A new generation of leucite-reinforced pressable ceramic systems.
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Aged↗
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Results for “Prosthesis Coloring”
Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.
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Aesthetic dilemma: maximizing aesthetics through proper tooth form and alignment.
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Adult↗
Tooth-colored post systems: a review.
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Carbon↗
Cerec veneers--practical procedure and case presentation.
The Cerec method offers experienced users the possibility of accomplishing veneers chairside which are capable of meeting the highest functional and esthetic requirements. "Esthetic shaping" directly on the patient requires a good eye for color and form, and this requires training. The present report outlines the clinical procedure and presents three clinical cases step by step, specifically discussing the external staining technique with Pro-CAD blocks.
Adolescent↗
Understanding the characteristics of naturally shaded composite resins.
Composite resin formulations have proliferated in recent years, and clinicians are challenged to understand the nuances and technical requirements involved in the successful application of each individual system. Depending on the user's material of choice, the restorative protocol follows the resin layering sequence traditionally used by either clinicians or laboratory technicians. To clarify comprehension of each, this presentation discusses the characteristics of a naturally shaded composite resin and demonstrates their application in the direct restoration.
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[Mitral valve bioprosthesis from bovine pericardium. Color Doppler echographic study and long-term follow up].
Pericardial heart valve bioprostheses have been utilized for 20 years. In spite of encouraging initial results, long-term follow-up showed a higher incidence of structural failures and primary tissue failures than porcine bioprostheses. Pericarbon represents the newest generation of bovine pericardial bioprostheses. Aim of this study is the long-term evaluation with echocardiographic and color Doppler technique of an innovative bioprostheses, in particular, its morfological and functional characteristics. From 1985 to 1989, 78 consecutive patients (21 males, 57 females, mean age 56.5 +/- 8.16 years) underwent mitral valve replacement with Pericarbon 29, by the same operator, who preserved the mitral posterior leaflet. One month after operation, 21 of these patients underwent echo-color Doppler evaluation, in normalized hemodynamic conditions (normality ranges). In 1995, at the end of the followup, 30 of the remaining 54 patients underwent new echo-color Doppler evaluation and these data were compared with normality ranges values. Leaflets' thickness increased from 0.98 +/- 0.09 to 2.87 +/- 0.73 mm (anterior leaflet; p < 0.0001) and from 1.02 +/- 0.08 to 2.71 +/- 0.45 mm (posterior leaflet; p < 0.0001) 43.3% of anterior leaflet and 53.3% of posterior leaflet showed fibrocalcic lesions. Mean transvalvular gradient increased from 3.4 +/- 0.2 to 6.6 +/- 3.4 mmHg (p < 0.0001); also functional area decreased (p < 0.0001). We have found no paraprosthetic regurgitation and a very low number of central prosthetic regurgitation. Left ventricular function, evaluated by ejection fraction and regional kinesis, remained substantially preserved.
Aged↗
Improved regional left ventricular performance in mitral valve replacement with orthotopic refixation of the anterior mitral leaflet.
BACKGROUND AND AIMS OF THE STUDY: To investigate the influence of different surgical techniques of chordal preservation in mitral valve replacement (MVR) on left ventricular size and function, we studied a series of 244 patients who underwent mitral valve replacement either with (n = 161) or without (n = 83) preservation of the subvalvular structures. RESULTS: Preoperatively there were no differences between the two patient groups. Three months postoperatively, echocardiography demonstrated that chordal preservation in MVR resulted in smaller left ventricular end-systolic diameter (LVESD) and end-diastolic diameter (LVEDD): preservation versus resection, LVESD: 43.4 +/- 7.8 mm versus 48.8 +/- 9.2 mm (p < 0.05), LVEDD: 57.3 +/- 7.8 mm versus 62.9 +/- 10.5 mm (p < 0.05) and a significantly decreased LV-L (long axis) (87.1 +/- 4.2 mm versus 97.5 +/- 5.7 mm; p < 0.05). There was no significant difference in cardiac dimensions between the three patient subgroups in whom chordal preservation was possible. In addition, left ventricular ejection fraction in the preservation groups was significantly improved compared with the resection group (54.2 +/- 11.2% versus 48.1 +/- 12.4%, p < 0.05); there were no differences between the preservation subgroups. Regional wall motion analysis revealed significantly improved segmental myocardial performance in all segments if both leaflets were preserved or the anterior mitral leaflet was reattached to the anterior mitral annulus.
Adult↗
Preoperative left ventricular systolic dysfunction correlates with the adverse postoperative consequences of annular-papillary disconnection in the course of mitral valve replacement for stenosis.
BACKGROUND AND AIMS OF THE STUDY: Preservation of chordae tendineae helps maintain ventricular performance in patients having surgery for mitral regurgitation. The importance of chordal integrity in patients with rheumatic mitral stenosis is unknown. The purpose of this study was to determine the influence of chordal preservation on left ventricular function following relief of rheumatic mitral stenosis. METHODS: A total of 142 patients with mitral stenosis had balloon valvulotomy (group 1, n = 63), surgical commissurotomy (group 2, n = 33) or mitral valve replacement (group 3, n = 46). Chordae were resected in all group 3 patients. Left ventricular dimension in end-diastole (LVEDD), end-systole (LVESD) and fractional shortening (FS) were measured at baseline and at a mean interval of 11 +/- months post intervention. RESULTS: At one year, FS increased in groups 1 and 2, but decreased in group 3 (+11.5%, +9%, -6.1%, p < 0.005 for group 3 versus groups 1 and 2). a borderline significant increase LVEDD was seen in group 1 compared with groups 2 and 3 (11%, 5%, 4% respectively, p = 0.05). Differences in FS at follow up were due mainly to diametrically opposite changes in LVESD in the subgroup of patients with baseline left ventricular dysfunction (-1.9%, 0%, +9.8%, p < 0.005 for group 3 versus groups 1 and 2). CONCLUSIONS: Deterioration of left ventricular function only in patients having mitral valve replacement indicates chordal resection as a putative mechanism. The result of this study suggest that chordal preservation is particularly important in patients with mitral stenosis who have depressed preoperative left ventricular systolic function.
Adult↗
Mitral valve repair: Intermediate to long-term echocardiographic follow-up.
OBJECTIVE: To review intermediate to long term echocardiographic follow-up after mitral valve repair for mitral regurgitation. DESIGN: Nonrandomized, retrospective and prospective observational study. SETTING: Sacré-Coeur Hospital, University of Montreal, Montreal, Quebec. PATIENTS: Echocardiographic findings in 37 patients (mean age 62.1 +/- 10 years) three to 197 months (median 45) after mitral valve repair were reviewed. INTERVENTIONS: Preoperative data were collated from hospital records. Between October 1994 and March 1995, all patients had a clinical evaluation and a complete transthoracic echocardiogram done by a cardiologist. RESULT: There was a significant reduction in the dimensions of the left-sided cavities compared with preoperative data. Left atrial diameter decreased from from 50.9 +/- 7.7 to 46.3 +/- 8.1 mm (P = 0.01), left ventricular end-diastolic diameter from 59.6 +/- 7.1 to 51.2 +/- 6.3 mm (P < 0.001) and left ventricular end-systolic diameter from 35.3 +/- 7.9 to 32.8 +/- 7.8 mm (P = 0.07). On colour Doppler echocardiography, nine patients had no mitral regurgitation, 25 had mitral regurgitation grade I to II/IV, and three had grade III/IV. The mean mitral valve gradient was 4.2 +/- 1.8 mmHg and the pressure half-time 121.9 +/- 48 ms. There was no difference in gradient, mitral valve area and mitral regurgitation in patients with degenerative (29) compared with rheumatic (five) mitral valve disease. CONCLUSIONS: Mitral valve repair is highly effective in reducing mitral regurgitation in the long term and is associated with a reduction in the dimensions of the left atrium and the left ventricle. However, it leaves a mild degree of mitral valve obstruction.
Aged↗
[The orbital implant after exenteration of the orbit with the preservation of the eyelids and the conjunctival sac].
In ophthalmology, the orbital exenteration presents the most mutilating surgical procedure. The surgical technique presented by authors, preserves the eyelids and conjunctival sac. This surgical procedure was suggested and repeatedly performed in adult patients with extensive benign tumors (mostly meningeomas) by J. Otradovec and J. Safár. The enucleation of the eyeball preceded this type of surgery. The final state made it possible to put the prosthesis into the conjunctival sac. Today we inform about further development of this surgical technique and according to our own experiences we widen its indications to some malignant tumors (rhabdomyosarcoma and metastases of the retinoblastoma, etc.) in children. The initial cutaneous incision starts in the eyebrow area and is directed toward the bone of the orbital rim. The preparation of the tissue underneath the intact conjunctival sac to the lower aspect of the bone orbital rim follows. After folding the conjuctival-cutaneous sac back, the real content of the orbit is exenterated in the classical manner. After the hemostasis in the orbital apex, the flap is returned to its primary position and suturing of the primary incision in anatomical layers terminates the surgery. The authors refer about a boy, now 17 years old, who underwent at the age of three years the exenteration of the orbit in this manner due to a rhabdomyosarcoma. The authors also refer about the development and application of a special type of prosthesis made from silicone rubber--implant grade--filling out the orbital space and forming the anterior segment of the eye. The prosthesis was created from a classical orbital implant, regularly used in enucleation surgery and a conjunctival implant, a convex-concave plate with diameter of 20 mm. Both parts are made from the same type of silicon rubber and were connected together by vulcanization. The orbital implant was eliptically extended according to the measurements of the orbital casting made from dental impression matter. The cosmetic part, simulating the colored iris and the pupil, was prepared from a polyester sheet, painted with acrylic paint. It was fixated on the conjunctival prosthesis and covered with a transparent silicone foil. For the first time, the prosthesis was applied at the age of seven years, and during the next ten-years period, it was three times exchanged mostly for a bigger model. This procedure guaranteed proper growing of the orbital area and symmetrical development of the face. The prosthesis also carries out the prosthetic role and cosmetically it looks similarly like after the enucleation without the implant.
Child, Preschool↗
Performance of a stentless xenograft aortic bioprosthesis up to four years after implantation.
Conventional biologic and mechanical prostheses have important limitations with regard to their hemodynamic characteristics and long-term durability. We evaluated the hemodynamic function of a stentless porcine aortic prosthesis in 10 patients by invasive pressure measurements and angiography with videodensitometry 8 +/- 4 days after operation, as well as by Doppler echocardiography 35 +/- 15 months after valve replacement. The early postoperative invasive study revealed a mean gradient of 8 +/- 6 mm Hg across the prosthesis, no regurgitation in eight patients, and mild regurgitation, defined as less than 20% regurgitant fraction, in the remaining two patients. The late postoperative Doppler echocardiographic study revealed a mean gradient across the aortic prosthesis of 6 +/- 3 mm Hg, mean Doppler-derived valve orifice area of 1.8 +/- 0.6 cm2, and color Doppler flow velocity mapping suggested no regurgitation in eight patients and mild regurgitation in two patients corresponding to early postoperative angiography. None of the 10 patients received anticoagulation therapy. The clinical course of all patients was without incident. This stentless aortic bioprosthesis may offer hemodynamic advantage; however, further studies are needed to allow comparison with conventional mechanical and biologic prostheses.
Adult↗
Elevated circulating levels of von Willebrand factor and D-dimer in patients with heart failure and mechanical prosthesis.
To test the hypothesis of association between heart failure and altered haemostatic balance in patients with a mechanical valve prosthesis, comparisons were made between 20 patients with mitral valve replacement and stable chronic heart failure (group A), 20 with the same prosthesis but satisfactory haemodynamics (group B) and 20 age-matched controls (group C). The left ventricular ejection fraction was significantly highest (p < 0.001) in group A. The pulmonary artery systolic pressure was also highest in group A (p < 0.001), without significant difference between groups B and C. Two group A patients had a transient ischaemic attack. The D-dimer plasma concentrations and the antigenic and biologic von Willebrand factor activities were significantly greatest in group A. Significant correlation was found between the plasma concentrations of these activities and pulmonary artery systolic pressure and between D-dimer and ejection fraction. Platelet-activating factor was detected only in six group A patients. The observed relationship between haemostatic factors and heart failure in patients with mechanical heart-valve prosthesis advocates careful evaluation of von Willebrand factor and D-dimer in order to prevent embolic events in such cases.
Atrial Function↗
[Assessment of umbilical vein transplants using digital subtraction angiography, duplex sonography and color-coded Doppler sonography].
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Angiography↗
[Indications for prosthesis of the anterior teeth with porcelain, plastic and combined crowns].
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Color↗
Primary patency of femoropopliteal arteries treated with nitinol versus stainless steel self-expanding stents: propensity score-adjusted analysis.
PURPOSE: To evaluate, in a propensity score-adjusted analysis, the intermediate-term primary patency rates associated with nitinol versus stainless steel self-expanding stent placement for treatment of atherosclerotic lesions in femoropopliteal arteries. MATERIALS AND METHODS: The authors analyzed the clinical and imaging data of 175 consecutive patients with peripheral artery disease and either intermittent claudication (n = 150) or critical limb ischemia (n = 25) who underwent femoropopliteal artery implantation of nitinol (n = 104) or stainless steel (n = 123) stents in a nonrandomized setting. The stents were placed owing to either significant residual stenosis (ie, >30% lumen diameter reduction) or flow-limiting dissection after initial balloon angioplasty of the femoropopliteal artery. Patients were followed up for a median period of 9 months (mean, 13 months; range, 6-66 months) for the detection of a first in-stent restenosis, defined as a greater than 50% lumen diameter reduction that was seen at color-coded duplex ultrasonography and confirmed at angiography. RESULTS: Cumulative patency rates at 6, 12, and 24 months were 85%, 75%, and 69%, respectively, after nitinol stent placement versus 78%, 54%, and 34%, respectively, after stainless steel stent placement (P =.008, log-rank test). There were no statistically significant differences in associated patency among the three different nitinol stents used (P =.72, log-rank test). Multivariate Cox proportional hazard analysis, in which the effect of propensity to receive a nitinol stent was considered, revealed a significantly reduced risk of restenosis with the nitinol stents compared with the risk of restenosis with the stainless steel stents (adjusted hazard ratio, 0.44; 95% confidence interval: 0.22, 0.85; P =.014). CONCLUSION: Nitinol stents are associated with significantly improved primary patency rates in femoropopliteal arteries compared with stainless steel stents. Randomized controlled trials are needed to confirm these results.
Aged↗
An assessment of recent advances in external maxillofacial materials.
A variety of new materials representing several polymer classes and diverse fabrication procedures are now becoming available for use as external maxillofacial prostheses. Because of the availability of these materials, the severely disfigured patient can now be provided an opportunity to elad a near-normal life in today's society. Remarkable advancements have been made in providing the patient with prostheses which feel and look more like skin. Progress has also been made in simplifying fabrication procedures, thus reducing cost. Much remains to be done in materials research. Processing time is still too long for most of the materials. Some of the materials give variable results in the quality and stability of the prostheses because of sensitivity to contaminants and to lab conditions and operator technique. Extrinsic coloration is extremely tedious and diffult with many of the products. The fitting and attachment of the prosthesis to the patient continues to need much improvement. Margins are difficult to mask even with the best materials. Large prostheses of most of the materials are much too heavy and are poorly retained. Staining of the prostheses by foods, cosmetics, and tobacco is a serious problem. The need for an improved material has been recognized by various government agencies and a few of the industrial suppliers of synthetic polymers. Additional advances are sure to result from these efforts.
Chemical Phenomena↗
Extensive corporeal fibrosis after penile irradiation.
A potent man with early signs and symptoms of Peyronie's disease 3 months in duration received 1,200 rad of external beam radiation to the penis and presented 5 months later with impotence. Physical examination revealed diffusely woody indurated corporeal tissue. Nocturnal penile tumescence testing was abnormal and pharmaco-cavernosometry demonstrated diffuse corporeal veno-occlusive dysfunction. Treatment by penile injections was unsuccessful. During penile prosthesis implantation bilateral rubbery erectile tissue was encountered, requiring extensive bilateral corporotomy and sharp corporeal tissue excision for prosthesis insertion. Histological analysis of excised corporeal tissue demonstrated extensive corporeal fibrosis and arterial vasculopathy. Computer assisted color histomorphometry revealed that the mean percentage of trabecular smooth muscle area to total erectile tissue area was 26.5 +/- 15.8 (normal 40 to 52%). Immunohistochemical staining with desmin confirmed extensive fibrosis. The most likely explanation for severe corporeal fibrosis is penile irradiation. The hypothesized mechanism of radiation associated fibrosis is ionizing injury to the endothelial cells of the lacunar spaces and cavernous/helicine arteries, which induced irreversible corporeal extracellular matrix structural changes. Penile irradiation, like vascular disease and priapism, is a potential cause of diffuse corporeal fibrosis.
Adult↗
[Team communication needed in treatment for fixed prosthesis. 2) Opinion from dental technician's standpoint].
The fabrication of a fixed prosthesis is influenced by the communication between the dentist and the laboratory technician. Especially for tooth-colored restoration of anterior teeth, the laboratory technician has the difficult task of understanding the shade selected by the dentist and reproducing it in the final restoration. Conventional shade analysis techniques using the Vita shade guide often result in subjective analysis and a resultant miscommunication of color. Over the years, many different techniques including picture-taking, drawing of diagrams, and using multiple shade guides have been formulated to help overcome this problem. Recently, digital shade analysis systems have been designed to eliminate the subjectivity of color analysis and provide precise information for laboratory buildup and fabrication. However, even these techniques have not completely erased the difficulties involved in communicating the choice of the proper shade for tooth-colored restoration. Many dentists are only familiar with techniques they were taught in dental school and/or their residency program, and they are unaware of other, superior methods that can be used. This review introduces various shade analysis systems that can be performed in dental clinical practice. Further, it highlights the importance of communication between the dentist, technician, and patient for the fabrication and delivery of aesthetic restorations.
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