J. Dent. 1990; 18: 258-262
258
Occupational
injuries to dental personnel
K. Porter, C. Scully, Y. Theyer and S. Porter Centre for the Study of Oral Disease, University Hospital and School, UK
Department
of Oral Medicine, Surgery and Pathology, Bristol Dental
ABSTRACT Occupational injuries to dental hospital personnel over 9 years (1980-1988 inclusive) were studied. Some 300 accidents were reported. Over one-half were sharps injuries. Over one-quarter were falls or collisions. Eye injuries accounted for some 10 per cent of incidents, bums and scalds the remainder. Serious complications
were rare, but many of the injuries could have been avoided. KEY WORDS: Occupational J. Dent. 1990;
injuries, Dental personnel
18: 258-262
(Received 5 June 1990;
reviewed 5 July 1990;
accepted 25 July 1990)
Correspondence should be addressed to: Professor C. Scully, Centre for the Study of Oral Disease, University Department of Oral Medicine, Surgery and Pathology, Bristol Dental Hospital and School, Lower Maudlin Street, Bristol BSl 2LY. UK.
INTRODUCTION Dental personnel work frequently with rotating and sharp instruments and various fairly noxious materials, and they are not infrequently exposed to the risk of burns (Scully et al., 1990). Rotating instruments are used both in the dental clinic and laboratory. With air turbine speeds of 250000 to 400000 rev./min, small particles can be projected at velocities of up to 10 m/s (Eichner, 1965) and, if they hit the eye, can cause at least conjunctivitis, but, more important, cornea1 abrasions or even dangerous penetrating wounds (Cooley et al., 1978; Cooley and Barkmeier, 1981). There are also risks from projected particles produced when grinding metals or plastics or cutting wire and dental staff have been wounded in this way. Some have been permanently blinded as a consequence (Gennari and Galli, 1971; Hurley, 1978). One Italian study suggested 18 per cent of dentists to have had eye lesions caused by foreign bodies (Gennari and Galli, 1971). The eyes, in particular, are also at risk from various chemicals used in clinical dentistry, particularly sodium hypochlorite and phosphoric, sodium hypochlorite, trichloracetic and chromic acids. Laboratory materials constitute a more significant hazard. Apart from acids, methyl methacrylate monomer, if splashed into the eye, can cause a painful reaction (Spealman et al., 1945); plaster of Paris contains small quantities of lime and quartz that can damage the eye; whilst pumice can abrade it (Hurley, 1978; Scully et al., 1990). 0 1990 Butterworth-Heinemann 0300-5712/90/050258-05
Ltd.
Eye infections may also be a problem (Fauchard Academy Poll, 1965). Herpetic keratitis is one of the worst ocular infections that can be contracted by clinical dental staff, but bacterial conjunctivitis caused by Staphylococcus aureus is more common (Scully et al., 1990). Other conjunctival pathogens such as Chlamydia trachomatis have been reported rarely to have been transmitted in dental practice (Midulla et al., 1987). The skin of clinical dental staff is at risk of maceration and dermatitis from repeated handwashing, occasional subsequent candidosis and other infections. Contact dermatitis to materials such as methylmethacrylate, in particular hydroquinolone stabilizer, can occasionally arise, although a vast number of other dental materials can give rise to allergic reactions (Scully et al., 1990). Sharps injuries are, not surprisingly, fairly common in dentistry, rates ranging from about 30 to 95 per cent over about 3 years of practice (Epstein et al., 1984; Samaranayake et al., 1987; McCartan and Samaranayake, 1988; Reichart et al., 1988; Klein, 1988; Yaacob and Samaranayake,l989; Porter et al., 1989) although these figures are based mainly on subjective impressions. Some 20 or more different infections have been recorded following sharps injuries (Evans, 1903; Baldwin et al., 1923; Beverleyetal., 1955; HambricketaJ., 1962; Sarasinet al., 1963; Chacko, 1966; Joffe and Diamond, 1966; Hill, 1971; Cannonet al., 1972; Sahn and Pierson, 1974; Sexton et al., 1975; Chappler et al., 1977; Emond et al., 1977; Meyersetal., 1977; Glaser andGarden, 1985; Oksenhendler et al., 1986; Collins and Kennedy, 1987; Scullyet al., 1990)
Porter et al.: Occupational injuries to dental personnel
although there is currently most concern about bloodborne viruses. Local infections such as herpetic whitlow can also be painful and incapacitating (Hambrick er al., 1962; Collins and Kennedy, 1987). However, although it is clear from the above that there are occupational hazards, most data on occupational injuries to dental personnel are subjective and there are few if any objective data. We have therefore undertaken a retrospective study of hospital dental personnel to determine the numbers and types of occupational accidents reported at the Bristol Dental Hospital (BDH) between the years 1980 and 1988 inclusively.
MATERlbiLS
AND
METHODS
The records of reported occupational
accidents to BDH staff during the years 1980-1988 inclusively were examined retrospectively. The numbers of individuals affected, occupation, causes and management of injuries were noted. Up to approximately 313 personnel are working in the BDH at any one time, but since this is a dynamic population with a range of occupations and a variety of time committments, it is quite impossible to give a precise Table I. Reported 1980
incidents
to personnel
RESULTS
A total of 302 dental hospital personnel reported accidents at work between 1980 and 1988. The annual numbers of accidents reported varied from 23 to 42 per year (mean = 33) (Table I). The accidents by occupation are shown in Table II. Accidents mainly involved dental surgery assistants and trainees (DSAs) (n = 131; 43.4 per cent), dentists or dental students (n = 73; 24.2 per cent) and ancillary staffporters, domestics and others (n = 59; 19.5 per cent). Technicians reported 16 (5.3 per cent) and receptionists 12 (4.0 per cent) accidents. Only three dental hygienists/ trainee hygienists (1.0 per cent) reported work-related injuries. The approximate numbers of personnel in each category working in the hospital are shown in Table II. Accidents could largely be grouped into four main categories (Table III), namely sharps injuries (n = 167; 55.3 per cent), falls and collisions with objects or people (n = 84; 27.8 per cent), eye injuries (n = 33; 10.9 per cent), and burns or scalds (n = 16; 5.3 per cent). Two persons (0.6 per cent) had accidents that could not be classified into any of these groups. Sharps injuries
No. injured
1980 1981
36 42 33:
Approximate % of total personnel injured * 11.5 13.4 12.5 12.1
1983 1984 1985 1986 1987 1988
figure as to the man-hour equivalents worked over this period.
between
and 1988
Year
1982
at BDH
259
12.1 10.2
z28 23 29 25
*Assumes a personnel of 313 reservations.
E 810 at any one time but see text for
Tab/e II. Number between
1980
Staff group Dentists* Hygienistst DSAstS Ancillary staff§ Technicianst Receptionists Others
of work-related and 1988
injuries
Sharps injuries formed the largest group of injuries, comprising 55 per cent of the total. The number reported between 1980 and 1988varied from 12 to 26 per year (mean 18.5 per year), and there was a trend over this period towards fewer sharps injuries. Sharps injuries were reported most frequently by DSAs (injuries n = 92; range 5-14 per year; mean 10.2per year) and next by dentists and dental students (n = 44; range 2-8 per year; mean 4.9 per year). Ancillary staff were the most commonly affected of other staff reported (n = 20; range l-5 per year; mean 2.22 per year).
reported
by different
groups
at BDH
Personnel in group (no.) *
Reported accidents (no.)
% of total accidents
200 10 50
73 3 131 59 16 12 8
24.2 1 .o 43.4 19.5 5.3 4.0 2.6
:s 11 variable
*These numbers are approximate only, as there were many visiting staff and staffing changes over the period. tlncludes trainees-not classified separately as they varied in experience and weekly sessions worked. #DSAs also includes five general nurses. §Forters and domestics.
260
J. Dent. 1990; 18: No. 5
Table 111. Main types of accidents to personnel at BDH between 1980
and 1988 Reported incidents
Type of injury
(no.1
% of total accidents
Sharps injuries Falls and collisions Eye injuries Burns and scalds
167 84 33 16
55.3 27.8 10.9 5.3
Equipment
causing sharps injuries
Sharps injuries were most often caused by needles, which included suture and irrigation needles as well as those used for giving local anaesthetics (n = 76; range 4-13 per year; mean 8.44 per year). Twenty-seven personnel received wounds from dental burs and 12 from scalpel blades. Thirty reported sharps injuries from other equipment including glass ampoules (three), local anaesthetic cartridges (two), human (two) and animal (one) bites, wax knives (three), matrix bands (three), perspex (one), screwdriver (one), staple (one), saw (one), metal splinters (two), plaster knife (one), prosthetic instrument (one), phantom head (one), scissors (two), rubbish (one), microtome blade (one), wood (one) and wire (one). Activities
associated
with sharps injuries
The most commonly reported activity in which hospital personnel received sharps injuries was whilst clearing away instruments or cleaning dental surgeries (n = 44). Indeed, 19 persons injured themselves while dismantling dental equipment, including venepuncture or local anaesthetic syringes, scalpels and even matrix bands. Twelve received sharps injuries while cleaning or sharpening dental instruments. Twenty-eight received injuries during the treatment of patients, whilst injecting patients, resheathing needles or scaling teeth. Both DSAs (n = 30) and dentists or students (n = 13) received sharps injuries from needles, scalpel blades or burs (especially when the handpiece was in its holder). One hygienist was bitten while treating a mentally handicapped patient, and a nurse was bitten by a child recovering from a general anaesthetic. Many injuries occurred because of poor disposal of sharps, for example in unsuitable bins, or even on the floor, and, a number of DSAs received injuries because of incorrect disposal of instruments by dentists on instrument trays. Sharps injuries were only rarely attributable to faulty equipment (n = 6). Other activities leading to sharps injuries included the handling of laboratory animals (one), and in one incident metal splinters entered a dental student’s fingers when she turned on a tap. One person was injured removing a staple from a radiograph with a screwdriver: this seemingly inocuous injury resulted in septicaemia and several weeks off work! In 21 instances, the victim did not give details about their activity prior to injury.
Management
of sharps injuries
Most of the 167 personnel reporting sharps injuries then received medical attention (135 or 80.8 per cent). Wounds were usually cleaned and dressed and the victim’s tetanus status checked. Eighty-six of the 135 staff seeking medical attention (63.7 per cent) had blood taken to assess their hepatitis B status, and in 24 instances (17.8 per cent) blood was taken from the involved patient for similar assessment. Where applicable, techniques used for dismantling syringes, scalpels, etc. were reviewed and appropriately corrected. The proportion of hospital personnel who sought medical treatment following sharps injuries and who had already been immunized or started active immunization against hepatitis B rose from 4.5 per cent in 1984to 62.5 per cent in 1988. No personnel are known to have seroconverted to HIV. Falls and collisions There were 43 incidents of falling downstairs, falling off objects or fainting. Thirteen of the injured personnel were dentists or students (31.0 per cent), 12 were DSAs (28 per cent), 13 were ancillary staff (31 per cent), two were technicians and two hygienists. One person did not state his or her status. In 18 cases (41.9 per cent) personnel fell on stairs whilst carrying loads (13) cleaning (two) or running (three). One person fell off a chair while opening a window. The other falls and faints were for a miscellany of reasons. Thirteen (88.4 per cent) sought medical treatment for their falls. Most injuries were minor cuts and bruises, but one person fractured a metatarsal bone and required external fixation for 6 weeks; one person strained ligaments in an arm and both shoulders when he attempted to stop himself falling downstairs; four twisted their foot; one sustained a capsular tear of the knee and one sprained a thumb. One required suturing of lacerations. Radiographs were taken in three instances to exclude (two) or confirm (one) fractures of affected areas. Forty-one incidents involved collisions (13.6 per cent of all injuries). Eye injuries Thirty-three personnel sustained eye injuries (10.9 per cent of total accidents over the period). Equal numbers of dentists or students and DSAs were affected (n = 13) with smaller numbers of technical and ancillary staff reporting eye injuries (n = 4; n = 3 respectively). Injurious
agents
Eye ‘injuries’ due to fluids entering the eye (n = 13; 39.4 per cent) were caused by chlorhexidine (four), alcohol (two), local anaesthetic solution (one), detergent (one), benzalkonium mouthwash (one), water and saliva (one),
Porter et al.: Occupational injuries to dental personnel
saline (one), modelling fluid (one) and cyst fluid (one). The injuries were sustained while cleaning equipment, opening suture packs, infiltrating local anaesthetic solution, irrigating infected sockets or assisting oral surgical procedures. In one case, water and saliva sprayed into the operator’s face because of poor angulation of the water jet in the spitoon. Solids or particulate matter also caused eye injuries in 13 (39.4 per cent): tooth fragments, restorations or calculus were the cause of injury in eight cases (24.2 per cent). Individual persons each reported damage to their eye caused by zinc oxideleugenol, polishing paste and saliva, powder (in a waste bin), metal particles (that were produced when grinding metal) and grit from a broken air duct. Most eye injuries caused by particulate matter occurred during the treatment of patients. Other eye injuries were caused by disconnecting suction tubing (one), cleaning composition material off dental impression trays (one), wiping eyes with wax-covered fingers (one) and by foreign bodies (glass (one), hospital file (one)). A serious eye injury occurred to a laboratory technician who failed to wear protective glasses. One patient did not report how his eye injury occurred. Management
of eye injuries
First aid usually involved irrigation of the eye with sterile saline or water. Thirty-one individuals (93.9 per cent) were asked to seek medical attention for their eye injuries. These, who were immediately examined by an ophthalmologist in the adjacent eye hospital, were sometimes prescribed antibiotic eye drops or ointment as a precautionary measure (n = 11). One patient with conjunctivitis caused by spray of alcohol into the eye was prescribed a topical corticosteroid preparation. No affected individual sustained permanent eye injury. Burns and scalds Sixteen persons reported burns or scalds during the period 1980-1988 (5.3 per cent of total). These injuries were most common in ancillary sterilizing department staff (n = 6; 37.5 per cent), but were also reported by five DSAs, two dentists, two technicians and one receptionist. Burns or scalds were most common during the unloading of autoclaves (n = 7; 43.8 per cent) with one injury caused by a fault in the autoclave such that boiling water poured over a DSA’s feet on opening the door after the completion of a cycle. Hot liquids (e.g. hot water) were other causes of thermal injury. One ancillary received a bum while cleaning a hotplate that had inadvertently been left switched on and one dentist burned herself with hot composition impression material. Bunsen burners only caused injuries in three persons; and the plastic handle of a faulty pin flame became molten in one case. The potentially most serious injury was caused when the oil in a female dental student’s hair ignited, but fortunately the flames were quickly extinguished with no permanent damage.
Management
261
of thermal injuries
Thirteen persons (81.3 per cent) sought medical treatment. Most required little but a dry dressing as the recommended first aid measure of rinsing the bum with copious amounts of cold water had usually been followed. Long-length heat-resistant gauntlet gloves were supplied to the central sterilizing unit to reduce bums from the autoclave and, where possible, preventive action was taken to reduce the incidence of bums caused by faulty or malpositioned burners. DISCUSSION This study of injuries to dental hospital personnel over the 9-year period 1980-1988 showed a total of over 300 injuries reported. Because of the constantly changing personnel in such an environment, precise injury rates are impossible to calculate. Nevertheless, if one takes the number of personnel working on any particular day and assumes there is a potential of one injury each day this gives an idea of the rate. With over 300 personnel working, assuming a 5-day week for each of 50 weeks over a 9-year period, this gives a figure of 675000 ‘potential incidents’. Using this rather arbitrary calculation, an accident rate of about 0.04 per cent can be calculated although there must be some other unreported incidents. Sharps injuries were the most frequently reported accidents to affect dental hospital personnel (Table III), DSAs reporting more injury of this type than any other group. The greater hazard to DSAs is emphasized when it is seen that over 40 per cent of all accidents affected DSAs yet they account for only about one-sixth of the hospital personnel. From informal discussion with personnel it would seem that the higher numbers of injuries reported by DSAs may partly reflect their training which emphasizes the need for such reporting. In addition, it is easier for nursing cover to be instituted in a hospital situation where there are a large number of DSAs on duty, while operators are less able to leave patients in mid-treatment to report injuries. This consideration would not of course be applicable in dental practice where only one DSA per dentist is usual. DSAs and ancillary staff are, however, more vulnerable to sharps injuries as their duties involve clearing away instruments, care of instruments and the cleaning of surgeries. Particular care must be taken and standard procedures adhered to during potential sharps injury risk procedures such as recapping or dismantling dental syringes and inserting or removing blades from scalpels. The wearing of rubber gloves, although now routine, does not prevent sharps injuries but the incidence of the latter can be reduced by careful technique (Wormseretal., 1988). Indeed, this present study showed that the number of reported sharps injuries has reduced in recent years. This may reflect an improvement in techniques. It is routine procedure in this hospital for clinical personnel to be immunized against hepatitis B virus, and the uptake of active immunization has been demonstrated by the increase to 1988 in the percentage of individuals
262
J. Dent
1990;
18:
No.
5
who reported sharps injuries who had also previously been vaccinated against hepatitis B. Eye injuries accounted for a substantial number of injuries. No permanent injuries resulted. This at least may partly be attributable to the rapid initiation of appropriate first aid measures. In any case, all should be familiar with first aid measures and the location of a stock of suitable eye irrigants. Close-viewing and treating anterior teeth increase the exposure to missile damage. Eyes must be protected from foreign bodies, infected material, chemicals, and the various forms of radiation. Some 53 per cent of dentists wear glasses because of sight defects (Harley, 1978) but the simplest and most effective method of preventing eye injury by missiles is the use of proper protective spectacles preferably with plastic lenses and side shields. In the laboratory, a plexiglass shield will reduce splatter and flying particles, and appropriate dust extraction should be used whilst grinding and polishing appliances. Face protectors such as the Zephyr (Racal Ltd, Wembley, UK), have the advantage of giving a flow of filtered cool air to the operator and protecting eyes and respiratory system simultaneously. Thermal injuries and falls were also in the main preventable. Heat-resistant gloves should be provided for DSAs using autoclaves, and flooring should be maintained in good order (Scully et al., 1990). Most occupational accidents reported by dental hospital personnel could have been avoided had due care been taken during procedures or if thought had been given to the lay-out of surgeries, maintenance of furnishings, or provision of adequate materials for a given procedure. First aid measures fortunately prevented serious complications. References Baldwin A H., McCallum F. and Doull J. A. (1923) A case of pharyngeal diphtheria probably due to auto-infection from a diphtheric lesion of the thumb. JAMA 80, 1375. Beverley J. K. A, Skipper E. and Marshall S. C. (1955) Acquired toxoplasmosis: with a report of a case of laboratory infection. Br. Med. J. 1, 577-578. Cannon N. J. Jr, Walker S. P. and Dismukes W. E. (1972) Malaria acquired by accidental needle puncture. JAMA 222, 1425. Chacko C. W. (1966) Accidental human infection in the laboratory with the Nichols rabbit-adapted virulent strain of Treponema pallidurn. Bull. WHO 35, 809-810. Chappler R. R., Hoke A W. and Borchardt K. A (1977) Primary inoculation with Mycobacterium ma&urn. Arch. Dermatol. 113, 380. Collins C. H. and Kennedy D. A. (1987) Microbiological hazards of occupational needlestick and ‘sharps’ injuries. J. Appl. Bacterial. 62, 385-402. Cooley R. L. and Barkmeier W. W. (1981) Prevention of eye injuries in the dental office. Quintessence Int. 9, 953. Cooley R. L., Cottingham A J. Jr, Abrams H. et al. (1978) Ocular injuries sustained in the dental office: methods of detection, treatment and prevention. JADA 97, 985-988. Eichner K. (1965) Investigation on cutting and grinding procedures on the hard tooth structure and ivory. Aust. Dent. J. 10,214-216.
Emond R. T. D., Evans B., Bowen E. T. W. et al. (1977) A case of Ebola virus infection. Br. Med. J. 2, 541-544. Epstein J. B., Buchner B. K. and Bonchard S. (1984) Hepatitis B and Canadian dental personnel. J. Can. Dent. Assoc. SO, 555-559. Evans N. (1903) A clinical report of a case of blastomycosis of skin from accidental inoculation. JAMA 40, 1772-1775. Fauchard Academy Poll (1965) Nearly a fourth have contracted illness as a result of practicing dentistry. Dent. Survey 41, 29. Gennari U. and Galli S. (1971) Le malattie professionali dei dentisti. Riv. Ital. Stomatol. 26, 747-755. Glaser J. B. and Garden A (1985) Inoculation of cryptococcosis without transmission of the acquired immunodeticiency syndrome. N. Engl. J. Med. 313,266. Hambrick G. W. Jr, Cox R. P. and Senior J. R. (1962) Primary herpes simplex infection of fingers of medical personnel. Arch. Dermatol. 85, 583-589. Harley J. L. (1978) Eye and facial injuries resulting from dental procedures. Dent. Clin. North Am. 22, 505-515. Hill A (1971) Accidental infection of man with Mycoplasma caviae. Br. Med. J. 2, 711-712. Joffe B. and Diamond M. T. (1966) Brucellosis due to selfinoculation. Ann. Intern. Med. 65, 564-565. Klein R S. (1988) Occupational transmission of HIV. In: Robertson P. B. and Greenspan J. S. (eds), Perspectives on Oral Manifestations of AIDS. Littleton, Massachusetts, PSG, pp. 12-27. McCartan B. E. and Samaranayake L. P. (1988) Awareness and acceptance of hepatitis B vaccine by Irish dental practitioners. .I. lrish Dent. Assoc. 33, 33-36. Meyers J. D., Dienstag J. L., Purcell R. H. et al. (1977) Parenterally transmitted non-A, non-B hepatitis: an epidemic reassessed. Ann. Intern. Med. 87, 57-59. Midulla M., Sollecito D., Fellepa F. et al. (1987) Infection by airborne Chlamydia trachomatis in a dentist cured with rifampicin. Br. Med. .J. 294, 742. Oksenhendler E., Harzic M., Le Roux J-M. et al. (1986) HIV infection with seroconversion after a superficial needlestick injury to the finger. N. Engl. J. Med. 315, 582. Porter K M., Scully C., Porter S. R. et al. (1989) Needlestick injuries to dental staff. Br. Dent. J. 167, 265-266. Reichart P. A., Bommerer M., Lange W. et al. (1988) Absence of antibodies to HIV among West Berlin dental personnel. AIDS-Forschung (AlFO) 6, 333-334. Sahn S. A and Pierson D. J. (1974) Primary cutaneous inoculation drug-resistant tuberculosis. Am. J. Med. 57, 676-678. Samaranayake L. P., Lamey P-J., MacFarlane T. W. et al. (1987) Attitudes of general dental practitioners towards the hepatitis B vaccine. Community Dent. Oral Epidemiol. 15, 125-127. Sarasin G., Tucker D. N. and Arean V. M. (1963) Accidental laboratory infection caused by Leptospira icterohaemorrhagicae. Am. J. Clin. Pathol. 40, 146-150. Scully C., Cawson R. A and Griffths M. J. (1990) Occupational hazards to dental staff. Br. Dent. J. (in press). Sexton D. J., Gallis H. A, McRae J. R. et al. (1975) Possible needle-associated Rocky Mountain spotted fever. N. Engl. J. Med. 292, 645. Spealman C. R., Main R J., Haag H. B. et al. (1945) Monomeric methyl methacrylate-studies on toxicity. Indust. Med. 14,292-298. Wormser G. P., Rabkin C. S. and Joline C. (1988) Frequency of nosocomial transmission of HIV infection among health care workers. N. Engl. J. Med. 319, 307-308. Yaacob H. B. and Samaranayake L. P. (1989) Awareness and acceptance of the hepatitis B vaccine by dental practitioners in Malaysia. J. Oral PathoJ. Med. 18, 236-239.
258
Occupational
injuries to dental personnel
K. Porter, C. Scully, Y. Theyer and S. Porter Centre for the Study of Oral Disease, University Hospital and School, UK
Department
of Oral Medicine, Surgery and Pathology, Bristol Dental
ABSTRACT Occupational injuries to dental hospital personnel over 9 years (1980-1988 inclusive) were studied. Some 300 accidents were reported. Over one-half were sharps injuries. Over one-quarter were falls or collisions. Eye injuries accounted for some 10 per cent of incidents, bums and scalds the remainder. Serious complications
were rare, but many of the injuries could have been avoided. KEY WORDS: Occupational J. Dent. 1990;
injuries, Dental personnel
18: 258-262
(Received 5 June 1990;
reviewed 5 July 1990;
accepted 25 July 1990)
Correspondence should be addressed to: Professor C. Scully, Centre for the Study of Oral Disease, University Department of Oral Medicine, Surgery and Pathology, Bristol Dental Hospital and School, Lower Maudlin Street, Bristol BSl 2LY. UK.
INTRODUCTION Dental personnel work frequently with rotating and sharp instruments and various fairly noxious materials, and they are not infrequently exposed to the risk of burns (Scully et al., 1990). Rotating instruments are used both in the dental clinic and laboratory. With air turbine speeds of 250000 to 400000 rev./min, small particles can be projected at velocities of up to 10 m/s (Eichner, 1965) and, if they hit the eye, can cause at least conjunctivitis, but, more important, cornea1 abrasions or even dangerous penetrating wounds (Cooley et al., 1978; Cooley and Barkmeier, 1981). There are also risks from projected particles produced when grinding metals or plastics or cutting wire and dental staff have been wounded in this way. Some have been permanently blinded as a consequence (Gennari and Galli, 1971; Hurley, 1978). One Italian study suggested 18 per cent of dentists to have had eye lesions caused by foreign bodies (Gennari and Galli, 1971). The eyes, in particular, are also at risk from various chemicals used in clinical dentistry, particularly sodium hypochlorite and phosphoric, sodium hypochlorite, trichloracetic and chromic acids. Laboratory materials constitute a more significant hazard. Apart from acids, methyl methacrylate monomer, if splashed into the eye, can cause a painful reaction (Spealman et al., 1945); plaster of Paris contains small quantities of lime and quartz that can damage the eye; whilst pumice can abrade it (Hurley, 1978; Scully et al., 1990). 0 1990 Butterworth-Heinemann 0300-5712/90/050258-05
Ltd.
Eye infections may also be a problem (Fauchard Academy Poll, 1965). Herpetic keratitis is one of the worst ocular infections that can be contracted by clinical dental staff, but bacterial conjunctivitis caused by Staphylococcus aureus is more common (Scully et al., 1990). Other conjunctival pathogens such as Chlamydia trachomatis have been reported rarely to have been transmitted in dental practice (Midulla et al., 1987). The skin of clinical dental staff is at risk of maceration and dermatitis from repeated handwashing, occasional subsequent candidosis and other infections. Contact dermatitis to materials such as methylmethacrylate, in particular hydroquinolone stabilizer, can occasionally arise, although a vast number of other dental materials can give rise to allergic reactions (Scully et al., 1990). Sharps injuries are, not surprisingly, fairly common in dentistry, rates ranging from about 30 to 95 per cent over about 3 years of practice (Epstein et al., 1984; Samaranayake et al., 1987; McCartan and Samaranayake, 1988; Reichart et al., 1988; Klein, 1988; Yaacob and Samaranayake,l989; Porter et al., 1989) although these figures are based mainly on subjective impressions. Some 20 or more different infections have been recorded following sharps injuries (Evans, 1903; Baldwin et al., 1923; Beverleyetal., 1955; HambricketaJ., 1962; Sarasinet al., 1963; Chacko, 1966; Joffe and Diamond, 1966; Hill, 1971; Cannonet al., 1972; Sahn and Pierson, 1974; Sexton et al., 1975; Chappler et al., 1977; Emond et al., 1977; Meyersetal., 1977; Glaser andGarden, 1985; Oksenhendler et al., 1986; Collins and Kennedy, 1987; Scullyet al., 1990)
Porter et al.: Occupational injuries to dental personnel
although there is currently most concern about bloodborne viruses. Local infections such as herpetic whitlow can also be painful and incapacitating (Hambrick er al., 1962; Collins and Kennedy, 1987). However, although it is clear from the above that there are occupational hazards, most data on occupational injuries to dental personnel are subjective and there are few if any objective data. We have therefore undertaken a retrospective study of hospital dental personnel to determine the numbers and types of occupational accidents reported at the Bristol Dental Hospital (BDH) between the years 1980 and 1988 inclusively.
MATERlbiLS
AND
METHODS
The records of reported occupational
accidents to BDH staff during the years 1980-1988 inclusively were examined retrospectively. The numbers of individuals affected, occupation, causes and management of injuries were noted. Up to approximately 313 personnel are working in the BDH at any one time, but since this is a dynamic population with a range of occupations and a variety of time committments, it is quite impossible to give a precise Table I. Reported 1980
incidents
to personnel
RESULTS
A total of 302 dental hospital personnel reported accidents at work between 1980 and 1988. The annual numbers of accidents reported varied from 23 to 42 per year (mean = 33) (Table I). The accidents by occupation are shown in Table II. Accidents mainly involved dental surgery assistants and trainees (DSAs) (n = 131; 43.4 per cent), dentists or dental students (n = 73; 24.2 per cent) and ancillary staffporters, domestics and others (n = 59; 19.5 per cent). Technicians reported 16 (5.3 per cent) and receptionists 12 (4.0 per cent) accidents. Only three dental hygienists/ trainee hygienists (1.0 per cent) reported work-related injuries. The approximate numbers of personnel in each category working in the hospital are shown in Table II. Accidents could largely be grouped into four main categories (Table III), namely sharps injuries (n = 167; 55.3 per cent), falls and collisions with objects or people (n = 84; 27.8 per cent), eye injuries (n = 33; 10.9 per cent), and burns or scalds (n = 16; 5.3 per cent). Two persons (0.6 per cent) had accidents that could not be classified into any of these groups. Sharps injuries
No. injured
1980 1981
36 42 33:
Approximate % of total personnel injured * 11.5 13.4 12.5 12.1
1983 1984 1985 1986 1987 1988
figure as to the man-hour equivalents worked over this period.
between
and 1988
Year
1982
at BDH
259
12.1 10.2
z28 23 29 25
*Assumes a personnel of 313 reservations.
E 810 at any one time but see text for
Tab/e II. Number between
1980
Staff group Dentists* Hygienistst DSAstS Ancillary staff§ Technicianst Receptionists Others
of work-related and 1988
injuries
Sharps injuries formed the largest group of injuries, comprising 55 per cent of the total. The number reported between 1980 and 1988varied from 12 to 26 per year (mean 18.5 per year), and there was a trend over this period towards fewer sharps injuries. Sharps injuries were reported most frequently by DSAs (injuries n = 92; range 5-14 per year; mean 10.2per year) and next by dentists and dental students (n = 44; range 2-8 per year; mean 4.9 per year). Ancillary staff were the most commonly affected of other staff reported (n = 20; range l-5 per year; mean 2.22 per year).
reported
by different
groups
at BDH
Personnel in group (no.) *
Reported accidents (no.)
% of total accidents
200 10 50
73 3 131 59 16 12 8
24.2 1 .o 43.4 19.5 5.3 4.0 2.6
:s 11 variable
*These numbers are approximate only, as there were many visiting staff and staffing changes over the period. tlncludes trainees-not classified separately as they varied in experience and weekly sessions worked. #DSAs also includes five general nurses. §Forters and domestics.
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Table 111. Main types of accidents to personnel at BDH between 1980
and 1988 Reported incidents
Type of injury
(no.1
% of total accidents
Sharps injuries Falls and collisions Eye injuries Burns and scalds
167 84 33 16
55.3 27.8 10.9 5.3
Equipment
causing sharps injuries
Sharps injuries were most often caused by needles, which included suture and irrigation needles as well as those used for giving local anaesthetics (n = 76; range 4-13 per year; mean 8.44 per year). Twenty-seven personnel received wounds from dental burs and 12 from scalpel blades. Thirty reported sharps injuries from other equipment including glass ampoules (three), local anaesthetic cartridges (two), human (two) and animal (one) bites, wax knives (three), matrix bands (three), perspex (one), screwdriver (one), staple (one), saw (one), metal splinters (two), plaster knife (one), prosthetic instrument (one), phantom head (one), scissors (two), rubbish (one), microtome blade (one), wood (one) and wire (one). Activities
associated
with sharps injuries
The most commonly reported activity in which hospital personnel received sharps injuries was whilst clearing away instruments or cleaning dental surgeries (n = 44). Indeed, 19 persons injured themselves while dismantling dental equipment, including venepuncture or local anaesthetic syringes, scalpels and even matrix bands. Twelve received sharps injuries while cleaning or sharpening dental instruments. Twenty-eight received injuries during the treatment of patients, whilst injecting patients, resheathing needles or scaling teeth. Both DSAs (n = 30) and dentists or students (n = 13) received sharps injuries from needles, scalpel blades or burs (especially when the handpiece was in its holder). One hygienist was bitten while treating a mentally handicapped patient, and a nurse was bitten by a child recovering from a general anaesthetic. Many injuries occurred because of poor disposal of sharps, for example in unsuitable bins, or even on the floor, and, a number of DSAs received injuries because of incorrect disposal of instruments by dentists on instrument trays. Sharps injuries were only rarely attributable to faulty equipment (n = 6). Other activities leading to sharps injuries included the handling of laboratory animals (one), and in one incident metal splinters entered a dental student’s fingers when she turned on a tap. One person was injured removing a staple from a radiograph with a screwdriver: this seemingly inocuous injury resulted in septicaemia and several weeks off work! In 21 instances, the victim did not give details about their activity prior to injury.
Management
of sharps injuries
Most of the 167 personnel reporting sharps injuries then received medical attention (135 or 80.8 per cent). Wounds were usually cleaned and dressed and the victim’s tetanus status checked. Eighty-six of the 135 staff seeking medical attention (63.7 per cent) had blood taken to assess their hepatitis B status, and in 24 instances (17.8 per cent) blood was taken from the involved patient for similar assessment. Where applicable, techniques used for dismantling syringes, scalpels, etc. were reviewed and appropriately corrected. The proportion of hospital personnel who sought medical treatment following sharps injuries and who had already been immunized or started active immunization against hepatitis B rose from 4.5 per cent in 1984to 62.5 per cent in 1988. No personnel are known to have seroconverted to HIV. Falls and collisions There were 43 incidents of falling downstairs, falling off objects or fainting. Thirteen of the injured personnel were dentists or students (31.0 per cent), 12 were DSAs (28 per cent), 13 were ancillary staff (31 per cent), two were technicians and two hygienists. One person did not state his or her status. In 18 cases (41.9 per cent) personnel fell on stairs whilst carrying loads (13) cleaning (two) or running (three). One person fell off a chair while opening a window. The other falls and faints were for a miscellany of reasons. Thirteen (88.4 per cent) sought medical treatment for their falls. Most injuries were minor cuts and bruises, but one person fractured a metatarsal bone and required external fixation for 6 weeks; one person strained ligaments in an arm and both shoulders when he attempted to stop himself falling downstairs; four twisted their foot; one sustained a capsular tear of the knee and one sprained a thumb. One required suturing of lacerations. Radiographs were taken in three instances to exclude (two) or confirm (one) fractures of affected areas. Forty-one incidents involved collisions (13.6 per cent of all injuries). Eye injuries Thirty-three personnel sustained eye injuries (10.9 per cent of total accidents over the period). Equal numbers of dentists or students and DSAs were affected (n = 13) with smaller numbers of technical and ancillary staff reporting eye injuries (n = 4; n = 3 respectively). Injurious
agents
Eye ‘injuries’ due to fluids entering the eye (n = 13; 39.4 per cent) were caused by chlorhexidine (four), alcohol (two), local anaesthetic solution (one), detergent (one), benzalkonium mouthwash (one), water and saliva (one),
Porter et al.: Occupational injuries to dental personnel
saline (one), modelling fluid (one) and cyst fluid (one). The injuries were sustained while cleaning equipment, opening suture packs, infiltrating local anaesthetic solution, irrigating infected sockets or assisting oral surgical procedures. In one case, water and saliva sprayed into the operator’s face because of poor angulation of the water jet in the spitoon. Solids or particulate matter also caused eye injuries in 13 (39.4 per cent): tooth fragments, restorations or calculus were the cause of injury in eight cases (24.2 per cent). Individual persons each reported damage to their eye caused by zinc oxideleugenol, polishing paste and saliva, powder (in a waste bin), metal particles (that were produced when grinding metal) and grit from a broken air duct. Most eye injuries caused by particulate matter occurred during the treatment of patients. Other eye injuries were caused by disconnecting suction tubing (one), cleaning composition material off dental impression trays (one), wiping eyes with wax-covered fingers (one) and by foreign bodies (glass (one), hospital file (one)). A serious eye injury occurred to a laboratory technician who failed to wear protective glasses. One patient did not report how his eye injury occurred. Management
of eye injuries
First aid usually involved irrigation of the eye with sterile saline or water. Thirty-one individuals (93.9 per cent) were asked to seek medical attention for their eye injuries. These, who were immediately examined by an ophthalmologist in the adjacent eye hospital, were sometimes prescribed antibiotic eye drops or ointment as a precautionary measure (n = 11). One patient with conjunctivitis caused by spray of alcohol into the eye was prescribed a topical corticosteroid preparation. No affected individual sustained permanent eye injury. Burns and scalds Sixteen persons reported burns or scalds during the period 1980-1988 (5.3 per cent of total). These injuries were most common in ancillary sterilizing department staff (n = 6; 37.5 per cent), but were also reported by five DSAs, two dentists, two technicians and one receptionist. Burns or scalds were most common during the unloading of autoclaves (n = 7; 43.8 per cent) with one injury caused by a fault in the autoclave such that boiling water poured over a DSA’s feet on opening the door after the completion of a cycle. Hot liquids (e.g. hot water) were other causes of thermal injury. One ancillary received a bum while cleaning a hotplate that had inadvertently been left switched on and one dentist burned herself with hot composition impression material. Bunsen burners only caused injuries in three persons; and the plastic handle of a faulty pin flame became molten in one case. The potentially most serious injury was caused when the oil in a female dental student’s hair ignited, but fortunately the flames were quickly extinguished with no permanent damage.
Management
261
of thermal injuries
Thirteen persons (81.3 per cent) sought medical treatment. Most required little but a dry dressing as the recommended first aid measure of rinsing the bum with copious amounts of cold water had usually been followed. Long-length heat-resistant gauntlet gloves were supplied to the central sterilizing unit to reduce bums from the autoclave and, where possible, preventive action was taken to reduce the incidence of bums caused by faulty or malpositioned burners. DISCUSSION This study of injuries to dental hospital personnel over the 9-year period 1980-1988 showed a total of over 300 injuries reported. Because of the constantly changing personnel in such an environment, precise injury rates are impossible to calculate. Nevertheless, if one takes the number of personnel working on any particular day and assumes there is a potential of one injury each day this gives an idea of the rate. With over 300 personnel working, assuming a 5-day week for each of 50 weeks over a 9-year period, this gives a figure of 675000 ‘potential incidents’. Using this rather arbitrary calculation, an accident rate of about 0.04 per cent can be calculated although there must be some other unreported incidents. Sharps injuries were the most frequently reported accidents to affect dental hospital personnel (Table III), DSAs reporting more injury of this type than any other group. The greater hazard to DSAs is emphasized when it is seen that over 40 per cent of all accidents affected DSAs yet they account for only about one-sixth of the hospital personnel. From informal discussion with personnel it would seem that the higher numbers of injuries reported by DSAs may partly reflect their training which emphasizes the need for such reporting. In addition, it is easier for nursing cover to be instituted in a hospital situation where there are a large number of DSAs on duty, while operators are less able to leave patients in mid-treatment to report injuries. This consideration would not of course be applicable in dental practice where only one DSA per dentist is usual. DSAs and ancillary staff are, however, more vulnerable to sharps injuries as their duties involve clearing away instruments, care of instruments and the cleaning of surgeries. Particular care must be taken and standard procedures adhered to during potential sharps injury risk procedures such as recapping or dismantling dental syringes and inserting or removing blades from scalpels. The wearing of rubber gloves, although now routine, does not prevent sharps injuries but the incidence of the latter can be reduced by careful technique (Wormseretal., 1988). Indeed, this present study showed that the number of reported sharps injuries has reduced in recent years. This may reflect an improvement in techniques. It is routine procedure in this hospital for clinical personnel to be immunized against hepatitis B virus, and the uptake of active immunization has been demonstrated by the increase to 1988 in the percentage of individuals
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No.
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who reported sharps injuries who had also previously been vaccinated against hepatitis B. Eye injuries accounted for a substantial number of injuries. No permanent injuries resulted. This at least may partly be attributable to the rapid initiation of appropriate first aid measures. In any case, all should be familiar with first aid measures and the location of a stock of suitable eye irrigants. Close-viewing and treating anterior teeth increase the exposure to missile damage. Eyes must be protected from foreign bodies, infected material, chemicals, and the various forms of radiation. Some 53 per cent of dentists wear glasses because of sight defects (Harley, 1978) but the simplest and most effective method of preventing eye injury by missiles is the use of proper protective spectacles preferably with plastic lenses and side shields. In the laboratory, a plexiglass shield will reduce splatter and flying particles, and appropriate dust extraction should be used whilst grinding and polishing appliances. Face protectors such as the Zephyr (Racal Ltd, Wembley, UK), have the advantage of giving a flow of filtered cool air to the operator and protecting eyes and respiratory system simultaneously. Thermal injuries and falls were also in the main preventable. Heat-resistant gloves should be provided for DSAs using autoclaves, and flooring should be maintained in good order (Scully et al., 1990). Most occupational accidents reported by dental hospital personnel could have been avoided had due care been taken during procedures or if thought had been given to the lay-out of surgeries, maintenance of furnishings, or provision of adequate materials for a given procedure. First aid measures fortunately prevented serious complications. References Baldwin A H., McCallum F. and Doull J. A. (1923) A case of pharyngeal diphtheria probably due to auto-infection from a diphtheric lesion of the thumb. JAMA 80, 1375. Beverley J. K. A, Skipper E. and Marshall S. C. (1955) Acquired toxoplasmosis: with a report of a case of laboratory infection. Br. Med. J. 1, 577-578. Cannon N. J. Jr, Walker S. P. and Dismukes W. E. (1972) Malaria acquired by accidental needle puncture. JAMA 222, 1425. Chacko C. W. (1966) Accidental human infection in the laboratory with the Nichols rabbit-adapted virulent strain of Treponema pallidurn. Bull. WHO 35, 809-810. Chappler R. R., Hoke A W. and Borchardt K. A (1977) Primary inoculation with Mycobacterium ma&urn. Arch. Dermatol. 113, 380. Collins C. H. and Kennedy D. A. (1987) Microbiological hazards of occupational needlestick and ‘sharps’ injuries. J. Appl. Bacterial. 62, 385-402. Cooley R. L. and Barkmeier W. W. (1981) Prevention of eye injuries in the dental office. Quintessence Int. 9, 953. Cooley R. L., Cottingham A J. Jr, Abrams H. et al. (1978) Ocular injuries sustained in the dental office: methods of detection, treatment and prevention. JADA 97, 985-988. Eichner K. (1965) Investigation on cutting and grinding procedures on the hard tooth structure and ivory. Aust. Dent. J. 10,214-216.
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