The effect of conditions of putrefaction on species determination in human and animal teeth.

Tooth fragments freshly extracted from humans and rats were stored at either 4 degrees C or room temperature in dry or humid conditions for periods ranging from 1 to 6 months. The fragments were reduced to powder and antigens were extracted. Comparison of these samples was carried out using Counter Current Electrophoresis. Extracted sera were tested against known specific antisera and resultant precipitin reactions stained for examination. Correct species identification was possible both from desiccated and humid fragments but there was species variation in the sensitivity of the method. All the extracts from human teeth were positive against human antisera. In the rat some test specimens were initially negative but became positive following further dilution of the extracts.

Antimicrobial properties of 2 aliphatic amines and chlorhexidine in vitro and in saliva.

The surfactants tetradecylamine, hexadecylamine and chlorhexidine have been compared with regard to their ability to inhibit microbial growth. Antibacterial activity was assessed by tube dilution methods. Tetradecylamine and chlorhexidine were similar in antibacterial activity, being effective at low concentrations against most organisms tested. Hexadecylamine also inhibited growth but at higher concentrations. Viable counts of salivary organisms were monitored in volunteers over 48 h after one rinse with the agents. The initial reduction in numbers of total viable salivary bacteria and streptococci by tetradecylamine and of streptococci by hexadecylamine had disappeared 3 h after a single mouth rinse, but the reduction in numbers of all salivary bacteria by chlorhexidine was more prolonged.