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“Differences in metabolism between different mercury species are well recognized. Conclusions that only a minor demethylation of methylmercury takes place in the brain are based primarily on results from short term studies. Results from a number of studies on humans exposed for many years to methylmercury have shown high concentrations of inorganic mercury in the brain in relation to total mercury. Similar evidence is available from studies on monkeys exposed for several years to methylmercury. The results indicate that a significant accumulation of inorganic mercury takes place with time despite the fact that the demethylation rate is slow. Differences in biological halftimes between different mercury species will explain the results. Some data do still need confirmation using different analytical methods. There is reason to believe that the one-compartment model for methyl mercury cannot be used without reservations. Inorganic mercury has a complicated metabolism. After exposure to metallic mercury vapor, inorganic mercury, probably bound to selenium, accumulates in the brain. A fraction of the mercury is excreted, with a long biological halftime. Studies on rats and monkeys indicate that inorganic mercury penetrates the blood-brain barrier only to a very limited extent.”

The importance of copper nutriture is obvious due to its requirement in enzyme systems. Often the adverse effects of copper toxicity are given more consideration than copper deficiency. However, copper balance is important particularly in relationship to other nutrients. Just as much consideration should be given to the possibility of copper deficiency as to copper toxicity.

“It is generally accepted that Selenium (Se) is necessary for optimum performance of the immune system. Selenium deficiency results in immune suppression but little is known concerning the effect of excess Se on immune function. Recent evidence suggests that oral Se supplementation may impede oncongenesis, but the mechanism of this action is currently unknown. Conversely, under certain conditions, Se is suspected of promoting neoplasia.”

“Fifty-four paired, approximal amalgam fillings, extended (E) versus unextended (NE) were placed in forty-three patients and followed up to 4 years. Yearly measurements between the alveolar crest and (a) the apical margin of the fillings (E, NE), and (b) the cemento-enamel junction of the control group, were performed using bite-wing radiographs joined to a translucent grid magnified ten-fold. The rate of alveolar crest resorption was similar for the control (C) and the unextended filling (NE) and reached 0.45 mm after 4 years of follow-up. The resorption of the alveolar crest under the extended (E) filling was significantly higher and reached 0.80 mm after 4 years (P less than 0.001).”

Analyses of whole and parotid saliva were performed in ten patients with subjective symptoms resembling galvanic pain and in their eight asymptomatic counterparts. Salivary flow rates, protein, IgA, lysozyme, sodium, potassium, chloride, calcium phosphate, copper, and magnesium contents were measured. The concentrations of protein, sodium, chloride, and phosphate in the whole saliva of the patients with symptoms were significantly higher, but concentrations of calcium, magnesium, and IgA were lower than in the asymptomatic controls. In parotid saliva, too, protein, lysozyme, and calcium concentrations were significantly altered in patients with oral symptoms. The analysis of free amino acids serine, proline, glutamic acid + glutamine, and glycine in the whole saliva did not show any significant differences between the two groups studied. The results suggest the importance of salivary contents in the development of oral soreness. Such changes in the salivary constituents could modulate the amount and character of the salivary macromolecules absorbed onto the teeth. This could lead to passivation or activation of the surfaces in metallic restorations and consequently to the onset of the intraoral electric currents.

This paper relates materials science, physiology, biochemistry, pharmacology, immunology, pathology and toxicology to the study of metabolism of degradation and corrosion products arising from tissue/material interactions. The mechanisms of absorption and distribution of released substances, either in solution or as particles, are considered together with their related chemistry. The importance of immune processes is discussed and their potential use for immunological analysis is illustrated by reference to nickel and mercury as used in the oral cavity.

One hundred thirty-one patients with primary trigeminal neuralgia and 77 patients with atypical facial neuralgia or pain were treated by oral surgical procedures, with complete or almost complete pain remission in 88% of the cases and without persistent residual anesthesias, dysesthesias, or dysalgesias. The following conditions were related to patients’ pain perceptions: cavities in alveolar bone at tooth extraction sites, bone fistulas, periodontal infections, and maxillary sinus infections draining into alveolar bone. The bone cavities and fistulas mentioned above were usually not visualized by standard x-ray diagnostic procedures, and their detection required a new diagnostic approach which is described. Microbiologic findings indicated involvement of a mixed, variable flora in the above conditions. Histopathologic observations of scrapings from involved bone showed a variable incidence of bone necrosis, predominantly chronic inflammatory cell populations and fibrous tissue.

The prevalence of “pathological granules” in the unexposed cementum of 20 teeth with pulpitis was compared with that of 20 teeth with heavily infected root canals. It was found that 35% of the teeth with microbe-laden root canals exhibited this cemental change. Teeth with pulpitis, but without massive numbers of bacteria in their root canals, did not have this structural change. The results support the suggestion that bacteria play an important role in the formation of pathological granules in cementum and the underlying dentin.

“The thrust of this chapter is to cover the more practical aspects of labeling with the 8-azidopurine analogs as well as to emphasize the many types of biological questions that can best be answered utilizing these probes. In general they can be used to determine the cellular or subcellular distribution of purine nucleotide binding proteins. They may be used to follow changes in these proteins during cellular developmental or transformational processes, and are useful in identifying the catalytic or regulatory subunits of specific protein complexes. Structural information about the purine binding sites of proteins can also be obtained via sequencing of photolabeled binding site peptides. All of these will be discussed more fully in the sections dealing with uses of the individual analogs.”