Prosthetic considerations

Implants have changed prosthodontics more than any other innovation in dentistry. Replacement of lost teeth by a fixed or removable prosthesis is considered to be a restitutio ad similem, while implants may provide a feeling of restitutio ad integrum. Implant prosthodontics means restoring function, aesthetics, and providing technology; biology and technology are combined. Placement of implants is a reconstructive, preprosthetic surgical intervention and is therefore different from most goals in oral surgery that consist of tooth extraction, treating infection and removing pathology from soft or hard tissues. Thus, implants are part of the final prosthetic treatment which encompasses functional, aesthetic and social rehabilitation. The patient's needs and functional status determine the goal of prosthetic treatment. Treatment outcomes in implant prosthodontics are survival of implants and prostheses, impact on physiological and psychological status, oral health-related impact on quality of life, and initial and maintenance costs. A variety of prosthetic solutions are available to restore the partially and completely edentulous jaw and more recently specific methods have been developed such as computer guided planning and CAD-CAM technologies. These should allow more uniform quality and passive fit of prostheses, and simultaneously enables processing of biologically well-accepted materials.

Prosthetic treatment planning on the basis of scientific evidence

The objective of this report is to summarize the results on survival and complication rates of different designs of fixed dental prostheses (FDP) published in a series of systematic reviews. Moreover, the various parameters for survival and risk assessment are to be used in attempt to perform treatment planning on the basis of scientific evidence. Three electronic searches complemented by manual searching were conducted to identify prospective and retrospective cohort studies on FDP and implant-supported single crowns (SC) with a mean follow-up time of at least 5 years. Patients had to have been examined clinically at the follow-up visit. Failure and complication rates were analyzed using random-effects Poisson regression models to obtain summary estimates of 5- and 10-year survival proportions. Meta-analysis of the studies included indicated an estimated 5-year survival of conventional tooth-supported FDP of 93.8%, cantilever FDP of 91.4%, solely implant-supported FDP of 95.2%, combined tooth-implant-supported FDP of 95.5% and implant-supported SC of 94.5% as well as resin-bonded bridges 87.7%. Moreover, after 10 years of function the estimated survival decreased to 89.2% for conventional FDP, to 80.3% for cantilever FDP, to 86.7% for implant-supported FDP, to 77.8% for combined tooth-implant-supported FDP, to 89.4% for implant-supported SC and to 65% for resin-bonded bridges. When planning prosthetic rehabilitations, conventional end-abutment tooth-supported FDP, solely implant-supported FDP or implant-supported SC should be the first treatment option. Only as a second option, because of reasons such as financial aspects patient-centered preferences or anatomical structures cantilever tooth-supported FDP, combined tooth-implant-supported FDP or resin-bonded bridges should be chosen.

Fluorescent annexin A1 reveals dynamics of ceramide platforms in living cells

Upon its genesis during apoptosis, ceramide promotes gross reorganization of the plasma membrane structure involving clustering of signalling molecules and an amplification of vesicle formation, fusion and trafficking. The annexins are a family of proteins, which in the presence of Ca(2+), bind to membranes containing negatively charged phospholipids. Here, we show that ceramide increases affinity of annexin A1-membrane interaction. In the physiologically relevant range of Ca(2+) concentrations, this leads to an increase in the Ca(2+)sensitivity of annexin A1-membrane interaction. In fixed cells, using a ceramide-specific antibody, we establish a direct interaction of annexin A1 with areas of the plasma membrane enriched in ceramide (ceramide platforms). In living cells, the intracellular dynamics of annexin A1 match those of plasmalemmal ceramide. Among proteins of the annexin family, the interaction with ceramide platforms is restricted to annexin A1 and is conveyed by its unique N-terminal domain. We demonstrate that intracellular Ca(2+)overload occurring at the conditions of cellular stress induces ceramide production. Using fluorescently tagged annexin A1 as a reporter for ceramide platforms and annexin A6 as a non-selective membrane marker, we visualize ceramide platforms for the first time in living cells and provide evidence for a ceramide-driven segregation and internalization of membrane-associated proteins.

Cumulative costs for the prosthetic reconstructions and maintenance in young adult patients with birth defects affecting the formation of teeth

OBJECTIVES: To assess retrospectively the cumulative costs for the long-term oral rehabilitation of patients with birth defects affecting the development of teeth. METHODS: Patients with birth defects who had received fixed reconstructions on teeth and/or implants > or =5 years ago were asked to participate in a comprehensive clinical, radiographic and economic evaluation. RESULTS: From the 45 patients included, 18 were cases with a cleft lip and palate, five had amelogenesis/dentinogenesis imperfecta and 22 were cases with hypodontia/oligodontia. The initial costs for the first oral rehabilitation (before the age of 20) had been covered by the Swiss Insurance for Disability. The costs for the initial rehabilitation of the 45 cases amounted to 407,584 CHF (39% for laboratory fees). Linear regression analyses for the initial treatment costs per replaced tooth revealed the formula 731 CHF+(811 CHF x units) on teeth and 3369 CHF+(1183 CHF x units) for reconstructions on implants (P<.001). Fifty-eight percent of the patients with tooth-supported reconstructions remained free from failures/complications (median observation 15.7 years). Forty-seven percent of the patients with implant-supported reconstructions remained free from failures/complications (median observation 8 years). The long-term cumulative treatment costs for implant cases, however, were not statistically significantly different compared with cases reconstructed with tooth-supported fixed reconstructions. Twenty-seven percent of the initial treatment costs were needed to cover supportive periodontal therapy as well as the treatment of technical/biological complications and failures. CONCLUSION: Insurance companies should accept to cover implant-supported reconstructions because there is no need to prepare healthy teeth, fewer tooth units need to be replaced and the cumulative long-term costs seem to be similar compared with cases restored on teeth.

Prosthetic valve endocarditis caused by a Pasteurella dagmatis-like isolate originating from a patient's cat

Pasteurella species are part of the oral flora of cats and dogs. In humans, they are frequently found in infected animal bite wounds, but invasive infections are rare. This is the first report of prosthetic-valve endocarditis with a Pasteurella dagmatis-like species, which originated from the patient's cat.

The Role of Online Platforms for Media Markets – Two‐Dimensional Spatial Competition in a Two‐Sided Market

We analyze the market for online and offline media in a model of two-dimensional spatial competition where media outlets sell content and advertising space. Consumer preferences are distributed along the style and type of news coverage where the distance costs may vary across dimensions. For integrated provision of online and offline platforms we show that entering the online market reduces average profits and may even constitute a prisoner's dilemma. Specialized provision may yield polarization in the style and type dimensions. This is in contrast to the maximum–minimum differentiation result previously established in the literature on multidimensional horizontal competition. We show that maximal differentiation in both dimensions occurs due to the discrete nature of the type dimension and asymmetric advertising markets.

Patients with oral tumors. Part 1: Prosthetic rehabilitation following tumor resection. Resection prosthetics: surgery, implants and prosthetic treatment

The present study reports on the surgical and prosthodontic rehabilitation of 46 patients, 31 male and 15 female, after resection of oral tumors. The treatment was carried out from 2004 to 2007 at the Department of Prosthodontics, University of Bern, with a follow-up time of 3 to 6 years. The average age at diagnosis was 54 years. 76% of all tumors were squamous cell carcinoma, followed by adenocarcinoma. Resection of the tumors including soft and/or hard tissues was performed in all patients. 80% of them additionally underwent radiotherapy and 40% chemotherapy. A full block resection of the mandible was perfomed in 23 patients, and in 10 patients, the tumor resection resulted in an oronasal communication. 29 patients underwent grafting procedures, mostly consisting of a free fibula flap transplant. To enhance the prosthetic treatment outcome and improve the prosthesis stability, a total of 114 implants were placed. However, 14 implants were not loaded because they failed during the healing period or the patient could not complete the final treatment with the prostheses. The survival rate of the implants reached 84.2% after 4 to 5 years. Many patients were only partially dentate before the tumors were detected, and further teeth had to be extracted in the course of the tumor therapy. Altogether, 31 jaws became or remained edentulous. Implants provide stability and may facilitate the adaptation to the denture, but their survival rate was compromised. Mostly, patients were fitted with removable prostheses with obturators in the maxilla and implant-supported complete dentures with bars in the mandible. Although sequelae of tumor resection are similar in many patients, the individual intermaxillary relations, facial morphology and functional capacity vary significantly. Thus, individual management is required for prosthetic rehabilitation.

Unusual cause of myocardial infarction and congestive heart failure in a patient with prosthetic valve endocarditis

In a patient with staphylococcus lugdunensis prosthetic aortic valve endocarditis and coronary septic embolism accompanied by antero-lateral myocardial infarction, embolic material was successfully aspirated from the bifurcation of the left anterior descending coronary artery and the first diagonal branch. A good angiographic result was documented six months thereafter when the patient presented with a second complication, pulsatile compression of the left main coronary artery by an abscess cavity originating between the aortic and mitral annulus, leading to congestive heart failure. The patient underwent successful surgical replacement of the aortic valve prosthesis with concomitant patch reconstruction of the annulus as well as tricuspid annuloplasty.

"Deal of the day” platforms: what drives consumer loyalty?

Maintaining a loyal customer base is challenging for “Deal of the Day” (DoD) platforms. DoD providers market and sell deals on products and services, yet it is the merchants who ultimately deliver those to consumers. Low entry and switching costs drive competition in this market. However, research on the determinants of user loyalty in the DoD context is limited. This study uses Grounded Theory and Structural Equation Modeling to explore the phenomenon of DoD platform loyalty. Particularly, monetary benefits, signal-to-noise ratio, perceived risk, and service friendliness during a merchant encounter emerge as powerful determinants of loyalty in this novel context.

Variability between laboratories performing coagulation tests with identical platforms: a nationwide evaluation study.

BACKGROUND While the assessment of analytical precision within medical laboratories has received much attention in scientific enquiry, the degree of as well as the sources causing variation between them remains incompletely understood. In this study, we quantified the variance components when performing coagulation tests with identical analytical platforms in different laboratories and computed intraclass correlations coefficients (ICC) for each coagulation test. METHODS Data from eight laboratories measuring fibrinogen twice in twenty healthy subjects with one out of 3 different platforms and single measurements of prothrombin time (PT), and coagulation factors II, V, VII, VIII, IX, X, XI and XIII were analysed. By platform, the variance components of (i) the subjects, (ii) the laboratory and the technician and (iii) the total variance were obtained for fibrinogen as well as (i) and (iii) for the remaining factors using ANOVA. RESULTS The variability for fibrinogen measurements within a laboratory ranged from 0.02 to 0.04, the variability between laboratories ranged from 0.006 to 0.097. The ICC for fibrinogen ranged from 0.37 to 0.66 and from 0.19 to 0.80 for PT between the platforms. For the remaining factors the ICC's ranged from 0.04 (FII) to 0.93 (FVIII). CONCLUSIONS Variance components that could be attributed to technicians or laboratory procedures were substantial, led to disappointingly low intraclass correlation coefficients for several factors and were pronounced for some of the platforms. Our findings call for sustained efforts to raise the level of standardization of structures and procedures involved in the quantification of coagulation factors.

The treatment and outcome of peri-prosthetic infection of the ankle: a single cohort-centre experience of 34 cases

The treatment of peri-prosthetic joint infection (PJI) of the ankle is not standardised. It is not clear whether an algorithm developed for hip and knee PJI can be used in the management of PJI of the ankle. We evaluated the outcome, at two or more years post-operatively, in 34 patients with PJI of the ankle, identified from a cohort of 511 patients who had undergone total ankle replacement. Their median age was 62.1 years (53.3 to 68.2), and 20 patients were women. Infection was exogenous in 28 (82.4%) and haematogenous in six (17.6%); 19 (55.9%) were acute infections and 15 (44.1%) chronic. Staphylococci were the cause of 24 infections (70.6%). Surgery with retention of one or both components was undertaken in 21 patients (61.8%), both components were replaced in ten (29.4%), and arthrodesis was undertaken in three (8.8%). An infection-free outcome with satisfactory function of the ankle was obtained in 23 patients (67.6%). The best rate of cure followed the exchange of both components (9/10, 90%). In the 21 patients in whom one or both components were retained, four had a relapse of the same infecting organism and three had an infection with another organism. Hence the rate of cure was 66.7% (14 of 21). In these 21 patients, we compared the treatment given to an algorithm developed for the treatment of PJI of the knee and hip. In 17 (80.9%) patients, treatment was not according to the algorithm. Most (11 of 17) had only one criterion against retention of one or both components. In all, ten of 11 patients with severe soft-tissue compromise as a single criterion had a relapse-free survival. We propose that the treatment concept for PJI of the ankle requires adaptation of the grading of quality of the soft tissues. Cite this article: Bone Joint J 2014;96-B:772-7.

New generation genomic platforms in investigation of complex diseases and BEN.

(Full text is available at http://www.manu.edu.mk/prilozi). New generation genomic platforms enable us to decipher the complex genetic basis of complex diseases and Balkan Endemic Nephropathy (BEN) at a high-throughput basis. They give valuable information about predisposing Single Nucleotide Polymorphisms (SNPs), Copy Number Variations (CNVs) or Loss of Heterozygosity (LOH) (using SNP-array) and about disease-causing mutations along the whole sequence of candidate-genes (using Next Generation Sequencing). This information could be used for screening of individuals in risk families and moving the main medicine stream to the prevention. They also might have an impact on more effective treatment. Here we discuss these genomic platforms and report some applications of SNP-array technology in a case with familial nephrotic syndrome. Key words: complex diseases, genome wide association studies, SNP, genomic arrays, next generation sequ-encing.

Extraspinal ossifications after implantation of vertical expandable prosthetic titanium ribs (VEPTRs).

INTRODUCTION Though developed for thoracic insufficiency syndrome, the spinal growth-stimulating potential and the ease of placement of vertical expandable titanium ribs (VEPTRs) has resulted in their widespread use for early-onset spine deformity. Observation of implant-related ossifications warrants further assessment, since they may be detrimental to the function-preserving non-fusion strategy. PATIENTS AND METHODS Radiographs (obtained pre and post index procedure, and at 4-year follow-up) and the records of 65 VEPTR patients from four paediatric spine centres were analysed. Ossifications were classified as type I (at anchor points), type II (along the central part) or type III (re-ossification after thoracostomy). RESULTS The average age at the index procedure was 6.5 years (min 1, max 13.7). The most prevalent spine problem was congenital scoliosis (37) with rib fusions (34), followed by neuromuscular and syndromic deformities (13 and 8, respectively). Idiopathic and secondary scoliosis (e.g. after thoracotomy) were less frequent (3 and 4, respectively). Forty-two of the 65 (65 %) patients showed ossifications, half of which were around the anchors. Forty-five percent (15/33) without pre-existing rib fusions developed a type II ossification along the implant. Re-ossifications of thoracostomies were less frequent (5/34, 15 %). The occurrence of ossifications was not associated with patient-specific factors. CONCLUSIONS Implant-related ossifications around VEPTR are common. In contrast to harmless bone formation around anchors, ossifications around the telescopic part and the rod section are troublesome in view of their possible negative impact on chest cage compliance and spinal mobility. This potential side effect needs to be considered during implant selection, particularly in patients with originally normal thoracic and spinal anatomy.