Search

Rotational coherence spectroscopy (RCS) implemented by time-resolved ionization depletion (TRID) was used to examine the structure of naphthalene trimer. Results provide evidence for a C3h structure in which three symmetrically equivalent naphthalene moieties are oriented with their long axes parallel. Results also show that the sensitivity of ionization detection coupled with the selectivity of mass analysis available through RCS-TRID permit high-resolution analysis not obtainable by other methods.

Contamination in dental unit waterlines (DUWLs) may be successfully controlled using standard maintenance procedures and or advanced filtration systems, particularly at the point of use. Water samples from four DUWLs with varying filtration systems were analyzed microscopically after two months of use. An older DUWL with no filtration system had significant plankton and bacterial growth while a similar newer unit had only traces of growth. One DUWL with filters throughout the system had no evidence of growth. Growth was reduced substantially in a DUWL with filters in the handpiece.

Dental procedures designed to prevent the spread of infectious diseases have come under great scrutiny since HIV was found to cause AIDS. Most attention has focused on barrier techniques, namely those that prevent contact with the bodily fluids of either the patient or the dentist by the other. Less focus has been placed on sterilization of dental instruments. This study examined the effectiveness of sterilization techniques in the dental office in adequately sterilizing dental instruments. A randomly chosen sample of 900 dentists in Minnesota were contacted and asked to participate in the study, of which 497 agreed to participate. Biological indicators (BI) were sent to the dentists to be used in their sterilizing equipment to test the effectiveness of this equipment. BIs are strips or ampules that contain spores of certain bacteria that are highly resistant to sterilization. If the sterilizing equipment can adequately destroy these spores, it is considered more than adequate in destroying other infectious agents on the instruments. Four BI strips were sent to each dentist for each sterilizer, 3 to be used in the sterilizer and 1 to serve as a control. Strips were again sent to dentists when either the control strip tested negative or one of the test strips tested positive. For the first series of strips sent, usable samples for evaluation were returned by 381 dentists involving 406 sterilizers. Only one of the control strips was adversely affected by the mailing procedure and tested negative for spores. Results from the first series showed that 18 percent of the sterilizers failed to adequately sterilize the strips. By sterilizer type, 43 percent of dry heat ovens failed, 16 percent of steam autoclaves and chemical vapor sterilizers failed, and no ethylene oxide sterilizers failed. After the third series of tests, only three sterilizers failed to sterilize the strips. The major cause of failure was operator error, with minor defects in the equipment causing the remaining failures. The results demonstrate that sterilization failures are too high and that such failures are easily preventable. Proper training of operators and frequent testing with BIs would greatly reduce the incidence of failures. (Consumer Summary produced by Reliance Medical Information, Inc.)