February 2013, Volume 34, Issue 2
Published by AEGIS Communications
Compendium has compiled Abstracts from key recently published articles in the dental literature on infection control. These PubMed-indexed articles offer clinical relevance to the dental practitioner and can be applied to a range of situations.
Assessment of microbial contamination of radiographic equipment and materials during intraoral imaging procedures
This study assessed microbial contamination of radiology procedures. Patients who needed radiographic exams were selected, and the bisecting technique was used: G1 - (control): absence of plastic barrier and overgloving or disinfectant solutions; G2 - alcohol spraying; G3 - protection of the film with a plastic barrier and alcohol spray; G4 - protection of film with plastic barrier, use of overgloving and alcohol spray. Regions assessed were: trigger switch, X-ray tube, sleeve of the portable dark chamber, water, developer, and fixer. The areas for microbiological sample collection were standardized with a label cut internally so that the hollow area was 5-cm long and 2-cm wide. One mL of the developer, water, and fixer were also collected before and after developing the films. The samples were incubated under anaerobiosis and aerobiosis. Results were submitted to the Cochran’s Q and Mann-Whitney tests. The sleeve of the developing chamber showed greater anaerobic contamination followed by the X-ray tube, and only the use of alcohol associated with mechanical barriers was efficient to control this microbiota. The trigger showed higher aerobic microbial contamination, and the use of alcohol or alcohol associated with mechanical barriers was efficient to control this microbiota. The developing solutions presented no significant growth of anaerobic and aerobic bacteria.
The efficacy of foam cleaners in removing debris from two endodontic instruments
This study compared the efficacy of a file cleaner and a nanostructured foam in removing debris from two rotary nickel-titanium instruments during and after instrumentation. Twenty mandibular premolars were decoronated and instrumented up to either no. 40.04 RaCe (no. 40.04) or K3 (no. 40.04) instruments (n = 10). Each group of files was randomly divided into two groups: file cleaner and nano foam cleaner. The instruments were examined under a scanning electron microscope (SEM) before and after placement into the canals. Subsequently, instruments were introduced into each cleaner and examined again under SEM. The amount of debris removal from the instruments was determined by a software program; data were subjected to Kruskal-Wallis and Mann-Whitney tests at a .05 level of significance. The amount of debris removal was significantly different between the groups (P = .002) and was significantly higher in K3 with the nano foam cleaner than with the file cleaner (P = .009). CONCLUSION: Nanostructured foam can remove debris from endodontic files, especially from those with complex cross-section. This method is recommended to help optimize debris removal with the further possibility of instrument sterilization and reduced risk of cross-contamination.
Controlling bacterial contamination of dental impression guns
Dental impression material handgun cartridge dispensers are contaminated easily during clinical use. The authors attempted to quantify contamination by bacteria, including methicillin-resistant Staphylococcus aureus (MRSA), of impression guns used in an academic dental clinic after five infection-prevention protocols were followed. The authors obtained samples from four commercially available impression guns at four specific sites (button, handle, latch, trigger) after routine clinical use, disinfection, steam sterilization (also known as autoclaving), steam sterilization followed by use of plastic impression gun covers, and steam sterilization followed by use of plastic impression gun covers and disinfection. The authors found that after routine clinical use, bacteria—including MRSA—heavily contaminated the impression guns. After the impression guns underwent disinfection, there was a 6% decrease in bacterial counts. The use of steam sterilization achieved sterility without harming the impression guns. Use of steam-sterilized impression guns with plastic impression gun covers decreased bacterial isolates by approximately 60%. Use of steam-sterilized impression guns plus covers and disinfection resulted in an approximately 95% reduction in contamination.