Search results for " Opera"
showing 10 items of 3606 documents
In vitro comparison of the efficacy of two fractured implant-prosthesis screw extraction methods: Conventional versus mechanical.
2019
Abstract Statement of problem Implant-supported prostheses may be subject to esthetic, biological, or mechanical complications. Protocols for dealing with these mechanical problems are sparse. Purpose The purpose of this in vitro study was to compare the efficacy of a mechanical system for extracting fractured implant-prosthesis screws with the conventional method. Material and methods A total of 60 screws were divided into 2 groups according to their morphology (flat screws with a smooth shaft and threaded apical area and screws with a completely threaded body) and subjected to fatiguing and static load testing until fracture. The specimens were assigned to 3 operators with varying levels …
Cementless acetabular reconstruction and structural bone-grafting in dysplastic hips. Surgical technique.
2007
BACKGROUND: Studies of acetabular reconstruction with use of cement and bulk bone graft have demonstrated increasing rates of cup failure in patients with dysplastic hips seven years after total hip arthroplasty. Comparable data on the long-term results of bulk bone-grafting done in conjunction with cementless implants are limited. The aim of this study was to review the clinical and radiographic results of autologous bulk bone-grafting in conjunction with a cementless cup. METHODS: From 1987 to 1992, forty-seven patients (forty women and seven men, with an average age of 50.4 years) who had developmental dysplasia of the hip underwent fifty-six total hip arthroplasties and received a struc…
High frequency of lumbar fusion in patients denied surgical treatment of the sacroiliac joint.
2019
Purpose: Effective treatment of medical conditions relies on proper diagnosis. Clinical trials show the safety and effectiveness of sacroiliac joint (SIJ) fusion in patients with chronic SI joint dysfunction. To what extent is the condition under recognised? Objective: To determine whether under recognition of SIJ pain affects healthcare trajectories in Spanish patients with low back pain. Methods: Retrospective study of characteristics and consequences of 189 patients with persistent SIJ pain seen in an outpatient neurosurgery clinic. Results: Patients with SIJ pain who were denied surgical treatment had a longer pain duration, higher likelihood of prior lumbar fusion, and a high rate (63%…
Elección del implante intraarticular en el tratamiento de las lesiones del ligamento cruzado anterior
1992
Los autores hacen una revisión de los diferentes implantes usados para la sustitución intraarticular del ligamento cruzado anterior (LCA). Se analizan los injertos autólogos, los materiales sintéticos y los aloinjertos tendinosos. Nos encontramos ante un tema sujeto a controversia, aunque la tendencia actual es el uso de autoinjertos de hueso -tendón rotuliano- hueso. No obstante, ninguno de los tejidos sustitutivos puede remedar por completo la anatomía del LCA original. The authors review the different implants used for the intra-articular substitution of the anterior cruciate ligament (ACL), analyzing the autologous grafts, synthetic materials and tendinous allografts. We find ourselves …
Cemented and screw-retained implant-supported single-tooth restorations in the molar mandibular region: A retrospective comparison study after an obs…
2015
Objectives: The aim of this study was to evaluate the survival and compare the appearance of different mechanical and biological complications, in screw-retained and cemented-retained single-tooth implant-supported restorations localized in the molar mandibular region, over a period of 1 to 4 years. Material and Methods: A retrospective study was carried out with a total of eighty implant-supported restorations, which were placed in eighty patients for prosthetic rehabilitation of a mandibular molar. Forty patients were rehabilitated with a cemented-retained restoration and the other forty with a screw-retained restoration. The presence of the following complications was recorded for both t…
Traction test of temporary dental cements
2017
Background Classic self-curing temporary cements obstruct the translucence of provisional restorations. New dual-cure esthetic temporary cements need investigation and comparison with classic cements to ensure that they are equally retentive and provide adequate translucence. The objective is to analyze by means of traction testing in a in vitro study the retention of five temporary cements. Material and methods Ten molars were prepared and ten provisional resin restorations were fabricated using CAD-CAM technology (n=10). Five temporary cements were selected: self-curing temporary cements, Dycal (D), Temp Bond (TB), Temp Bond Non Eugenol (TBNE); dual-curing esthetic cements Temp Bond Clear…
Screw‐in‐screw fixation of fragility sacrum fractures provides high stability without loosening—biomechanical evaluation of a new concept
2020
Surgical treatment of fragility sacrum fractures with percutaneous sacroiliac (SI) screw fixation is associated with high failure rates. Turn-out is detected in up to 20% of the patients. The aim of this study was to evaluate a new screw-in-screw implant prototype for fragility sacrum fracture fixation. Twenty-seven artificial hemipelvises were assigned to three groups (n = 9) for instrumentation of an SI screw, the new screw-in-screw implant prototype, ora transsacral screw. Before implantation, a vertical osteotomy was set in zone 1 after Denis. All specimens were biomechanically tested to failure in upright position. Validated setup and test protocol were used for complex axial and torsi…
Improving the cementation of the tibial component in knee arthroplasty : a study of four techniques in the cadaver.
2021
Aims The main objective of this study is to analyze the penetration of bone cement in four different full cementation techniques of the tibial tray. Methods In order to determine the best tibial tray cementation technique, we applied cement to 40 cryopreserved donor tibiae by four different techniques: 1) double-layer cementation of the tibial component and tibial bone with bone restrictor; 2) metallic cementation of the tibial component without bone restrictor; 3) bone cementation of the tibia with bone restrictor; and 4) superficial bone cementation of the tibia and metallic keel cementation of the tibial component without bone restrictor. We performed CT exams of all 40 subjects, and mea…
Novel Digital Technique to Quantify the Area and Volume of Cement Remaining and Enamel Removed after Fixed Multibracket Appliance Therapy Debonding: …
2020
The aim of this study was to construct a novel, repeatable, reproducible, and accurate measurement protocol for the area and volume of the remaining cement after removal of fixed multibracket appliances, the area and volume of remaining cement after cement removal, the area and volume of enamel removed after cement removal, and the volume of cement used to adhere fixed multibracket appliances. A total of 30 brackets were cemented and removed with over 30 extracted teeth embedded into three experimental models of epoxy resin. The models were scanned before and after bracket placement, bracket debonding, and polishing the remaining cement. The brackets were submitted to micro-computed tomogra…
CRT-727 Percutaneous Balloon Atrial Septostomy for Direct Left Heart Decompression in Patients on Extra Corporeal Membrane Oxygenation
2014
Severe myocardial dysfunction and added afterload from the Extra Corporeal Membrane Oxygenation (ECMO) arterial cannula may lead to significant rise in left ventricular (LV) end-diastolic and left atrial (LA) pressures. This may result in ischemia, lower likelihood of ventricular recovery and hence