tree vegetation.
Subject(s)
Calcium , Plant Structures , Trees , Calcium Sulfate , Soil Aridity , MexicoABSTRACT
BACKGROUND: Improving the nutritional condition of grapevine in spring to regulate bloom, fruit set, and yield is among the management goals of vineyards. METHODS: In the present study, the early season spray of calcium sulfate (C; 0.00 and 2.00%), potassium sulfate (K; 0.00 and 3.00%), and agricultural grade mineral oil (V; 0.00 and 1.00%) on flower and fruit phenology, nutrient concentration, and cluster biophysical indices and yield of Sultana grapevine ( Vitis vinifera L.) were investigated for two consecutive years. RESULTS: Based on the results, the spray of this nutrient combined with mineral oil significantly affected all the treatments except cluster length, berry length, and phosphorus concentration. The highest concentrations of potassium, calcium, and magnesium were obtained in the vines treated with V0K1C1, and the highest concentrations of zinc and iron were obtained only in the vines treated with mineral oil. In treatments containing mineral oil, especially in combination with the second level of calcium and potassium (V1K1C1), bloom time, berries pea-sized time, and harvest time were delayed by 3, 3, and 6 days compared with control vines. While in vines treated with a combination of the second level of potassium and calcium (V0K1C1), bloom time, berries pea-sized time, and harvest time were advanced by 5, 4, and 1.50 days, respectively, compared with control vines. Regarding the biophysical indices of the cluster, it was found that the vines treated with V1K1C1 had higher cluster weight, berry weight, fruit, and raisins yield than other treatments. Also, the highest berry quality, including total soluble solids, titratable acidity, and total phenol content, were obtained in the vines treated with V0K1C1. However, the lowest berry quality was observed in the vines treated with mineral oil. CONCLUSIONS: Therefore, the combination of nutrients with mineral oil can alleviate the adverse effect of mineral oil solely on some phenological indices and berry quality-related traits in vineyards.
Subject(s)
Vitis , Potassium , Calcium Sulfate , Mineral Oil , FruitABSTRACT
Purpose: Two important factors in dental prosthesis are making an accurate impression and producing a suitable cast which represents the exact relationship between prepared tooth and oral structures. This study, aimed to investigate the effects of different combinations of impression and pouring materials on marginal and internal adaptation of premolar zirconia crowns. Material and Methods: Forty maxillary premolars were prepared considering round shoulder finish line. The impressions were made either by additional (Panasil) or condensation (Speedex) silicon, and poured by two different types of gypsum materials (Siladent or GC gypsum) (N=10). Zirconia crowns were fabricated using a CAD-CAM system. The crowns were cemented, and the samples were cut in bucco-lingual direction. Marginal and internal gaps were measured by stereomicroscope (×25). Results: The mean marginal gaps for Pansil-Siladent, Panasil-GC, Speedex-Siladent, and Speedex-GC were 141 µm, 143 µm, 131 µm, and 137 µm respectively. The internal gaps were 334 µm, 292 µm, 278 µm, and 257 µm respectively. The independent T-Student test showed no significant differences in average marginal or internal gap among various impression and gypsum materials or their interactions (p>0.05). Two-way ANOVA test showed no significant differences in maximum marginal or internal gap among various impression and gypsum materials and their interactions (p>0.05). Conclusion: The present study revealed no statistically significant difference in marginal/internal gap among crowns prepared using different combinations of impression-pouring materials evaluated.
Introducción: Dos factores importantes en la prótesis dental son hacer una impresión precisa y la producción de un modelo adecuado que represente la relación exacta entre el diente preparado y las estructuras orales. Este estudio, tuvo como objetivo investigar los efectos de diferentes combinaciones de materiales de impresión y vertido sobre la adaptación marginal e interna de coronas de zirconio premolar. Material y Métodos: Se prepararon cuarenta premolares maxilares considerando la línea de meta del hombro redondo. Las impresiones se realizaron con silicio adicional (Panasil) o de condensación (Speedex) y se vertieron con dos tipos diferentes de materiales de yeso (yeso Siladent o GC) (N = 10). Las coronas de zirconio se fabricaron utilizando el sistema CAD-CAM. Las coronas se cementaron y las muestras se cortaron en dirección buco-lingual. La brecha marginal e interna se midió con estereomicroscopio (×25). Resultados: Las brechas marginales medias para Pansil-Siladent, Panasil-GC, Speedex-Siladent y Speedex-GC fueron de 141µm, 143µm, 131µm y 137µm, respectivamente. Las brechas internas fueron 334µm, 292µm, 278µm y 257µm, respectivamente. La prueba de T-Student independiente no mostró diferencias significativas en la brecha marginal o interna promedio entre varios materiales de impresión y yeso o sus interacciones (p>0.05). La prueba ANOVA bidireccional no mostró diferencias significativas en el espacio marginal o interno máximo entre varios materiales de yeso y de impresión y sus interacciones (p>0.05). Conclusión: El presente estudio no reveló diferencias estadísticamente significativas en la brecha marginal/interna entre las coronas preparadas con diferentes combinaciones de materiales de impresión y vertido evaluados.
Subject(s)
Humans , Dental Prosthesis/methods , Crowns , Dental Impression Materials , Zirconium/chemistry , Bicuspid , Calcium Sulfate , Computer-Aided Design , Dental Cements , Dental Restoration, PermanentABSTRACT
Studies related to the monitoring of soil quality by physical attributes are important for the evaluation and maintenance of the sustainability of agricultural systems, besides indicating the appropriate management of the environment, aiming at its conservation and productivity. The objective of this study was to evaluate the stability of aggregates and organic carbon after the application of gypsum, soil scarification and a succession of crops. The treatments consisted of an absence and addition of gypsum, absence and presence of soil scarification, and three systems of crops in succession. The experimental design was made of randomized blocks, in a 2x2x4 factorial scheme, with eight replications. The aggregates were evaluated as stabled in water and soil organic carbon content. The treatment where gypsum was applied, as well as the soybean/maize/brachiaria/fallow (SMBF) succession system, presented better results in soil aggregation and higher levels of organic carbon.
Estudos relativos ao monitoramento da qualidade do solo pelos atributos físicos são importantes para a avaliação e manutenção da sustentabilidade dos sistemas agrícolas, além de sinalizar o manejo adequado do ambiente, visando à sua conservação e produtividade. Este trabalho teve por objetivo avaliar a estabilidade de agregados e teor de carbono orgânico, após a aplicação de gesso, escarificação do solo e sucessão de culturas. Os tratamentos consistiram na ausência e adição de gesso agrícola, ausência e presença de escarificação do solo, e três sistemas de sucessão de culturas. O delineamento experimental foi em blocos casualizados, em esquema fatorial 2x2x3 com oito repetições. Sendo avaliada a estabilidade dos agregados estáveis em água e teor de carbono orgânico do solo. O tratamento onde foi aplicado gesso agrícola e o sistema de sucessão SMBP apresentaram melhores resultados na agregação do solo e maiores teores de carbono orgânico.
Subject(s)
Soil , Soil Quality , Soil Treatment , Glycine max , Calcium Sulfate , Carbon , Soil Acidity , Soil Characteristics , Zea mays , Brachiaria , Crop ProductionABSTRACT
Soil liming is a common practice in agriculture. It aims to reduce soil acidity and to supply calcium and magnesium. Lime, however, is not easily soluble in the soil, and its reaction products are often concentrated in the application zone, which is mainly the topsoil layer. In order to increase the concentration of nutrients in deeper layers, agricultural gypsuma byproduct of phosphoric acid production process, rich in calcium and sulfuris used. In this context, the objective of this study was to evaluate the chemical attributes of the oxysoil and the corn Ìs yield to the application of gypsum associated with potassium (K) rates. The study was developed in Uberaba city, Minas Gerais state, Brazil. The factorial scheme was used 5x5, with five rates of K (0, 100, 180, 240, 360 kg ha-1 K2O) and five gypsum rates (0, 500, 1000, 2000, 4000 kg ha-1) in a randomized complete block design with four replications. The soil chemical attributes were evaluated at 0.0-0.20 m and 0.20-0.40 m depth and the biometric and productive attributes of corn. The application of gypsum resulted in the increase of calcium (Ca) and sulfur (S) contents in all depths; reduced the levels of pH, manganese, potential acidity (H + Al) in the 0.0-0.20 m depth, and increase the levels of base of saturation and sum of bases on the 0.20-0.40 m depth. Corn yield and biometric attributes no were influenced by the factors evaluated.
A calagem é uma prática comum na agricultura. Esta prática visa reduzir a acidez do solo, além de fornecer cálcio e magnésio. Contudo, devido ao fato de o calcário apresentar baixa solubilidade no solo, os produtos de sua reação ficam retidos na camada onde o produto foi aplicado, a qual geralmente é na camada superficial do solo. Para se aumentar a concentração de nutrientes em camadas mais profundas, o gesso agrícola - um subproduto da produção de ácido fosfórico, rico em cálcio e enxofre tem sido usado. Neste contexto, o objetivo deste trabalho foi avaliar a influência da aplicação de diferentes doses de gesso em associação a doses de potássio, nos atributos químicos do solo e na produtividade de grãos de milho. O estudo foi conduzido no Instituto Federal de Educação, Ciência e Tecnologia do Triângulo Mineiro (IFTM), Campus Uberaba, localizado no município de Uberaba-MG, Brasil. O experimento foi instalado em esquema fatorial 5x5, sendo cinco doses de gesso (0, 500, 1000, 2000 e 4000 kg ha-1) e cinco doses de K2O (0, 100, 180, 240 e 360 kg ha-1) no delineamento em blocos completos casualizados, com quatro repetições. Os atributos químicos do solo foram avaliados nas camadas de 0,0 a 0,20 m e de 0,20 a 0,40 m, além das características biométricas e produtivas da cultura do milho. A aplicação de gesso resultou no aumento de cálcio e enxofre em ambas as profundidades; reduziu os níveis de pH, manganês, acidez potencial (H + Al) na camada de 0,0-0,20m; e, aumentou os níveis de saturação por bases e soma de bases na camada de 0,20-0,40 m. A produção de milho não foi influenciada pelos fatores avaliados.
Subject(s)
Potassium , Soil , Calcium Sulfate , Zea maysABSTRACT
Background: Plaster of Paris (POP) is being used in different ways in the field of medicine, dentistry and rehabilitation. One of its uses is in the manufacture of models of body segments in prosthetics and orthotics. It is used as a one-off procedure in which the used material is dismantled and discarded. The disposal of discarded materials does not allow easy decomposition which then pollutes the environment. It is not known whether this material could be reused if recycled. Objectives: The main objective of the study was to recycle POP models and determine its reuse in producing models with identical qualities, and thus reduce environmental pollution. Method: The procedure adopted was to break discarded models into small pieces, remove impurities and dirt; then the sample models were milled, washed, dried and pulverised. The POP models were heated to evaporate crystalline water in order to determine for how many times it could be recycled while retaining the desired strength, setting time and working characteristics. Results: The recycled POP reached higher setting temperatures and was stronger in terms of compressive strain and strength than the virgin POP. The highest temperature recorded for recycled POP was 40°C, which was higher than that for virgin powder (32.5°C). Testing compressive strength of all cylinders in all groups showed that the average compressive strength of the recycled powder mixed with water in a ratio of 1:1 was 2407 KN/m² and the ratio of 2:3 resulted in a compressive strength of 1028 KN/m², whereas the average compressive strength of virgin POP powder mixed with water in a ratio of 1:1 was 1807 KN/m² and the ratio of 2:3 resulted in a compressive strength of 798 KN/m². There were no differences in working properties between the recycled POP and the virgin POP. Conclusion: It was therefore concluded that under controlled conditions, such as grinding size, heating temperature, time and avoidance of contamination, used POP could be continuously recycled, resulting in stronger and workable casts
Subject(s)
Agnosia , Calcium Sulfate , Compressive Strength , RecyclingABSTRACT
Abstract Objective: To determine diametral tensile strength and water absorption ability of Carbonate-apatite blocks fabricated from gypsum precursors (CaSO4) through a dissolution-precipitation method, with different solution molarities and immersion times. Material and Methods: Thirty-six CaSO4 gypsum specimens with 6 mm diameter; 3 mm height (Group A for diametral tensile strength) and 36 specimens of 6 mm diameter; 3 mm thickness (Group B for water absorption ability) were used. Each group was divided into 4 group treatments of: 1) dissolution-precipitation in solution of 0.5mol / L Na2CO3 + 0.5mol / L Na3PO4 for 48 hours and 72 hours; 1mol / L Na2CO3 + 1mol / L Na3PO4 for 48 hours and 72 hours. The C-Ap blocks were then tested using ATR-FTIR spectrometer to identify the formation of C-Ap functional groups. Furthermore, Group A specimens were tested for diametral tensile strength using Universal Testing Machine, and Group B specimens were tested for water adsorption ability using an analytical balance by measuring initial and final weight after immersion in saline solution at 37oC for 24 hours. Results: The formation of carbonate-apatite (C-Ap) in groups with solution molarity of 1 mol/L for 48 hours and 72 hours resulted in a lower diametral tensile strength and water absorption ability than the groups with a 0.5 mol/L solution. Conclusion: Solution with different molarities and dissolution-precipitation duration affect the formation of carbonate-apatite blocks.
Subject(s)
Tensile Strength , Calcium Sulfate/therapeutic use , Adsorption , Dental Materials , Analysis of Variance , Spectroscopy, Fourier Transform Infrared/instrumentation , Statistics, Nonparametric , Indonesia/epidemiologyABSTRACT
This study aimed to evaluate soil biomass and microbial activity and soybean yield under different limestone and gypsum doses and different cover crops. The experiment was carried out in the experimental area of the Fundação de Apoio a Pesquisa Agropecuária de Chapadão, on a Dystrophic Red Latosol, using cultivar Desafio. The experiment consisted of a randomized blocks design, in a split-plot factorial scheme (3x4x3), with three replications. Plots consisted of three gypsum doses: control (without gypsum), recommended dose (2.3 Mg ha-1), and double dose (4.6 Mg ha-1). Subplots consisted of four limestone doses (2, 4, and 6 Mg ha-1) and the control (without limestone). Each block had three different cover crops: Brachiaria, Millet, and allow. The values obtained with the test revealed that brachiaria had better basal respiration in the absence of gypsum. Conversely, millet had better basal respiration in with the gypsum dose. Basal respiration, using brachiaria as cover crop, was higher at the dose of 2700 kg ha-1 of limestone. However, for the fallow and the millet, basal respiration was higher when using the highest limestone dose of 6000 kg ha-1. The variable microbial biomass showed differences between cover crops only in the absence of gypsum. Brachiaria and fallow presented the highest mean for microbial biomass. The use of millet as a cover crop together with gypsum doses increased the microbial biomass. The variables mass of 100 grains and grain yield had higher mean at the limestone dose of 6000 kg ha-1 .
O objetivo do trabalho foi avaliar a biomassa e atividade microbiana do solo, e produtividade da soja sob efeito das diferentes doses de calcário e gesso e diferentes coberturas de solo. O experimento foi conduzido na área experimental da Fundação de Apoio a Pesquisa Agropecuária de Chapadão, sob Latossolo Vermelho Distrófico, com a cultivar Desafio. O delineamento experimental utilizado foi em blocos casualizados, em esquema fatorial (3x4x3) de parcelas subdividas, com 3 repetições. As parcelas foram constituídas por 3 quantidades de gesso agrícola, sendo: controle (sem gesso), recomendado (2,3 Mg ha-1) e o dobro (4,6 Mg ha-1), as subparcelas por 4 doses de calcário (2, 4 e 6 Mg ha-1), além do controle (sem calcário), onde cada bloco apresentou 3 coberturas diferentes: Braquiaria, Milheto e Pousio. Os resultados foram submetidos ao teste de Tukey 5%. Com os valores obtidos pudemos observar que a respiração basal foi melhor para braquiária na ausência de gesso, e na presença o milheto se saiu melhor. A respiração basal, utilizando a braquiária como cobertura, foi maior na dose de 2700 kg ha-1 de calcário. Já utilizando o pousio e o milheto foi na maior dose 6000 kg ha-1. A variável biomassa microbiana apresentou diferença entre as coberturas apenas na ausência de gesso, onde a braquiária e o pousio apresentaram as maiores médias para esta variável. A utilização do milheto como cobertura em conjunto com as doses de gesso acarretou aumento da biomassa microbiana. A massa de 100 grãos e a produtividade de grãos apresentaram maior média na dose de 6000 kg ha-1 de calcário.
Subject(s)
Glycine max , Biomass , Calcium Sulfate , MilletsABSTRACT
Se realizaron mediciones en los ejes x, y, z sobre modelos dentales de yeso, digitalizados e impresos con impresoras 3D, con fines comparativos, estadísticos y evaluativos, cuyo objetivo fue estimar el grado de coincidencia significativa entre los modelos, realizados por dos profesionales, en dos momentos diferentes. Los resultados arrojaron datos de gran precisión en forma y tamaño en los tres estudios, con mínima distorsión (no significativa, p =0,05), lo que determinó la importancia de implementación en forma institucional o privado el estudio digital de los mismos, para realizar comparaciones, mediciones, diagnósticos y acopio de modelos virtuales en un ordenador, siendo estos más precisos y de menor tiempo de trabajo (AU)
Measurements were made in the x, y, z axes on gypsum dental models, digitized and printed with 3D printers, for comparative, statistical and evaluative purposes, whose objective was estimate the degree of significant coincidence between models, that were made by two professionals, at two different times.The results were the achieve of data with a great shape´s and size´s precisionat the three studies, with minimal distortion (not significant, p = 0.05), which determined the importance of the institutional or private way of an implementation of the model´s digital studies, with the aim of doing comparisons, measurements, diagnostics, and collection of virtual models in a computer, to being more precise and with less work time (AU)
Subject(s)
Image Processing, Computer-Assisted , Calcium Sulfate , Models, Dental , Printing, Three-Dimensional , Stereolithography , Imaging, Three-DimensionalABSTRACT
Resumen: El incremento en la cirugía de artroplastía total de cadera es motivado por muchos factores, como el aumento en la expectativa de vida, mejoría continua en la técnica quirúrgica e innovaciones en el diseño y los materiales de los implantes que, sumados, han convertido a este procedimiento en una solución efectiva a la degeneración articular, con excelentes resultados. Sin embargo, a pesar de los avances tecnológicos, la infección periprotésica se ha mantenido como una de las complicaciones más devastadoras. Este estudio evalúa la aplicación profiláctica de perlas de sulfato de calcio medicadas en el canal femoral y superficie acetabular para prevenir infecciones periprotésicas en pacientes que fueron sometidos a una artroplastía total de cadera primaria no cementada contra un grupo control mediante la medición de reactantes de fase aguda y cultivo de líquido sinovial. Se sometieron al estudio 146 individuos: 67 a quienes se les aplicaron perlas de sulfato de calcio medicado y 79 a quienes se les aplicó antibiótico profiláctico intravenoso de Septiembre de 2013 a Agosto de 2016. Como método diagnóstico de infección periprotésica temprana se evaluaron la proteína C reactiva asociada a velocidad de sedimentación globular aumentada, una fístula que comunicara con la prótesis, cultivo positivo de dos o más sitios periprotésicos de líquido sinovial o tejido. Los resultados clínicos demostraron que hubo una disminución en los valores de los reactantes de fase aguda en los sujetos a quienes se les aplicaron las perlas de sulfato de calcio medicado. Se encontró que 14 personas presentaron infección en el grupo con profilaxis parenteral, comparado con tres del grupo con profilaxis local con perlas de sulfato de calcio medicado; ambos grupos con ceftriaxona. Se consideró que el uso profiláctico de perlas de sulfato de calcio dentro de canal medular y la superficie acetabular es una buena opción para prevenir infecciones periprotésicas en quienes han sido sometidos a una artroplastía total de cadera primaria no cementada; sin embargo el estudio amerita seguimiento con más pacientes para tener significancia estadística.
Abstract: The increase in total hip arthroplasty occurs by many factors, such as increasing life expectancy, improving surgical technique as well as innovating the design and implant material. However, despite technological advances, peri-prosthetic infection has remained one of the most devastating complications. This study evaluates the prophylactic application of calcium sulfate pearls medicated in the femoral canal and acetabular surface to prevent peri-prosthetic infections in patients who underwent total uncemented primary hip arthroplasty against a control group by measuring acute phase reactants. 146 patients, 67 were applied calcium sulfate pearls medicated and 79 prophylactic antibiotic intravenous in the period from 2013 to 2016. To perform the diagnosis of peri-prosthetic infection was assessed PCR associated with VSG, communication between fistula and prostheses and positive culture in 2 or more different sites. There was a decrease in the values of acute-phase reactants in patients who were given calcium sulfate pearls. 14 patients presented infection in the control group and 3 in the study group. The prophylactic use of calcium sulphate pearls within the medullary canal and acetabular surface is an option for the prophylaxis of peri-prosthetic infections, however the study deserves follow-up with more patients.
Subject(s)
Humans , Calcium Sulfate/therapeutic use , Arthroplasty, Replacement, Hip , Hip Prosthesis , Prosthesis Design , Reoperation , Prosthesis FailureABSTRACT
PURPOSE: The purpose of this study was to compare two novel impression methods and a conventional impression method for edentulous jaws using 3-dimensional (3D) analysis software. MATERIALS AND METHODS: Five edentulous patients (four men and one woman; mean age: 62.7 years) were included. Three impression techniques were used: conventional impression method (CI; control), simple modified closed-mouth impression method with a novel tray (SI), and digital impression method using an intraoral scanner (DI). Subsequently, a gypsum model was made, scanned, and superimposed using 3D analysis software. Mean area displacement was measured using CI method to evaluate differences in the impression surfaces as compared to those values obtained using SI and DI methods. The values were confirmed at two to five areas to determine the differences. CI and SI were compared at all areas, while CI and DI were compared at the supporting areas. Kruskal-Wallis test was performed for all data. Statistical significance was considered at P value .05); the difference was .05). CONCLUSION: The CI, SI, and DI methods were effective in making impressions of the supporting areas in edentulous patients. The SI method showed clinically applicability.
Subject(s)
Female , Humans , Male , Calcium Sulfate , Jaw , Jaw, Edentulous , Maxilla , MethodsABSTRACT
PURPOSE: The purpose of this study was to verify the effect of the abutment superimposition process on the final virtual model in the scanning process of single and 3-units bridge model using a dental model scanner. MATERIALS AND METHODS: A gypsum model for single and 3-unit bridges was manufactured for evaluating. And working casts with removable dies were made using Pindex system. A dental model scanner (3Shape E1 scanner) was used to obtain CAD reference model (CRM) and CAD test model (CTM). The CRM was scanned without removing after dividing the abutments in the working cast. Then, CTM was scanned with separated from the divided abutments and superimposed on the CRM (n=20). Finally, three-dimensional analysis software (Geomagic control X) was used to analyze the root mean square (RMS) and Mann-Whitney U test was used for statistical analysis (α=.05). RESULTS: The RMS mean abutment for single full crown preparation was 10.93 µm and the RMS average abutment for 3 unit bridge preparation was 6.9 µm. The RMS mean of the two groups showed statistically significant differences (P<.001). In addition, errors of positive and negative of two groups averaged 9.83 µm, −6.79 µm and 3-units bridge abutment 6.22 µm, −3.3 µm, respectively. The mean values of the errors of positive and negative of two groups were all statistically significantly lower in 3-unit bridge abutments (P<.001). CONCLUSION: Although the number of abutments increased during the scan process of the working cast with removable dies, the error due to the superimposition of abutments did not increase. There was also a significantly higher error in single abutments, but within the range of clinically acceptable scan accuracy.