Saliva: The clear, viscous fluid secreted by the SALIVARY GLANDS and mucous glands of the mouth. It contains MUCINS, water, organic salts, and ptylin.Saliva, Artificial: A solution used for irrigating the mouth in xerostomia and as a substitute for saliva.Salivary Proteins and Peptides: Proteins and peptides found in SALIVA and the SALIVARY GLANDS. Some salivary proteins such as ALPHA-AMYLASES are enzymes, but their composition varies in different individuals.Salivation: The discharge of saliva from the SALIVARY GLANDS that keeps the mouth tissues moist and aids in digestion.Parotid Gland: The largest of the three pairs of SALIVARY GLANDS. They lie on the sides of the FACE immediately below and in front of the EAR.Salivary Glands: Glands that secrete SALIVA in the MOUTH. There are three pairs of salivary glands (PAROTID GLAND; SUBLINGUAL GLAND; SUBMANDIBULAR GLAND).Submandibular Gland: One of two salivary glands in the neck, located in the space bound by the two bellies of the digastric muscle and the angle of the mandible. It discharges through the submandibular duct. The secretory units are predominantly serous although a few mucous alveoli, some with serous demilunes, occur. (Stedman, 25th ed)Mouth: The oval-shaped oral cavity located at the apex of the digestive tract and consisting of two parts: the vestibule and the oral cavity proper.Sublingual Gland: A salivary gland on each side of the mouth below the TONGUE.Immunoglobulin A, Secretory: The principle immunoglobulin in exocrine secretions such as milk, respiratory and intestinal mucin, saliva and tears. The complete molecule (around 400 kD) is composed of two four-chain units of IMMUNOGLOBULIN A, one SECRETORY COMPONENT and one J chain (IMMUNOGLOBULIN J-CHAINS).Xerostomia: Decreased salivary flow.Streptococcus mutans: A polysaccharide-producing species of STREPTOCOCCUS isolated from human dental plaque.Dental Plaque: A film that attaches to teeth, often causing DENTAL CARIES and GINGIVITIS. It is composed of MUCINS, secreted from salivary glands, and microorganisms.Dental Pellicle: A thin protein film on the surface of DENTAL ENAMEL. It is widely believed to result from the selective adsorption of precursor proteins present in SALIVA onto tooth surfaces, and to reduce microbial adherence to the TEETH.Dental Caries: Localized destruction of the tooth surface initiated by decalcification of the enamel followed by enzymatic lysis of organic structures and leading to cavity formation. If left unchecked, the cavity may penetrate the enamel and dentin and reach the pulp.Histatins: A group of small, histidine-rich, cationic peptides in human SALIVA which are antibacterial and antifungal.Actinomyces: A genus of gram-positive, rod-shaped bacteria whose organisms are nonmotile. Filaments that may be present in certain species are either straight or wavy and may have swollen or clubbed heads.Mouth Mucosa: Lining of the ORAL CAVITY, including mucosa on the GUMS; the PALATE; the LIP; the CHEEK; floor of the mouth; and other structures. The mucosa is generally a nonkeratinized stratified squamous EPITHELIUM covering muscle, bone, or glands but can show varying degree of keratinization at specific locations.Mucin-5B: A gel-forming mucin that is predominantly expressed by submucosal glands of airway tissues and the SUBLINGUAL GLAND. It is one of the principal components of high molecular weight salivary mucin.Proline-Rich Protein Domains: Protein domains that are enriched in PROLINE. The cyclical nature of proline causes the peptide bonds it forms to have a limited degree of conformational mobility. Therefore the presence of multiple prolines in close proximity to each other can convey a distinct conformational arrangement to a peptide chain.Secretory Rate: The amount of a substance secreted by cells or by a specific organ or organism over a given period of time; usually applies to those substances which are formed by glandular tissues and are released by them into biological fluids, e.g., secretory rate of corticosteroids by the adrenal cortex, secretory rate of gastric acid by the gastric mucosa.
Saliva testing: Saliva testing is a diagnostic technique that involves laboratory analysis of saliva to identify markers of endocrine, immunologic, inflammatory, infectious, and other types of conditions. Saliva is a useful biological fluid for assaying steroid hormones such as cortisol, genetic material like RNA, proteins such as enzymes and antibodies, and a variety of other substances, including natural metabolites, including saliva nitrite, a biomarker for nitric oxide status (see below for Cardiovascular Disease, Nitric Oxide: a salivary biomarker for cardio-protection).Dredge turning gland: Dredge Turning Gland is a Trailing Suction Hopper Dredger component.Submandibular gland: The paired submandibular glands are major salivary glands located beneath the floor of the mouth. They each weigh about 15 grams and contribute some 60–67% of unstimulated saliva secretion; on stimulation their contribution decreases in proportion as the parotid secretion rises to 50%.Serous demiluneStreptococcus mutans: Streptococcus mutans is facultatively anaerobic, Gram-positive coccus-shaped bacterium commonly found in the human oral cavity and is a significant contributor to tooth decay.Dental plaque: Dental plaque is a biofilm or mass of bacteria that grows on surfaces within the mouth. It appears as a white or pale yellow "slime layer", that is commonly found between the teeth and along the cervical margins.Dental cariesHistatin: Histatins are proteins found in saliva. They are antimicrobial and antifungal proteins, and have been found to play a role in wound-closure.Actinomyces israelii: Actinomyces israelii is a species of Gram-positive, rod-shaped bacteria within the Actinomyces. Known to live commensally on and within humans, A.
(1/131) Fatigue and tensile strength of dental gallium alloys after artificial saliva immersion.
Fatigue strength using the stair-case method and tensile strength of dental gallium alloys after artificial saliva immersion were measured for evaluating the effects of corrosive environment storage on the mechanical properties of the gallium alloys. The fatigue and the tensile strengths of both gallium alloys stored in artificial saliva were significantly decreased after 12-month storage, while those stored in air increased with storage period. The fracture surfaces of the specimens in artificial saliva showed not only metallic luster but also dark areas. In the dark area, the matrix might have dissolved during immersion. These results suggested that the concern over corrosion resistance of gallium alloys still remained. (+info)
(2/131) Polymeric films as vehicle for buccal delivery: swelling, mechanical, and bioadhesive properties.
PURPOSE: To investigate the suitability of an SCMC (sodium carboxymethyl cellulose/polyethylene glycol 400/carbopol 934P) and an HPMC (hydroxypropylmethyl cellulose/polyethylene glycol 400/carbopol 934P) films as drug vehicle for buccal delivery. METHODS: The mechanical and in vitro bioadhesive strength properties of the films were investigated using texture analyzer equipment, while swelling behavior was studied in different media, namely, distilled water and simulated saliva solution. In addition, the in vivo bioadhesion of the film was studied by estimating the film residence time on buccal mucosa of human volunteers. RESULTS: Increase in carbopol 934P content was found to elevate the elasticity, softness and bioadhesive strength but decrease the strength and degree of swelling of both SCMC and HPMC films. SCMC films swelled more extensively in distilled water while HPMC films in simulated saliva solution. HPMC films exhibited greater in vivo bioadhesion although the in vitro bioadhesive strength was lower than SCMC films. Correlation existed between the in vivo and in vitro bioadhesion data within the polymer, but no rank correlation was observed between the two polymers. CONCLUSION: HPMC films may be preferred over SCMC films as drug vehicle for buccal delivery as the former was tougher, more elastic, more bioadhesive in vivo and swelled in a more tolerable manner in the oral cavity than the latter. (+info)
(3/131) Wearing behaviors of a hybrid composite resin for crown and bridge.
The wearing behaviors of a hybrid composite resin for crown and bridge (ES) were examined using a two-body impacting-sliding wear test with a porcelain (PO), Au-Ag-Pd alloy (PD), direct restorative composite resin (CR) and tooth enamel (TO). Although PO was the hardest of all, it showed the largest wear together with ES in the combination of ES-PO, which was probably initiated from the superficial destruction by their impact. The wear in ES-PD was the second largest. It was noted in this combination that the surface of ES was partially contaminated by scraped thin layers of PD to a degree distinguished by the naked eye. The mutual wears of the components were relatively low in the combination of ES with CR, TO or ES itself. It is suggested from these findings that the hybrid composite resin may be useful as an alternative to porcelain for posterior crown and bridge unless it opposes porcelain or alloys. (+info)
(4/131) Effects of fluoride and dissolved oxygen concentrations on the corrosion behavior of pure titanium and titanium alloys.
The effects of dissolved-oxygen concentration and fluoride concentration on the corrosion behaviors of commercial pure titanium, Ti-6Al-4V and Ti-6Al-7Nb alloys and experimentally produced Ti-0.2Pd and Ti-0.5Pt alloys were examined using the corrosion potential measurements. The amount of dissolved Ti was analyzed by inductively coupled plasma mass spectroscopy. A decrease in the dissolved-oxygen concentration tended to reduce the corrosion resistance of Ti and Ti alloys. If there was no fluoride, however, corrosion did not occur. Under low dissolved-oxygen conditions, the corrosion of pure Ti and Ti-6Al-4V and Ti-6Al-7Nb alloys might easily take place in the presence of small amounts of fluoride. They were corroded by half or less of the fluoride concentrations in commercial dentifrices. The Ti-0.2Pd and Ti-0.5Pt alloys did not corrode more, even under the low dissolved-oxygen conditions and a fluoride-containing environment, than pure Ti and Ti-6Al-4V and Ti-6Al-7Nb alloys. These alloys are expected to be useful as new Ti alloys with high corrosion resistance in dental use. (+info)
(5/131) Patient preferences in a preliminary study comparing an intra-oral lubricating device with the usual dry mouth lubricating methods.
OBJECTIVE: To compare an intra-oral device to relieve oral dryness with the other methods of lubricating the mouth at night. DESIGN: Multidisciplinary single blind randomised cross over study. SETTING: The subjects were drawn from patients attending a dry mouth clinic. MATERIALS AND METHODS: Thirty-four dentate subjects attended on five occasions at intervals of 4 weeks. At the first visit the teeth were scaled and impressions were recorded. The device was fitted either on the second or the fourth visit. At all visits samples were taken of the resting and stimulated saliva for volumetric analysis and the dry mouth score recorded. Data were collected from the lubrication timings and the questionnaire. RESULTS: Ten water, nine saliva substitute and ten sugar-free chewing gum lubricators completed the study. There were 27 female and two male subjects with an average age of 62 years. Nine out of 10 of those lubricating with chewing gum preferred wearing the device (P = 0.037). After the device wearing period the subjects' self assessment of mouth dryness (P = 0.056), speech (P = 0.009) and swallowing (P = 0.031) were more favourable when compared with the alternative lubrication with 66% preferring the intra-oral device to their alternative method of lubrication. CONCLUSIONS: The majority of the subjects preferred wearing the device at night compared with their normal method of lubrication. Subjects' perception of dryness, speech and swallowing became closer to the clinician's assessment after wearing the device. (+info)
(6/131) The corrosion behavior of Nd2Fe14B and SmCo5 magnets.
Rare earth magnets have corrosive problems associated with their use in prostheses in various fields including orthodontics. The purpose of this study is to investigate the corrosion behavior of an Nd2Fe14B magnet and a SmCo5 magnet in an oral environment. The relations among the attractive force changes, the released elements, the weight changes and the anodic polarization measurements of the magnets were examined under immersions in 1% NaCl, 1% lactic acid, 0.05% HCl, 0.1% Na2S and Greenwood's artificial saliva at 37 degrees C for forty-two days. The results showed that the rare earth magnets underwent high corrosive assaults and large attractive force reductions by the immersions in 1% lactic acid and 0.05% HCl. The problem of corrosion of the magnets could be overcome by sealing them within laser-welded stainless steel capsules. (+info)
(7/131) Proton currents through amiloride-sensitive Na channels in hamster taste cells. Role in acid transduction.
The activity of taste cells maintained in the intact hamster tongue was monitored in response to acid stimulation by recording action currents from taste receptor cells with an extracellular "macro" patch pipette: a glass pipette was pressed over the taste pore of fungiform papillae and perfused with citric acid, hydrochloric acid, or NaCl. Because this technique restricted stimulus application to the small surface area of the apical membranes of the taste cells, many nonspecific, and potentially detrimental, effects of acid stimulation could be avoided. Acid stimulation reliably elicited fast transient currents (action currents of average amplitude, 9 pA) which were consistently smaller than those elicited by NaCl (29 pA). The frequency of action currents elicited by acid stimuli increased in a dose-dependent manner with decreasing pH from a threshold of about pH 5.0. Acid-elicited responses were independent of K+, Na+, Cl-, or Ca2+ at physiological (salivary) concentrations, and were unaffected by anthracene-9-carboxylic acid, tetraethylammonium bromide, diisothiocyanate-stilbene-2,2'-disulfonic acid, vanadate, or Cd2+. In contrast, amiloride (< or = 30 microM) fully and reversibly suppressed acid-evoked action currents. At submaximal amiloride concentrations, the frequency and amplitude of the action currents were reduced, indicating a reduction of the taste cell apical conductance concomitant with a decrease in cell excitation. Exposure to low pH elicited, in addition to transient currents, an amiloride-sensitive sustained d.c. current. This current is apparently carried by protons instead of Na+ through amiloride-sensitive channels. When citric acid was applied while the taste bud was stimulated by NaCl, the action currents became smaller and the response resembled that produced by acid alone. Because of the strong interdependence of the acid and salt (NaCl) responses when both stimuli are applied simultaneously, and because of the similarity in the concentration dependence of amiloride block, we conclude that amiloride-sensitive Na+ channels on hamster taste receptor cells are permeable to protons and may play a role in acid (sour) taste. (+info)
(8/131) An in vitro study into the corrosion of intra-oral magnets in the presence of dental amalgam.
The aim of this investigation was to study the corrosion behaviour and products of uncoated neodymium-iron-boron magnets in the presence of dental amalgam. Microcosm plaques were grown on discs of neodymium-iron-boron magnets or amalgam in a constant depth film fermentor. The biofilms were supplied with artificial saliva and growth was determined by viable counting. The results showed that the neodymium-iron-boron magnets corroded with an average daily weight loss of 0.115 +/- 0.032 per cent. However, when the magnets were in close proximity to the amalgam the amount of corrosion was reduced to a daily loss of 0.066 +/- 0.023 per cent. The highest loss of constituent elements from the corrosion products of the magnets was observed for iron. The composition of the microcosm plaques altered markedly between the two materials with less streptococci and more Veillonella spp. present in the biofilms grown on magnets in the presence of amalgam. The corrosion of neodymium-iron-boron magnets is limited and in the presence of amalgam is reduced further. This suggests that amalgam present in the mouth will not cause an increased clinical risk in terms of biocompatibility with neodymium-iron-boron magnets. (+info)