Oral restorations

Youdelis WV and Youdelis RA (1981) Silver-copper-germanium alloys (potential for oral restorations). Can Dent Assoc J 47 101-106. 

The calcium chelate cements are limited to the use of a cavity liner. They may be placed directly over an exposed tooth pulp to protect the pulp and stimulate the growth of secondary dentin, or used as a therapeutic insulating base under permanent restorations. The high alkalinity and high solubihty of these materials prohibits use in close proximity to soft tissues or in contact with oral fluids. 

Elastomer Impression Materials. Dentistry requires impression materials that are easily handled and accurately register or reproduce the dimensions, surface details, and interrelationship of hard and soft oral tissues. Elexible, elastomeric materials are especially needed to register intraoral tooth stmctures that have undercuts. The flexibility of these elastomers allows their facile removal from undercut areas while their elasticity restores them to their original shape and size. 

Oral corrosion of metallic restorations does not, per se, generally result in serious damage to the structure. Corrosion can result, however, in various local and systemic effects, notably the hypersensitivity and allergic reactions reported by many workers. Galvanic cells created by mixed metal couples can delay fracture healing and induce oral lesions and cancer. 

The reactivation of enzymes (after their partial inactivation in an acid medium) upon passing into a medium of pH 8 is also of great importance for oral use (Fig. 25). Enzymes immobilized in crosslinked polyelectrolytes are characterized by a structural memory even after considerable inactivation. Under changed conditions, this leads to a considerable or almost complete reactivation of the enzyme, whereas in the reactivation of a free enzyme in solution under similar conditions the enzymatic activity is restored on a lower level. 

Bergenholtz, G., Cox, C. F., Loesche, W. J. Syed, S. A. (1982). Bacterial leakage around dental restorations its effect on dental pulp. Journal of Oral Pathology, 11, 439-50. 

Lloyd, C. H. Mitchell, L. (1984). The fracture toughness of tooth coloured restorative materials. Journal of Oral Rehabilitation, 11, 257-72. 

Williams, J. Billington, R. W. (1991). Changes in compressive strength of glass ionomer restorative materials with respect to time periods of 24 h to 4 months. Journal of Oral Rehabilitation, 18, 163-8. 

Hals, E. (1975). Histology of natural secondary caries associated with silicate cement restorations. Archives of Oral Biology, 20, 291-6. 

Spangberg, L., Rodrigues, H., Langeland, L. Langeland, K. (1973). Biological effects of dental materials. 2. Toxicity of anterior tooth restorative materials on HeLa cells in vitro. Oral Surgery, Oral Medicine, Oral Pathology, 36, 713-24. 

Despite all these endeavours, as Brauer himself admits, the rapid disintegration under oral conditions prevents their use in permanent restorations (Brauer, Stansbury Argentar, 1983) and subsequent development has taken place in a quite different direction. 

For acute symptomatic hypocalcemia, 200 to 300 mg of elemental calcium is administered IV and repeated until symptoms are fully controlled. This is achieved by infusing 1 g of calcium chloride or 2 to 3 grams of calcium at a rate no faster than 30 to 60 mg of elemental calcium per minute. More rapid administration is associated with hypotension, bradycardia, or cardiac asystole. Total calcium concentration is commonly monitored in critically ill patients. Under normal circumstances, about half of calcium is loosely bound to serum proteins while the other half is free. Total calcium concentration measures bound and free calcium. Ionized calcium measures free calcium only. Under usual circumstances, a normal calcium level implies a normal free ionized calcium level. Ionized calcium should be obtained in patients with comorbid conditions that would lead to inconsistency between total calcium and free serum calcium (abnormal albumin, protein, or immunoglobulin concentrations). For chronic asymptomatic hypocalcemia, oral calcium supplements are given at doses of 2 to 4 g/day of elemental calcium. Many patients with calcium deficiency have concurrent vitamin D deficiency that must also be corrected in order to restore calcium homeostasis.2,37,38... 

Bioavailability of Metals, Nonmetals and Xenobiotics Immobilized on Soil Components, (4) Distribution and Activity of Biomolecules in Terrestrial Systems, (5) Interactions between Soil Microbial Biomass and Organic Matter/Nutrient Transformations, and (6) Impact of Interactions among Soil Mineral Colloids, Organic Matter and Biota on Risk Assessment and Restoration of Terrestrial Ecosystems. There were 2 plenary lectures, 9 invited speakers, 36 oral presentations and 45 posters. Dr. N. Senesi from University of Bari, Italy, presented an IUPAC lecture entitled Metal-Humic... 

Mehorta and coworkers (1989) observed that isolated fractions of brain and heart cells from rats orally administered 0.5-10 mg endrin/kg showed significant inhibition of Ca+2 pump activity and decreased levels of calmodulin, indicating disruption of membrane Ca+2 transport mechanisms exogenous addition of calmodulin restored Ca+2-ATPase activity. In vitro exposure of rat brain synaptosomes and heart sarcoplasmic reticuli decreased total and calmodulin-stimulated calcium ATPase activity with greater inhibition in brain preparations (Mehorta et al. 1989). However, endrin showed no inhibitory effects on the calmodulin-sensitive calcium ATPase activity when incubated with human erythrocyte membranes (Janik and Wolf 1992). In vitro exposure of rat brain synaptosomes to endrin had no effect on the activities of adenylate cyclase or 3, 5 -cyclic phosphodiesterase, two enzymes associated with synaptic cyclic AMP metabolism (Kodavanti et al. 1988). 

It was reported in 1980 that vanadate showed insulin activity (415) at about the same time it was demonstrated that vanadate is reduced to vanadium(IV) in vivo (416,417). Subsequently it was found that orally administered vanadate restored blood glucose levels and cardiac function to normal in rats (418). Vanadyl sulfate, less toxic than vanadate, also lowers blood sugar levels and ameliorates cardiac... 

Adrenalin is rapidly destroyed by the enzyme amino-oxadize and is therefore ineffective orally. It may be injected, snorted or possibly dissolved under the tongue. It is of considerable value to restore heart beat after sudden heart failure. This is due to its powerful stimulating effect. 

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