Rings and watches: should they be removed prior to operative dental procedures?

0300-5712(95)00038-O

Journal of Dentistry Vol. 24,Nos 1-2, pp. 65-69,1996 Copyright0 1996ElsevierScienceLtd. All rights reserved Printed in Great Britain. 0300-5712/96$15.00+ 0.00

.ELSEVIER

Rings and watches: should they be removed prior to operative dental procedures? E. A. Field, P. McGowan, P. K. Pearce and M. V. Martin Department

of Clinical Dental Sciences,

The University of Liverpool, School of Dentistry, Liverpool, UK

ABSTRACT Objectives: There is no clear evidence to support the recommendation that rings and watches should be

removed prior to operative dental procedures. The aim of this study was to measure and identify the bacteria isolated from the skin under rings and watches worn by a group of dental surgeons and to compare the results with a group of non-clinical staff. Methods: Forty volunteers participated in the study; of these 20 were dental surgeons and 20 were non-clinical staff. Four skin sites were sampled for each volunteer; the skin directly under the ring and on the same finger of the other hand and the skin under the watch face and wrist of the control hand. Bacteria on the swabswere dispersed and inoculated onto plates, which were incubated aerobically for 24 h at 31” C. Resdts: In both groups of volunteers there was a significantly greater number of bacteria isolated from under rings and watches compared with control sites. Few qualitative differences were found between the microflora found on the skin under rings and watches in the two volunteer groups. Conclusions: The bacterial flora isolated from volunteers do not commonly cause oral infections but could pose a threat to the immunocompromised patient, particularly in the event of gloves becoming torn or perforated. Effective hand disinfection is difficult to achieve if rings and watches are not removed; they should therefore be removed prior to hand disinfection and donning of gloves. KEY WORDS: Watches, Operative J. Dent. 1996; 24: 65-69

(Received

procedures,

Dentistry

14 June 1993; reviewed 29 July 1993; accepted 1 July 1994)

INTRODUCTION Removal of rings and watches is obligatory prior to surgical hand disinfection and donning sterile gloves in an operating theatre suite. There has, however, been some resistance to the removal of rings (particularly wedding rings) and watches prior to hand disinfection and glove wearing in dental practice. Handwashing regimens in some dental hospitals’ have recommended that jewellery is removed prior to handwashing. There is little scientific evidence to support the contention that there is an increased risk of cross-infection from microflora on the skin under rings and watches worn by dental practitioners. The aim of this study was to measure and identify the bacteria isolated from the skin under rings and watches worn by a group of dental surgeons and to compare the results with a group of non-clinical dental staff.

Correspondence should be addressed to: Mrs E. A. Field, Clinical Dental Sciences, The University of Liverpool, School of Dentistry, Liverpool L69 3BX, UK.

MATERIALS

AND METHODS

Subjects and sampling Forty volunteers from Liverpool Dental Hospital took part in this study. One group consisted of 20 qualified dental surgeons and the other group included 20 nonclinical staff-mainly receptionists, secretaries and research technicians. Each group had an equal number of males and females. Dentists who routinely undertook oral surgical procedures, necessitating surgical hand disinfection, were excluded from the study. All participants wore their rings continuously and these were all wedding or ‘signet-type rings’ (i.e. not rings with mounted stones). Wrist watches were worn continuously by all the volunteers throughout the day but most were removed at night. Sampling of skin sites and rings was carried out at the same time each morning and before the dentists had started clinical duties. Microbiological swabs (Medical Wire Co., Corsham, Wiltshire, UK) moistened

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1996;24:

Nosl-2

in sterile saline were used. Four skin sites were sampled from each volunteer; the skin directly under the ring and on the same finger of the other hand; the skin under the watch face and a similar site on the wrist of the other hand. The inner (fitting surface) of each ring was also swabbed. A standard sampling technique was used and each site swabbed once only. The investigator wore a new pair of latex gloves when sampling each volunteer to avoid cross contamination. All participants were allocated a test number to maintain anonymity. The microbiological swabs were transported immediately to the laboratory.

Microbiology Bacteria on the swabs were dispersed into 1 ml of sterile water by vortexing for 4.5 s. The bacteria were then inoculated onto 5% (v/v) horse blood agar in Columbia agar base (Oxoid, London, UK), using Cruickshank’s modification of the method of Miles and Misra2. The inoculated plates were incubated for 24 h at 37” C aerobically; no attempt was made to grow anaerobes. The resultant colonies were counted and indentified using the API systems (API, BioMerieux, Basingstoke, UK).

Data handling and statistics The number of colony forming units (CFU) on each swab from both sites for individual volunteers was calculated, together with a mean value for each group. The different types of bacteria isolated from test sites Table 7. Number of bacteria, expressed the ‘dentist’ and ‘non-dentist’ group

in both the dentist and non-dentist groups were also noted. The number of CFU from the control and test sites in both the dentist and non-dentist groups were compared statistically using the Wilcoxon signed rank test 3 and the Wilcoxon and rank sum test 3.

RESULTS Ring study Table I shows the number of CFU for each swab isolated from the ring fingers and control fingers of volunteers in both experimental groups. There was a wide variation in the number of CFU recovered from the fitting surface of the rings and these values were not analysed (results not shown). Comparison of the number of bacteria from the skin of the ring fingers and control fingers reveals that there was a greater bacterial count obtained from the ring fingers in both the dentist and non-dentist groups and these differences were significant (dentists, P = 0.01 and nondentists P = 0.003). Greater numbers of CFU were obtained from the non-dentists’ ring finger than the dentists’ ring finger and the difference was statistically significant (P = 0.02). There were also significantly greater numbers of bacteria obtained from the nondentists’ control finger than the dentists’ control finger (P = 0.02). Table II shows the different types of bacteria isolated

from the skin of test and control fingers in both groups

as the number of CFU, isolated from finger sites in

Volunteer no.

Ring finger

Control finger

Non-dentist group Control Ring finger finger

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

720 292 2 17 29 4 120 4 85 610 53 3 127 556 101 209 149 2 550 610

610 14 80 30 6 6 53 36 15 20 28 3 45 680 4 44 15 0 0 45

590 620 594 524 1 510 574 660 680 740 720 616 7 540 104 538 166 12 15 560

710 51 36 5 49 28 300 14 684 45 111 82 198 53 204 524 2 15 6 60

Mean

212

438.6

158.8

Dentist group

86.7

Field et al. : Removal of rings and watches

Table 2. Types of bacteria (‘non-dentists’ and ‘dentists’), of bacteria was identified

isolated from ring and control finger sites in both groups expressed as total number of times an isolate from each group

Dentists Ring finger

Control finger

Non-dentists Control finger

Bacteria identified

Ring finger

DNase- and coagulasepositive S. aureus DNase- and coagulase-

11

8

9

6

23

20

24

30

4

5

3

10

0

0

2

2

1

2

2

2

1

0

1

4

staphylococci Micrococcus species Coliforms and enterococci Gram-negative bacilli NE Gram-positive bacilli

67

NE, non-Enterobacteriaceae.

of volunteers. The greatest number of isolates were in the DNase- and Coagulase-negative group of staphylococci and this group of bacteria accounted for approximately half the total number of different isolates from both volunteer groups. The majority of bacteria were identified as Staphylococcus epidermidis, but others ineluded S. hominis, S. xylosus, S. waneri and S. caprae. The second most frequently isolated group of bacteria was the DNase-and Coagulase-positive S. aureus and

Table 3. Number of bacteria, expressed ‘dentist’ and ‘non-dentist’ groups

there were similar numbers at both test sites in the two volunteer groups.

Watch study Table III shows the number of CFU for each swab isolated from the watch and control sites of volunteers in both volunteer groups together with a mean value. The dentist and non-dentist groups both had signifi-

as the number of CFU, isolated from wrist sites in the

Volunter no.

Under watch

Dentist group Control wrist

Non-dentist group Control Under wrist watch

1 2 3 4 5 6 7 a 9 10 11 12 13 14 15 16 17 18 19 20

520 386 40 116 4 0 584 129 85 77 21 198 642 295 38 715 710 0 0 694

64 1 1 0 5 1 4 0 15 85 77 160 26 605 22 15 17 0 0 20

629 1 582 542 520 2 696 684 710 1 704 718 2 13 130 682 34 4 a 720

Mean

262.7

55.9

368.9

8 3 5 4 1 6 37 3 648 5 42 1 0 16 16 9 17 1 14 56 44.6

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Tab/e 4. Types of bacteria isolated from watch and control wrist sites in both groups (‘non-dentists’ and ‘dentists’), expressed as the total number of times an isolate from each group of bacteria was identified Dentists Bacteria indentified DNase- and coagulasepositive S aureus DNase- and coagulasenegative staphylococci Micrococcus species Coliforms and enterococci Gram-negative bacilli NE Gram-positive bacilli

Under watch

Control wrist

Non-dentists Under Control watch wrist

7

5

4

7

17

16

23

24

5

3

5

6

0

2

1

0

0

0

2

2

2

1

1

1

NE. non-Enterobacteriaceae.

cantly greater numbers of bacteria isolated from their watch sites than their control sites (dentists, P = 0.006; non-dentists’ P = 0.001). There were, however, no significant differences between the dentists’ watch site and the non-dentists’ watch site or the dentists’ control site and the non-dentists’ control site. Table IV showsthe different types of bacteria isolated from watch and control sites in both groups of volunteers. As in the ring study, the greatest number of isolates were DNase- and Coagulase-negative staphylococci. There were, however, approximately equal numbers of isolates of both S. aureus and the Micrococcus species from both test sites and from both groups of volunteers.

DISCUSSION This study has shown that in both experimental groups there was a greater number of bacteria isolated from under rings and watches compared with the control sites. Dental surgeons wash and disinfect their hands frequently throughout the day and it would be expected that the bacterial counts from both their ring and control finger sites would be less than in the non-clinical group. Dentists tend not to wash and disinfect their wrists as thoroughly as their hands and this would explain the fact that similar numbers of bacteria were isolated from both control and watch sites in the two volunteer groups. However the different types of bacteria isolated from both groups were similar and consistent with other studies on the hand microflora of dentists4. There was no evidence that frequent disinfection or glove wearing in the the clinical group resulted in any bacteria being selectively eliminated or encouraged, and this is in accordance with recent evidence5.

This study did not attempt to measure the carriage rate of different species/groups of bacteria. The relevance of these findings to cross-infection control in dental practice has to be put in perspective. Hands have been identified as important vectors of cross-infection and BDA guidelines state that dentists’ hands should be disinfected before donning protective glove@. Pre-gloving disinfection of the hands is important, as it provides a second.line of protection if gloves develop perforations and also reduces both the transient and resident hand flora7. If the dentist does not remove a ring prior to handwashing then there is a potential source of bacterial contamination from the underlying skin, which may pose a cross-infection risk; however, most of the organisms should be well contained in the glove provided it does not perforate or tear. Comparatively few oral infections are caused by S. aweus but this bacteria has been isolated from cases of osteomyelitis, salivary gland infections and angular cheilitis. The increased number of bacteria found under rings could possibly cause infection in immunocompromised patients, in the event of a glove tearing. Effective disinfection of the hands and wrists is difficult to achieve if rings and watches are not removed. Donning of gloves over a ringed finger can be difficult and a glove may become damaged or torn by the ring. The watch may also become splattered with blood and saliva during dental treatment, particularly if the watch is not covered by gloves or the sleeve of a clinical coat. Failure to remove rings prior to handwashing and wearing gloves also predisposes to the development of hand dermatitis. Irritants such as chemical handwashes or glove powder tend to acccumulate under rings where they are difficult to remove by rinsing. The occluded skin under the ring becomes macerated due to accumulation of sweat; failure to dry the area compounds the

Field eta/.: Removal of rings and watches

problem. All these factors create ideal conditions for the development of an irritant contact dermatitis which often starts under a ring and spreads to the rest of the hands8. A contact allergy to nickel-plated rings may also occur and certain metals, especially alloys of copper and silver, can serve as primary irritants in the presence of an adequate concentration of salt. The relatively high concentration of bacteria which was found in the skin under rings in this study also predisposes to secondary infection of macerated skin under the rings. Infected, eczematous skin may act as a portal of entry for acquired infections, thereby posing a possible infection risk to the dentist. There have been few previous studies on the effects of wearing rings on the microflora of the skin. One study examined the micro-organisms isolated from the skin under rings permanently worn by 50 nurses working on medical and surgical wards’. The results of this investigation showed that there was a significant difference between the number of bacteria comprising the normal Gram-positive flora at ring sites compared with those at control sites. The same strains of Gram-negative bacilli were also persistently isolated from 16 of the nurses over several months suggesting that these organisms were persistent colonisers rather than transient contaminants. The design of this study was deliberately simple, with each volunteer acting as their own control. Inclusion of a group of non-dentists provided a further, external control for the investigation. The method used for sampling hands was chosen, as it had been used in other studies on this problem’. The experimental design of our study did not, however, allow for the resampling of participants over a period of time, so it would be difficult to predict whether the bacteria isolated from test sites were transient or resident organisms. Interestingly, there did not appear to be any obvious differences in the types of micro-organisms isolated from the skin of either the test sites or in the two volunteer groups. Hoffman et al.9 felt that it would be difficult to predict the bacterial flora under rings because changes encouraged by occlusion could be offset by the release of toxic metal ions, such as silver and copper, from gold alloys. During the course of this investigation, dentist volunteers were asked why they did not remove jewellery prior to handwashing (results not shown). Various reasons were given, and included anxiety about losing rings, inconvenience (if watches were not worn) and also inability to remove rings that had become too tight. A number of married dentists did not want to remove their wedding rings for sentimental reasons.

69

Many staff felt that wearing of jewellery would not pose a threat to cross-infection control, although most agreed that rings might tear or weaken gloves. The majority of dentists, who did not wear rings under their gloves, felt that doing so might predispose to skin problems and some of these individuals had already suffered from hand eczema. The results of this present microbiological study and experience of dermatological problems reported by a significant proportion of dentists would suggest that rings should be removed prior to handwashing and glove wearing. Effective disinfection of wrists is difficult to achieve if watches are worn and these can become splattered with blood and other debris. Watches should therefore also be removed prior to hand disinfection and donning of gloves. Unfortunately adoption of these practices creates a number of practical difficulties which may be difficult to overcome. Acknowledgments The authors would like to thank the staff of the Dental Hospital who participated in this study. We would also like to thank Dr John K. Field, Senior Lecturer, Department of Clinical Dental Sciences and Dr Clodagh King, Consultant Dermatologist, Royal Liverpool University Hospital for their support and advice. Mrs Brenda Smith kindly typed the manuscript. References 1. Field EA, JedynakiewiczNM, King CM. A practical gloving and handwashingregimen for dental practice. Br Dent J 1992;172: 111-113.

CruickshankR, Dugind JP, Marmion BP, Swain RHA. Medical Microbiology vol 2, 12th edn. Churchhill Livingstone. 1975;307. 3. Kirkwood BR. Essentials of Medical Statistics. Oxford, BlackwellScientificPublications,1992; 147-1.51. 4. Field EA, Martin MV. Handwashing:soap or disinfectant? BrDentJ 1986; 160: 278-280. 5. Millns B, Martin MV, Field EA. An investigation of chlorhexidineand cetyl pyridinium chloride resistantflora on the handsof dental studentsand theatre staff. J Hosp

2.

6.

Infect 1994; 26: 99-104. The Control of Cross-infection in Dentistry.

(Al2 Advice Sheet.)London, British Dental AssociationAdvisory Service, 1991. Ayliffe GAJ, BabbJR, QuoraishiAH. A test for hygienic hand disinfection. J Clin Path01 1978; 31: 923-928. Field EA, King CM. Skin problemsassociatedwith routine wearing of protective glovesin dental practice. Br DentJ

1990;169: 281-285.

Hoffman PN, Cooke EM, McCarville MR et al. Microorganismsisolated from skin under wedding rings worn by hospital staff. Br Med J 1985; 290: 206-207.