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At least 307 records · Page 17Linked to original sources

Clinical evaluation of the wax trial denture.

A complete denture is a mechanical object, much of which is fabricated outside the dental operatory. Its specific fabrication, however, is dictated by clinical facts, as outlined in instructions provided by the dentist. This mechanical object must function in a biologic atmosphere, and every effort must be made to assure a harmonious relationship between the mechanical and the biologic. The wax trial denture stage becomes a critical phase of complete denture care in evaluating this relationship. The wax trial denture should be evaluated relative to trial base stability, vertical dimension, centric and protrusive jaw relationships, tooth selection, the level of the occlusal plane, buccolingual and anteroposterior tooth position, and occlusal articulation. Although all of these factors should be further evaluated at the denture insertion stage as well as at each recall visit, only at the wax trial denture stage can significant changes be easily accomplished. The wax trial denture evaluation should receive adequate consideration in any complete denture technique.

Dental Occlusion, Balanced↗

Improved diethylene glycol distearate embedding wax.

Diethylene glycol distearate wax and cellulose caprate resin, 4:1 respectively by weight, were melted together at 75 C for five hours with occasional stirring. The resin tempered the extreme brittleness of the wax without softening it, and raised the melting point only one degree to 50 C. Fixed plant tissues were dehydrated in ethanol, cleared in xylene, and infiltrated with wax. Modified diethylene glycol distearate was easier to trim and shape, and formed flat sections more consistently than the pure wax. Sections were cut singly on Ralph knives with attached water pools on an ultramicrotome. Sectionability was excellent at 2-3 micrometers, variable at 1.0 micrometer, but impossible at 0.5 micrometer. Sections were transferred onto water drops on slides, dried, dewaxed, stained, and coverglasses applied as in the paraffin method. Histological feature of plant tissues were much sharper in modified diethylene glycol distearate sections than in paraffin sections, and were similar to plastic sections.

Cellulose↗

Separation and partial purification of wax and fatty alcohol from Okinawan sugar cane rind lipids.

A composition analysis of Okinawan sugar cane rind materials was conducted, and it was found that the main components were lipids, crude fiber and water indicating about 27%, 19.6% and 14.6%, respectively. The lipids were effectively extracted from rind materials by benzene. Wax (18%) and fatty alcohol (8%) were found to be the main components, totaling up to 96% of the lipids. Separation and partial purification of wax and fatty alcohol were attempted by means of silica gel column chromatography, thin-layer chromatography (TLC), infrared (IR) absorption spectra and gas-liquid chromatography-mass spectrometry (GC-MS). The major components of the wax were considered to be two compounds with the molecular weights of 408 (C-26) and 436 (C-28), and those of fatty alcohol were di-ol with molecular weights of 440 (C-29) and 468 (C-31). Both wax and fatty alcohol were purified by rechromatography on a silica gel column and the samples obtained seemed to be satisfactory for use in experimental rats' diets.

Fatty Alcohols↗

[Reaction of the bone- and soft tissues to implanted bone wax in the sheep].

2,5 gr. of bone wax (Knochenwachs) were implanted in the iliac crest of 10 sheep. The induction of a foreign body reaction and chronic inflammation was proven demonstrable until the 12th week after implantation of the bone wax. In this period only partial resorption of the wax occurred simultaneously with significantly retarded osseous regeneration. From a clinical point of view it therefore seems necessary when using bone wax to pay particular attention to inflammatory reactions, reduced new bone formation and eventual occurrence of pseudo-arthrosis.

Animals↗

[Acute deterioration of the CO diffusion capacity following exposure to ski-wax vapors].

In cross country skiing use of hot wax is of importance. 90% of the active swiss cross country skiers have their own, self maintained equipment. Long unprotected exposure to hot wax fumes may cause disturbance of lung function. To examine short lasting disturbance in pulmonary function, CO-diffusion capacity and dynamic and static lung volumes in five healthy human subjects after exposure for one hour to hot wax (containing Paraffin and Cera-F) were determined. The subjects complained about burning eyes and tears, sore throat and coughing. Immediately after exposure all subjects showed a significant decrease of the CO-diffusion capacity of 10.6% (SEM 3.9), related to the ventilated alveolar space (DCOSB/VA). Maximal decrease of 13.6% (SEM 2.4) was after 90 min. After 24 hours the reduction persisted with 9.4% (SEM 2.1). The dynamic and static lung volumes remained unchanged. In summary a reduction of the CO-diffusion capacity after inhalative hot wax exposure was observed for at least 24 hours.

Adult↗

[Thermal dimensional stability of dental registration wax].

Three bite registration waxes were tested for their thermic dimensional behavior under several heating and cooling conditions. Aluwax showed the smallest changes in length. Difficulties of application are expected because of its low softening temperature. There were greater dimensional changes with Beauty Pink Hard-Wax, but Kerr No. 8-Wax showed the greatest changes. The cooling method had a small, the heating temperature, however, a strong influence on the thermic dimensional behavior. These are the recommendations for the clinical application of the tested waxes: The bite registration material should not be heated more than necessary for achieving a sufficiently plastic quality for the registration. It should be stored in ice water to be resistant enough to deformation during the model mounting.

Jaw Relation Record↗

[Moulages--wax models in dermatology].

Wax models have been used for more than 2,000 years. In the 17th century, wax moulages--besides anatomical drawings--became more and more important as three-dimensional illustrations in the training of medical students and physicians. During the 19th century, dermatological and venereological diseases, too, were imitated by colored wax models. When new procedures of pictorial representation such as photography and film were introduced, the wax models temporarily lost their instructive value. Since then, we have gradually discovered their historical significance, as well as their importance as works of art. Our article deals with the development of moulages from Roman death masks up to the modern models of medical instruction and is illustrated by quotations from reknowned moulage artists.

History, 17th Century↗

Hydrocarbon and multibranched ester waxes from the uropygial gland secretion of grebes (Podicipediformes).

The uropygial gland secretion of some grebes (Podicipediformes) had been shown to contain saturated and unsaturated aliphatic hydrocarbons and monoester waxes. While ester waxes are common constituents of preen gland secretions, nonisoprenoid hydrocarbons have not been detected hitherto. The wax constituents are very complex, belonging to several multibranched homologous series, including unusual acids with ethyl branches. The waxes were identified by gas-liquid chromatography-mass spectrometry and equivalent chain length comparisons. A method for the prediction of equivalent chain length values of unknown methyl esters is offered. The results are discussed from a chemotaxonomic viewpoint.

Animals↗

Comparative incidence of side effects of a wax-matrix and a sustained-release iron preparation.

The side effects of a wax-matrix iron preparation and a sustained-release iron preparation were compared in a single-blind study of 181 subjects. Evaluations after four and eight weeks of therapy revealed moderate or severe side effects in 52% of the subjects who received the sustained-release preparation but in only 25% of those who received the wax-matrix preparation. Further analysis of the data demonstrated fewer side effects overall among patients who received the wax-matrix preparation. These findings suggest that the wax-matrix preparation is better tolerated than the sustained-release preparation.

Adolescent↗

Evaluation of bone-wax extract on the frequency of chromosomal aberrations in the bone marrow of Swiss mice.

Indigenously developed bone wax was evaluated for cytogenetic effects of a saline extract of the bone wax. Swiss mice were assigned to 5 groups of 6 animals each. Groups I, II, III were given non-lethal doses of 2.5, 5.0 or 10.0 ml bone-wax saline extract/kg body wt and Groups IV and V received sterile 0.9% saline vehicle or cyclophosphamide ip as controls. After 24 h the mice were sacrificed by cervical dislocation. Bone marrow preparations were stained with Giemsa's stain and examined by light microscopy. Abnormalities such as numbers of chromosome gaps, breaks and translocations were noted. The bone-wax saline extract did not induce chromosomal aberrations in the bone marrow of Swiss mice under our laboratory conditions.

Animals↗

Effect of bone wax extract on the frequency of bone marrow erythrocyte micronuclei in mice.

The present study evaluated the induction of micronuclear potency of indigenously developed bone wax saline extract. The experiment was designed with 2 batches, each consisting of 8 groups with 3 male Swiss albino mice each. In each batch, the first 3 groups received Chitra's bone wax saline extract and the second 3 groups received Johnson & Johnson bone wax saline extract at 12.5, 25.0 or 50.0 ml/kg body weight ip for 2 d. The remaining 2 groups were vehicle (saline) and positive (cyclophosphamide) controls. Animals were sacrificed 24 and 36 h after the second dosing and bone marrow smears were prepared and evaluated for micronuclei. The Chitra's and Johnson & Johnson's bone wax extracts failed to induce micronuclei in bone marrow erythrocytes of mice.

Animals↗

Assessment of a prototype battery operated wax-knife for domiciliary and surgery use.

The aims of this study were to examine a prototype battery operated wax-knife, assess the extent to which manufacturer's claims have been achieved and determine its potential for clinical use. The mean time required for the wax-knife to achieve an operating temperature of 150 degrees C was 20.2(+/-4.3) s. The mean operating temperature of the ceramic blade was 155.4(+/-3.9) degrees C, range 150 degrees C to 162 degrees C. The mean usage time following full battery recharge was 42 (+/-2) minutes. The wax-knife provided a direct heating tool which retained many of the characteristics of the traditional wax-knife and was suitable for use in the surgery and in domiciliary situations.

Burns↗

Human anatomy in wax during Florentine enlightenment.

The high mortality rate of mothers and children during delivery was not taken into consideration by science before the end of the XVII Century; gynaecology became an official discipline in the Schools of Medicine at the beginning of the next century. The knowledge of anatomy was fundamental for doctors but human cadavers were still difficult to obtain; thus the need of models for the teaching. Anatomical models were obtained by injection of salts and alcohol on bodies or part of bodies: the procedure was difficult and the preparation did not last for a long time. Models in wax proved to be scientifically reliable, and everlasting. Schools of anatomical wax modelling were established in Italy: first in Bologna and later in Florence at the Museum "La Specola", a laboratory which soon became famous all through Europe. Description follows of the technique and the material used for the construction of the models; the scientists and the workers in the laboratory. Short notes on Felice Fontana, Paolo Mascagni, Giuseppe Galletti, Clemente Susini, Luigi Calamai, Egisto Tortori. A last chapter is devoted to the XVII Century Sicilian wax modeller Gaetano Giulio Zumbo, mainly renouned for the "Plague waxes" and some anatomical heads: most of his works are exhibited in the Museum La Specola in Florence.

Anatomy↗

Polyethylene glycol/microfibrillar collagen composite as a new resorbable hemostatic bone wax.

Although bone wax is effective at achieving hemostasis, it is nonresorbable, causes a foreign body reaction, and inhibits osteogenesis. We report development of a polyethylene glycol/microfibrillar collagen composite (PEG/MFC) that has inherent hemostatic qualities, is biodegradable, and is compatible with bone repair. PEG/MFC composite (n = 42) was placed in 5 mm cranial defects in New Zealand white rabbits. Hemostasis and healing were compared to unfilled defects (n = 32) and defects filled with standard bone wax (n = 10). Both PEG/MFC and bone wax handled well and stopped bleeding. The polyethylene glycol component was resorbed by 8 h, and the microfibrillar collagen was resorbed over 2 months, eliciting only a minor inflammatory response during the first month. Defects filled with the PEG/MFC composite showed similar amounts of bony regeneration as did unfilled control defects. At 4 weeks, healing bone accounted for 43 +/- 13% in those treated with PEG/MFC and 47 +/- 19% defect area in untreated holes. In contrast, less than 1% of the area was bone in defects filled with bone wax (p < 0.05). PEG/MFC composite provided excellent bony hemostasis and did not inhibit bone growth.

Animals↗

Oligosaccharide release from frozen and paraffin-wax-embedded archival tissues.

Altered glycosylation is a feature of many solid tissue diseases such as ulcerative colitis, Crohn's disease, cancer, and connective tissue disorders. Conventionally, oligosaccharide changes have been studied by immunohistochemical techniques. We have adapted existing techniques, developed for purified protein preparations, to allow the release of intact oligosaccharides from archival tissues, so that the oligosaccharides may be structurally characterized. In our study, sections cut from paraffin-wax blocks were dewaxed and oligosaccharides were released using hydrazine and labeled with 2-aminobenzamide. Sialylated oligosaccharides were compared by passing through a GlycoSep C divinylbenzene anion exchange resin column and neutral oligosaccharides were compared by passing through a BioGel P4 column. The oligosaccharide profiles obtained from the same fresh frozen versus archival paraffin-wax-embedded, normal liver, and tumor tissues showed remarkable similarity in terms of their sialylated and neutral structures. Matrix-assisted laser desorption ionization mass spectrometry has shown that the oligosaccharides are not affected by fixation in formalin and storage in paraffin wax. The results indicate that while the proteins themselves may be denatured, oligosaccharides are not adversely affected by fixation in formalin and storage in paraffin wax. By applying these methods, oligosaccharides from archival tissues, where the natural history of the disease has been followed, may now be liberated and structurally characterized.

Animals↗

Blood perfusion and remodelling activity in canine tibial diaphysis after filling with a new bone cement compared to bone wax and poly(methyl methacrylate) cement.

Six dogs each had one tibia filled with standard poly(methyl methacrylate) (PMMA) bone cement and the contralateral tibia filled with a new methyl methacrylate-n-decyl methacrylate-isobornyl methacrylate (MMA-DMA-IBMA) bone cement (Boneloc) with lowered polymerization heat and monomer leakage. An additional six dogs each had one tibia filled with MMA-DMA-IBMA and the contralateral tibia filled with bone wax. There was a higher diaphyseal blood flow, measured with a microsphere technique, in the legs filled with MMA-DMA-IBMA than in those filled with PMMA. The wax-filled bones presented higher blood perfusion than those with MMA-DMA-IBMA. We found a tendency towards higher 99mtechnetium-labelled methylene diphosphonate (99mTcMDP) uptake, and autoradiograms revealed a tendency towards larger subperiosteal apposition and more blackening, both at the subperiosteal apposition and the cortex, in the bones filled with new bone cement in the first series, but in wax-filled bone in the second series. It is concluded that the new bone cement, compared to standard acrylic bone cement, seems to inhibit the vascular response and bone remodelling activity less, making earlier remodelling possible. However, the new bone cement still seems to inhibit bone blood perfusion compared to bone wax.

Animals↗

Surface structures and epicuticular wax composition of spruce needles after long-term treatment with ozone and acid mist.

Epicuticular wax structures and epicuticular wax composition were studied in needles of Picea abies (L.) Karst. plants after a long-term fumigation experiment. SEM observations showed aggregated as well as undamaged waxes without any relation to treatments. The chemical wax analysis revealed clone specific differences, but only one compound, the nonacosan-10-ol (C(29)-ol), was found enriched in ozone/acid mist treatments.

Journal Article↗

Amperometric determination of hydrazine at manganese hexacyanoferrate modified graphite-wax composite electrode.

Fabrication, characterization and application of a manganese hexacyanoferrate (MnHCF) modified graphite-wax composite electrode are described. The MnHCF mixed with graphite powder was dispersed into molten paraffin wax to yield a conductive composite, which was used as electrode material to construct a renewable three-dimensional MnHCF modified electrode. The characterization of the modified electrode has been studied by electrochemical techniques. The cyclic voltammogram of the MnHCF modified graphite-wax composite electrode prepared under optimum composition, showed a well-defined redox couple due to Fe(CN)(6)(4-)/Fe(CN)(6)(3-) system. The electrocatalytic oxidation of hydrazine by MnHCF modified graphite-wax composite electrode has been investigated in an attempt to develop a new sensor for its determination. It was found that the mediator catalyzed the oxidation of hydrazine. The electrocatalytic oxidation of hydrazine was also studied under hydrodynamic and chronoamperometric conditions. The anodic current increases linearly with increase in the concentration of hydrazine in the range of 3.33x10(-5)M to 8.18x10(-3)M. The detection limit was found to be 6.65x10(-6)M (S/N=3). The modified electrode can also be used for on-line detection of hydrazine. The proposed method has also been applied for the determination of hydrazine in photographic developer solution.

Electrochemistry↗