Chewing efficiency

Dentures require accurate fit, reasonable chewing efficiency, and lifelike appearance (189). The chewing efficiency of artificial dentures is one-sixth that of natural dentition (190). AcryHc resins are generally used as powder/Hquid formulations for denture base, bone cement, and related appHcations. Polymerization is achieved thermally using initiators photochemicaHy using photoactive chemicals and either uv or visible light irradiation and at ambient temperatures using initiator/activator systems. 

Beat-Cured Restm. For optimum comfort and to impede further loss of chewing efficiency, close adaptation of the denture base to contiguous oral tissues is required, which necessitates custom-made appHances. Nearly all dentures are made of acryHc resins. A wax pattern is used to form a custom denture base in which the denture teeth are embedded. A plaster or dental-stone investment spHt mold of this wax denture base and teeth is prepared. The wax portion is removed and the surface of the resulting mold cavity is painted with a separating medium, usually an aqueous solution of alginate, to aid in the removal of the cured acryHc from the plaster mold. 

Chewable Tablets. It has already been noted that most elderly patients experience a decrease in their ability to chew efficiently [125,137,138,143]. Therefore, by virtue of their design, chewable tablets are not often recommended for use by elderly patients (particularly those who are edentulous) 155-163,164], Most chewable formulations also rely on an adequate amount of chewing action to obtain full release of their ingredients (e.g., chewing promotes the foaming action provided by some chewable antacid products). So, aside from being difficult form the elderly patient to use, full benefit of a chewable dosage form may not be achieved by these patients. Additionally, the use of chewable tablets by denture wearers may cause local irritation in the oral cavity [155]. 

Helkimo, E., Carlsson, G.E. and Helkimo, M. (1977). Chewing efficiency and state of dentition. Acta Odont. Scand. 36, 33-41. 

Wilding, R.J.C. (1993). The association between chewing efficiency and occlusal contact area in man. Arch. Oral Biol. 38, 589-596. 

When smoked, nicotine is very rapidly and efficiently (90%) absorbed into the bloodstream. When chewed, absorption is slower but the duration of effect is longer. The average cigarette contains approximately 12 mg of nicotine and delivers approximately 1 mg to the smoker (Fuku-... 

Enzymes are very efficient natural catalysts present in plants and animals. They do not require high temperatures to break down the starch to maltose. In humans, a salivary amylase breaks down the starch in our food. If you chew on a piece of bread for several minutes, you will notice a sweet taste in your mouth. The above hydrolysis reactions are summarised in Figure 15.21. 

Endosulfan acts as a stomach or contact poison, depending on the insect species involved. It has a very wide spectrum of action, and it is efficient against a great number of chewing and sucking insects. 

Carbaryl is a very potent contact and respiratory poison and its spectrum of action is different from that of most of the carbamic acid derivatives. It is very efficient against chewing insects, and proved particularly successful for the control of insect pests in orchards. It is 70 times more toxic than DDT towards bees, but is inefficient against red spider mite (Georghiou and Metcalf, 1962 Haynes et al., 1957 Johnson and Stansbury, 1965). 

The cusps of opposing molars (i.e. on opposite jaws) are complementary to each other, which increases the efficiency of grinding food during chewing. 2. (in anatomy) A flap forming part of a valve. 3. (in mathematics) A point at which two arcs of a curve intersect. 

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