scholarly journals FEM Analysis of Mandibular Prosthetic Overdenture Supported by Dental Implants: Evaluation of Different Retention Methods

2015 ◽  
Vol 2015 ◽  
pp. 1-16 ◽  
Author(s):  
M. Cicciù ◽  
G. Cervino ◽  
E. Bramanti ◽  
F. Lauritano ◽  
G. Lo Gudice ◽  
...  

Prosthetic rehabilitation of total edentulous jaws patients is today a common technique that clinicians approach in their daily practice. The use of dental implants for replacing missing teeth is going to be a safe technique and the implant-prosthetic materials give the possibility of having long-term clinical success. Aim of this work is to evaluate the mechanical features of three different prosthetic retention systems. By applying engineering systems of investigations like FEM and von Mises analyses, how the dental implant material holds out against the masticatory strength during the chewing cycles has been investigated. Three common dental implant overdenture retention systems have been investigated. The ball attachment system, the locator system, and the common dental abutment have been processed by Ansys Workbench 15.0 and underwent FEM and von Mises investigations. The elastic features of the materials used in the study have been taken from recent literature data. Results revealed different response for both types of device, although locator system showed better results for all conditions of loading. The data of this virtual model show all the features of different prosthetic retention systems under the masticatory load. Clinicians should find the better prosthetic solution related to the patients clinical condition in order to obtain long-term results.

2018 ◽  
Vol 12 (1) ◽  
pp. 219-229 ◽  
Author(s):  
Gabriele Cervino ◽  
Umberto Romeo ◽  
Floriana Lauritano ◽  
Ennio Bramanti ◽  
Luca Fiorillo ◽  
...  

Purpose: The objective of this investigation is to study prosthodontics and internal components resistance to the masticatory stress and considering different force directions by using Finite Element Method analysis (FEM). The structural materials of the components are usually Titanium alloy grade 4 or 5 and thus, guarantee the integration of the fixture in the bone due to the osteointegration phenomena. Even if the long-term dental implant survival rate is easy to be obtained and confirmed by numerous researches, the related clinical success, due to the alteration of the mechanical and prosthodontics components is still controversial. Methods: By applying engineering systems of investigations like FEM and Von Mises analyses, it has been investigated how dental implant material was held against the masticatory strength during the dynamic masticatory cycles. A three-dimensional system involved fixture, abutment and the connection screws, which were created and analyzed. The elastic features of the materials used in the study were taken from recent literature data. Results: Data revealed a different response for both types of devices, although implant neck and dental abutment showed better results for all conditions of loading while the abutment screw represented aweak point of the system. Conclusion: The data of this virtual model showed all the features of different prosthetic retention systems under the masticatory load. Clinicians should find better prosthetic balance in order to better distribute the stress over the component and to guarantee patients’ clinical long-term results.


Materials ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 592 ◽  
Author(s):  
Marco Cicciù ◽  
Gabriele Cervino ◽  
Dario Milone ◽  
Giacomo Risitano

The objective of this investigation was to analyze the mechanical features of two different prosthetic retention devices. By applying engineering tools like the finite element method (FEM) and Von Mises analyses, we investigated how dental implant devices hold out against masticatory strength during chewing cycles. Two common dental implant overdenture retention systems were analyzed and then compared with a universal—common dental abutment. The Equator® attachment system and the Locator® arrangement were processed using the FEM Ansys® Workbench. The elastic features of the materials used in the study were taken from recent literature. Results revealed different responses for both the devices, and both systems guaranteed a perfect fit over the axial load. However, the different design and shape involves the customized use of each device for a typical clinical condition of applying overdenture systems over dental implants. The data from this virtual model showed different features and mechanical behaviors of the overdenture prosthodontics attachments. A three-dimensional system involved the fixture, abutment, and passant screws of three different dental implants that were created and analyzed. Clinicians should find the best prosthetic balance to better distribute the stress over the component, and to guarantee the patients clinical long-term results.


VASA ◽  
2013 ◽  
Vol 42 (5) ◽  
pp. 340-349 ◽  
Author(s):  
Ivan Kralj ◽  
Irene Boos ◽  
Uwe Müller-Bühl

Background: Advances in stent technology have widened the field of indications for stent treatment of femoro-popliteal artery lesions, however the use of stents in bending arterial segments is restricted because some first- and second-generation nitinol stent designs did not respond well to the mechanical forces of femoro-popliteal segments in motion which pose a substantial risk of stent fracture inducing in-stent-stenosis. New generation nitinol stents are supposed to overcome these limitations but long-term results are rare. Patients and methods: In forty-five patients (mean age 68 y, range 50 - 85) with peripheral arterial disease (TASC II A-C, Rutherford category 2 - 5) forty-six lesions of the superficial femoral artery (37) or popliteal artery (9) were treated [25 high-grade stenoses, mean length 53 mm (range 30 - 145 mm); 21 chronic total occlusions, mean length 74 mm (range 30 - 180 mm)]. 74 % of lesions were located in the mobile bending arterial segments in the distal femoral or the popliteal segment. Clinical reevaluation performed at discharge, at 6, 12, 24, and 36 months included at least the measurement of ankle-brachial index (ABI) and duplex sonography. Results: Procedural success rate was 100 %. At 6, 12, 24, and 36 months, cumulative primary patency rate was 93.5 %, 84.8 %, 80.5 %, and 74.3 % (SE<10); freedom from target lesion revascularization rate was 95.7 %, 89.2 %, 84.9 %, and 79.3 % (SE<10); Rutherford category and ABI improved in all patients and clinical success was maintained in more than 85 % of patients. Conclusions: Sustained technical and clinical success and good clinical long-term results were achieved with Misago™ nitinol stent implantation in femoro-popliteal lesions with moderate risk for in-stent-stenosis, and in the distal femoral and popliteal mobile segment.


Author(s):  
Dominik Kaczmarek ◽  
Jacob Nattermann ◽  
Christian Strassburg ◽  
Tobias Weismüller

Abstracts Introduction Pancreatic fluid collection (PFC) is a common complication of acute pancreatitis. Endoscopic ultrasound (EUS)-guided drainage, which is often followed by direct endoscopic necrosectomy (DEN), has become the primary approach to treat PFC, including pancreatic pseudocysts (PP) and walled-off necrosis (WON). We aimed to determine retrospectively the short- and long-term results of patients treated in our endoscopy unit and to identify parameters that are associated with treatment efficacy and outcome. Methods The data of 41 consecutive patients with post-pancreatitic PFC, who underwent endoscopic transmural intervention between 2014 and 2016, were analyzed retrospectively. After an initial EUS-guided puncture, one or more plastic stents were placed and DEN was performed if necrotic tissue remained. Results The mean diameter of the PFC was 74.0 ± 4.8 mm. Of the PFCs, 29.3% were classified as PP and 70.7% as WON. Altogether, 196 transmural endoscopic procedures were performed, including 73 endoscopic necrosectomies in a subgroup of 21 patients (20 WON, 1 PP). Initial technical success was achieved in 97.6% of patients and the short-term clinical success rate was 90.2%. The long-term clinical success rate was 82.9%, since four patients died from septic shock and/or multiple organ failure and three patients developed recurrent PFC some months after the initial discharge from endoscopic treatment. Procedural complications were registered in 9 patients during 10 of 196 endoscopic procedures (5.1%): bleeding (6), cardiorespiratory insufficiency (2), perforation with pneumoperitoneum (1), aspiration with respiratory insufficiency (1), and non-perforating superficial damage of the gastric wall (1). Neither the size of the PFC nor the initial value of C-reactive protein (CRP) or other biochemical markers were correlated with efficacy or outcome of treatment. Only the cumulative number of days with CRP > 50 mg/L significantly correlated with the number of follow-up endoscopic sessions and DEN. Fungal colonization of PFC correlated significantly (p < 0.05) with the risk of mortality (44% vs. 0%), need for intensive care treatment (66.7% vs. 25%), and sepsis (55.6% vs. 12.5%). Conclusions We confirm that EUS-guided drainage followed by DEN in patients with solid necrotic material is an effective and relatively safe therapeutic approach. Prolonged elevation of CRP and fungal colonisation of the PFC are associated with a worse course of the disease.


2020 ◽  
Vol 79 (3) ◽  
pp. 312-315 ◽  
Author(s):  
Annette van der Helm-van Mil ◽  
Robert B M Landewé

The favourable long-term results of early treatment in patients with classified rheumatoid arthritis have resulted in an increasing interest in the diseases phases preceding clinical arthritis. The hypothesis to test is that an intervention in these early phases may better prevent or reduce disease persistence than an intervention when arthritis has become clinically manifest. While several placebo-controlled trials are still ongoing, to date there is no firm evidence that this hypothesis truly holds. Therefore, it is important to reflect on the current status of arthralgia preceding clinical arthritis. Inherent to every new field of research, attitudes are conflicting, with opinions propagating innovation (based on the fear of undertreatment) on the one hand, and critical sounds pleading for more restraint (fear of overtreatment) on the other hand. In this Viewpoint, we will examine these divergent opinions, relate them to a preferred ultimate scenario and provide considerations for future studies and daily practice.


VASA ◽  
2001 ◽  
Vol 30 (3) ◽  
pp. 212-218
Author(s):  
Robert A. Bucek ◽  
G. Schnürer ◽  
M. Haumer ◽  
M. Reiter ◽  
A. Ahmadi ◽  
...  

Background: Long term results of systemic lysis therapy with ultrahigh-dose urokinase (UHUK) in reopening aorto-iliac occlusive disease have not yet been evaluated. This prospective trial investigates the long-term primary patency rate, the rate of complications and assesses the role of different expected influence parameters on the primary patency rate. Patients and methods: 72 patients with aorto-iliac occlusive disease received daily intravenous infusions of UHUK either until reperfusion or – after at least 3 cycles – no progress in recanalization could be stated on two consecutive days by duplex scanning. Results: Systemic lysis therapy was morphological at least partially successful in 44 patients (61.1%). Concomitant percutaneous transluminal angioplasty was performed in 41 patients (56.9%), surgery in 7 patients (9.7%) and both in further 5 patients (6.9%). In patients without surgery hemodynamical success could be achieved in 39 patients (54.2%) and even more important clinical success in 51 patients (70.8%). Compared to baseline results patients improved significantly in ankle/brachial pressure index and in Fontaine stages (p < 0,001), the same results could be seen after a mean follow-up period of 62 months. Thrombolysis was complicated in 4 patients (5.6%) by macroembolizations but no major bleedings or deaths occurred. Primary patency was 76%, 64%, and 43% after 1, 5 and 10 years. Male sex and distal localization were significantly correlated with lower primary clinical patency. Conclusion: Systemic lysis therapy is an alternative to surgical intervention in acute and subacute aorto-iliac occlusive disease, because it offers acceptable long-term results with a low rate of complications.


Sign in / Sign up

Export Citation Format

Share Document