Instrumented root canals of extracted human teeth were inoculated with known pulpal bacterial isolates. The inoculated teeth were immersed in the appropriate culture media and incubated at 37 degrees C for varying periods. Streptococci multiplied in the root canals and invaded the radicular dentinal tubules. The extent of bacterial invasion was time-dependent. This experimental model of bacterial invasion was time-dependent. This experimental model may be useful in investigating the effect of intra-canal medicaments on microorganisms lodged in the pulpal dentin wall.

Frequent eating of small amounts of sucrose for a period of three days resulted in the in vivo accumulation in plaque of about 1% dextran and about 3% levan.

No abstract

Aerosols generated by the air turbine handpiece contain oral microorganisms that are a potential health hazard to the dentist. The effectiveness of different face masks in preventing cross contamination varied greatly but in all instances was significant.