Advancements in Instrument Sterilization - Barnstead - #1

Advances in instrument sterilization

Already popular overseas, Tabletop Class B sterilizers offer enhancements that are making them an increasingly important part of the infection control arsenal in the United States.

By Drs. Jennifer A. Harte, MS and David G. Charlton, MSD

Dr. Jennifer Harte, MS is the Chief Military Consultant for Dental Infection Control to the Air Force Surgeon General, US Air Force Dental Evaluation and Consultation Service, Great Lakes, Ill.

he Centers for Disease Control and Pre­vention's (CDC's) publication Guide­lines for Infection Control in Dental Health-Care Settings—2003 recommends heat-sterilizing critical and semicritical instruments before each use using medical sterilization equipment cleared by the Food and Drug Ad­ministration (FDA) (see Table "CDC's general recommendations," page 4).¹

In dental practices, heat-tolerant instruments usually are sterilized by the following meth­ods: steam under pressure (autoclaving), dry heat, or unsaturated chemical vapor. Each of these methods offers advantages and disad­vantages (see Table "Heat Sterilization," page 3).^2,3,4 Although the 2003 CDC guidelines are much more extensive than those of previous publications—especially in respect to instru­ment processing—regulatory and legal issues prevent the CDC from commenting on the val­ue or efficacy of specific products. Therefore, dental professionals must decide for them­selves what sterilization method and equip­ment best meet their needs. Although steam, dry heat, and unsaturated chemical vapor ster­ilizers all do have disadvantages, steam steril­izers (i.e., autoclaves) are very popular in den­tal offices.² In fact, steam sterilization has been

available for more than a century, and is the most widely used sterilization method for items that are not sensitive to heat and moisture.^1,2 In large part, the autoclave's popularity is based on the fact that when it is used appropriately, it is very efficient, as well as reliable and eco­nomical. This article reviews basic concepts of steam sterilization and focuses on recent ad­vances in tabletop steam sterilizers.

Steam sterilizers are available in a range of sizes, from smaller tabletop models to large floor-standing units. The two basic types of steam sterilizers are the gravity displacement and the prevacuum sterilizers. Until recently, grav­ity displacement sterilizers have constituted the majority of sterilizers used in dentistry. To bet­ter understand the advantages that prevacuum sterilizers offer compared to gravity displace­ment models, one must first have a basic under­standing of the principles of steam sterilization and how prevacuum and gravity displacement sterilizers operate. Prevacuum sterilizers with large chamber sizes have been available for many years in hospitals, dental schools, and large clinics, but it has been only recently that smaller tabletop versions have been developed

Dr. David Charlton, MSD is a Senior Scientist, Applied Clinical Sciences Department, Naval Institute for Dental and Biomedical Research, Great Lakes, Ill.