Universal precautions were introduced by the Centers for Disease Control in 1987. Their purpose was to allay the fears expressed by health care workers regarding the occupational acquisition of AIDS. An essential feature of universal precautions (UPs) was the wearing of gloves by dental personnel for all intra-oral procedures. Since the late 1980s gloves have become an entrenched feature of our profession’s clinical paraphernalia. Indeed, UPs catalyzed a dramatic alteration in dentists’ behavior since, prior to their introduction, gloves were seldom worn for surgical procedures and using them for restorative, prosthetic or orthodontic treatment was a rarity. Although concerns regarding AIDS might have justified this behavioral modification, what is surprising is the rapidity by which gloves were accepted by the profession without any confirmed proof or knowledge of their effectiveness or potential hazards.
Designing current studies to gain this understanding is difficult because some might consider it unethical to perform treatment without gloves therefore, eliminating the ability of having the necessary controls.
A retrospective analysis of the ability of gloves to prevent disease transmission before the use of UPs would eliminate the potential ethical dilemma. This article describes such a study.
METHOD
It is accepted that hepatitis B might be transferred from dentist to patient and from patient to dentist. In the late 1980s two
events occurred that, to a greater or lesser degree, might have influenced the potential for transmission. The first, and possibly the most significant, was the ready availability of effective hepatitis B vaccinations. The second was the introduction of UPs. Therefore, if the effectiveness of gloves in preventing hepatitis B transmissions is to be assessed it becomes necessary to analyze published cases of such transmissions in the pre-vaccination, pre-universal precautions era. Such an exercise might reveal instances where an infected dentist who did not wear gloves prior to a transmission but did following a transmission acted as a “self-control” or, where a trans mitting but ungloved dentist was compared to colleagues who did wear gloves.
A library search retrieved nine published instances of HBV transmissions by dental personnel that satisfied most of the above criteria. A cut-off date of 1987 was established since cases after that date could have been influenced by hepatitis B vaccinations and universal precautions.
FINDINGS
The nine articles are listed as references 1 through 9. Due to space restrictions, detailed descriptions of each case will not be included in this report but are available from the author.
The analysis of the cases revealed some significant findings on the transmissibility of hepatitis B and the usefulness of gloves to prevent such transmissions.
Dentists, procedures and hepatitis B transmission The authors of the various reports1-9 were in general agreement that:
• The transmission of HBV by infected dentists is infrequent and not considered as a major route by which the infection is spread;
• The presence of HBe antigen in an infected dentist correlates with the risk of that practitioner transmitting hepatitis B;
• Transmission, when it does occur, is by infected serum from cuts, abrasions or dermatitis on the dentists’ hands passing into open intra-oral wounds;
The risk of transmission appears to be related to the extent of the surgical invasion of the oral mucosa. In other words, “low risk” activities such as; examinations, impression taking, digital imaging, restorative care and orthodontic therapy are associated with infinitesimal, if any, risk of transmissions.
Two factors regarding the potential for HBV transmission during dental care are noteworthy. The first is the presence of a “high risk dentist.” This is a den- tist exhibiting the hepatitis B e antigen. The second is the presence of a hierarchy of clinical risks dependent on the nature and length of the procedure being performed. For example, it appeared that compared to single extractions, multiple “high risk” extractions involving more time, larger areas of mucosal disruption and more opportunities for lacerations or abrasions resulted in increased rates of HBV transmissions. In deed, the investigators were unable to associate transmissions with the ‘low risk” procedures identified above or with relatively invasive procedures such as starting an IV line or performing intubations. It is necessary to appreciate the significance of “high risk” dentist and “high risk” procedure. The terminology does not suggest that all “high risk” dentists will always transmit HBV irrespective of the procedures they perform, or that all “high risk” procedures will result in transmission whether or not the dentist is infected. It simply implies that if an outbreak of hepatitis B is traced to a dentist, that dentist is likely to be “high risk” and to have performed “high risk” procedures.
The influence of gloves
The analysis identified uniform agreement among the various investigators that gloves should be worn to prevent hepatitis B transmission. It is necessary to appreciate what evidence exists to support this recommendation.
In two cases, hepatitis B infected dentists continued to transmit the virus after wearing gloves. 3,4 These could be considered as “self controls.” Three studies showed that acutely infected dentists and oral surgeons who did not wear gloves did not spread HBV. 2,4,5 Indeed, a “high risk” oral surgeon who did not ear gloves failed to transmit the virus to 1,000 of his patients. 5 These could be considered as “controls” for colleagues who did wear gloves.
Two investigations demonstrated that dentists who were suspected of transmitting HBV while not wearing gloves did not transmit the infection after wearing
gloves. 5,6 However, in these examples, the absence of infectivity might be due to; decreasing levels of HBe-antigen and hence infectivity, the performance of less invasive procedures or the adoption of safer surgical techniques to avoid cuts and abrasions. Accordingly, a direct relationship could not be established between glove use and the absence of transmission.
A number of dentists ceased practicing after being implicated in the transmission of hepatitis B and could not be used as controls. 1,7-9
An interesting observation from the review is that patients acquired hepatitis B whether or not their dentists wore gloves but that the level of transmission did not exceed general background rates. This finding combined with the experiences of the above “controls” questions the role that gloves play in preventing HBV transmissions.
COMMENTS FROM THE CDC
The majority of studies in this review were authored or co-authored by CDC personnel. Therefore, it is interesting to speculate why such officials recommended the use of gloves when the above findings do not support that recommendation.
The CDC officials were of the opinion that gloves would prevent the seepage of blood from small cuts and abrasions occurring to the operators’ fingers especially during invasive procedures. However, it is difficult to imagine how
a thin layer of rubber or vinyl could remain intact while the integrity of the underlying skin was broken. Therefore, the physical preventive properties of gloves must be questioned. The fact that the CDC did not address this issue, did not indicate how gloves would prevent puncture wounds created by ligature wires during oral surgical and orthodontic procedures and did not define “small cuts” weakens the strength of their recommendation.
The analysis identifies statements by the CDC that suggest the organization had some suspicions as to the efficacy of gloves. In refe
rence 4, in response to concerns regarding transmission from infected health care workers in clud ing dentists, the CDC stated, “it is difficult to suggest that the use of gloves alone is the answer to the problem of medical personnel who are HBsAg carriers…” In reference 7, with regard to avoiding spread from high risk dentists performing high risk procedures, the CDC noted that, “the efficacy of gloves in preventing further transmission of hepatitis in similar situations is not well established.” In reference 5, the CDC made the frank admission that, “the use of gloves and masks may not completely interrupt HBV transmission.” In attempting to understand why there were so few transmissions from high risk dentists, the CDC concluded in reference 8 that, “failure to wear gloves is an unlikely explanation; only 24% of oral surgeons (and presumably fewer dentists) wear gloves routinely during patient contact.”
DISCUSSION
These quotations combined with the above findings and the experiences of the “controls’ give the impression that the CDC were unable to justify gloves on the basis of legitimately derived evidence, but rather because it appeared to be a reasonable behavioral modification to a perceived threat. Therefore, it must be concluded that the recommendation to use gloves was an opinion not supported by field observations or experiments. If this is an accurate
interpretation of the CDC’s approach to gloves in the mid-1980s, it detracts from the credibility of universal precautions announced in 1987. This is especially significant since these precautions have had a dramatic influence on the practice of dentistry.
Studies performed subsequent to the introduction of universal precautions have not provided acceptable evidence attesting to the effectiveness of gloves. Agreement on this deficiency comes from two sources. In 1998 Whitehouse et al, commenting on the use of gloves and similar devices reported that, “virtually no controlled tudies support the use of such control measures.” 10 In its 2003, Guidelines for Infection Control in Dental Health-Care Settings, the CDC emphasized the need for research to, “determine the effectiveness of gloves.” 11 In other words, 16 years after recommending that dentists should use gloves the CDC admitted that the effectiveness of gloves remained unknown.
CONCLUSION
It may be argued that the “controls” used in this analysis are less than ideal. However, they are the only clinically relevant ones that exist prior to hepatitis B vaccinations and universal precautions. As such, they fail to provide convincing endorsements on the need for or the effectiveness of gloves. In addition, the review identified that whether gloves are, or are not used, the transmission of HBV is dependent primarily
on a high risk dentist performing high risk procedures, and even then does not occur at a higher rate than general background levels of infection.
Since hepatitis B is the most potent of the bloodborne infections encountered in dentistry, the usefulness of gloves in preventing the spread of other bloodborne diseases remains in doubt.
The conclusion from this analysis is that the recommendation to use gloves was based on an intuitive opinion emanating from the CDC. In turn, it was accepted with minimal critical appraisal by most dental associations, academic institutions and regulatory agencies. Surely, the opinion of an informed clinician is as valid. Accordingly, the decision to wear gloves should be made by the practitioner and patient assuming that both are aware of the questionable usefulness of gloves and their known side effects. This approach should not be deemed as retrograde or as a failure to comply with official recommendations, but as the actions of a morally and ethically responsible dentist.
OH
Dr. Hardie was intimately involved in the development of the RCDSO 1996 evidence-based guide lines. Since then he has maintained an interest in this topic and how it and related diseases have influenced dental infection control recommendations.
Oral Health welcomes this original article.
REFERENCES
1. Levine ML, Maddrey WC, Wands JR, Mendeloff AI. Hepatitis B Transmission by Dentists. JAMA 1974; 228 (9): 1139-41.
2. Williams SV, Pattison CP, Berquist KR. Dental infection With Hepatitis B. JAMA 1975; 232 (12): 1232-33.
3. Goodwin D, Fannin SL, McCraken BB. An Oral Surgeon Related Hepatitis B Outbreak. California Morbidity, Infectious Disease Section, Department of Health. 1976; April 16, No 14.
4. Rimland D, Parkin WE, Miller GB, Schrack WD. Hepatitis B Outbreak Traced To An Oral Surgeon. NEJM 1977; 296 (17): 953-58.
5. Ahtone J, Goodman RA. Hepatitis B and dental personnel: transmission to patients and prevention issues. JADA 1983; 106; 219-222.
6. Hadler SC, Sorley DL, Acrce KH, Webster HM, Schable CA, Francis DP, Maynard JE. An Outbreak of Hepatitis B in a Dental Practice. Ann Int Med 1981; 95: 133-38.
7. Reingold AL, Kane MA, Murphy BL, Checko P, Francis DP, Maynard JE. Transmission of Hepatitis B by an Oral Surgeon. J Infect Dis; 145(2): 262-68.
8. Shaw FE, Barret CL, Hamm R, Peare RB, Coleman PJ, Hadler SC, Fields HA, Maynard JE. Lethal Outbreaks of Hepatitis B in a Dental Practice. JAMA 1986; 255(23): 3260-64.
9. Cournayer JJ, Brandenburg K, Schwartz E, Zumbrunnen C. Epidemiologic Notes and Reports: Outbreak of Hepatitis B Associated with an Oral Surgeon-New Hampshire. MMWR 1987; 36(9); 132-3.
10. Whitehouse JD, Sexton DJ, Kirkland KB, Infection Control: Past, Present and Future Issues. Comp Ther 1998; 24920: 71-77.
11. Guidelines for Infection Control in Dental Health Care Settings — 2003. MMWR 2003; 52(RRR17): 1-61.
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What is surprising is the rapidity by which gloves were accepted by the profession without any confirmed proof or knowledge of their effectiveness or potential hazards
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It is difficult to suggest that the use of gloves alone is the answer to the problem of medical personnel who are HBsAg carriers…
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The decision to wear gloves should be made
by the practitioner and patient assuming that both are aware of the questionable usefulness of gloves and their known side effects
