{'fraction_non_alphanumeric': 0.025837988826815643, 'fraction_numerical': 0.008379888268156424, 'mean_word_length': 4.575875486381323, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
A methodologic study of the effect of dental materials on growth and adhesion of animal cells in vitro.

– An in vitro method was used to investigate the ability of animal cells to (a) grow in the proximity of various dental materials, (b) adhere to and grow on the surface of the same materials during long-term contact. Disks (30 × 1 mm), made from the different materials, were placed in the center of plastic Petri dishes and incubated with human epithelial cells (NCTC 2544) and mouse fibroblasts (L 929). The growth around and on the surface of the disks was followed by measuring the amount of deoxyribonucleic acid (DNA) and/or cell number. The cultures were stained with crystal violet to visualize the distribution of the cells. In the presence of gold alloy, growth was similar to that obtained in control cultures, whereas the other materials tested showed various degrees of a toxic effect. With the two heat-cured acrylics tested, a transient toxic effect was observed on the surface of the disks. In the presence of silicate cement, various degrees of growth inhibition were observed, both on the surface of and around the disks. A toxic effect of silver amalgam was evident on the surface of and in the close proximity of the disks, whereas Addent 12® and copper amalgam appeared to have a general toxic effect. The present method might thus be of value in the evaluation of the tissue compatibility of biomaterials.