Search

A protease from the culture fluid of this microorganism was purified and characterized using DEAE-Sephadex and chromatofocusing and classified as a thiol protease with a mol. wt estimated as 27,500. It abolished the inhibitory activity of parotid saliva on the precipitation of calcium phosphate from supersaturated solutions. Such proteases may contribute to dental calculus formation.

Gingival conditions of 1323 junior high schoolchildren aged 12-15 were examined, and 132 children who had either healthy gingivae or severe gingivitis were called to the clinic. More precise examination of gingivitis was performed by assessment of Jackson's gingivitis index (G.I.), probing depth (P.D.), and bleeding on probing. Whole saliva was collected, and the salivary concentrations of estradiol, progesterone, and testosterone were determined by radioimmunoassay. Subgingival bacterial plaque was sampled from 36 children, and total bacterial counts and morphological differentiation were performed under a phase-contrast microscope. For statistical analysis, both males and females were divided into two groups according to the concentration of each sex hormone and subgrouped by the results of clinical examinations. Chi-square analysis using 2-by-2 tables was performed to determine the relation between salivary steroid hormone levels and gingival inflammation. The results suggest that unbalanced secretion of certain hormones might be one of the factors promoting gingivitis at puberty.