Dental Tribune U.S. Edition

Dental Tribune U.S. Edition | May 2013A4 CLINICAL Infection control M ore than 20 years ago, a dental patient named Kimberly Bergalis was diagnosed with AIDS. The source of her HIV infection was her dentist. Even though the exact path of transmission is still not known, this first proven transmission of HIV from dentist to patient — and the subse- quent intense coverage by the media — set off tremendous confusion and panic amongst dental patients. It was her unfortunate death in 1991 that changed the dental profession almost overnight, prompting all sorts of new regulations and guidelines, including the sterilization of dental instruments. The document Guidelines for Infec- tion Control in Dental Health-care Set- tings was published by the U.S. Centers for Disease Control and Prevention (CDC) on Dec. 19, 2003, providing some of the current and available scientific rationale for infection-control practi- ces, for which recommendations were made.1 These suggestions were followed closely by various governing dental health organizations, including the U.S. Occupational Safety and Health Administration (OSHA) and Health Canada. In dentistry, we see patients from dif- ferent walks of life every day and they bring all kinds of pathogens to our dental offices. It is our responsibility to arrest the path of these pathogens and attempt to prevent them from in- fecting others and spreading beyond our practices. Following the CDC rec- ommended infection-control guide- lines and procedures can help stop and prevent transmission of infectious organisms through blood, oral and res- piratory secretions and contaminated equipment during the course of dental treatment. Assessing risk One factor to consider in assessing the risk of contamination is the type of bodily substances to which dental health-care personnel (DHCP) are ex- posed. It is generally understood that human blood has a high infectious potential.2 In addition to bacteria and fungi, human saliva has been found to be capable of harbouring many kinds of infectious viruses.3,4 Without the benefits of a quick and reliable refer- ence, DHCP have to assume that every- one is a potential carrier. This is the fundamental reason that dental prac- tices should have a universal infection prevention protocol. Amongs many other related issues, the CDC guidelines explain the man- ner in which to wear surgical gloves properly and implement a glove proto- col. These recommendations will help properly prevent contamination from our patients’ oral tissues and fluids. Re- garding surgical masks, laser ablation of human tissue or dental restorations can cause thermal destruction and can create smoke byproducts containing dead and live cellular material (in- cluding blood fragments), viruses, and possible toxic gases and vapors. One concern is that aerosolized infectious material in the laser plume, such as the herpes simplex virus and human papil- lomavirus, may come into contact with the nasal mucosa of the laser operator and nearby DHCP. Although no evi- dence exists that HIV or the hepatitis B virus (HBV) has been transmitted via aerosolization and inhalation, there are scientific studies that confirm the risk of this possible route of contamin- ation.5,6 The risk to DHCP from expos- ure to laser plumes and smoke is real, and, along with other measures such as strong high-volume suction, the use of a high-filtration mask is strongly rec- ommended (Fig. 1). Sterilization is a multistep proced- ure that must be performed care- fully and correctly by the DHCP to help ensure that all instruments are uniformly sterilized and safe for pa- tient use. Cleaning, which is the first basic step in all decontamination and sterilization processes, involves the physical removal of debris and reduces the number of micro-organisms on an instrument or device. If visible debris or organic matter is not removed, it can interfere with the disinfection or sterilization process. Proper monitor- ing of sterilization procedures should include a combination of process indi- cators and biological indicators, and should be assessed at least once a week (Fig. 2). Patient-care items are generally div- ided into three groups, depending on their intended use and the potential risk of disease transmission. Critical items are those that penetrate soft tis- sue, touch bone or contact the blood- stream. They pose the highest risk of transmitting infection and should be heat sterilized between patient uses. Examples of critical items are surgical instruments, periodontal scalers, sur- gical dental burs, optical fibres (Fig. 3) and contact tips (Fig. 4). It is extremely important to examine, cleave, polish and sterilize optical fibres and contact tips after each use. Alternatively, ster- ile, single-use, disposable devices can be used. Semi-critical items are those that come into contact with only mucous membranes and do not penetrate soft tissues. As such, they have a lower risk of transmission. Examples of semi- critical instruments are dental mouth mirrors, amalgam condensers and im- pression trays. Most of the equipment in this category is heat tolerant, and should therefore be heat sterilized be- tween patient uses. For heat-sensitive instruments, high-level disinfection is appropriate. Non-critical items are instruments and devices that come into contact only with intact (unbroken) skin, which serves as an effective barrier to micro- organisms. These items carry such a low risk of transmitting infections that they usually only require cleaning and low-level disinfection. Examples of in- struments in this category include X- ray head/cones, blood pressure cuffs, low-level laser emission devices and laser safety glasses. For low-level laser therapy, the use of a transparent bar- rier similar to disposable sleeves for curing lights is acceptable. For safety glasses, the use of a low-level disinfect- ant is suitable if it has a label claim ap- proved by OSHA for removing HIV and HBV. The disposal of used instruments and excised biological tissues should be managed separately. A cleaved optical fibre, broken contact tips or dispos- able fibres should be disposed of prop- erly in a sharps container. Harvested biological waste should be placed in a container labelled with a biohazard symbol. In order to protect the individ- uals handling and transporting biopsy specimens, each specimen must be placed in a sturdy, leak-proof container with a secure lid to prevent leakage during transport. By following these guidelines, the spread of pathogens amongst dental patients, DHCP and their families can be prevented, and the passing of Kimberly Bergalis will not have been in vain. Disclosure and editor’s notes Dr. Yung has no commercial or finan- cial interest regarding this article. A list of references is available from the publisher. This article was first published in the Jour- nal of Laser Dentistry,2/18 (2010): 68–70. FRank Y. W. Yung, DDS, MSc, graduated with honors from the Faculty of Dentistry at the University of Toronto, Ontario, Canada, in 1980. In 2005 he was awarded the Educator Certifi- cate from the Acade- my at the University of California San Francisco. In 2007, he was the recipient of the Leon Goldman Award for Clinical Excellence. He is a fellow of the American Society for Laser in Medicine and Sur- gery, and a member of the Society for Oral Laser Applications and the American Dental Educa- tion Association. He can be contacted by email at drfrankyung@gmail.com. You can learn more about his work at www.drfrankyung.com. Fig. 2: An example of the submission of indicators to a testing service for assessment of office sterilization equipment’s effectiveness. Fig. 3: An example of sterilized optical fibres and handpieces. Fig. 4: An example of sterilized rigid glass tips and handpieces. Fig. 1: An example of a high-filtration protective mask, which is recommended for use with dental lasers. Photos/Dr. Frank Y. W. Yung Aerosolized infectious material in the laser plume is just one of many concerns By Frank Y. W. Yung, DDS, MSc