Occupational hazards in dentistry

Dr. preyas joshi
Rajasthan Dental College & Hospital
Jaipur

1. Occupational Hazards in Dentistry Dr. Preyas Joshi 3 rd Year Postgraduate Deptt . Of Public Health Dentistry Rajasthan Dental College & Hospital

2. Table of contents Hazards Risk Occupational medicine Types of hazards Global prevalence of Occupational Health Hazards in dentistry Factors responsible for Occupational Health Hazards in dentistry

3. Biological health hazards: HBV & HIV Stress Allergic reactions: Latex hypersensitivity Occupational respiratory hypersensitivity Noise Radiation Ergonomics Dental materials

4. Legal hazards Overhead expenses of a dentist WHO recommendations for routine immunization of Healthcare Workers. Recommended adult immunization by GoI . Routine precautions Conclusion References

5. What is a hazard? A  hazard  is any source of potential damage, harm or adverse health effects on something or someone under certain conditions at work. Basically, a hazard can cause harm or adverse effects (to individuals as health effects or to organizations as property or equipment losses).

6. Examples of a Hazard Examples of Hazards and Their Effects Workplace Hazard Example of Hazard Example of Harm Caused Thing Knife Cut Substance Benzene Leukemia Material Asbestos Mesothelioma Source of Energy Electricity Shock, electrocution Condition Wet floor Slips, falls Process Welding Metal fume fever Practice Hard rock mining Silicosis

7. Workplace hazards also include practices or conditions that release uncontrolled energy like: An object that could fall from a height ( potential or gravitational energy ). A run-away chemical reaction ( chemical energy ). The release of compressed gas or steam ( pressure; high temperature ). Entanglement of hair or clothing in rotating equipment ( kinetic energy ). Contact with electrodes of a battery or capacitor ( electrical energy ).

8. What is risk? Risk  is the chance or probability that a person will be harmed or experience an adverse health effect if exposed to a hazard. It may also apply to situations with property or equipment loss. Factors that influence the degree of risk include: How much a person is exposed to a hazardous thing or condition, How the person is exposed (e.g., breathing in a vapour , skin contact), and How severe are the effects under the conditions of exposure.

9. Occupational medicine Diagnostic, preventive, remedial, and therapeutic medicine practices relating to occupational hazards. The branch of clinical medicine most active in the field of occupational health. OM specialists work to ensure that the highest standards of occupational health and safety can be achieved and maintained.

10. Bernardino Ramazzini  THE FATHER OF OCCUPATIONAL MEDICINE (3 November, 1633 – 5 November, 1714) His most important contribution to medicine was his book on occupational diseases,  De Morbis Artificum Diatriba ("Diseases of Workers"). He proposed that physicians should extend the list of questions that Hippocrates recommended they ask their patients by adding, "What is your occupation?"

11. What types of hazards are there? Canadian Centre for Occupational Health and Safety A common way to classify hazards is by category: Biological  - bacteria, viruses, insects, plants, birds, animals, and humans, etc., Chemical  - depends on the physical, chemical and toxic properties of the chemical. Ergonomic  - repetitive movements, improper set up of workstation, etc., Physical  - radiation, magnetic fields, pressure extremes (high pressure or vacuum), noise, etc, Psychosocial  - stress, violence, etc., Safety  - slipping/tripping hazards, inappropriate machine guarding, equipment malfunctions or breakdowns

12. National Institute of Occupational Health The NIOH is the premier institute, under the aegis of the   Indian Council of Medical Research (ICMR) under the  Department of Health Research ,  Ministry of Health and Family Welfare , Govt. of India. The Institute started functioning as "Occupational Health Research Institute" (OHRI) at the B. J. Medical College, Ahmadabad, in the year 1966. The OHRI was rechristened as "National Institute of Occupational Health" (NIOH) in 1970 and moved to the present premises.

13. The National Institute of Occupational Health (NIOH) has been established with the following objectives: To promote intensive research to evaluate environmental stresses/factors at the workplace. To promote the highest quality of occupational health through fundamental and applied research. To develop control technologies and health programmes through basic and fundamental research and to generate human resources in the field. The Institute functions as a WHO Collaborative and Reference Centre for Occupational Health

14. Global Prevalence of Occupational Health Hazards in Dentistry An Italian multicenter study on infection hazards during dental practice reported that some Italian dental surgeries show high bio contamination. With regard to Legionella spp. (Aerobic, Gram-negative, Non- sporeforming , rod-shaped bacteria), the proportion of positive samples was 33.3%. 1 In India an investigation among Navy dentists revealed that 47% of them experienced an injury from a sharp instrument during the past six months and backache was the commonest hazard in 70.6% of the personnel followed by occasional anxiety and wrist ache. 2 Castiglia P et al. Italian multicenter study on infection hazards during dental practice: Control of environmental microbial contamination in public dental surgeries. BMC Public Health 2008; 8:187. Chopra SS et al. Occupational Hazards among Dental Surgeons. Medical Journal Armed Forces India 2007; 63(1):23-25.

15. Another study carried out among dental professionals in Chandigarh, India reported that injury from “sharps” was the most common occupational hazard (77%). Of the other occupational problems job related stress (43.3%), musculoskeletal problems (39.8%), and allergies (23.8%) from things used in dental clinics were most common. 3 In a study carried out among dentists in southern Thailand revealed that The most common occupational health problems were musculoskeletal pain (78 percent) and percutaneous injury (50 percent). 4 Abhishek Mehta et al. Status of occupational hazards and their prevention among dental professionals in Chandigarh, India: A comprehensive questionnaire survey. Dent Res J (Isfahan) 2013; 10(4): 446–451. Suthipong Chowanadisai et al. Occupational health problems of dentists in southern Thailand. International Dental Journal 2000; 50: 36-40.

16. Fatigue (94.7%) and back pain (91.0%) were the most prevalent physical complaints reported by Lithuanian Dentists. Hypertension, joint diseases and allergy were the most prevalent diagnosed and treated diseases during the previous 12 months . 5 A survey from Belgium found that Flemish dentists reported occupational health complaints such as low back pain, 54% (stress-correlated); vision problems, 52.3% (age correlated); infections, 9%; allergies, 22.5% (mainly latex). 6 Alina Puriene et al. Self-Reported Occupational Health Issues among Lithuanian Dentists. Industrial Health 2008; 46: 369–374. F Gijbels et al. Potential occupational health problems for dentists in Flanders, Belgium. Clin Oral Invest 2006; 10: 8–16.

17. A study in Malaysian dental schools revealed a high prevalence (93%) of musculoskeletal disorders among clinical year students. 7 Saad A Khan and Kwai Yee Chew. Effect of working characteristics and taught ergonomics on the prevalence of musculoskeletal disorders amongst dental students. BMC Musculoskelet Disord 2013; 14: 118. Adebola Fasunloro , Foluso John Owotade . Occupational hazards among clinical dental staff. The journal of contemporary dental practice 2004; 5(2):134-52. A survey on occupational hazards among the clinical dental staff at the dental hospitals of Nigeria found that backache was the most frequently experienced hazard in 47% of the subjects. 8

18. In a study carried out among dentists and dental auxiliaries in Riyadh, Saudi Arabia to know the prevalence of hearing problems in the last five years, 16.6% of subjects reported to be suffering from tinnitus, 30% of the subjects had difficulty in speech discrimination and 30.8% of the subjects had speech discrimination in a background noise. 9 Another study conducted among dentists in Southern Iran reported that 33% of them were suffering from lower back pain while 28% had neck pain. 10 Al Wazzan KA, Al Qahtani MQ, Al Shethri SE, Al Muhaimeed HS, Khan N. Hearing problems among dental personnel. J PakDent Assoc 2005; 14: 210-214. Pargali N, Jowkar N. Prevalence of musculoskeletal pain amongdentists in Shiraz, Southern Iran. International J Occup Environ Med 2010; 1: 69-74.

19. In a recent study it was found that seventy-eight percent of dental practitioners in a city in the southern state of Andhra Pradesh, India had a prevalence of at least one Musculoskeletal Disorders symptom over the past twelve months. Most common areas affected by MSD in order of magnitude were neck (52%), low back (41%), shoulders (29%) and wrist (26%). One third of the practitioners (40%) required sick leave from their practice during the preceding twelve months. 11 Dhanya Muralidharan et al. Musculoskeletal Disorders among Dental Practitioners: Does It Affect Practice? Epidemiology Research International Volume 2013 (2013), Article ID 716897.

20. Wide variety of factors responsible for occupational hazards in dentistry 12 Agrawal Neha et al. Occupational Hazards in Modern Dentistry: A Review. International Journal of Medicine & Health Research 2014;1(1):1-9

21. Biological Health Hazards Dentists constitute a group of professionals who are likely to become exposed to biological health hazards. These hazards are constituted by infectious agents of human origin and include viruses, bacteria and fungi. From the occupational view point percutaneous exposure incidents particularly needlestick and sharp instrument injuries represents the most efficient method for transmitting blood born infections between patients and health care workers. 13 Leggat et al. Occupational health problems in modern dentistry – a review. Industrial health 2007; 45: 611-621

22. This exposure is related to the fact that dentists work in a limited-access and restricted-visibility field and frequently use sharp devices. Percutaneous exposure incidents facilitate transmission of bloodborne pathogens such as human immunodeficiency virus [HIV], hepatitis C virus [HCV] and hepatitis B virus [HBV]. Needles and drilling instruments such as burs represented the most common devices as the cause of exposure and injury. 12

23. Shah SM et al carried out a study in Washington which revealed that 66.7% of the percutaneous injuries are sustained by dentists and most of the injuries (70%) occurred during administration of local anesthesia, recapping a needle and performing surgical procedures. 14 In a epidemiological study of needle stick and sharp instrument accidents in a Nigerian hospital it was found that needle stick accidents during the previous year were reported by 27% of 474 HCWs, including 100% of dentists, 81% of surgeons, 32% of nonsurgical physicians, and 31% of nursing staff. The rate of needle stick injuries was 2.3 per person-year for dentists . 15 Shah SM et al. Percutaneous injuries among dental professionals in Washington State. BMC Public Health 2006; 6: 269. Adegboye AA et al. The epidemiology of needlestick and sharp instrument accidents in a Nigerian hospital. Infect Control Hosp Epidemiol 1994 ;15(1):27-31.

24. Dental environment is also associated with a significant risk of exposure to various micro-organisms. Agents may be present in blood or saliva, as a consequence of bacterimia or viremia associated with systemic infections. Dental patients and Dental Health Care Workers [DHCW] may be exposed to variety of microorganisms via blood or oral or respiratory secretions.

25. These micro-organisms may include: Cytomegalo virus Hepatitis B virus Hepatitis C virus Herpes simplex virus types 1 and 2 HIV Mycobacterium tuberculosis Other viruses and bacteria, especially those that infect the upper respiratory tract.

26. A DIRECT INFECTION occurs when: Microorganisms enter through a cut on the skin of hand while performimg a dental procedure. Any dental procedure resulting in an accidental biting of the patient. By the patient, or through a needle wound created while imparting anaesthesia .

27. An indirect infection occurs when an infectious agent is transmitted into the dental care giver through the so-called carrier. The following are the main sources of INDIRECT INFECTION : Aerosols of saliva Gingival fluid Natural organic dust particles (dental caries tissue) mixed with air and water Accidental breakage of dental instruments and devices

28. The following are the main entry points of infection: Epidermis of hands Oral epithelium Nasal epithelium Epithelium of upper airways Bronchial tubes Alveoli Conjunctival epithelium

29. All members of the dental dental personnel team are at risk of exposure to Hepatitis B virus (HBV), HIV infection, and other types of communicable infections. In the United Kingdom for example, the carrier rate of HBV in the general population is 0.5%, while dentists have a carrier rate of approximately 1.6%.

30. Hepatitis B India has approximately HBV carrier rate of 3.0% with a high prevalence rate in the tribal population. With a population of more than 1.25 billion, India has more than 37 million HBV carriers and contributes a large proportion to Global HBV burden. India harbors 10–15% of the entire pool of HBV carriers of the world ( 2.96% of the total indian polpulation is infected with HBV ).

31. Every 34 th patient Coming to your dental practice Is Infected with HBV

32.   Human immunodeficiency virus (HIV) The risk of HIV transmissions to healthcare workers approximately range from 0.2 to 0.3% for parenteral exposures and 0.1% or less for mucosal exposures. A report published by the Centers for disease control and prevention (CDC) studied the 208 dental exposures ( percutaneous , mucous membrane, and prolonged skin exposures) reported to the CDC from 1995 to 2001, 13% had HIV-positive source patients and did not lead to a seroconversion (75% of exposed individuals took the three-drug PEP regimen for variable lengths of time). Cleveland JL et al. The National Surveillance System for Health Care Workers Group of the Centers for Disease Control and Prevention. Use of HIV post-exposure prophylaxis by dental health personnel: An overview and updated recommendations. J Am Dent Assoc 2002;133:1619-26.

33. A major concern among dentists is cross-infection, i.e. from an infected patient to the dentist and further from the dentists to other patients in case of an accidental needle stick injury. In 2011-12 at least 2.7 per cent of the total HIV infected population caught HIV through unknown and unspecified routes, leading them to believe it could be dental surgery. Taking stock of the situation, National AIDS Control Organisation (NACO) is thinking about highlighting the infection spread through dental surgery.

34. If someone is seropositive for HIV (the Human Immunodeficiency Virus), it means their body has been producing antibodies for HIV. Seroconversion is the point at which the body changes from being seronegative to seropositive . The National AIDS Control Organization reports that 2.3% of the Indian population is HIV seropositive (Approx. 28.75 million). Every 43 rd patient visiting a dental practice in India is infected with HIV.

35. Infectious agents may gain access to the human host through a wide variety of exposure events

36. A management pathway which can be applied to a range of biological risks in dental practice

37. Stress The dental profession is often perceived as rather stressful, and a number of studies pay attention to psychological stress and stress-related health problems in the dental population. A strict time schedule , coping with anxious patients or painful treatments are frequently referred to as major stressors, procedures connected with anaesthetization of patients , overcoming of pain and fear , unanticipated emergency situations in which a patient’s life is in danger, or procedures with hesitant prognosis . 12

38. Dentistry Stands third among the top 11 Professions with Highest Suicide Rates Source: http://www.businessinsider.com/most-suicidal-occupations-2011-10

39. Rankin and Harris (1990) stated that causing pain and discomfort in patients was the source of stress that was most often stated by all examined doctors, and that this issue was more stressful for female doctors than for male doctors. 16 Furthermore, dental practitioner reporting psychological stress would have more musculoskeletal complaints. 12 Ayers KM et al. (2008) conducted a study to investigate job stressors and coping strategies among New Zealand dentists and found that the most commonly reported stressors were treating difficult children (52%), constant time pressure (48%) and maintaining high levels of concentration (43%) 17 . Rankin J, Harris M: A comparision of stress and coping in male and female dentists. J Dent Pract Admin 1990; 7: 166-172. Ayers KM et al. Job stressors of New Zealand dentists and their coping strategies. Occup Med ( Lond ) 2008; 58(4):275-81.

40. A nationwide cross-sectional survey was undertaken on 2,441 GDPs in the UK. The main findings were that Health behaviours such as alcohol use was associated with work stress and over a third of GDPs were overweight or obese . Sixty per cent of GDPs reported being nervy, tense or depressed, 58.3% reported headache, 60% reported difficulty in sleeping and 48.2% reported feeling tired for no apparent reason. 18 Gortzak RA et al. (1995) in their study on ambulant 24-hour blood pressure and heart rate of dentists found that Blood pressure and heart rate are shown to be significantly higher during work than during other activities, whereas these differences could not be observed in a non-dentist population. 19 Myers HL et al. ‘It’s difficult being a dentist’: stress and health in the general dental practitioner. Br Dent J 2004; 197: 89-93. Gortzak RA et al. Ambulant 24-hour blood pressure and heart rate of dentists. Am J Dent 1995;8:242–244.

41. Allergic Reactions An occupational allergic reaction particularly of the hands like contact dermatitis and atopic dermatitis is a common problem among dental personnel. In southern Thailand Nearly one fifth (18.1 percent) of male dentists and over one quarter (25.3 percent) of female dentists reported experiencing contact dermatitis. 12 In New-Zealand over 40 percent of dentists had experienced symptoms of contact dermatitis at some stage during their practicing life. 20 Sinclair NA. Prevalence of self-reported hand dermatoses in New Zealand dentists. New Zealand Dent J 2004; 100:38-41

42. Latex Hypersensitivity Currently, gloves are worn routinely by most general dental practitioners while diagnosing and treating patients, with latex being the most commonly used glove material universally. The clinical symptoms of latex allergies include: Urticaria Conjunctivitis accompanied by lacrimation and swelling of eyelids Mucous rhinitis Bronchial asthma Anaphylactic Shock.

43. Agrawal A et al. (2010) conducted a study to assess the prevalence of allergy to latex gloves among dental professionals in Udaipur, Rajasthan. A total of 26 (16%) dental professionals reported allergy to latex gloves, of which females (27.3%) reported significantly greater allergy than males (11.8%). 21 Vangveeravong M et al. (2011) conducted a cross sectional survey to study the prevalence of latex-related symptoms, latex-sensitization. It was found that the prevalence of latex allergy in dental students is 5%. 22 Agrawal A et al. Prevalence of allergy to latex gloves among dental professionals in Udaipur, Rajasthan, India. Oral Health Prev Dent 2010; 8(4):345-50. Vangveeravong M et al. Latex allergy in dental students: a cross-sectional study. J Med Assoc Thai 2011; 94(3):S1-8.

44. Occupational Respiratory Hypersensitivity Allergic contact dermatitis caused by acrylate compounds is common in dental personnel; they also often complain of work-related respiratory symptoms. In a study conducted by Piirilä P et al. (1998), twelve cases of respiratory hypersensitivity were found to be caused by acrylates among dental personnel (six dentists and six dental nurses) in 1992-97. 23 Piirilä P et al. Occupational respiratory hypersensitivity caused by preparations containing acrylates in dental personnel. Clin Exp Allergy 1998; 28(11):1404-1411.

45. Noise The danger to hearing from the dental-clinic working environment in a dental school cannot be underestimated. The noise levels of modern dental equipment have now fallen below 85dB(A), the widely used benchmark standard, below which the risk of hearing loss is minimal. 24 Nonetheless some dentists may still be at risk particularly when older and non standardized equipments are used. 25 Setcos JC et al. Noise levels encountered in dental clinical and laboratory practice. Int J Prosthodont 1998; 11: 150-157. Suthipong Chowanadisai et al. Occupational health problems of dentists in southern Thailand. International Dental Journal 2000; 50: 36-40.

46. Dental personnel are exposed to noise of different sound levels while working in dental clinics or laboratories. Dental laboratory machine, dental hand piece, ultrasonic scalers , amalgamators, high speed evacuation devices and other items produce sound at different levels which is appreciable. As reported in an earlier study by Caballero AJ et al. (2010) conducted among dentists and dental auxiliaries, 16.6% of subjects reported of tinnitus, 30% had difficulty in speech discrimination and 30.8% had speech difficulty in a background noise.

47. The noise levels of modern dental equipment is below 85 db and up to this point the risk of hearing loss is negligible. But the risk is amplified while using older or faulty equipment. In dental practical classes, the acoustic environment is characterized by higher noise levels, in relation to other teaching areas, due to exaggerated noise produced by some of these devices and due to the use of a single dental equipment by many users at the same time. This situation is aggravated when the classrooms have hard surfaces which act as noise reflectors, as is usually the case.

48. Ultrasonic scalers sometimes may be a potential hazard to the auditory system of both clinicians and patients. Damage to operator hearing is possible through air-borne subharmonics of the ultrasonic scaler . For the patient, damage can occur through the transmission of ultrasound through the tooth contact to the inner ear via the bones of the skull. This later hazard is possible during the scaling of molar teeth. Tinnitus is an early sign of hearing loss and may occur following ultrasonic scaling in some individuals. A small number of dentists have experienced tinnitus or numbness of the ear after the prolonged use of ultrasonic scaler , which indicates a small potential risk to hearing.

49. Kilpatrick (1981) has listed the decibel ratings for various office instruments and equipment, which amount to: 70–92 dB for highspeed turbine hand pieces 91 dB for ultrasonic cleaners ( decontamination of dental instruments) 86 dB for ultrasonic scalers 84 dB for stone mixers 74 dB for low-speed hand pieces.

50. EFFECTS OF NOISE Auditory effects Auditory Fatigue (90dB or 4000 Hz) Deafness- Temporary (4000-6000Hz) Permanent (100dB) NON AUDITORY EFFECTS Interference with speech Annoyance Reduction in efficiency Physiologic damage (increased intracranial pressure, increased heart rate, headache etc)

51. Radiation Harmful radiation like Non-ionizing radiation (visible and UV light) and ionizing radiation (X-rays) can cause damage to various body cells. Ionizing radiation is a well established risk factor for cancer. Ramandeep Singh Gambhir et al. (2011) reviewed various studies related to occupational hazards in dental profession and found that the secondary radiation scattered from bones in the patient’s head is now representing the greatest source of radiation received by dentists and dental workers. 26 Ramandeep Singh Gambhir et al. Occupational Health Hazards in Current Dental Profession- A Review. The Open Occupational Health & Safety Journal 2011;3:57-64.

52. Non-ionizing radiation has become an important concern with the use of blue light and UV light (ultra-violet) to cure various dental materials. Exposure to the radiations emitted by these can cause damage to the various structures of the eye including the retina and the cornea. 27 Yenogopal V et al. Infection control among dentists in private practice in Durban. SADJ 2001; 56: 580-4.

53. Ergonomics Musculoskeletal Disorders (MSD) and diseases of the peripheral nervous system Muscular pain is a common affliction in dentists which begins at the time they start their professional studies and it stays with them during their professional practice affecting the spine, neck, shoulders and hands, among others. It has been proven that postures which may exert a higher pressure on intervertebral disk as well as prolonged spinal hypomobility are among important factors leading to degenerative changes in the lumbar spine and subsequent lower back pain.

54. In Greek, “Ergo,” means work and, “ Nomos ,” means natural laws or systems. Ergonomics,therefore , is an applied science concerned with designing products and procedures for maximum efficiency and safety.

55. A study in Greece indicated that 62% of dentists complained at least one musculoskeletal complaint, 30% chronic complaints, and 16% sought medical care. 28 A Finnish study reports musculoskeletal symptoms from the back and neck of 30% of the dentists. 29 In an American study, 57% of 960 dentists in a Dental Society reported occasional back pain. 29 Alexopoulos EC et al. Prevalence of musculoskeletal disorders in dentists. BMC Musculoscelet Disord 2004;5:16 Moen BE et al. Musculoskeletal symptoms among dentists in a dental school. Occup Med 1996; 46: 65-6..

56. Cumulative trauma disorders (CTDS) are health disorders arising from repeated biomechanical stress to the hands, wrist, elbows, shoulders, neck and back. Most common CTDS are Carpal tunnel syndrome and Low back pain . CTS is defined as symptomatic compression of the median nerve within the carpal tunnel, which is the space between the transverse carpal ligament on the palmar aspect of the wrist and the carpal bones on the dorsal aspect of the wrist.

57. At work, the dentist works in a strained posture (both while standing and sitting close to a patient), which eventually leads to overstress of the spine and limbs. This refers to the 37.7% of the work time . The overstress produces a negative effect on the musculoskeletal system and the peripheral nervous system; above all, it affects the peripheral nerves of the upper limbs and the neck nerve roots. 30,31 Rundcrantz BL et al. Cervical pain and discomfort among in dentist. Epidemiological, clinical and therapeutic aspects. Part 1. A survey of pain and discomfort. Swed Dent J 1990;14: 71-80. Rundcrantz BL et al. Pain and discomfort in the musculoskeletal system among dentists: a prospective study. Swed Dent J 1991; 15: 219-28.

58. In a recent study (2013) on Musculoskeletal disorders and symptom severity among Australian dental hygienists it was found that MSD were frequently reported by dental hygienists in the neck (85%), shoulder (70%), and lower back (68%). 32 Operations carried out during extractions stress not only the elbow joint and the wrist joint but may result in chronic tendon sheath inflammation. The long-term effect of all those adverse circumstances occurring in the work of the dental doctor may lead to diseases described as cumulative trauma disorders. Hayes MJ et al. Musculoskeletal disorders and symptom severity among Australian dental hygienists. BMC Res Notes 2013 Jul 4;6:250.

59. Dental Materials There are many potentially toxic materials that are used in dentistry that may pose a health hazard in the absence of appropriate precautionary measures. Most of the dental materials undergo an extensive range of tests both before and after use. Even so, some dental materials are aerosolized during high speed cutting and finishing and may thereby be inhaled by dental staff. Other dental materials are volatile and may give rise to dermatological and respiratory effects ( Application of bonding agents during performance of dental fillings ).

60. Occupational exposure of dental staff to elemental mercury vapor released from dental amalgam is an issue of concern because of the possible immunological and neurological adverse outcomes. Farahat SA et al. (2009) conducted a study aimed at investigating mercury body burden in dental staff and the relation of this burden to the potential impact of mercury on thymus gland hormone level ( thymulin ). The results showed that dentists and dental nurses have significant exposure to mercury vapor. 33 Decreased production of thymulin results in immunosuppression Farahat SA et al. Effect of occupational exposure to elemental mercury in the amalgam on thymulin hormone production among dental staff. Toxicol Ind Health 2009;25(3):159-67

61. BE Moen et al. (2008) conducted a study with the aim to compare the occurrence of neurological symptoms among dental assistants likely to be exposed to mercury from work with dental filling material, compared to similar health personnel with no such exposure. Results showed that the higher occurrence of neurological symptoms among the dental assistants may be related to their previous work exposure to mercury amalgam fillings. 34 BE Moen et al. Neurological symptoms among dental assistants: a cross-sectional study. Journal of Occupational Medicine and Toxicology  2008,3:10

62. National Council Against Health Fraud (NCAHF) believes that amalgam fillings are safe, that anti-amalgam activities endanger public welfare, and that so-called "mercury-free dentistry" is substandard practice. NCAHF Position Paper on Amalgam Fillings (2002) recommended ( To Consumers ): Not to worry about the safety of amalgam fillings. Avoid health professionals who advise you that amalgam fillings cause disease or should be removed as a "preventive measure." Report any such advice to the practitioner's state licensing board. Source: http://www.ncahf.org/pp/amalgampp.html

63.  In 2009, the U.S. Food and Drug Administration (FDA) evaluated this research which found no reason to limit the use of amalgam. The FDA concluded that amalgam fillings are safe for adults and children ages 6 and above. The FDA issued a final rule on 28 July, 2009 which classified dental amalgam as a "Class II" (moderate risk) device, placing it in the same category as composite resins. In a press release announcing the reclassification, the agency again stated that "the levels [of mercury] released by dental amalgam fillings are not high enough to cause harm in patients."

64. Chemicals used in radiology can also lead to occasional health problems. Developing solutions contain chemicals that control the processing speed, a preservative and a hardening agent. Fixing solutions include a neutralizer, a clearing agent to remove underdeveloped silver bromide ions, a preservative and a hardening agent.

65. Mixing of processor chemical components also causes the release of sulphur - dio -oxide from decomposition of sulphite . Chronic exposure may result in bronchospasm . Ammonia, a highly soluble respiratory irritant, is another potential by-product released from the breakdown of processing chemicals. Another source of vapor release is the silver recovery unit. It is important that the lid be tightly secured and only opened in a well-ventilated area.

66. Raghuwar D. Singh et al. (2014) assessed the awareness and performance towards dental waste and practices among the dental practitioners in North India. An epidemiologic survey was conducted among 200 private dental practitioners. 45.0% of the dentists dispose of the developer and fixer solutions by letting them into the sewer, 49.4% of them dilute the solutions and let them into sewer and only 5.6% return them to the supplier. 35 Fixer solution contains silver and if put into sewer it will increase the metal load in the sewer which is not allowed as per environmental protection rules. We have to store it separately and handle it over to certified buyers who will extract silver from it. Raghuwar D. Singh et al. Mercury and Other Biomedical Waste Management Practices among Dental Practitioners in India. BioMed Research International 2014

67. Legal Hazards In every nation there are relevant laws and regulations which apply to the practice of dentistry. The breach of any of these may warrant that legal actions be taken against a dental practitioner particularly in developed countries where the populace appear more aware of their rights. To help assure a safe work environment in dental treatment, the hazard awareness and prevention of legal risks should be made known to all dental professionals.

68. A few dental negligent acts Failure to attend an emergency is negligence: A patient cannot be refused treatment on the ground that it is a medico legal case and therefore to be seen in a government or approved hospital. It is the dentist’s responsibility to prevent cross infection between patients. Endangering the health or lives of other patients (even without injury) can invite criminal negligence ( Sec 336 IPC ). Lack of informed consent is a cause of malpractice action, and without it, unlawful touching can be alleged.

69. Failure to give advice clearly results in complication. Dentist must give clear instructions regarding diet and postoperative care. If prescriptions are not clear and if they do not have proper instructions, the dentist is deemed to have been negligent. Failure of dentist to advice a crown for root canal filled tooth with significant loss of tooth substance can result in fracture of tooth. Dentist will be held liable. Accidental ingestion of crowns, dental instrument, teeth etc. can also be considered as negligence.

70. Patient was given local anesthesia without test dose and developed anaphylaxis and died. Dentist will be held liable. Under Public Liability Insurance Act, a dentist can be held liable for harm caused to the public by inadvertant exposure of harmful substances like mercury, arsenic and even radiations. 36

71. Non-negligent acts Not obtaining a consent form in an emergency is not negligent. Patient’s dissatisfaction with the progress of treatment cannot be called negligence. Not getting desired relief is not negligence. Charging, what the patient thinks is exorbitant is not negligence. When patient does not follow advice of the doctor and does not get satisfactory results, dentist cannot be held negligent. 36 Rajan Dhawan et al. Legal aspects in dentistry. Journal of Indian Society of Periodontology 2010;14(1):81-84

72. Overhead Expenses of a Dentist A solo dental practitioner has certain overhead costs to meet: utilities, rent, equipment, supplies, staff, payroll and insurance. 37 These expenses must be met regardless of whether or not patients come and whether or not fees are collected. Many dentists graduate from the dental schools heavily in debt because of the high costs of their education and thus have a strong incentive to begin showing profits soon after they begin practice. Burt BA, Eklund SA. Dentistry, Dental Practice and the Community. 6th ed. Missouri: Elsevier Saunders 2005.

73. Failure to meet the overhead expenses and unable to pay the above mentioned debts, creates a tension situation in the minds of the dentist. Many cases of suicidal tendencies are noted because of the above mentioned reasons. 37 Failure to earn more also creates a stress situation in the families of the concerned dentists. Therefore, proper and sound earning is also very essential for a good living and good relationship.

74. WHO recommendations for routine immunization of Healthcare workers

75. It is expected that HCWs are fully vaccinated per the national vaccination schedule in use in their country. Source: http://www.who.int/immunization/policy/Immunization_routine_table4.pdf?ua=1 [Accessed on: 28/12/2015]

76. The cardinal rule of health care is “First, do no harm.” Yet unsafe injection practices pose serious health risks to recipients, health workers , and the general public. 95% injections are administered for therapeutic purposes, rather than for immunization and many of these “curative” injections may be unnecessary, ineffective, or inappropriate. The provision of auto disable syringes by the Government of India and the implementation of Central Pollution Control Board (CPCB) outlined waste management procedures are attempts to improve injection safety in the immunization program. Immunization Handbook for Medical Officers, 2008 Published by: Department of Health and Family Welfare, Government of India

77. In 2005 Becton Dickinson India Private Limited (BD - India) donated BD SoloShot ™ LX auto-disable syringes for BCG ( Bacille Calmette Guérin ) vaccination against tuberculosis (TB) to the District Immunization Officer of Rewari , Government of Haryana. BD donated over 300,000 auto-disable syringes to facilitate the immunization program in District Rewari . WHO estimates that 260,000 HIV infections (5% of global burden) and 21 million (32% of global burden) HBV infections and 2 million HCV infections per year were caused by use of reusable syringes and unsafe injections.

78. WHO urges India to advocate use of auto-disable syringes ( Wednesday, February 25, 2015 ) It is a very proud moment for India that WHO has chosen India as the focus country to  tackle the pervasive issue of unsafe injection practices   and also because the global leader and innovator in AD syringes happens to be an Indian company – Hindustan Syringes and Medical Device Ltd (HMD) shall work hand in glove with WHO’s global directive for use of Auto Disposable syringes in public healthcare systems.

79. Recommended adult immunization schedule, by vaccine and age group CD Alert. National Centre for Disease Control. Directorate General of Health Services, Government of India 2011;14(2):1-8.

80. ROUTINE PRECAUTIONS 40 Immunisation : All dental health care workers are advised to be immunized against HBV unless immunity from natural infection or previous immunization had been documented. Protective coverings: Uniforms: Uniforms should be changed regularly and whenever soiled. Gowns or aprons should be worn during procedures that are likely to cause spattering or splashing of blood. Raja.K et al. OCCUPATIONAL HAZARDS IN DENTISTRY AND ITS CONTROL MEASURES – A REVIEW. World Journal of Pharmacy and Pharmaceutical Sciences 2014;3(6):397-415

81. Hand protection: Gloves must be worn for procedures involving contact with blood, saliva or mucous membrane. A new pair of gloves should be used for each patient. If a glove is damaged, it must be replaced immediately. Hands should be washed thoroughly with a proprietary disinfectant liquid soap prior to and immediately after the use of gloves. Disposable paper towels are recommended for drying of hands. Any cuts or abrasions on the hands or wrists should be covered with adhesive water proof dressings at all times.

82. Protective glasses, masks or face shields: Protective glasses, masks or face shields should be worn by operators and close-support dental surgery assistants to protect the eyes against the spatter and aerosols which may occur during cavity preparation, scaling and the cleaning of instruments.

83. Sharp instruments and needles: Sharp instruments and needle should be handled with great care to prevent unintentional injury. Needles should never be recapped by using both hands or by any other technique that involves moving the point of a used needle towards any part of the body. The 'one-handed' technique for recapping a needle.

84. First aid and inoculation injuries: An inoculation/splash injury may be defined as: - Sticking or stabbing with a needle or other sharp instrument Splashes in the eyes or mouth i.e. mucous membranes or open lesions on the skin surface Cuts from any equipment contaminated with blood or body fluids Bites or scratches inflicted by a person where the skin is broken.

85. ACTION IN THE EVENT OF INOCULATION/SPLASH INJURY Low or significant exposure will be determined by the injured staff member and their immediate supervisor using the Risk Assessment Check List. Significant exposure is defined as: Percutaneous Injury – breaks in the skin e.g. from needles, instruments, bone fragments or a significant bite. Exposure of broken skin – e.g. due to eczema, cuts, abrasions or injury. Exposure of mucous membrane including the eye.

86. The RISK of acquisition of HIV increases if: The injury is deep A needle has been used in the patient’s artery or vein There is visible blood on the device The patient has HIV, AIDS or a high viral load If the Risk Assessment Check List indicates Significant Exposure, and an increased risk of HIV, the incident should be reported to the on call Consultant Microbiologist immediately. The Consultant Microbiologist in consultation with the injured party will make a decision on the need for Post Exposure Prophylaxis (PEP).

87. PEP regimens are typically classified as Basic and Expanded: Basic regimens consist of two nucleoside reverse transcriptase inhibitors (NRTIs), typically zidovudine plus lamivudine ; other combinations of NRTIs can be recommended as alternative regimens.

88. An Expanded regimen consists of a Basic regimen plus one or more additional ARV( antiretrovirals ) such as nelfinavir (NFV) or efavirenz (EFV) . Expanded regimens offer the possibility of greater potency, but there is no direct evidence that expanded PEP regimens are more effective in this setting than basic regimens, and expanded regimens typically involve a higher pill burden and more potential for toxicity.

89. CONCLUSION One thing should kept in mind that every technology, no matter how beneficial, can exert a negative impact on some members of the population. Immunization against various infectious diseases like HIV, HBV etc. is very essential for every Dental Health Care Worker. Dentists should control their working hours, pace of work, be aware of occupational hazards and observe their mental health.

90. Serious infections due to percutaneous exposure incidents(PEI) can be avoided by use of appropriate barrier techniques and high level sterilization. Dental personnel should be familiar with the major signs and symptoms of allergic reactions. High production demands in combination with stressful working conditions will affect health.

91. Various continuing dental education programs should be organized so that dental professionals can gain knowledge about various newer methods and developments.

92. References Castiglia P et al. Italian multicenter study on infection hazards during dental practice: Control of environmental microbial contamination in public dental surgeries. BMC Public Health 2008; 8:187. Chopra SS et al. Occupational Hazards among Dental Surgeons. Medical Journal Armed Forces India 2007; 63(1):23-25. Abhishek Mehta et al. Status of occupational hazards and their prevention among dental professionals in Chandigarh, India: A comprehensive questionnaire survey. Dent Res J (Isfahan) 2013; 10(4): 446–451. Suthipong Chowanadisai et al. Occupational health problems of dentists in southern Thailand. International Dental Journal 2000; 50: 36-40. Alina Puriene et al. Self-Reported Occupational Health Issues among Lithuanian Dentists. Industrial Health 2008; 46: 369–374. F Gijbels et al. Potential occupational health problems for dentists in Flanders, Belgium. Clin Oral Invest 2006; 10: 8–16.

93. Saad A Khan and Kwai Yee Chew. Effect of working characteristics and taught ergonomics on the prevalence of musculoskeletal disorders amongst dental students. BMC Musculoskelet Disord 2013; 14: 118. Adebola Fasunloro , Foluso John Owotade . Occupational hazards among clinical dental staff. The journal of contemporary dental practice 2004; 5(2):134-52. Al Wazzan KA, Al Qahtani MQ, Al Shethri SE, Al Muhaimeed HS, Khan N. Hearing problems among dental personnel. J PakDent Assoc 2005; 14: 210-214. Pargali N, Jowkar N. Prevalence of musculoskeletal pain amongdentists in Shiraz, Southern Iran. International J Occup Environ Med 2010; 1: 69-74. Dhanya Muralidharan et al. Musculoskeletal Disorders among Dental Practitioners: Does It Affect Practice? Epidemiology Research International Volume 2013 (2013), Article ID 716897. Agrawal Neha et al. Occupational Hazards in Modern Dentistry: A Review. International Journal of Medicine & Health Research 2014;1(1):1-9 Leggat et al. Occupational health problems in modern dentistry – a review. Industrial health 2007; 45: 611-621

94. Shah SM et al. Percutaneous injuries among dental professionals in Washington State. BMC Public Health 2006; 6: 269. Adegboye AA et al. The epidemiology of needlestick and sharp instrument accidents in a Nigerian hospital. Infect Control Hosp Epidemiol 1994 ;15(1):27-31. Rankin J, Harris M: A comparision of stress and coping in male and female dentists. J Dent Pract Admin 1990; 7: 166-172. Ayers KM et al. Job stressors of New Zealand dentists and their coping strategies. Occup Med ( Lond ) 2008; 58(4):275-81. Myers HL et al. ‘It’s difficult being a dentist’: stress and health in the general dental practitioner. Br Dent J 2004; 197: 89-93. Gortzak RA et al. Ambulant 24-hour blood pressure and heart rate of dentists. Am J Dent 1995;8:242–244. Sinclair NA. Prevalence of self-reported hand dermatoses in New Zealand dentists. New Zealand Dent J 2004; 100:38-41

95. Agrawal A et al. Prevalence of allergy to latex gloves among dental professionals in Udaipur, Rajasthan, India. Oral Health Prev Dent 2010; 8(4):345-50. Vangveeravong M et al. Latex allergy in dental students: a cross-sectional study. J Med Assoc Thai 2011; 94(3):S1-8. Piirilä P et al. Occupational respiratory hypersensitivity caused by preparations containing acrylates in dental personnel. Clin Exp Allergy 1998; 28(11):1404-1411. Setcos JC et al. Noise levels encountered in dental clinical and laboratory practice. Int J Prosthodont 1998; 11: 150-157. Suthipong Chowanadisai et al. Occupational health problems of dentists in southern Thailand. International Dental Journal 2000; 50: 36-40. Ramandeep Singh Gambhir et al. Occupational Health Hazards in Current Dental Profession- A Review. The Open Occupational Health & Safety Journal 2011;3:57-64. Yenogopal V et al. Infection control among dentists in private practice in Durban. SADJ 2001; 56: 580-4.

96. Alexopoulos EC et al. Prevalence of musculoskeletal disorders in dentists. BMC Musculoscelet Disord 2004;5:16 Moen BE et al. Musculoskeletal symptoms among dentists in a dental school. Occup Med 1996; 46: 65-6.. Rundcrantz BL et al. Cervical pain and discomfort among in dentist. Epidemiological, clinical and therapeutic aspects. Part 1. A survey of pain and discomfort. Swed Dent J 1990;14: 71-80. Rundcrantz BL et al. Pain and discomfort in the musculoskeletal system among dentists: a prospective study. Swed Dent J 1991; 15: 219-28. Hayes MJ et al. Musculoskeletal disorders and symptom severity among Australian dental hygienists. BMC Res Notes 2013 Jul 4;6:250. Farahat SA et al. Effect of occupational exposure to elemental mercury in the amalgam on thymulin hormone production among dental staff. Toxicol Ind Health 2009;25(3):159-67 BE Moen et al. Neurological symptoms among dental assistants: a cross-sectional study. Journal of Occupational Medicine and Toxicology 2008,3:10

97. Raghuwar D. Singh et al. Mercury and Other Biomedical Waste Management Practices among Dental Practitioners in India. BioMed Research International 2014 Rajan Dhawan et al. Legal aspects in dentistry. Journal of Indian Society of Periodontology 2010;14(1):81-84 Burt BA, Eklund SA. Dentistry, Dental Practice and the Community. 6th ed. Missouri: Elsevier Saunders 2005. Source: http://www.who.int/immunization/policy/Immunization_routine_table4.pdf?ua=1 [Accessed on: 28/12/2015] CD Alert. National Centre for Disease Control. Directorate General of Health Services, Government of India 2011;14(2):1-8. Raja.K et al. OCCUPATIONAL HAZARDS IN DENTISTRY AND ITS CONTROL MEASURES – A REVIEW. World Journal of Pharmacy and Pharmaceutical Sciences 2014;3(6):397-415