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The effect of autogenous marrow and calcitonin on reactions to a tricalcium phosphate ceramic was studied by subcutaneous implantation in rats. No bone formation was evident in association with uncoated and calcitonin-coated ceramic. At four weeks and thereafter bone formation was evident in association with all marrow-coated implants.

The pulps of permanent teeth of monkeys were surgically exposed and left open to the oral environment. One half the pulps were treated with an antibiotic preparation and one half with a starch control. The pulps were evaluated microscopically at the end of 30 and 90 days. The results for the antibiotic-treated teeth were more favorable than were those for the starch-control teeth.

Bacteria were found in histologic sections and cultures of unexposed pulp in 48 of 67 teeth from dogs. Deep Class V cavities had been prepared in these teeth. The dogs had been intravenously inoculated with bacteria of the same immunologic types as those identified in pulps.

A survey of the dental literature revealed various methods of treating carious exposures of dental pulps and maintaining them in a healthy condition. Many of these studies were empirical, and little histologic evidence was presented in evaluating the results.1-14 In recent years, two clinical techniques have been recommended for the management of carious pulp exposures in primary teeth of children. After coronal pulpotomy, one technique makes use of a formalin-containing compound which apparently devitalizes the pulp and produces a degree of pulp fixation,15-17 whereas the other technique involves the use of a calcium hydroxide pulp dressing which reportedly maintains the vitality of the remaining pulp.18 Presently, there is insufficient evidence from clinical and laboratory research to justify recommending one technique over the other. The major objective of this study was to attempt to duplicate, in monkeys, these two clinical procedures on primary and young permanent teeth and to note the differences, if any, in the reactions of the pulp and periapical tissues of these teeth to formocresol and calcium hydroxide therapy after varying time intervals. The pulp responses to the dressing materials were determined microscopically, using serial sections through the pulps of extracted teeth, as well as through quadrants of jaws sectioned en bloc.

Cavities were prepared in deciduous and permanent teeth of monkeys. Some were left open; some were restored with zinc oxide and eugenol; some were restored with croton oil, for 90 days. The amount of tertiary dentin was similar irrespective of the treatment.

The effect of levamisole on DMBA-induced carcinogenesis in the cheek pouch of the hamster was studied. Findings indicate that levamisole modified the response of the pouch to DMBA at six weeks, while this effect was not maintained after 12 weeks of DMBA application.

BOTH the origin and function of phosphatase in saliva are still in question. Several sources for this enzyme, including desquamated epithelial cells,' gingival tissue,2' and microorganisms of the saliva,-5 have been postulated, the latter being the most probable. Adamson' and Smith2 were among the first to propose that phosphatase, which is capable of liberating inorganic phosphate from organic phosphate may play a role in the formation of calculus. Glock, Murray, and Pincus4 and Ennever and Warner9 found that the organisms most commonly associated with calculus, namely, Actinomyces, show marked phosphatase activity. Tenenbaum and Karshan,0 showed that, in general, people with calculus have higher Ca and P levels in the saliva, and hence they hold tenable the theory that phosphatase plays a role in calculus formation. Saltzmann," on the other hand, using a limited number of patients (fourteen), found that the degree of phosphatase in saliva was not related to the presence and quantity of calculus in the mouth. The relation of phosphatase to caries activity has also been studied. Lactobacilli, generally associated with the caries process, have been found to possess some phosphatase activity, although of a very low order.7' 8, 12 Rae'3 reported no apparent relationship between the phosphatase content of saliva and the susceptibility to caries in thirty-nine boys; however, Fitzgerald,8 in an initial trial with thirty cases, claimed to have obtained generally parallel results between acid phosphatase activity and lactobacillus counts, and he suggested further study of acid phosphatase activity of saliva as an additional laboratory test for caries activity. The purpose of this investigation was to study simultaneously the relationship of phosphatase levels to the presence of calculus and Lactobacillus counts in the same individuals.

SYNOPSIS IN INTERLINGUA UN METHODO A COLORANTES FLUORESCENTE PRO LE DEMONSTRATION DE ESCAPPAMENTO CIRCUM RESTAURATIONES DENTAL.—Le colorantes fluorescente rhodamina B, fluoresceina, e demethylchlortetracyclina esseva usate pro demonstrar microescappamento circum restaurationes dental in dentes bovin. Esseva usate un nove technica de sectionage e breve periodos de immersion, e le colorantes-con un exception-demonstrava satisfactorimente microescappamento sub lumine ultraviolette. Le colorantes non demonstrava microescappamento de restaurationes con eugenol a oxydo de zinc in consequentia del extinction del fluorescentia. Le margines del plumbage a amalgama de 24 horas, applicate sin revestimento del cavitate, monstrava marcate escappamento. Vernissage del cavitate reduceva le escappamento marginal marcatemente. Omne le restaurationes a guttapercha monstrava grossier escappamento.

Subdermal implants of calcium hydroxide, magnesium hydroxide, plaster of Paris, and a control material were made in rats. A tetracycline and a chloro-s-triazine dye were given at various intervals to some rats. Histochemical and fluorescence studies showed an amorphous, lamellar, noncellular, mineralized tissue in the capsules surrounding the inorganic implants.

Surgically exposed, infected permanent teeth of monkeys were capped with four agents. Microscopic study after 30 and 90 days revealed considerable success in teeth treated with a mixture of vancomycin and calcium hydroxide, or with calcium hydroxide and methyl cellulose.

SYNOPSIS IN INTERLINGUA LE EFFECTO DE TETRACYCLINAS SUPER DENTES E OSSOS.—Esseva ideate quatro experimentos con rattos visante a studiar le effectos macroscopic e histologic del 4 homologos tetracyclinic, i.e., chlortetracyclina (CTC), demethylchlortetracyclina (DCTC), tetracyclina (TC), e oxytetracyclina (OTC). Adulte rattos mascule del linea Wistar esseva tractate durante 21 dies con le tetracyclinas per via oral al recommendate doses therapeutic adjustate al peso del animales. Juvene adulte rattos feminin recipeva le varie tetracyclinas durante le curso de un pregnantia. Rattos feminin in stato lactifere recipeva le homologos durante 21 dies post le parturition. Rattos de etates dislactatori recipeva 39 diurne doses therapeutic del tetracyclinas a partir del vinti-prime die de lor vitas.