C.K. Claycomb

Evaluation of laboratory tests for the estimation of caries activity

Abstract Two groups of children having high and low caries rates were studied over 3 and 4 years, respectively; clinical examinations, usually supplemented with bite-wing radiographs, were conducted periodically and paraffin stimulated specimens of saliva were collected monthly during the school year. Correlations were made between the laboratory data obtained from salivary lactobacillus counts, Snyder tests, alpha amylase determinations, Rickles tests and acid buffering capacity with clinical changes observed in selected time intervals. The coefficients obtained indicated that reliable estimation or prediction of new caries experience on an individual basis for any one of the five tooth surfaces recorded was not possible for these children. Group significant values were frequently obtained for Snyder tests and lactobacillus counts.

The periodontium and periodontal pathology in the howler monkey

Abstract One hundred and six formalin fixed and sixty-five defleshed skulls of wild howler monkeys were surveyed grossly for evidence of periodontal disease. Sixteen wet specimens displayed clinically detectable pocket formation. Roentgenograms confirmed the presence of osseous lesions. Similar bone lesions were noted in the dried skulls. Two normal animals were studied microscopically. All areas of gross pathology, periodontal and periapical, were prepared and studied similarly. The periodontal lesions were quite similar to those seen in man, grossly, roentgenographically, and microscopically. No generalized periodontal disease, such as is commonly found in man, was noted. Two dehiscences and one hundred and fifty fenestrations were noted in the dried skulls. The existence of these osseous defects did not appear to be related to periodontal problems. The howler monkey would appear to have distinct advantages for future studies of periodontal disease.

Presence of Se75 in Rat Saliva after Intracardiac Injection of Radioactive Sodium Selenite

The present study was planned to determine whether or not the major salivary glands of the rat are permeable to selenium in the form of a buffered selenite administered directly into a heart chamber. Nineteen male Sprague-Dawley albino rats, weighing approximately 250 gm., were ether-anesthetized and given intracardiac injections of 0.1 ml. of sodium selenite, phosphate-buffered to pH 6.8. Including the carrier selenium, each animal in a group received 37.5 mg of Se which contained 28 microcuries of radioactivity. At intervals of 2, 3, 5, 9, and 24 hours after isotope injection, each animal was anesthetized with nembutal (3 mg/100 gm) and then given pilocarpine nitrate, 5.0 mg/kg, subcutaneously. Following the injection of the sialagogue, saliva was collected from the anesthetized rats in test tubes, using a plastic animal holder. At the conclusion of a 10-minute collection period, each

Effect of Dietary Selenium on Dental Caries in Sprague-Dawley Rats

The trace element selenium has been reported by D. M. Hadjimarkos, C. A. Storvick, and L. B. Remmert (J. Pediat., 40:3, 1951) and D. M. Hadjimarkos and C. W. Bonhorst (J. Pediat., 52:274, 1958) to be directly related to the prevalence of dental caries. In an experimental study (J. C. MUHLER and W. G. SHAFER. J. dent. Res., 36:895, 1957) selenium had no effect upon dental caries incidence; however, the selenium was incorporated into the diet in increasing amounts during the experimental period, and the control animals gained almost twice as much weight as the experimental group. The purpose of the present study was to determine whether a constant amount of dietary selenium would influence the incidence of dental caries without significantly altering the weight gain between groups. Sixty weanling littermate rats were divided into two equal groups and placed on the following high-