A generic term for all substances having the properties of stretching under tension, high tensile strength, retracting rapidly, and recovering their original dimensions fully. They are generally POLYMERS.
Polymers of silicone that are formed by crosslinking and treatment with amorphous silica to increase strength. They have properties similar to vulcanized natural rubber, in that they stretch under tension, retract rapidly, and fully recover to their original dimensions upon release. They are used in the encapsulation of surgical membranes and implants.
Salts and esters of the 10-carbon monocarboxylic acid-decanoic acid.
Silicone polymers which consist of silicon atoms substituted with methyl groups and linked by oxygen atoms. They comprise a series of biocompatible materials used as liquids, gels or solids; as film for artificial membranes, gels for implants, and liquids for drug vehicles; and as antifoaming agents.
A prosthetic appliance for the replacement of areas of the maxilla, mandible, and face, missing as a result of deformity, disease, injury, or surgery. When the prosthesis replaces portions of the mandible only, it is referred to as MANDIBULAR PROSTHESIS.
A broad family of synthetic organosiloxane polymers containing a repeating silicon-oxygen backbone with organic side groups attached via carbon-silicon bonds. Depending on their structure, they are classified as liquids, gels, and elastomers. (From Merck Index, 12th ed)
A group of thermoplastic or thermosetting polymers containing polyisocyanate. They are used as ELASTOMERS, as coatings, as fibers and as foams.
The susceptibility of the DENTAL ENAMEL to dissolution.
Synthetic or natural materials, other than DRUGS, that are used to replace or repair any body TISSUES or bodily function.
The testing of materials and devices, especially those used for PROSTHESES AND IMPLANTS; SUTURES; TISSUE ADHESIVES; etc., for hardness, strength, durability, safety, efficacy, and biocompatibility.
Artificial substitutes for body parts and materials inserted into organisms during experimental studies.
Polymers of high molecular weight which at some stage are capable of being molded and then harden to form useful components.
The maximum stress a material subjected to a stretching load can withstand without tearing. (McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed, p2001)
Production of a radiographic image of a small or very thin object on fine-grained photographic film under conditions which permit subsequent microscopic examination or enlargement of the radiograph at linear magnifications of up to several hundred and with a resolution approaching the resolving power of the photographic emulsion (about 1000 lines per millimeter).
Polymers of organic acids and alcohols, with ester linkages--usually polyethylene terephthalate; can be cured into hard plastic, films or tapes, or fibers which can be woven into fabrics, meshes or velours.
Chronic inflammation and granuloma formation around irritating foreign bodies.
Materials in intermediate state between solid and liquid.
Compounds formed by the joining of smaller, usually repeating, units linked by covalent bonds. These compounds often form large macromolecules (e.g., BIOPOLYMERS; PLASTICS).
Loose connective tissue lying under the DERMIS, which binds SKIN loosely to subjacent tissues. It may contain a pad of ADIPOCYTES, which vary in number according to the area of the body and vary in size according to the nutritional state.
Devices used for influencing tooth position. Orthodontic appliances may be classified as fixed or removable, active or retaining, and intraoral or extraoral. (Boucher's Clinical Dental Terminology, 4th ed, p19)
"In the context of medicine, 'textiles' refers to the use of woven, knitted, or nonwoven materials, often as components of medical devices such as bandages, sutures, or implantable materials, which can be designed to have specific properties like biocompatibility, breathability, or antimicrobial activity."
Substances that inhibit or arrest DENTAL CARIES formation. (Boucher's Clinical Dental Terminology, 4th ed)
A highly poisonous compound used widely in the manufacture of plastics, adhesives and synthetic rubber.
A tooth's loss of minerals, such as calcium in hydroxyapatite from the tooth matrix, caused by acidic exposure. An example of the occurrence of demineralization is in the formation of dental caries.
Alicyclic hydrocarbons in which three or more of the carbon atoms in each molecule are united in a ring structure and each of the ring carbon atoms is joined to two hydrogen atoms or alkyl groups. The simplest members are cyclopropane (C3H6), cyclobutane (C4H8), cyclohexane (C6H12), and derivatives of these such as methylcyclohexane (C6H11CH3). (From Sax, et al., Hawley's Condensed Chemical Dictionary, 11th ed)
Antineoplastic agent that is also used as a veterinary anesthetic. It has also been used as an intermediate in organic synthesis. Urethane is suspected to be a carcinogen.
Contraceptive devices used by females.
The properties and processes of materials that affect their behavior under force.
Organic compounds that contain the -NCO radical.
Materials fabricated by BIOMIMETICS techniques, i.e., based on natural processes found in biological systems.
Characteristics or attributes of the outer boundaries of objects, including molecules.
Objects that produce a magnetic field.
Inorganic salts of hydrofluoric acid, HF, in which the fluorine atom is in the -1 oxidation state. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed) Sodium and stannous salts are commonly used in dentifrices.
Polymers where the main polymer chain comprises recurring amide groups. These compounds are generally formed from combinations of diamines, diacids, and amino acids and yield fibers, sheeting, or extruded forms used in textiles, gels, filters, sutures, contact lenses, and other biomaterials.
Identification and measurement of ELEMENTS and their location based on the fact that X-RAYS emitted by an element excited by an electron beam have a wavelength characteristic of that element and an intensity related to its concentration. It is performed with an electron microscope fitted with an x-ray spectrometer, in scanning or transmission mode.
Derivatives of caproic acid. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain a carboxy terminated six carbon aliphatic structure.
Destruction by passage of a galvanic electric current, as in disintegration of a chemical compound in solution.
Water swollen, rigid, 3-dimensional network of cross-linked, hydrophilic macromolecules, 20-95% water. They are used in paints, printing inks, foodstuffs, pharmaceuticals, and cosmetics. (Grant & Hackh's Chemical Dictionary, 5th ed)
Works containing information articles on subjects in every field of knowledge, usually arranged in alphabetical order, or a similar work limited to a special field or subject. (From The ALA Glossary of Library and Information Science, 1983)
A purely physical condition which exists within any material because of strain or deformation by external forces or by non-uniform thermal expansion; expressed quantitatively in units of force per unit area.
The properties, processes, and behavior of biological systems under the action of mechanical forces.

Structural conformation of in vitro and in vivo aged orthodontic elastomeric modules. (1/162)

The objectives of this study were to investigate the structural characteristics of open and closed elastomeric modules in the as-received condition, and following (a) 24-hour in vitro loading determined as a 50 per cent extension relative to their original length; (b) 24-hour intra-oral exposure; (c) 3-week intra-oral exposure. Ten specimens of each type (open and closed) of the three brands of elastic chains were included in the study (total of 60). All specimens were subjected to (a) optical transmission microscopy utilizing phase contrast and polarized light modes, (b) micro MIR FT-IR spectroscopy, and (c) scanning electron microscopy and electron probe X-ray microanalysis. Stretched elastomers demonstrated a honeycomb pattern of filament detachment corresponding to strained areas. The chains possessing a well-differentiated inter-modular link presented higher strain concentration gradients located in the link. Phase contrast imaging revealed that the stress adsorption mechanism of these materials involved macromolecular chain orientation and elongation co-axially to the applied load. The specimens retrieved after 24 hours had acquired a proteinaceous film rich in alcohol groups with minimal evidence of phosphate mineralization, while the 3-week retrieved specimens presented precipitation of Ca- and P-forming calcium phosphates. The high protein content of the biofilm organized on the surface of these materials, as well as the calcification pattern found, were similar to a non-specific mechanism of film adsorption of biomaterials exposed to body fluids. The results have clinical implications for aspects of retraction control through sliding mechanics with the use of elastomeric ligatures, and the potential detrimental effects on dental and periodontal tissues such as decalcification and gingival inflammation, respectively. In addition, the experimental protocols adopted for the in vitro study of the force decay of elastomerics should be modified to include parameters pertinent to adsorption phenomena and calcification processes documented to occur in vivo.  (+info)

Adsorption and pharmacokinetics of cyclosporin A in relation to mode of infusion in bone marrow transplant patients. (2/162)

Two main factors that affect the pharmacokinetics of cyclosporin A (CsA) during 24-h durable intravenous (DIV) administration have been reported, namely physiological changes after bone marrow transplantation, and blood sampling through indwelling lines. In addition, it has been found that infusion sets made of polyvinyl chloride (PVC) markedly adsorb CsA. We conducted in vitro adsorption studies of CsA on infusion sets, and the administration routes that are used in the treatment of patients with bone marrow transplantation. We also examined the effects of administration route on CsA pharmacokinetics in clinical practice. The in vitro adsorption study using 30-mm segments of lumen from commercially available infusion sets showed that the degree of CsA adsorption per area of lumen made of PVC was significantly higher than that in those made of polyethylene (PE) or polybutadiene (PB), which showed no adsorption of CsA. Due to its adsorption, use of infusion sets made of PVC resulted in about a 40-50% loss of CsA dose, which affected the pharmacokinetic parameters during 24-h DIV, while those made of PE and PB did not. The use of non-PVC infusion sets should allow for accurate monitoring of CsA results, and provide cost benefit in the treatment of bone marrow transplantation.  (+info)

Fabrication of elastomer arterial models with specified compliance. (3/162)

A simple way of making elastic tubes using a mechanical lathe for precise control of the wall thickness is proposed in this study. These tubes are particularly useful for modeling properties of large arteries. Tubes with different geometric parameters and hence different elastic behavior have been made with a silicon elastomer (Rhodorsil RTV 1556). They have been created to be used for compliance measurements in hemodynamics research. Within a limited range of pressures, depending on the wall thickness, such tubes can be used to study models in which the compliance value is assumed to be constant.  (+info)

Fluoride-releasing elastomerics--a prospective controlled clinical trial. (4/162)

A prospective controlled clinical trial was undertaken to evaluate the effectiveness of stannous fluoride-releasing elastomeric modules (Fluor-I-Ties) and chain (Fluor-I-Chain) in the prevention of enamel decalcification during fixed appliance therapy. Forty-nine patients (782 teeth) were included in the experimental group, where the fluoride-releasing elastomerics were used. Forty-five patients (740 teeth) who received non fluoride-releasing elastomerics formed the control group. All patients had their elastomerics replaced at each visit. Enamel decalcification incidence and distribution were recorded using an index by direct clinical observation. In the control group enamel decalcification occurred in 73 per cent of patients and in 26 per cent of all teeth. In the experimental group the corresponding incidence was 63 and 16 per cent, respectively. The overall reduction in score per tooth produced by the fluoride-releasing elastomerics was 49 per cent, a highly significant difference (P < 0.001). A significant difference was seen in all but the occlusal enamel zones. The majority (over 50 per cent) of lesions occurred gingivally. The teeth most severely affected were the maxillary lateral incisors and mandibular second premolars. There was no difference in treatment duration between groups.  (+info)

A novel method of assessing the effectiveness of protective gloves--results from a pilot study. (5/162)

We have devised a novel method for evaluating the effectiveness of protective gloves and have undertaken a small study to assess this approach. Three types of glove were tested in a standardised simulation test with a permethrin-based pesticide. Prewashed cotton gloves were used to collect the samples. One was worn over the protective glove on one hand to measure the potential deposition of pesticide on the hands had the gloves not been worn. A second was placed under the protective glove on the opposite hand to measure the actual deposition of permethrin on the hands when the gloves were worn. This regime was reversed half way through each test in an attempt to prevent bias. Measurable inner glove contamination occurred on 25 out of 30 occasions. Geometric mean protection factors were calculated from the ratio of outer and inner sampling glove contamination, with average protection factors of 470, 200 and 96 being obtained for the two nitrile and PVC gloves, respectively. The PVC gloves were the least effective in preventing inner glove contamination, probably because the glove was thick and fairly inflexible, causing more pesticide to enter the glove around the cuff. Although the tasks were standardised, variability occurred due to worker behaviour and equipment failure. The spray pump failed on five occasions, resulting in higher levels of inner glove contamination and a geometric mean protection factor of 32. On the occasions when the pump worked correctly, the level of protection provided by the gloves rose dramatically with mean protection factors of 220 and 450 being obtained for workers categorised as "messy" and "tidy", respectively.  (+info)

Slip resistance of industrial floor surfaces: development of an elastomer suited to in-situ measurement. (6/162)

Slips contribute to 12% of occupational accidents. A slip resistant floor is a mean to prevent slipping accidents occurring in workshops. Floor slip resistance is often evaluated by measuring a friction index, proportional to the force opposing slipping of a reference elastomer on the floor surface under test. When implementing a portable appliance, slip resistance measurements carried out on lubricated floors were not stabilized. The authors advanced the hypothesis of oil impregnating the elastomer. A new elastomer suited to in-situ measurement has been developed to achieve stable measuring conditions. This study highlights the fact that the nature and characteristics of a reference elastomer must be specified when slip resistance measurements are carried out.  (+info)

Bacterial colonization associated with fixed orthodontic appliances. A scanning electron microscopy study. (7/162)

This investigation was undertaken to assess bacterial plaque accumulation adjacent to orthodontic brackets. Experiments were carried out on 11 subjects who were scheduled for orthodontic treatment including extraction of two or four premolars. Metal brackets were bonded to the premolars to be extracted using macro-filled bonding composite. A conventional elastomeric ring was placed around one bracket and a steel ligature wire around the bracket on the contralateral tooth. The subjects were told to continue their normal oral hygiene regimen. Teeth were extracted at 1, 2, or 3 weeks after bracket bonding. Scanning electron microscopic (SEM) examination of brackets, excess composite, and buccal enamel revealed that mature plaque was present on excess composite at 2 and 3 weeks after bonding, whereas plaque on the gingival enamel surface was still at an early stage of development. The results demonstrate that excess composite around the bracket base is the critical site for plaque accumulation due to its rough surface and the presence of a distinct gap at the composite-enamel interface. The method of ligation does not appear to influence the bacterial morphotypes on both composite and enamel surfaces.  (+info)

Strength decay of orthodontic elastomeric ligatures. (8/162)

AIM: To evaluate, over a 12-week period, the tensile strength (TS) and extension to TS of elastomeric ligatures (both clear and coloured) obtained from two companies. SETTING: Ex vivo study. METHOD: Seven replicates of five ligatures from two orthodontic companies were tested using an ex vivo assembly which simulated a clinical situation. RESULTS: The ligatures tested had a similar TS decay pattern, with the TS gradually decreasing over the duration of the study. The Unitek ligatures exhibited a greater TS than their respective Ormco ligatures. Generally, all of the ligatures tested experienced an increase in the extension to TS over time. The pre-stretching procedure used in this study did not produce any long-term detrimental effects on the TS and extension to TS of the ligatures tested. CONCLUSIONS: The results of this study confirm there are differences in TS, and extension to TS between clear and coloured elastomeric ligatures, and that some significant differences also exist between different brands of elastomeric ligatures.  (+info)

Elastomers are a type of polymeric material that exhibit elastic behavior when subjected to deforming forces. They have the ability to return to their original shape and size after being stretched or compressed, making them ideal for use in applications where flexibility, resilience, and durability are required.

Elastomers are composed of long chains of repeating molecular units called monomers, which are cross-linked together to form a three-dimensional network. This cross-linking gives elastomers their unique properties, such as high elasticity, low compression set, and resistance to heat, chemicals, and weathering.

Some common examples of elastomers include natural rubber, silicone rubber, neoprene, nitrile rubber, and polyurethane. These materials are used in a wide range of applications, from automotive parts and medical devices to footwear and clothing.

Silicone elastomers are a type of synthetic rubber made from silicone, which is a polymer composed primarily of silicon-oxygen bonds. They are known for their durability, flexibility, and resistance to heat, cold, and moisture. Silicone elastomers can be manufactured in various forms, including liquids, gels, and solids, and they are used in a wide range of medical applications such as:

1. Breast implants: Silicone elastomer shells filled with silicone gel are commonly used for breast augmentation and reconstruction.
2. Contact lenses: Some contact lenses are made from silicone elastomers due to their high oxygen permeability, which allows for better eye health.
3. Catheters: Silicone elastomer catheters are flexible and resistant to kinking, making them suitable for long-term use in various medical procedures.
4. Implantable drug delivery systems: Silicone elastomers can be used as a matrix for controlled release of drugs, allowing for sustained and targeted medication administration.
5. Medical adhesives: Silicone elastomer adhesives are biocompatible and can be used to attach medical devices to the skin or other tissues.
6. Sealants and coatings: Silicone elastomers can be used as sealants and coatings in medical devices to prevent leakage, improve durability, and reduce infection risk.

It is important to note that while silicone elastomers are generally considered safe for medical use, there have been concerns about the potential health risks associated with breast implants, such as capsular contracture, breast pain, and immune system reactions. However, these risks vary depending on the individual's health status and the specific type of silicone elastomer used.

Decanoates are a type of esterified form of certain drugs or medications, particularly in the case of testosterone. The decanoate ester is attached to the testosterone molecule to create a longer-acting formulation. Testosterone decanoate is a slow-release form of testosterone that is used as a replacement therapy for individuals who have low levels of natural testosterone. It is administered through intramuscular injection and has a duration of action of approximately 2-3 weeks.

Other medications may also be available in decanoate ester form, but testosterone decanoate is one of the most commonly used. As with any medication or treatment plan, it's important to consult with a healthcare provider to determine the best course of action based on individual needs and medical history.

Dimethylpolysiloxanes are a type of silicone-based compound that are often used as lubricants, coatings, and fluid ingredients in various industrial and consumer products. In medical terms, they can be found in some pharmaceutical and medical device formulations as inactive ingredients. They are typically included as anti-foaming agents or to improve the texture and consistency of a product.

Dimethylpolysiloxanes are made up of long chains of silicon and oxygen atoms, with methyl groups (CH3) attached to the silicon atoms. This gives them unique properties such as low toxicity, thermal stability, and resistance to oxidation and water absorption. However, some people may have allergic reactions or sensitivities to dimethylpolysiloxanes, so they should be used with caution in medical applications.

A maxillofacial prosthesis is a custom-made device used to replace all or part of a facial feature, such as an eye, ear, nose, or lip, that has been lost due to trauma, cancer surgery, or other causes. It is typically made from materials like silicone, acrylic, or nylon and is designed to mimic the appearance and texture of natural skin and tissues.

Maxillofacial prostheses are created by trained professionals called maxillofacial prosthodontists, who have specialized training in the diagnosis, treatment planning, and rehabilitation of patients with facial defects. The process of creating a maxillofacial prosthesis typically involves taking an impression of the affected area, creating a custom-made mold, and then fabricating the prosthesis to fit precisely over the defect.

Maxillofacial prostheses can help improve patients' appearance, self-confidence, and quality of life by restoring their facial symmetry and functionality. They may also help protect the underlying tissues and structures from injury or infection, and can be used in conjunction with other treatments, such as radiation therapy or chemotherapy, to enhance their effectiveness.

Silicones are not a medical term, but they are commonly used in the medical field, particularly in medical devices and healthcare products. Silicones are synthetic polymers made up of repeating units of siloxane, which is a chain of alternating silicon and oxygen atoms. They can exist in various forms such as oils, gels, rubbers, and resins.

In the medical context, silicones are often used for their unique properties, including:

1. Biocompatibility - Silicones have a low risk of causing an adverse reaction when they come into contact with living tissue.
2. Inertness - They do not react chemically with other substances, making them suitable for use in medical devices that need to remain stable over time.
3. Temperature resistance - Silicones can maintain their flexibility and elasticity even under extreme temperature conditions.
4. Gas permeability - Some silicone materials allow gases like oxygen and water vapor to pass through, which is useful in applications where maintaining a moist environment is essential.
5. Durability - Silicones have excellent resistance to aging, weathering, and environmental factors, ensuring long-lasting performance.

Examples of medical applications for silicones include:

1. Breast implants
2. Contact lenses
3. Catheters
4. Artificial joints and tendons
5. Bandages and wound dressings
6. Drug delivery systems
7. Medical adhesives
8. Infant care products (nipples, pacifiers)

I'm sorry for any confusion, but "Polyurethanes" are not a medical term. They are a type of polymer that is used in a variety of industrial and consumer products, including foam cushions, insulation, and packaging materials. Polyurethanes are created through a chemical reaction between diisocyanates and polyols. While they have many applications in the medical field, such as in the production of medical devices and equipment, they are not a medical term themselves.

Dental enamel solubility refers to the degree to which the mineral crystals that make up dental enamel can be dissolved or eroded by acidic substances. Dental enamel is the hard, outermost layer of a tooth that helps protect it from damage. It is primarily made up of minerals, including hydroxyapatite, which can dissolve in an acidic environment.

When the pH in the mouth drops below 5.5, the oral environment becomes acidic and dental enamel begins to demineralize or lose its mineral content. This process is known as dental caries or tooth decay. Over time, if left untreated, dental caries can lead to cavities, tooth sensitivity, and even tooth loss.

Certain factors can increase the solubility of dental enamel, including a diet high in sugar and starch, poor oral hygiene, and the presence of certain bacteria in the mouth that produce acid as a byproduct of their metabolism. On the other hand, fluoride exposure can help to reduce dental enamel solubility by promoting remineralization and making the enamel more resistant to acid attack.

Biocompatible materials are non-toxic and non-reacting substances that can be used in medical devices, tissue engineering, and drug delivery systems without causing harm or adverse reactions to living tissues or organs. These materials are designed to mimic the properties of natural tissues and are able to integrate with biological systems without being rejected by the body's immune system.

Biocompatible materials can be made from a variety of substances, including metals, ceramics, polymers, and composites. The specific properties of these materials, such as their mechanical strength, flexibility, and biodegradability, are carefully selected to meet the requirements of their intended medical application.

Examples of biocompatible materials include titanium used in dental implants and joint replacements, polyethylene used in artificial hips, and hydrogels used in contact lenses and drug delivery systems. The use of biocompatible materials has revolutionized modern medicine by enabling the development of advanced medical technologies that can improve patient outcomes and quality of life.

I'm happy to help! However, I must clarify that "materials testing" is not a medical term per se. It is a term used in various fields, including engineering and materials science, to describe the process of subjecting materials to different tests to evaluate their properties and performance under various conditions.

In the context of medical devices or implants, materials testing may refer to the evaluation of the physical and mechanical properties of materials used in their construction. These tests can include assessments of strength, durability, biocompatibility, and other factors that are critical to ensuring the safety and efficacy of medical devices.

Medical device manufacturers must comply with regulatory standards for materials testing to ensure that their products meet specific requirements for performance, safety, and quality. These standards may vary depending on the type of device, its intended use, and the country or region in which it will be marketed and sold.

Experimental implants refer to medical devices that are not yet approved by regulatory authorities for general use in medical practice. These are typically being tested in clinical trials to evaluate their safety and efficacy. The purpose of experimental implants is to determine whether they can be used as a viable treatment option for various medical conditions. They may include, but are not limited to, devices such as artificial joints, heart valves, or spinal cord stimulators that are still in the developmental or testing stage. Participation in clinical trials involving experimental implants is voluntary and usually requires informed consent from the patient.

Synthetic resins are artificially produced substances that have properties similar to natural resins. They are typically created through polymerization, a process in which small molecules called monomers chemically bind together to form larger, more complex structures known as polymers.

Synthetic resins can be classified into several categories based on their chemical composition and properties, including:

1. Thermosetting resins: These resins undergo a chemical reaction when heated, resulting in a rigid and infusible material that cannot be melted or reformed once it has cured. Examples include epoxy, phenolic, and unsaturated polyester resins.

2. Thermoplastic resins: These resins can be repeatedly softened and hardened by heating and cooling without undergoing any significant chemical changes. Examples include polyethylene, polypropylene, and polystyrene.

3. Elastomeric resins: These resins have the ability to stretch and return to their original shape when released, making them ideal for use in applications that require flexibility and durability. Examples include natural rubber, silicone rubber, and polyurethane.

Synthetic resins are widely used in various industries, including construction, automotive, electronics, and healthcare. In the medical field, they may be used to create dental restorations, medical devices, and drug delivery systems, among other applications.

Tensile strength is a material property that measures the maximum amount of tensile (pulling) stress that a material can withstand before failure, such as breaking or fracturing. It is usually measured in units of force per unit area, such as pounds per square inch (psi) or pascals (Pa). In the context of medical devices or biomaterials, tensile strength may be used to describe the mechanical properties of materials used in implants, surgical tools, or other medical equipment. High tensile strength is often desirable in these applications to ensure that the material can withstand the stresses and forces it will encounter during use.

Microradiography is a radiographic technique that uses X-rays to produce detailed images of small specimens, such as microscopic slides or individual cells. In this process, the specimen is placed in close contact with a high-resolution photographic emulsion, and then exposed to X-rays. The resulting image shows the distribution of radiopaque materials within the specimen, providing information about its internal structure and composition at a microscopic level.

Microradiography can be used for various applications in medical research and diagnosis, including the study of bone and tooth microstructure, the analysis of tissue pathology, and the examination of mineralized tissues such as calcifications or osteogenic lesions. The technique offers high resolution and contrast, making it a valuable tool for researchers and clinicians seeking to understand the complex structures and processes that occur at the microscopic level in living organisms.

I'm sorry for any confusion, but "Polyesters" is not a medical term. It is a term used in materials science and textile industry to describe a type of synthetic fiber made from polymers characterized by the presence of ester groups in their main chain. If you have any questions related to medical terminology or concepts, I'd be happy to help with those instead!

A foreign-body reaction is an immune response that occurs when a non-native substance, or "foreign body," is introduced into the human body. This can include things like splinters, surgical implants, or even injected medications. The immune system recognizes these substances as foreign and mounts a response to try to eliminate them.

The initial response to a foreign body is often an acute inflammatory reaction, characterized by the release of chemical mediators that cause vasodilation, increased blood flow, and the migration of white blood cells to the site. This can result in symptoms such as redness, swelling, warmth, and pain.

If the foreign body is not eliminated, a chronic inflammatory response may develop, which can lead to the formation of granulation tissue, fibrosis, and encapsulation of the foreign body. In some cases, this reaction can cause significant tissue damage or impede proper healing.

It's worth noting that not all foreign bodies necessarily elicit a strong immune response. The nature and size of the foreign body, as well as its location in the body, can all influence the severity of the reaction.

Liquid crystals (LCs) are not exclusive to the medical field, but they do have important applications in medicine, particularly in the development of display technologies for medical devices. Here is a general definition:

Liquid crystals are a state of matter that possess properties between those of conventional liquids and solid crystals. They can flow like liquids but have molecules oriented in a way that they can reflect light, creating birefringence. This unique property makes them useful in various applications, such as LCDs (liquid crystal displays) found in many electronic devices, including medical equipment.

In the context of medicine, liquid crystals are primarily used in LCD screens for medical devices like monitors, imaging systems, and diagnostic equipment. They enable high-resolution, clear, and adjustable visualization of medical images, which is crucial for accurate diagnosis and treatment planning.

In the context of medical definitions, polymers are large molecules composed of repeating subunits called monomers. These long chains of monomers can have various structures and properties, depending on the type of monomer units and how they are linked together. In medicine, polymers are used in a wide range of applications, including drug delivery systems, medical devices, and tissue engineering scaffolds. Some examples of polymers used in medicine include polyethylene, polypropylene, polystyrene, polyvinyl chloride (PVC), and biodegradable polymers such as polylactic acid (PLA) and polycaprolactone (PCL).

Subcutaneous tissue, also known as the subcutis or hypodermis, is the layer of fatty connective tissue found beneath the dermis (the inner layer of the skin) and above the muscle fascia. It is composed mainly of adipose tissue, which serves as a energy storage reservoir and provides insulation and cushioning to the body. The subcutaneous tissue also contains blood vessels, nerves, and immune cells that support the skin's functions. This layer varies in thickness depending on the location in the body and can differ significantly between individuals based on factors such as age, genetics, and weight.

Orthodontic appliances are devices used in orthodontics, a branch of dentistry focused on the diagnosis, prevention, and treatment of dental and facial irregularities. These appliances can be fixed or removable and are used to align teeth, correct jaw relationships, or modify dental forces. They can include braces, aligners, palatal expanders, space maintainers, and headgear, among others. The specific type of appliance used depends on the individual patient's needs and the treatment plan developed by the orthodontist.

I'm sorry for any confusion, but "textiles" is not a term that is typically used in a medical context. In general, textiles refer to the broad category of flexible materials made by weaving, knitting, braiding, or felting fibers together. They include things like clothing, upholstery, and other soft goods.

In a medical setting, terms such as "medical textiles" or "healthcare textiles" might be used to refer to textile-based products that are specifically designed for use in medical applications, such as bandages, wound dressings, sutures, and implantable materials. These products must meet strict regulatory requirements to ensure their safety and effectiveness.

However, it's important to note that while some healthcare professionals may be familiar with the term "textiles" in this context, it is not a standard medical term and would not be used in a formal medical definition.

Cariostatic agents are substances or medications that are used to prevent or inhibit the development and progression of dental caries, also known as tooth decay or cavities. These agents work by reducing the ability of bacteria in the mouth to produce acid, which can erode the enamel and dentin of the teeth and lead to cavities.

There are several types of cariostatic agents that are commonly used in dental care, including:

1. Fluorides: These are the most widely used and well-studied cariostatic agents. They work by promoting the remineralization of tooth enamel and making it more resistant to acid attacks. Fluoride can be found in toothpaste, mouthwashes, gels, varnishes, and fluoridated water supplies.
2. Antimicrobial agents: These substances work by reducing the population of bacteria in the mouth that contribute to tooth decay. Examples include chlorhexidine, triclosan, and xylitol.
3. Casein phosphopeptide-amorphous calcium phosphate (CPP-ACP): This is a complex protein that has been shown to help remineralize tooth enamel and reduce the risk of dental caries. It can be found in some toothpastes and mouthwashes.
4. Silver diamine fluoride: This is a topical fluoride compound that contains silver ions, which have antimicrobial properties. It has been shown to be effective in preventing and arresting dental caries, particularly in high-risk populations such as young children and older adults with dry mouth.

It's important to note that while cariostatic agents can help reduce the risk of tooth decay, they are not a substitute for good oral hygiene practices such as brushing twice a day, flossing daily, and visiting the dentist regularly.

Acrylonitrile is a colorless, flammable liquid with an unpleasant odor. It is used in the manufacture of plastics, resins, and synthetic fibers. In terms of medical toxicology, acrylonitrile is classified as a volatile organic compound (VOC) and can cause irritation to the eyes, skin, and respiratory tract. Exposure to high levels of acrylonitrile can lead to symptoms such as headache, dizziness, nausea, and vomiting. Chronic exposure has been associated with an increased risk of certain types of cancer, including lung, laryngeal, and esophageal cancer. However, it's important to note that occupational exposure limits are in place to minimize the risks associated with acrylonitrile exposure.

Tooth demineralization is a process that involves the loss of minerals, such as calcium and phosphate, from the hard tissues of the teeth. This process can lead to the development of dental caries or tooth decay. Demineralization occurs when acids produced by bacteria in the mouth attack the enamel of the tooth, dissolving its mineral content. Over time, these attacks can create holes or cavities in the teeth. Fluoride, found in many toothpastes and public water supplies, can help to remineralize teeth and prevent decay. Good oral hygiene practices, such as brushing and flossing regularly, can also help to prevent demineralization by removing plaque and bacteria from the mouth.

Cycloparaffins, also known as naphthenes or cycloalkanes, are a type of hydrocarbon molecule that contain one or more closed rings of carbon atoms. These rings can be saturated, meaning that they contain only single bonds between the carbon atoms, and may also contain one or more alkyl substituents.

The term "cycloparaffin" is used in the context of organic chemistry and petroleum refining to describe a specific class of hydrocarbons. In medical terminology, cycloparaffins are not typically referenced directly, but they may be relevant in certain contexts, such as in discussions of industrial chemicals or environmental exposures.

Cycloparaffins can be found in various sources, including crude oil and natural gas, and they are often used as feedstocks in the production of various chemicals and materials. They are also found in some foods, such as vegetable oils and animal fats, and may be present in trace amounts in some medications or medical devices.

While cycloparaffins themselves are not typically considered to have direct medical relevance, exposure to certain types of cycloparaffins or their derivatives may be associated with various health effects, depending on the level and duration of exposure. For example, some cycloparaffin-derived chemicals have been linked to respiratory irritation, skin and eye irritation, and potential developmental toxicity. However, it is important to note that these effects are typically associated with high levels of exposure in occupational or industrial settings, rather than with normal environmental or dietary exposures.

Urethane is not a term typically used in medical definitions. However, in the field of chemistry and pharmacology, urethane is an ethyl carbamate ester which has been used as a general anesthetic. It is rarely used today due to its potential carcinogenic properties and the availability of safer alternatives.

In the context of materials science, polyurethanes are a class of polymers that contain urethane linkages (-NH-CO-O-) in their main chain. They are widely used in various applications such as foam insulation, coatings, adhesives, and medical devices due to their versatile properties like flexibility, durability, and resistance to abrasion.

Contraceptive devices for females refer to medical products designed to prevent pregnancy by blocking or interfering with the sperm's ability to reach and fertilize an egg. Some common examples of female contraceptive devices include:

1. Diaphragm: A shallow, flexible dome made of silicone that is inserted into the vagina before sexual intercourse to cover the cervix and prevent sperm from entering the uterus.
2. Cervical Cap: Similar to a diaphragm but smaller in size, the cervical cap fits over the cervix and creates a barrier to sperm entry.
3. Intrauterine Device (IUD): A small, T-shaped device made of plastic or copper that is inserted into the uterus by a healthcare professional. IUDs can prevent pregnancy for several years and work by changing the chemistry of the cervical mucus and uterine lining to inhibit sperm movement and implantation of a fertilized egg.
4. Contraceptive Sponge: A soft, round sponge made of polyurethane foam that contains spermicide. The sponge is inserted into the vagina before sexual intercourse and covers the cervix to prevent sperm from entering the uterus.
5. Female Condom: A thin, flexible pouch made of polyurethane or nitrile that is inserted into the vagina before sexual intercourse. The female condom creates a barrier between the sperm and the cervix, preventing pregnancy and reducing the risk of sexually transmitted infections (STIs).
6. Vaginal Ring: A flexible ring made of plastic that is inserted into the vagina for three weeks at a time to release hormones that prevent ovulation, thicken cervical mucus, and thin the lining of the uterus.
7. Contraceptive Implant: A small, flexible rod made of plastic that is implanted under the skin of the upper arm by a healthcare professional. The implant releases hormones that prevent ovulation and thicken cervical mucus to prevent pregnancy for up to three years.

It's important to note that while these contraceptive devices can be highly effective at preventing pregnancy, they do not protect against STIs. Using condoms in addition to other forms of contraception is recommended to reduce the risk of both pregnancy and STIs.

I'm sorry for any confusion, but "mechanical phenomena" is not a standard medical term. The term "mechanical phenomenon" is more commonly used in the fields of physics and engineering to refer to events or processes that involve physical forces and movements, such as the movement of a lever or the flow of a fluid due to pressure differences.

If you have any questions about a specific medical concept or condition, I would be happy to try to help you with that instead!

Isocyanates are a group of highly reactive chemicals that are widely used in the production of flexible and rigid foams, fibers, coatings, and adhesives. The most common isocyanates are toluene diisocyanate (TDI) and methylene diphenyl diisocyanate (MDI). Exposure to isocyanates can cause a range of health effects, including irritation of the eyes, nose, throat, and skin, as well as respiratory symptoms such as coughing, wheezing, and shortness of breath. Long-term exposure has been linked to the development of asthma and other respiratory diseases. Isocyanates are also known to be potential sensitizers, meaning that they can cause an allergic response in some individuals. It is important for workers who handle isocyanates to use appropriate personal protective equipment (PPE) and follow proper safety protocols to minimize exposure.

Biomimetic materials are synthetic or natural substances that mimic the chemical, physical, and biological properties of living systems or tissues. These materials are designed to interact with cells, tissues, and organs in ways that resemble the body's own structures and processes. They can be used in a variety of medical applications, including tissue engineering, drug delivery, and medical devices.

Biomimetic materials may be composed of polymers, ceramics, metals, or composites, and they can be designed to have specific properties such as mechanical strength, biocompatibility, and degradability. They may also incorporate bioactive molecules, such as growth factors or drugs, to promote healing or prevent infection.

The goal of using biomimetic materials is to create medical solutions that are more effective, safer, and more compatible with the body than traditional synthetic materials. By mimicking the body's own structures and processes, these materials can help to reduce inflammation, promote tissue regeneration, and improve overall patient outcomes.

Surface properties in the context of medical science refer to the characteristics and features of the outermost layer or surface of a biological material or structure, such as cells, tissues, organs, or medical devices. These properties can include physical attributes like roughness, smoothness, hydrophobicity or hydrophilicity, and electrical conductivity, as well as chemical properties like charge, reactivity, and composition.

In the field of biomaterials science, understanding surface properties is crucial for designing medical implants, devices, and drug delivery systems that can interact safely and effectively with biological tissues and fluids. Surface modifications, such as coatings or chemical treatments, can be used to alter surface properties and enhance biocompatibility, improve lubricity, reduce fouling, or promote specific cellular responses like adhesion, proliferation, or differentiation.

Similarly, in the field of cell biology, understanding surface properties is essential for studying cell-cell interactions, cell signaling, and cell behavior. Cells can sense and respond to changes in their environment, including variations in surface properties, which can influence cell shape, motility, and function. Therefore, characterizing and manipulating surface properties can provide valuable insights into the mechanisms of cellular processes and offer new strategies for developing therapies and treatments for various diseases.

In the context of medical devices, magnets are objects made of magnetic material that produce a magnetic field. They are used in various medical applications such as in magnetic resonance imaging (MRI) machines to generate detailed images of internal organs and tissues, and in some types of surgical instruments to help guide and control the positioning of implants. Magnets can also be found in some assistive devices for people with disabilities, such as magnetic bracelets or shoe inserts that are claimed to provide therapeutic benefits, although these claims are not always supported by scientific evidence.

Fluorides are ionic compounds that contain the fluoride anion (F-). In the context of dental and public health, fluorides are commonly used in preventive measures to help reduce tooth decay. They can be found in various forms such as sodium fluoride, stannous fluoride, and calcium fluoride. When these compounds come into contact with saliva, they release fluoride ions that can be absorbed by tooth enamel. This process helps to strengthen the enamel and make it more resistant to acid attacks caused by bacteria in the mouth, which can lead to dental caries or cavities. Fluorides can be topically applied through products like toothpaste, mouth rinses, and fluoride varnishes, or systemically ingested through fluoridated water, salt, or supplements.

I believe there may be some confusion in your question. "Nylons" is a common term for a type of synthetic fiber often used in clothing, hosiery, and other textile applications. It is not a medical term or concept. If you have any questions related to medical terminology or concepts, I would be happy to try and help clarify!

Electron Probe Microanalysis (EPMA) is a technique used in materials science and geology to analyze the chemical composition of materials at very small scales, typically on the order of microns or less. In this technique, a focused beam of electrons is directed at a sample, causing the emission of X-rays that are characteristic of the elements present in the sample. By analyzing the energy and intensity of these X-rays, researchers can determine the concentration of different elements in the sample with high precision and accuracy.

EPMA is typically performed using a specialized instrument called an electron probe microanalyzer (EPMA), which consists of an electron column for generating and focusing the electron beam, an X-ray spectrometer for analyzing the emitted X-rays, and a stage for positioning and manipulating the sample. The technique is widely used in fields such as mineralogy, geochemistry, metallurgy, and materials science to study the composition and structure of minerals, alloys, semiconductors, and other materials.

One of the key advantages of EPMA is its ability to analyze the chemical composition of small regions within a sample, even in cases where there are spatial variations in composition or where the sample is heterogeneous. This makes it an ideal technique for studying the distribution and behavior of trace elements in minerals, the microstructure of alloys and other materials, and the composition of individual grains or phases within a polyphase material. Additionally, EPMA can be used to analyze both conductive and non-conductive samples, making it a versatile tool for a wide range of applications.

"Caproates" is not a term commonly used in medical terminology. It appears to be a derivative of "caproic acid," which is an organic compound with the formula CH3CH2CH2CH2CO2H. Caproic acid is one of several saturated fatty acids that are abundant in animal fats and have a distinctive rancid odor when they spoil or break down.

However, I was unable to find any specific medical definition or use of the term "caproates" in the context of medicine or healthcare. It is possible that this term may be used in a different field or context, such as chemistry or biochemistry. If you have more information about the context in which you encountered this term, I may be able to provide a more accurate answer.

Electrolysis is a medical procedure that involves the use of electrical current to permanently remove hair growth. It works by passing a thin, solid metal electrode (called a probe) into the natural opening of the hair follicle and applying an electrical charge to destroy the hair root. This process can be used to remove hair from any part of the body, including the face, legs, arms, underarms, and bikini area.

During electrolysis, a trained professional called an electrologist inserts a small needle into the hair follicle and applies a mild electrical current. The current heats up and destroys the hair root, preventing future growth. Multiple treatments are usually necessary to achieve permanent hair removal, as only one or two hairs can be treated at a time.

Electrolysis is considered a safe and effective method for permanent hair removal, but it can cause some discomfort during and after treatment. Common side effects include redness, swelling, and tenderness in the treated area. These side effects typically resolve within a few hours to a few days after treatment.

It's important to note that electrolysis should only be performed by a licensed and trained electrologist. Improper technique can cause scarring, infection, or other complications. Before undergoing electrolysis, it's recommended to consult with a dermatologist or other healthcare provider to discuss the risks and benefits of the procedure.

Hydrogels are defined in the medical and biomedical fields as cross-linked, hydrophilic polymer networks that have the ability to swell and retain a significant amount of water or biological fluids while maintaining their structure. They can be synthesized from natural, synthetic, or hybrid polymers.

Hydrogels are known for their biocompatibility, high water content, and soft consistency, which resemble natural tissues, making them suitable for various medical applications such as contact lenses, drug delivery systems, tissue engineering, wound dressing, and biosensors. The physical and chemical properties of hydrogels can be tailored to specific uses by adjusting the polymer composition, cross-linking density, and network structure.

An encyclopedia is a comprehensive reference work containing articles on various topics, usually arranged in alphabetical order. In the context of medicine, a medical encyclopedia is a collection of articles that provide information about a wide range of medical topics, including diseases and conditions, treatments, tests, procedures, and anatomy and physiology. Medical encyclopedias may be published in print or electronic formats and are often used as a starting point for researching medical topics. They can provide reliable and accurate information on medical subjects, making them useful resources for healthcare professionals, students, and patients alike. Some well-known examples of medical encyclopedias include the Merck Manual and the Stedman's Medical Dictionary.

Mechanical stress, in the context of physiology and medicine, refers to any type of force that is applied to body tissues or organs, which can cause deformation or displacement of those structures. Mechanical stress can be either external, such as forces exerted on the body during physical activity or trauma, or internal, such as the pressure changes that occur within blood vessels or other hollow organs.

Mechanical stress can have a variety of effects on the body, depending on the type, duration, and magnitude of the force applied. For example, prolonged exposure to mechanical stress can lead to tissue damage, inflammation, and chronic pain. Additionally, abnormal or excessive mechanical stress can contribute to the development of various musculoskeletal disorders, such as tendinitis, osteoarthritis, and herniated discs.

In order to mitigate the negative effects of mechanical stress, the body has a number of adaptive responses that help to distribute forces more evenly across tissues and maintain structural integrity. These responses include changes in muscle tone, joint positioning, and connective tissue stiffness, as well as the remodeling of bone and other tissues over time. However, when these adaptive mechanisms are overwhelmed or impaired, mechanical stress can become a significant factor in the development of various pathological conditions.

Biomechanics is the application of mechanical laws to living structures and systems, particularly in the field of medicine and healthcare. A biomechanical phenomenon refers to a observable event or occurrence that involves the interaction of biological tissues or systems with mechanical forces. These phenomena can be studied at various levels, from the molecular and cellular level to the tissue, organ, and whole-body level.

Examples of biomechanical phenomena include:

1. The way that bones and muscles work together to produce movement (known as joint kinematics).
2. The mechanical behavior of biological tissues such as bone, cartilage, tendons, and ligaments under various loads and stresses.
3. The response of cells and tissues to mechanical stimuli, such as the way that bone tissue adapts to changes in loading conditions (known as Wolff's law).
4. The biomechanics of injury and disease processes, such as the mechanisms of joint injury or the development of osteoarthritis.
5. The use of mechanical devices and interventions to treat medical conditions, such as orthopedic implants or assistive devices for mobility impairments.

Understanding biomechanical phenomena is essential for developing effective treatments and prevention strategies for a wide range of medical conditions, from musculoskeletal injuries to neurological disorders.

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