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Year : 2008  |  Volume : 20  |  Issue : 4  |  Page : 125-128 Table of Contents   

Biohazards in dentistry

Department of Oral Medicine and Radiology, V S Dental College and Hospital, Bangalore-560 004, Karnataka, India

Date of Web Publication18-Jun-2009

Correspondence Address:
R Bhanushree
Department of Oral Medicine and Radiology, V S Dental College and Hospital, Bangalore-560 004, Karnataka
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/0972-1363.52822

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Dentists constitute a group of professionals who are likely to be exposed to biological health hazards in the course of their work. Relying on relevant literature, the present paper discusses selected occupational biohazards as well as baseline precautionary measures. A dentist can become infected either directly or indirectly as they deal with the potential carriers of these biohazards. So it is important and mandatory for every practitioner of dentistry to know about biohazards.

Keywords: Airborne, biohazard, blood borne, engineering control, universal precaution

How to cite this article:
Manjunath M, Deepak T A, Krishna S, Bhanushree R. Biohazards in dentistry. J Indian Acad Oral Med Radiol 2008;20:125-8

How to cite this URL:
Manjunath M, Deepak T A, Krishna S, Bhanushree R. Biohazards in dentistry. J Indian Acad Oral Med Radiol [serial online] 2008 [cited 2022 Aug 19];20:125-8. Available from: https://www.jiaomr.in/text.asp?2008/20/4/125/52822

   Introduction Top

Dentistry is a profession dedicated to promoting and enhancing oral health leading to the overall wellbeing of an individual. While accomplishing this, dentists are likely to be exposed to various biological health hazards. A biological hazard or biohazard is an organism, or substance derived from an organism, that poses a threat to (primarily) human health. This can include medical waste, samples of a microorganism, prions, virus or toxin (from a biological source) that can impact human health [Figure 1].

Charles Baldwin, a retired environmental health engineer, in 1966 developed a symbol of biohazard. Labels must be fluorescent orange or orange-red with the biohazard symbol or biohazardous waste lettering in a contrasting color [Figure 2].

The United States' Centers for Disease Control and Prevention (CDC) categorize various diseases in levels of biohazards, Level 1 being minimum risk and Level 4 being extreme risk. [1]

[Table 1] shows a summary of levels of biohazards. [1] [Table 2],[Table 3],[Table 4],[Table 5] depict the different biohazards in a work place, their mode of transmission and effects on humans. [2]

Any of the body fluids or body fluid contaminated with blood or saliva from dental procedures or saliva laced with blood or skin and tissue cultures are potentially infectious materials in the dental setting [Flow charts 1 and 2]. The chain of reaction spreads from the source including patients, employees, environment, equipment, and visitors to the host based on the criteria of age, nutrition, disease, treatment, skin injury, immunity, life style and socioeconomic status through the transmission mode of airborne, direct or indirect contact [Flow chart 1- [Additional file 1] and Flow chart 2 - [Additional file 2] ]. [3],[4],[5]

Theoretically almost any infectious disease could be transmitted in the dental setting. From a practical standpoint there are a few that are of primary importance. These include blood borne - hepatitis B, hepatitis C, HIV, and airborne tuberculosis. [3],[4],[5],[6]

Hepatitis B virus which infects the liver can survive outside the body for seven days at room temperature and spreads more easily than HIV. Ninety percent of the people contracting this disease recover fully and develop immunity and up to 10% will become carriers. In a workplace it spreads through laceration or puncture wounds from sharps, any break in the skin or even splashing contaminated body fluids into the mucous membrane of the nose, eyes or mouth. Non-infectious, yeast based vaccine developed for HBV is proven to be 90% successful. [3],[4],[5],[6]

The robust Hepatitis C virus identified in 1989 is a common cause for chronic liver disease, cirrhosis and cancer. It can be detected only in 60% of infected cases in 5-8 weeks after exposure. Carcinoma of the liver remains undetected for many years in 80-90% of HCV infection. The prevalence rate of this infection is estimated to be 170 million globally. No vaccine is available for this infection. [3],[4],[5],[6]

Human Immunodeficiency Virus (HIV) which causes Acquired Deficiency Syndrome (AIDS) depletes the immune system. It cannot survive well outside the body. There is yet no vaccine available. It is estimated that by 2010, because of AIDS 25 million children will become orphans. [3],[4],[5],[6]

The acid fast, airborne mycobacterium tuberculosis, man being the reservoir? causes tuberculosis. Elective dental treatment should be deferred until medical evaluation is complete and the patient's status should be confirmed. Active TB patients cannot receive routine dental treatment until they are confirmed to be noninfectious. [3],[5]

Dental treatment for active TB patients must take place in a facility designed to provide appropriate engineering controls for airborne infection isolation; surgical masks do NOT provide protection against transmission of M. tuberculosis. Clinicians treating active TB patients must wear disposable N-95 respirators that are tested for proper fit. [3]

The transmissible spongiform encephalopathies (TSEs) caused by prion proteins, termed as  Creutzfeldt-Jakob disease More Details (CJD) in humans, have a long incubation period of 10-30 years. Some materials used in periodontal and oral surgery use materials derived from cattle (i.e., certain collagen membranes and sutures) and are supposed to be the transmission agents. No treatment exists. [2],[3]

In any fraternity deterrence of untoward effects is through preventive measures. The transmission of the vast majority of infectious diseases can be prevented or greatly reduced by following employee protective measures, including universal precautions, training of employees, workplace controls, engineering controls, personal protective equipment, administrative controls and vaccines where possible. Control of infection should be the responsibility of everyone including the dentist, hygienist, staff, assistant and even the patient. [5],[6],[9],[10],[11],[13],[14]

Since medical history and physical examination cannot reliably identify all patients infected with HIV or other blood borne pathogens, blood and body fluid precautions should be consistently observed for all patients; hence the term universal precautions. Universal precautions are intended to supplement rather than replace recommendations for routine infection control such as hand washing and use of gloves to prevent gross microbial contamination of hands. [3] Standard universal precautions include hand washing, gloves, eye and face protection, gowns, patient care equipment, environmental controls, linens, occupational health and blood borne pathogen exposure reduction. [3],[5],[6],[12]

Workplace controls aim to reduce or minimize an employee's exposure to blood and body fluids by covering all open or weeping skin lesions, forbidding eating, drinking, smoking or applying cosmetics in areas of potential exposure. Red bag waste must be immediately placed in a labeled container and stored in designated area. Maintenance of hand hygiene with the use of alcohol based soap, rubbing hand vigorously 10-15 seconds, and then washing under running water is effective in killing bacteria. [4],[6],[12]

Personal protective equipment should include gloves, gown, and protective eye and face shield, mask, boots, shoe covers and CPR shield. [3],[6],[12]

Engineering controls are the methods used to reduce employees' exposure by either removing the hazard or isolating the hazard including sharps, disposable containers, self sheathing needles, safer medical devices - needle less systems, or sharps with engineered injury protection. [4],[6],[12]

Disinfect all the surfaces of the dental care surfaces or equipment by removing all debris and organic matter by cleaning with disinfectant preferably approved by Dental Association and follow the manufacturer's directions. [5],[6],[12]

Biomedical wastes or non-anatomical wastes including blood soaked material and sharps, needles, or scalpels should be placed in separate yellow liner bags. Anatomical wastes including human tissues should be placed in red liner bags and should be handed over to certified professional waste disposal personnel. [7],[8]

All biohazard materials should be placed in biohazard labeled bag and in turn into a biohazard labeled box. Ensure that excess air is removed from the bag. Twist excess of bag from the top of the waste end of the bag. Tape the twisted end of the bag. Loop the twisted end of the bag over itself and tape again. Close and tape the flaps of the box in 'H' design. [3],[4],[5],[7],[8]

   Conclusion Top

A dental office generates a number of hazardous wastes that can be detrimental to the environment if not properly managed, as a result of which dental practitioners have been increasingly prone to be exposed to these biohazardous waste materials. So it is important for the dentist to know how to manage and prevent this exposure by securing basic knowledge of biohazards components.

This article is a brief review of levels of biohazards and baseline preventive measures as applicable to dentistry. It is an ethical responsibility to be aware and follow all the preventive measures against biohazards to help oneself, patients and the environment.

A proactive approach will allow our profession to succeed in an era of increased public environmental concern and environmentally proactive legislation. It is not only our legal obligation to provide dental services that benefit the public at minimal expense to the environment, but also our moral and ethical obligation.

   References Top

1.Available from:http://www.dallas-biohazardcleanup.com; December 9, 2007.   Back to cited text no. 1    
2.Occupational hazards of dentistry. Ann Agric Environ Med 1999;6:13-9.  Back to cited text no. 2    
3.University of Kentucky College of Dentistry Infection Control Manual V. 3.0 10/1/06.  Back to cited text no. 3    
4.Office of Occupational Safety and Health - 2006.  Back to cited text no. 4    
5.Infection Control Update 06. Nicholas J. Grimaudo, University of Florida College of Dentistry.  Back to cited text no. 5    
6.Community college of Philadelphia operating procedures for exposure to infectious agents-EXPCONTR/5/2/TG.  Back to cited text no. 6    
7.Available from: http://www.cda-adc.ca/jcda.February2007;73:1  Back to cited text no. 7    
8.Ontario guidelines.  Back to cited text no. 8    
9.Howard University College of dentistry policy manual 2006- 2007.  Back to cited text no. 9    
10.JCDA. Available from: http://www.cda-adc.ca/jcda.September 2007;73:7.  Back to cited text no. 10    
11.Dental hygiene manual 2007-2008.  Back to cited text no. 11    
12.Occupational exposure to blood borne pathogens; final rule. CFR part 1910:1030. September 23, 2002.  Back to cited text no. 12    
13.University Hospital Foundation Medical Research Competition Guidelines - 2007.  Back to cited text no. 13    
14.School of dentistry, 2007-2008, committee assignments and charges, September 27, 2007.  Back to cited text no. 14    


  [Figure 1], [Figure 2]

  [Table 1], [Table 2], [Table 3], [Table 4], [Table 5]

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