Pharmacological actions of chemical constituents
C. P. Khare in Evidence-based Ayurveda, 2019
Resins are a complex group of solids (occasionally liquid), insoluble in water, but soluble in alcohol, ether, and chloroform. They are obtained from many plants either spontaneously or as a result of the injury. Resins are often associated with essential oils, gum resins or with oil and gum. The resin compounds which mainly comprise diterpenenes. The essential resin is a mixture of resin acids (resinols), resin alcohols (resinols) or resin phenols (resino-tannols), oleo resins and gum resins mixed with volatile oils and gums. Other resins are complexed with aromatic balsamic acids like benzoic and cinnamic acids (which partially increase their solubility in water) and are referred to as balsamic resins. The balsams have been used as antiseptic and wound dressing for several centuries. In Western herbal medicine, 90% of tinctures of myrrh and marigold (Calendula officinalis) are used as an effective topical application for infection of mucosal surfaces.
Catalog of Herbs
James A. Duke in Handbook of Medicinal Herbs, 2018
Aloe contains several anthraquinone glycosides, as aloin (barbaloin), isobarbaloin, and emodin. Aloin is a lemon-yellow to dark-yellow powder, with a slight odor of aloe and an intense bitter taste, used as a cathartic or combined with other cathartics or antispasmodic drugs. The aloin content of Aloe barbadensis is ca. 30%, that of A. perryi ca. 25 to 28%, and that of A. ferox ca. 10%. Aloin consists mostly of barbaloin and other pentosides, resins, saponins, and other substances. On hydrolysis, barbaloin yields aloe-emodin and D-arabinose.17 The resins consist of resinotannols with cinnamic or p-hydroxy-cinnamic (p-coumanc) acids, etc. In the pulp (96% water), researchers have found arabinose, galactose, glucose, mannose, and xylose.17,29,59 Guar and locust bean gums are frequently mixed with aloe (which contains a similar glucomannan) to increase its viscosity and yield.29
Nail Product Rheology
Laba Dennis in Rheological Proper ties of Cosmetics and Toiletries, 2017
The original nitrocellulose nail lacquers simply included nitrocellulose, solvents, plasticizers, and small amounts of soluble red dyes. In order to increase wear resistance and gloss, natural resins such as dewaxed dammar gum were introduced (1). Toluene-sulfonamide resin has been the resin of choice as a modifying resin for nitrocellulose for many years, since its introduction in the mid-1930s. It provides many desirable properties, and a superior product compared to those that do not contain the resin. Toluene sulfonamide resin has been available in two grades. One is an 80% solution, the other is a solid. Depending on the supplier, these products are not necessarily a solution of the solid in a solvent. The original supplier, Monsanto, provided two distinct resins, with the solid form providing a harder film than the solution, when compared on an equal weight basis. An important advantage of the toluene sulfonamide resin is that relatively large amounts can be added without tremendously increasing the viscosity. Toluene sulfonamide resin, although receiving a good rating from the Cosmetic Ingredient Review (6), has been claimed to cause sensitization in some individuals, and is often a candidate for replacement.
Bulk Fill flow resin contraction using 3D finite element model and calibration by Fiber Bragg Grating measurement
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2020
Claudio Antunes Junior, Emílio Graciliano Ferreira Mercuri, Ana Paula Gebert de Oliveira Franco, Manoella Costa, Leandro Zen Karam, Hypolito José Kalinowski, Osnara Maria Mongruel Gomes
Resin based materials are widely used in restoration processes in dental practice. However, the polymerization shrinkage and the variation of the physical properties of the resin during polymerization in relation to the surrounding materials may cause damage to the interfaces between the dental resins, adhesives and tooth structures (Pearson and Hegarty 1987). The accumulation of damage may result in gaps at the interfaces, postoperative sensitivity, marginal stains, pulp damage, and recurrence of caries (Meredith and Setchell 1997). Damage can also trigger a fracture, cracking on the surrounding walls or even loss of restoration. In particular, the difference between the mechanical properties can lead to the appearance of stress concentration during the process of chewing or temperature change. In order to reduce these problems changes are made in the chemical composition of these materials (Causton et al. 1985; McCullock and Smith 1986). The stresses resulting from the polymerization shrinkage of the composites used in the restorations depend on a number of factors such as restoration size, cavity shape, whether composite application is incremental or single, composite creep effect, motion of the cusps and the intensity of the incident light during the polymerization process (Feilzer et al. 1990; Koike et al. 1990; Feilzer et al. 1995; Silikas et al. 2000). Cyclic loads may lead the restored tooth to fatigue and ultimately may result in material failure (Ausiello et al. 2001).
Development of antibacterial composite resin containing chitosan/fluoride microparticles as pit and fissure sealant to prevent caries
Published in Journal of Oral Microbiology, 2022
Chun-Cheng Lai, Chun-Pin Lin, Yin-Lin Wang
C/F was prepared from chitosan/fluoride microparticles and a light-curable polymer matrix. This polymer matrix was prepared by mixing Bis-GMA, TEGDMA, EDMAB, and CQ in a weight ratio of 69:30:1:1 (Sigma-Aldrich, St. Louis, MO). The previously prepared silanized silica nanoparticles and C/F act as inorganic fillers, making up 20% of the composite resin. The polymer matrix was temporarily heated to 50°C, which enhanced the flowability and avoided trapped bubbles. Subsequently, the inorganic fillers were slowly added and stirred into matrix. The experimental composite resin was divided into three groups based on the composition of inorganic fillers: 1) 0% C/F and 20% silanized silica nanoparticles, abbreviated as 0% C/F; 2) 2% C/F and 18% silanized silica nanoparticles, abbreviated as 2% C/F; and 3) 4% C/F and 16% silanized silica nanoparticles, abbreviated as 4% C/F. ClinproTM fissure sealant (3 M ESPE, USA) was used as a control. Subsequent polymerization was carried out using an LED curing light with luminosity over 1,200 mw/cm2 and a wavelength of 460–510 nm (Motion LED-320D, Taipei, Taiwan).
Marginal gap and fracture resistance of CAD/CAM ceramill COMP and cerasmart endocrowns for restoring endodontically treated molars bonded with two adhesive protocols: an in vitro study
Published in Biomaterial Investigations in Dentistry, 2020
Israa Atif Kassem, Ibrahim Elsebai Farrag, Samir Mahmoud Zidan, Jylan Fouad ElGuindy, Reham Said Elbasty
Resin cements are low-viscosity composite materials with filler distribution and initiator content adjusted to allow for a low film thickness and suitable working and setting times. They are widely used for luting low-strength ceramic and laboratory-processed composite restorations.[9] Currently, cements can be classified into total-etch, self-etch, and self-adhesive resin cements according to the dental tissue treatment or adhesion strategy.[10] total-etch systems contain phosphoric acid to pretreat the dental hard tissues before rinsing and subsequent application of an adhesive. Total-etch adhesives are offered as two- or three-step systems, depending on whether the primer and bonding come separate or combined in a single bottle.
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