SEARCH · PubMed Health

Results for “INVESTMENTS”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 145 records · Page 8Linked to original sources

PubMed1976

Relationship of investing medium to occlusal changes and vertical opening during denture construction.

Four groups of 20 dentures with nonanatomic teeth were processed using four different investing techniques. The incisal guide pin was measured and recorded before processing and again after processing and remounting of each denture on the articulator. The difference between the two readings indicated vertical changes during processing. The least vertical opening and a complete absence of occlusal changes occurred in the dentures invested in the plaster of paris core with an artificial stone cap. The following conclusions were made: (1) Vertical opening in denture processing can be minimized by investing in plaster of paris molds with a stone occlusal matrix. (2) Tooth movement is minimized by the use of this investment combination. (3) Inadequate investing procedures contribute to vertical opening and occlusal discrepancies. (4) Vertical opening of dentures processed by compression molding technique may be due to other factors. This can only be determined by further investigation.

Calcium Sulfate↗

PubMed1995

Mold filling of Ti castings using investments with different gas permeability.

OBJECTIVES: The aim of this work was to study mold filling during casting of standardized five-unit Ti bridges vs. the gas permeability of the investments. METHODS: An Ar arc casting machine with a separate melting and mold chamber was used. Both chambers were evacuated before Ar was introduced into the melting chamber. A rubber sealer was inserted between the top of the steel ring of the mold and the steel floor between the two chambers. The mold cavity required the same Ar pressure as the melting chamber prior to casting. Four different investments for Ti casting were investigated: 1) Bellavest T (BEGO), 2) Rematitan Plus (Dentaurum), 3) Titavest CB (Morita) and 4) Titanium Vest (Ohara Co.). Three castings were made with each investment. The molds were fired according to the manufacturers' instructions and cooled to room temperature. The Ar gas pressures in the two chambers were recorded during casting, and the mold filling was evaluated initially by visual inspection and subsequently by studying the margins of the crowns in a microscope. RESULTS: In the melting and molding chambers, the Ar pressure was found to be: 1) Bellavest T: 400 and 1 torr; 2) Rematitan Plus: 600 and 85 torr; 3) Titavest CB:600 and 150 torr; and 4) Titanium Vest: 600 and 85 torr, respectively. This indicates substantial differences in the gas permeability of the molds. Bellavest T produced poorly filled molds, Rematitan Plus and Titanium Vest resulted in poor margins and Titavest CB produced complete castings. SIGNIFICANCE: Proper mold filling is promoted by investments with a high gas permeability, so the gases in the mold cavity can escape through the investment to the mold chamber.

Argon↗

PubMed2005

Understanding the return on health, safety and environmental investments.

INTRODUCTION: Traditionally, health safety and environmental (HS & E) investments have been viewed as expensive but necessary. HS & E professionals had a difficult task of providing data showing that these investments can also contribute to business success. An ORC task force developed a way for traditional financial analysis methods to be applied to HS & E investments and decisions. METHOD: The result of the task force effort is the software called the ORC Return on Health, Safety and Environmental Investments (ROHSEI), a supporting tool to provide a comprehensive look at health, safety or environmental investment projects and their potential financial impacts. RESULTS: Since its development, more than 200 companies, government agencies, and educational institutions have been trained in the ROHSEI process and software. CONCLUSIONS: HS & E professionals who are able to evaluate and communicate the business value of health, safety and environmental efforts will improve understanding of the impacts HS & E projects and contribute to better decision making by their organizations.

Cost Savings↗

PubMed2001

Measurement of the setting and thermal expansion of dental investments used for the superplastic forming of dental implant superstructures.

OBJECTIVES: The study examined the setting and thermal expansions of seven dental casting investments intended for use in the superplastic forming (SPF) of Ti6A14V for dental implant superstructures. The total expansion is compared with the coefficient of thermal expansion of the alloy. METHODS: The unrestricted setting expansion of the investment was measured at room temperature using a lined brass trough and dial gauge. The thermal expansion was measured at a heating rate of 5 degrees C/min up to 900 degrees C. The thermal expansion of Ti6A14V was measured at a heating rate of 15 degrees C/min. RESULTS: The Selevest investment had a small shrinkage on setting. The largest setting expansions were observed with Rema Exakt and Fujivest. Selevest DM and Fujivest had the greatest thermal expansions. Rema Exakt had the greatest overall expansion. The total expansion of Rematitan most closely matched the thermal expansion of Ti6A14V when the manufacturer's recommended special liquid to water ratio for crowns and bridges was used. SIGNIFICANCE: SPF is a novel technique which is being applied to the manufacture of dental prostheses. As dental casting investments are used to make the dies used for SPF the dimensional changes associated with these materials should be matched to the dimensional changes of the Ti6A14V alloy used in order to achieve a passive fit. This study has identified Rematitan as an investment whose total expansion may enable an accurately fitting SPF implant superstructure to be made.

Algorithms↗

PubMed2003

Adherence of investment to Au-Pd-Ag alloy using a vacuum-argon pressure casting machine.

OBJECTIVE: The removal of adhered investment material from marginal metal surfaces represents a possible risk of poor marginal adaptation. The aim of this work was to evaluate the effects of argon on investment adherence to the casting surface and on the alloy surface microstructure. METHODS: A die of stainless steel was used. 10 wax copings were cast by vacuum-argon pressure, while 10 copings by vacuum-air pressure using a Combilabor CLG-77 A in a graphite crucible; supply was direct with curved sprues of slashed circle 3.5 mm. The alloy used was Herabond. After coarse investment, removal of all specimens were investigated with scanning electron microscopy and semi-quantitative digital densitometry. RESULTS: The specimens cast under vacuum-argon pressure showed less amount of investment adhered (unpaired t test of grouped specimens, difference 2.896x10(5)pixel; p=0.002) while the grain size on the casting surface increased significantly p=0.000 (difference 5.968(microm). SIGNIFICANCE: Vacuum-argon pressure supply during casting reduces the investment adherence to the metal surface, and increases the packing density and size of the grains, especially on the casting surface. These minimize the risk of marginal distortions due to casting cleaning procedures and facilitate the finishing and polishing procedures.

Adhesiveness↗

PubMed2002

Debt, investment and endowment accumulation: the case of not-for-profit hospitals.

Not-for-profit hospitals benefit from special tax rules that allow state authorities to issue tax-exempt bonds on their behalf, which may affect their investment and financing choices. Hospitals may respond by increasing their investment in physical assets; however, they may also engage in tax arbitrage by using the tax-exempt debt while maintaining endowment assets. The paper combines data from tax (information) returns and the annual survey of hospitals by the American Hospital Association for 1993-1996. Overall, the results are consistent with substantial tax planning by not-for-profit hospitals. Of the US$ 55.9 billion in tax-exempt liabilities of hospitals in 1996, as much as US$ 32.6 billion could have been eliminated if hospitals spent their endowments instead of borrowing. Furthermore, controlling for hospital size (in terms of revenues and operating assets), endowment assets are associated with a higher ratio of tax-exempt (or total) debt to operating assets. In contrast, endowment assets are not related to taxable debt suggesting that the effects of the endowment on borrowing are motivated by tax incentives. Investment and endowment accumulation regressions suggest that increases in debt increase both physical investment and endowment accumulation but these effects are concentrated among cash-rich hospitals for which the effects on endowment accumulation effects are larger than the effects on physical investment.

Accounts Payable and Receivable↗

PubMed1997

Effect of burnout temperature on strength of phosphate-bonded investments.

OBJECTIVE: The high-temperature strength behaviour of dental phosphate-bonded investments is not clearly understood. The present purpose was to determine their variation in strength with temperature and to seek explanations for that variation. METHODS: The clamped-edge disc-rupture test was used in a sequential testing protocol, with a variable casting metal mass, to determine the effect of burnout temperature (ranging from 400 to 1100 degrees C) on the strength of six phosphate-bonded investments. RESULTS: The strength of phosphate-bonded investment is temperature sensitive, generally showing a distinct minimum in the tested temperature range. Low temperature strength gives little information about high temperature behaviour. The variation of strength with temperature seems amenable to explanation in terms of investment composition. CONCLUSION: Since strength varies greatly with temperature and brand, the inconsistency of previous results is explained. On the other hand, low-temperature strength is no guide for the high-temperature strength, so that information on both the room and the service temperature strength is required. Inversion of silica at high temperature may decrease the strength of phosphate-bonded investments.

Chromium Alloys↗

PubMed2000

Effects of four mixing methods on setting expansion and compressive strength of six commercial phosphate-bonded silica investments.

Six commercial phosphate-bonded silica investments were mixed with four different mixing methods such as hand, two conventional blade-driven vacuum mixers and a new planetary mixing device, and examined for their setting expansion and compressive strength. The two properties often altered, depending upon the mixing method and the investment. The setting expansion of three investments were significantly affected by the mixing method while those of the other three were not. Compressive strength of all six investments varied by changing the mixing method. It is emphasized here that a mixing method and mixing condition must be properly set for each investment to improve the fit of the final metallic castings. This study also suggests that the planetary mixing device is a useful substitute for conventional blade-driven vacuum mixers.

Compressive Strength↗

PubMed1998

Gypsum-bonded alumina dental investment for high-fusing casting.

In this study, we developed a new gypsum-bonded investment for high-fusing alloys. The investment was composed of gypsum as a binder and alumina as a refractory. Effects of type of alumina powder and gypsum content on characteristics of the gypsum-bonded alumina investment were investigated. Obtained characteristics of this experimental investment were as follows: fluidities ranged from 48.8 to 88.9 mm; setting times ranged from 21.2 to more than 120 minutes; setting expansions ranged from 0.4 to 1.3%; green strengths showed 0.5 to 4.5 MPa; fired strengths ranged from 0.2 to 1.7 MPa; thermal expansions after firing were -1.60 to 2.16%. Thermal expansion occurred because of the chemical reaction between Al2O3 and CaO decomposed from gypsum. These results suggest that this gypsum-bonded alumina investment with 20 or 25 mass% gypsum content possessed the fundamental properties for high-fusing alloy casting.

Aluminum Oxide↗

PubMed2001

Experimental ammonia-free phosphate-bonded investments using Mg(H2PO4)2.

In previous study, we found that Mg(H2PO4)2 instead of NH4H2PO4 was available as a binder material for phosphate-bonded investments and possibly could be used to develop the phosphate-bonded investment without ammonia gas release. The purpose of the present study was to develop the experimental ammonia-free phosphate-bonded investments by investigating suitable refractories. Mg(H2PO4)2.nH2O and MgO were prepared as a binder. Cristobalite and quartz were selected as refractories. The power ratio of MgO/Mg(H2PO4)2.nH2O was set constant at 1.2 according to our previous findings. Fundamental properties of dental investment such as strength, manipulation and expansion were evaluated. Using cristobalite as the refractory material, further investigations were performed. The refractory/binder ratio was definitely effective. The increase of this ratio led to low mold strength and large mold expansion. The present findings suggested that C5 was desirable for dental investment.

Ammonia↗

PubMed2000

Capital investment strategies in health care systems.

Capital investment decisions are among the most important decisions made by firms. They determine the firm's capacity for providing services and commit the firm's cash for an extended period of time. Interviews with chief financial officers of leading health care systems reveal capital investment strategies that generally follow the recommendations of modern finance theory. Still, there is substantial variation in capital budgeting techniques, methods of risk adjustment, and the importance of qualitative considerations in investment decision making. There is also variation in delegation of investment decision making to operating units and methods of performance evaluation. Health care systems face the same challenges as other organizations in developing and implementing capital investment strategies that use consistent methods for evaluation of projects that have inconsistent aims and outcomes.

Budgets↗

PubMedDate not supplied

Association of market, mission, operational, and financial factors with hospitals' level of cash and security investments.

Using a resource dependency framework and financial theory, this study assessed the market, mission, operational, and financial factors associated with the level of cash and security investments in hospitals. We ranked hospitals in the study sample based on their cash and security investments as a percentage of total assets: hospitals in the high cash/security investment category were in the top 25th percentile of all hospitals; those in the low cash/security investment group were in the bottom 25th percentile. Findings indicate that high cash/security investment hospitals are under either public or private nonprofit ownership and have greater market share. They also serve more complex cases, offer more technology services, generate greater profits, incur a more stable patient revenue base, and maintain less debt.

Accounts Payable and Receivable↗

PubMed2001

Realizing positive returns from your e-health investments.

Although the healthcare industry still is in the beginning stages of e-health adoption and has yet to achieve a significant return on e-health investments, healthcare organizations can anticipate increasingly positive results over time. To capitalize on the potential of e-health, financial managers need to adopt a clear, concise approach to valuing e-health investment options, making investment decisions, and managing an organization's return on invested capital. Key actions to take are developing a strategy, looking beyond cost reduction to other advantages of e-health strategies, understanding the needs of the stakeholders, becoming comfortable with experimentation, having realistic expectations, and instituting a process for valuing e-health investments that does not duplicate valuation processes for traditional information technology projects.

Cost Allocation↗

PubMedDate not supplied

Effect of pressurized atmosphere on void size and quantity in dental stone and fine-grained phosphate-bonded investment.

This study investigated the effect of pressurized atmosphere on the size and number of voids in dental stones and investments. Control specimens of casts and invested patterns were bench set. Experimental specimens of casts and invested patterns were allowed to set under pressure. The specimens were then sectioned and voids counted and measured to establish a mean. Increased atmospheric pressure reduced the size and number of voids. This method produces improved cast surfaces and fewer, smaller voids in investments. Technicians are continuously searching for ways to improve the quality of their products. One method is placing dental casts and dental investments under increased atmospheric pressure while setting. Several pressure vessels are available for this purpose.

Calcium Sulfate↗

PubMed2001

Private investment in AIDS vaccine development: obstacles and solutions.

The development of vaccines for the prevention of AIDS, malaria, tuberculosis, and other diseases requires both public and private investment. Private investment, however, has been far lower than might have been hoped, given the massive human toll of these diseases, particularly in the poorest countries. With a view to understanding this situation and exploring potential solutions, the World Bank AIDS Vaccine Task Force commissioned a study on the perspectives of the biotechnology, vaccine, and pharmaceutical industries regarding investment in research and development work on an AIDS vaccine. It was found that different obstacles to the development of an AIDS vaccine arose during the product development cycle. During the earlier phases, before obtaining proof of product, the principal barriers were scientific. The lack of consensus on which approach was likely to be effective increased uncertainty and the risks associated with investing in expensive clinical trials. The later phases, which involved adapting, testing, and scaling up production for different populations, were most influenced by market considerations. In order to raise the levels of private research and development in an AIDS vaccine there will probably have to be a combination of push strategies, which reduce the cost and scientific risk of investment, and pull strategies, which guarantee a market.

AIDS Vaccines↗

PubMed2003

How have hospital investments navigated troubled waters?

The dismal stock-market returns of the past few years compel hospitals to examine their investment policies. The asset-allocation decisions of hospital CFOs and trustees generally are based on market trends. Some of their key concerns include volatility of investment returns, lack of internal resources for investment support, trustee and committee fiduciary and investment education, and retaining experienced investment advisory services.

Capital Financing↗

PubMedDate not supplied

The relationship between the fit of MOD inlays and the storage time and conditions of investing.

It has been traditional either to cast invested wax patterns immediately after the investment has set or to store the invested patterns in a humidor for casting later. This study compared the fit of MOD inlays to parent dies after casting immediately following set of the investment, after casting 1 hour following the setting of the investment in air, storage in a humidor for 7 days, and after storage in air for 7 days. The only significant differences in fit were in the group stored in a humidor, and then only at the axiogingival junctions.

Analysis of Variance↗

PubMedDate not supplied

[Surface roughness of investment samples and their metal castings].

Three phosphate bonded investments and three calcium type were studied observing the influence of investment on the final cast surface roughness. Increased dilution also incremented roughness for the phosphate investments. Between the two types of investments there was only significant difference concerning two specific commercial brands, but there were differences in the same type of investment among these different brands.

Dental Casting Investment↗