478 research outputs found
Christensen’s phenomenon: a geometric-mathematical demonstration. Ann Stomat LIV (1), 12-16, 2005
No full textL’implantologia orale nelle creste edentule atrofiche e nei difetti ossei: diagnosi e terapia.
No full textHigh resolution 3-T MR imaging in the evaluation of the trigeminal nerve course
No full textBACKGROUND: The evaluation of the trigeminal course and his anatomical relationships with surrounding structures, is important for the assessment of the injury that may occur in tumors and several orofacial trauma and for avoiding the damage during surgeries. AIM: The aim of this retrospective study was to assess the use of 3-T MRI in the evaluation of the course of the four segments of the trigeminal nerve: cisternal and Meckels's cave, cavernous sinus, skull base and mandibular extracranial segments. PATIENTS AND METHODS: 78 patients were studied, for a total of 156 trigeminal nerves examined. T2-weighted 3D Fast imaging employing steady-state acquisition and T1-weighted Fast spoiled gradient recalled echo sequences were used. Two radiologists (reader A and B), independently, evaluated the course of the four segments of the trigeminal nerve according to a qualitative scale. The Intraclass correlation coefficient (ICC) and Pearson correlation coefficient were used to assess the intraobserver and interobserver variability in the nerve course evaluation. RESULTS: Reader A evaluated 47 trigeminal nerves excellent, 94 good, 12 fair and 3 poor. Reader B rated 43 trigeminal nerves excellent, 92 good, 16 fair and 5 poor. The intraobserver variability was ICC = 0.937 in reader A and ICC = 0.894 in reader B. The interobserver variability was 0.734 (p = 0.01). CONCLUSIONS: High resolution 3-T MRI imaging allows an accurate study of the trigeminal nerve and especially of its mandibular branch. The knowledge of the course and of the anatomic relationships of these nerve bundles with surrounding structures, as well as of the anatomical variants, allow oral and maxillofacial surgical plannings thus reducing the risk of nerve damage
Evaluation of highly porous dental implants in postablative oral and maxillofacial cancer patients: a prospective pilot clinical case series report
No full textThe aim of this study was to evaluate the clinical efficacy of new porous tantalum trabecular metal (PTTM)-enhanced titanium dental implants used for the prosthodontic rehabilitation of postablative cancer patients. First-year interim results of a prospective clinical case series are presented
Funzionamento inverso di una pompa centrifuga: previsione delle prestazioni e confronto con i dati sperimentali
No full textE' presentato un procedimento per predire le prestazioni come turbina di una pompa centrifuga. Il metodo, basato sulla conoscenza delle caratteristiche geometriche e funzionali della pompa, consente di descrivere gli andamenti della caduta idrica e dei singoli rendimenti della fase turbina. L'attendibilità del procedimento è verificata confrontando i risultati teorici con i rilievi sperimentali eseguiti su due pompe centrifughe operanti come turbine
Computer-assisted implant placement and full-arch immediate loading with digitally prefabricated provisional prostheses without cast: a prospective pilot cohort study
No full textBackground Immediate loading of implant-supported full-arch rehabilitations has become routine practice when treating edentulous patients. The combination of static computer-aided implant surgery (s-CAIS) and digital prosthetic workflow could eliminate several treatment steps and facilitate prostheses delivery. The aim of this study is to evaluate the 1-year results of digitally prefabricated polymethyl methacrylate (PMMA) provisional prostheses without a cast for full-arch computer-assisted immediate loading. Materials and methods A digital pre-operative treatment planning was realized for all patients: dental implants and screw-retained abutments were selected in the planning software and two surgical templates were fabricated for each patient. The first template was mucosa or teeth-supported to drill the holes for fixating pins, while the second template was placed after raising a full-thickness flap and was supported by pins as well as soft or hard tissue distal support. Furthermore, based on the surgical planning, interim prostheses were digitally designed and milled of PMMA resin blocks with subsequent pink resin veneering. Osteotomies and implant placement were performed through the surgical guides and all implants were immediately loaded with prefabricated full-arch interim prostheses directly connected to titanium copings with a flowable resin. Results A total of 55 dental implants were placed in ten patients. In all cases, interim prostheses allowed the insertion of titanium copings without the need of access hole enlargement or adaptation. All the prostheses had 1 year of functional loading to simulate the long provisional phase. No screw loosening occurred at the first removal of the prostheses after implant osseointegration. No fracture occurred during the whole period. After 1 year, the mean marginal bone loss level was 0.37 +/- 0.06 mm, while the implant survival rate was 98.18% (n=54/55), with just one implant failing but not affecting final prosthesis delivery to the patient. Conclusions Within the limitations of the present study, the authors concluded that digitally prefabricated provisional prostheses for full-arch immediate loading with s-CAIS could be a valid alternative treatment modality. Milled PMMA restorations proved to be durable enough during the long provisional phase, without prosthetic complications
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