OBJECTIVEIt has been demonstrated that when a high-speed handpiece stops rotating, negative pressure will form. Thus, contaminating fluid in which there are many kinds of bacteria and viruses from the external environment will retract into various compartments of the handpiece and the dental unit. The purpose of the study is to compare the preventing effect of antisuction designed handpiece and conventional handpiece on viral contamination at different rotating times.

METHODSTwenty handpieces with or without antisuction device (10 of each) were used in the study. Each handpiece was submerged into 10(-6) microg/microl HBV particle solution rotating 5 and 10 times respectively (every time rotating for 10 seconds). Samples were obtained from the water line and chip air line of the handpieces and examined by RT-PCR.

RESULTSAt the same rotating times, there was statistical significance of the viral concentration between the two kinds of handpieces (P < 0.05) . However, there was no statistical significance of the viral concentration between different rotating times in each group (P > 0.05).

CONCLUSIONContamination taking place in both water and air lines of dental handpiece was not enhanced by increasing the number of rotating times of the handpiece. The antisuction devices installed into the water line and chip air line were demonstrated to prevent viral contamination effectively.

Dental High-Speed Equipment ; virology ; Equipment Contamination ; prevention & control ; Suction

This paper selects the bag-type infusion sets for single use as samples, which are produced by different manufacturers and based on the ethylene oxide sterilization. The ethylene oxide sterilization residues in different parts of samples are detected by colorimetric analysis. Combined the comparison of the ethylene oxide residues testing results in the different parts of the same sample with the actual situation in clinical use, more reasonable sampling positions are found to detect the ethylene oxide sterilization residues. The result of this experiment will play a guiding role in the detection of the actual samples.
Disposable Equipment ; Equipment Contamination ; prevention & control ; Ethylene Oxide ; analysis

OBJECTIVETo investigate the effects on performances of high-speed dental handpieces subjected to autoclaving.

METHODSThe method of trial used to evaluate the effect of autoclaving included that ten chemical and ten biological indicators were arranged in each trial group being set by one sort of temperature and sterilization time. The range of temperature was from 100 degrees C to 134 degrees C and the sterilization time was from 1 to 45 minutes. The reliability of autoclaving was evaluated by the result of chemical indicator and the endospores of Bacillus stearothermophilus subjected to autoclaving. Ten newly imported and ten new domestic dental handpieces in two different brands were used to carry out this trial. The effects produced by autoclaving on performances of dental handpieces subjected to different type autoclaves were evaluated by some parameters.

RESULTSThe eligible outcome in killing test of the 221 sterilized dental handpieces proved that the sterilization effect of autoclaving on dental handpieces was reliable. The chemical indicators showed that under the condition of 121 degrees C it needed 20 minutes to reach sterilization standard in the inner package and only 15 minutes on the outer package, and under the condition of 134 degrees C it took 4 minutes to reach sterilization standard in the inner package while only 2 minutes on the outer package. This outcome proved that material with package was more time-consuming than that without package during autoclaving. Autoclaving has positive effects on the performance of dental handpieces, while the autoclave with less-time full sterilization cycle has less effect on it. The performance of dental handpieces sterilized by the autoclave with 6-minute full sterilization cycle might be restorable within certain times of sterilization cycle.

CONCLUSIONThe sterilization effect of autoclaving is reliable. In order to reduce the influence on the performance of dental handpieces subjected to autoclaving, it should be reasonable to use the autoclave by which a full sterilization cycle might take less time and no use of package.

Dental High-Speed Equipment ; Equipment Contamination ; prevention & control ; Sterilization ; methods

OBJECTIVEAnalyzing the performance of microbial barrier of needleless positive pressure closed connectors.

METHODSThree kinds of brand needleless positive pressure closed connectors were chosen to do the access of microorganisms test.

RESULTSPositive results were detected in the three experimental groups.

CONCLUSIONSSo far, lots of the connectors are not qualified strictly on the market, some improvement is required in the structure design and process.

Equipment Contamination ; prevention & control ; Infusions, Parenteral ; instrumentation ; methods

Introduced the "particles" item testing progress and some notes, using Coulter Multisizer, about medical devices and drugs wrapper, with an expectation of some help for the "particles" item tests in the solution in these area.
Equipment Contamination ; prevention & control ; Equipment and Supplies ; Materials Testing ; instrumentation ; methods ; Particle Size ; Quality Control

The initial contamination of femoral head, femoral stem and femoral component producted by seven factories in Beijing is tested, all of the initial contamination values are 580 in total. Then these data is analyzed on statistics. The result indicates that the initial contamination values of three kinds of products according with normal distribution; The initial contamination values have not significant difference between femoral head and femoral component of the same factory; and the season has not significant effect on initial contamination in Beijing. According to the experimental data, the level of initial contamination is undulatory, so the factories should control the initial contamination and maintain the stability of initial contamination.
Equipment Contamination ; prevention & control ; Prostheses and Implants ; classification ; microbiology ; Surgical Equipment ; classification ; microbiology

Cross Infection ; prevention & control ; Dental Instruments ; microbiology ; Equipment Contamination ; prevention & control ; Humans ; Sterilization

OBJECTIVE: To explore the effect of Radii barrier sleeves on the cure depth of composite resin. METHODS: Cylinder mold was prepared, and the resin was filled strictly into the mold. The surface was flattened and then cured with plastic engraver's knife.The depth of composite resin which was cured by QHL75TM with or without Radii barrier sleeves was compared. RESULTS: The cure depth of composite resin which were cured by QHL75TM with or without Radii barrier sleeves of photo-curing machine was 4.38 mm and 4.27 mm respectively,with no statistical difference. CONCLUSION The cure depth of composite resin is not influenced by Radii barrier sleeves under the same light condition.
Composite Resins ; chemistry ; Cross Infection ; prevention & control ; Curing Lights, Dental ; Dental Equipment ; Disposable Equipment ; Equipment Contamination ; prevention & control ; Humans ; Light-Curing of Dental Adhesives ; instrumentation ; methods ; Technology, Dental ; instrumentation

To analyze the relevant documents of hospital infection administration of acupuncture manipulation with filiform needles and acupuncture aseptic technique with filiform needles. The current situation is that acupuncturists have understanding insufficiency in hospital infection management, lack the sterile concepts and consciousness of disinfection and isolation. Aseptic technic principles aren't strictly followed; disinfection and isolation systems are unsound; sanitary condition of hand of medical staff is unsatisfied; and there is shortness in traditional long filiform needle manipulation. In future, we should explore the new model of hospital infection administration of acupuncture manipulation with filiform needles from implementations of relevant rules of hospital infection administration, establishment and supervision of sound corresponding system, further research of manipulation of filiform needles and formulation of septic technic criterion of filiform needles.
Acupuncture Therapy ; instrumentation ; standards ; Cross Infection ; prevention & control ; Disinfection ; standards ; Equipment Contamination ; prevention & control ; Hospital Administration ; Humans ; Hygiene ; standards ; Needles

OBJECTIVETo understand current status of the uses of dental handpieces, methods of disinfection and sterilization and their effectiveness in dental-care hospitals and out-patient departments of stomatology in general hospitals.

METHODSTen dental-care hospitals and departments of stomatology in general hospitals at varied levels were randomly sampled during 2000 to 2001 to investigate the uses of dental handpieces and means of their disinfection and sterilization. One used dental handpiece from each hospital or department of stomatology in general hospital selected was detected for possible contamination of bacteria by aerobic bacterial count and Coliform bacterial examinations and hepatitis B surface antigen (HBsAg) on it, based on "The Technical Standards for Disinfection" set by the Ministry of Health of China, and the effectiveness of its disinfection and sterilization was evaluated as well.

RESULTSAnti-suction handpieces were used only in 5.9% of the hospitals or departments, 94.1% of them without anti-suction devices. Cleansing disinfection was applied for used dental handpieces in 62.9% of the dental-care hospitals and the departments of stomatology, with an effective rate of 26.17%, immersing disinfection in 10.0%, with an effective rate of 55.88%, and autoclave in 27.1%, with an effective rate of 80.43%. Used dental handpieces in the hospitals and departments of stomatology in general hospitals were all contaminated by bacteria and HBsAg could be detected in 1.67% of them.

CONCLUSIONSDental handpieces without anti-suction should be replaced soon by those with it or comprehensive dental unit with anti-suction device should be used. Used dental handpieces must be sterilized effectively before next use. Awareness on prevention from cross-infection should be improved for dental-care professional staff and operation of sterilization should be standardized.

Cross Infection ; prevention & control ; Dental Instruments ; microbiology ; Equipment Contamination ; prevention & control ; Hepatitis B Surface Antigens ; analysis ; Humans ; Sterilization ; methods