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Retention Capabilities (retention + capability)

Distribution by Scientific Domains

Polymers and Materials Science	50%
Medical Sciences	50%

Selected Abstracts

Parameters affecting retentive force of conus crowns

JOURNAL OF ORAL REHABILITATION, Issue 3 2004
M.A. Güngör
summary, The aim of this study was to determine the values of the retentive forces of the telescopic crowns. At the first step of the study, the samples having different heights and angles were compared in relation to retentive force. At the second step, the samples were subjected to removal procedures having a pre-determined speed, force and number. The obtained retention values were compared. Ninety dies were prepared in order to measure the retention of the conus crowns. The removal tests were performed with the insertion/separation device. The speed of the test device was 100 cm min,1 providing the placement of the pieces with 5 kgf in 100, 200, 300, 500, 1000, 5000 and 10 000 cycles. The mean of the retention values of the changes of the angles were found to be statistically different (P < 0,01). According to the results of the variant analysis, the differences in the changes of the height were statistically significant (P < 0·01). The differences between the changes of the number of procedures of all groups were statistically significant (P < 0·01). The number of procedures, height and angle interactions were statistically insignificant (P = 0·758). According to the results of this study, the effect of the angle and height factors in terms of retention among the groups were not independent of each other. In equal angles, as the height increased, increased retention measurements were obtained. In more acute angles, the increase in retention was more obvious. It was also found that an accessory device was necessary to maintain retention capabilities after a long-term use. [source]

Palatal Anchorage for the Retention of Interim Removable Prostheses

JOURNAL OF PROSTHODONTICS, Issue 8 2009
Alberto J. Ambard DDS
Abstract This paper describes a technique that involves the use of palatal implants to retain a maxillary interim prosthesis when extensive bone graft procedures are performed. The rationale is that some bone graft procedures require the removal of the denture flanges for graft success. Once the denture flanges are removed, the denture loses all its retention capabilities, making this lengthy interim phase difficult for the patient. While the use of palatal implants has been documented extensively, limited information is available to describe the use of palatal implants for prosthetic reasons. [source]

Charge storage of electrospun fiber mats of poly(phenylene ether)/polystyrene blends

POLYMER ENGINEERING & SCIENCE, Issue 12 2009
Deliani Lovera
Nonwoven fiber mats composed of poly(phenylene ether) (PPE) and polystyrene (PS) blends were prepared by electrospinning of PPE/PS solutions in a mixture of chloroform and hexafluoroisopropanol. The blends showed higher electrospinnability and led to thinner fibers (200 nm,1.3 ,m) than the pure components, because of a proper balance of electrical conductivity and interaction with the electrospinning solvent. The charge retention of the electrospun fibers was evaluated and related to the blend composition and the electret properties of the components. It was found that the nonwoven mats were able to retain up to 60% of the initial surface potential after several days of annealing at temperatures as high as 140°C, which is markedly higher than the charge retention of corona-charged compact films. The capability of the electrospinning technique, to inject charges into the bulk of the material and to orientate the dipoles of the PPE phase in the field direction at the same time, was related to the good surface potential stability of the PPE/PS electrospun fiber mats. The possibility of creating thin PPE/PS fibers with excellent charge retention capabilities makes these materials ideal candidates for electret filter and sensing applications. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers [source]

Preparation and characterization of highly polar polymeric sorbents from styrene,divinylbenzene and vinylpyridine,divinylbenzene for the solid-phase extraction of polar organic pollutants

JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 13 2003
Núria Fontanals
Abstract This article explores the synthesis of styrene,divinylbenzene resins with different surface areas and the influence of these surface areas on their performance in the solid-phase extraction of polar compounds from water samples. As expected, increasing the surface areas increases the retention capability of polar compounds. To improve the retention properties, we have used 4-vinylpyridine instead of styrene in the polymerization and evaluated the influence of the sorbent polarity and surface area on the retention properties. We have found that a compromise is required between the percentage of 4-vinylpyridine, which increases the polarity of the sorbent, and the percentage of divinylbenzene, which increases the surface area. In the solid-phase extraction of polar compounds, the results are best for a polymer containing 2.14% N and having a surface area of 710 m2/g. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 1927,1933, 2003 [source]