Mercury toxicity & hygiene

MERCURY TOXICITY

ANDMERCURY

HYGIENENESHEENA.V.K

3 rd year BDSPSM DC

CONTENTS INTRODUCTION FORM OF MERCURY MERCURY EXPOSURE IN DENTAL OFFICE SOURCES OF MERCURY EXPOSURE MERCURY LEVELS SIDE EFFECT OF MERCURY

ALLERGY TOXICITY

TREATMENT MERCURY HYGIENE MERCURY FREE ALLOYS CONCLUSION

Mercury poisoning (alsoKnown as hydrargyria or me-rcurialism) is a disease causedBy exposure to mercury or itsCompound .mercury (Hg) is a Heavy metal occurring in several forms,All of which can produce toxic effects in

High enough doses

INTRODUCTION

FORM OF MERCURY EXISTS IN THREE CHEMICAL FORM Elemental mercury

Inorganic mercury

Organic mercury

ELEMENTAL MERCURY - Most volatile - Exist in liquid/vapor form - Inhaled and absorbed into

lungs(80%) and GIT(0.01%)

- Most common form amalgam restoration

- Exposure to this form can occur due to accidental spillage of mercury in dental office

INORGANIC MERCURY - Normally mined as inorganic sulfide ore - Mainly in liquid form - Can also exist in other form than

sulfide - Irritating in nature - Main route of entry is through

lung(80%)

ORGANIC MERCURY

- Mainly in the form of methyl mercury - Main route of entry is absorption though GIT(95-98%) though food - Used in fungicide and pesticide - Found in vegetables , fruits and grains - Toxic in nature

Mercury exposure-dental office Amalgam raw material being stored in use During trituration , insertion & intraoral hardening Amalgam scrap During finishing & polishing Removal of old restoration

PATHWAYS – DENTAL AMALGAM

Hg˚ released from amalgam & inhaled with 80%uptake in the lung

Hg˚ distributes and throughout body and nervous system

Hg˚ breaks down to inorganic mercury (Hg˝)

Hg ˝ accumulates in the nervous system , liver and kidney

NEUROTOXICITYNEPHROTOXICITYTERATOGENICITY DEATH

Relative sources of mercury exposure

AMAL

GAM

VACCINES

SEAF

OOD

INDUSTRY

OTHER

020406080

100

9075

3010 4

Series 1

Amount of mercury releasedDuring manipulation of amalgam

Hg levels

OSHARECOMMENDED

TTLV=0.05mg/m³

MOST Dental office mercury level lie below 0.05mg/m³

Side effect of mercury

ALLERGY

TOXICITY

ALLERGY Allergy responses represent an antigen-antibody reaction marked by itching, rashes, sneezing, or other symptoms

Contact dermatitis or Comb's type IV hypersensitivity reaction represent the most likely physiologic side effect to dental amalgam

Usually small % age of people are allergic to mercury, when such a reaction has been documented by dermatologist or allergist, an

alternative material (e.g. Composite or ceramic) must be used unless the

reaction is self limiting (usually within 2 Wks)

Immediate HS reaction associated with the mercury

component of amalgam restoration

release of mercury induced an acute reaction which resulted in erythematous lesions, severe burning and itchy sensation and difficulty in breathing skin patch test results indicated a very strong positive reaction to mercury Amalgam restorations were replaced with composite filling material

TOXICITY

TOXIC EFFECTS OF MERCURY DEPEND UPON

- Amount of exposure - Length of exposure - Length of mercury accumulation in body - Amount of accumulated mercury - Overall health of the patient ( for detoxification)

LEVELS OF MERCURY TOXICITY

TOXIC EFFECT ON MERCURYFORM OF MERCURY

ELEMENTAL INORGANIC METHYLME- RCURY

ROUTE OF EXPOSURE

INHALTION ORAL ORAL –FISHCONSUMPTION

TARGET ORGAN

CNS , KidneyPeripheral nervous system

KIDNEY, PNS C N S

LOCAL CLINICAL SIGN

Lung ;bronchial irritation

GI-irritationSkin – irritation ulceration

SYSTEMIC EFFECTS Kidney-

proteinuriaCNS –mood changePNS - Tremors

Kidney – proteinuria,Tubular necrosisIs PNSTREMORSNUMBNESS

Developmental Effects in fetus And newborn.CNS IN ADULT TREMORS PARAESTHESIA

ccc

PSYCHOLOGICAL DISTURBANCES

-Fits of anger -short term memory loss -low self –esteem -loss of self control -sleepiness.A person may also suffer from the loss

of ability to learn new thing or things that require memorization

ORAL CAVITY PROBLEMs

-Inflammation of the mouth-loss of bone around teeth-ulcerated gums and other areas in

the mouth-Darkening of gums-taste of metal-Bleeding gums

G.I.T PROBLEMS -Cramps -inflamed colon -diarrhea C.V.S PROMBLEMS -Weak pulse -increase B.P -Chest pain/feeling of pressure in the chest area

RESPIRATORY PROMBLEMS -Weakness and problems with breathing - Emphysema -persistent cough

NEUROLOGICAL PROBLEMS -headaches -vertigo -tinnitus - twitching in various areas of the body (eyelid, feet etc.)

NEUROTOXICITY-- NEPHROTOXICITY--- TERATOGENICITY---- DEATH

HgDamageDevelopment

ofCNSIn

TheFetusDuringThe

Prenatalperiod

Toxic effects include damage to the brain, kidney and lung. Mercury poisoning can result in several diseases,

including:- Acrodynia (pink disease) Hunter- russell syndrome MINAMATA DISEASE

Peripheral neuropathy (Presenting as paresthesia / itching, burning or pain) skin discoloration swelling Desquamation(shedding of skin)

Sign and Symptoms

• Bleeding gums• Alveolar bone loss• Loosening of teeth• Excessive salivation• Foul breath • Metallic taste• Burning sensation, with tingling of lips, face• Tissue pigmentation(amalgam tattoo of

gum)• Stomatitis (sore in the mouth)• Ulceration of gingiva, palate, tongue

Mercury symptoms on oral cavity

Acrodynia (Pink disease) Considered to be a mercury allergy

o Erythema of the palms soles o Edema of hand and feeto Desquamating rash o Hair losso Prurituso Diaphoresiso Tachycardia, hypertensiono Photophobiao Irritability - Constipation/Diarrheao Anorexiao Insomniao Poor muscle tone

PINK DISEASE

HUNTER-RUSSELL SYNDROME

Syndrome is characterized by paresthesia,

visual field constriction, ataxia, impaired hearing, and speech impairment.

MINAMATA DISEASE Mercury in the marine environment identified as a health risk for humans-

MINAMATA DISEASE In 1952 a factory in minamata Japan was mercury as a catalyst --mercury washed into bay In 1953 fisherman and farmers

showed symptoms-neurological damage and fetal deformity

MINAMATA DISEASE Disease diagnosed in 1956 - linked to fish consumption 1957 fishing banned in area 1959- mercury identified as

cause 1960 source identified - factory effluent

Symptoms were:- 1.ataxic gait 2.convulsions 3.numbness in mouth & limbs 4.constriction in the visual field 5.difficulty in speaking

TREATMENT Chelation therapy is the administration

of chelating agents remove heavy metals from the body.

A chelating agent could be given orally, I.M, I.V DMSA(FDA approved use in children for treat- ing Hg toxicity 2,3-DIMERCAPTO-1-PROPANESULFONIC ACID(DMPS) D-PENCILLAMINE(DPCN) OR DIMERCAPROL (BAL)

MERCURY HYGIENE

DENTAL MERCURY HYGIENE RECOMMENDATIONS

1. Ventilation: provide proper ventilation in the place by having fresh air exchanges and periodic replacement of filters, which may act as traps for mercury 2. Monitor office: monitor the Hg vapor

level in the office periodically. This may be done by using dosimeter badges & vapor analyzer(Limit – 50µg/m³ 8 hr shift over 40 hr work week)

Dosimeter

3. Monitor personnel: monitor office by periodic analysis 4. Office design: use proper work area design to facilitate spill containment and cleanup 5. Pre-capsulated alloys: use pre-capsulated alloy. Eliminate the possibility of a bulk Hg spill, otherwise store bulk Hg properly in unbreakable containers on stable surface

6. Amalgamator cover: use an amalgamator fitted with a cover

7.Handling care: use care in handling amalgam avoid skin contact with mercury or freshly mixed amalgam .avoid dry polishing.

8. Evacuation systems: use high volume evacuation when finishing or removing amal-

gam .evacuation system have traps or filter. Check, clean / replace traps and filter periodically

Pre -capsulated alloy

9. Masks: Change mask as necessary when removing amalgam restoration.

10. Contaminated items: Dispose of Hg contaminated items in sealed bags according to applicable regulation

11.Spills: clean up Hg properly by using bottle tapes/ fresh mixes of amalgam to pick- up droplets/ use commercial clean up kits. Do not use household vacuum cleaner.

12. Clothing: Wear professional clothing only in dental operatory

13. Select an appropriate alloy: Proper Hg: alloy ratio to avoid the need to remove excess Hg before packing.

14. Recycling: store amalgam scrap under radiographic fixer solution in covered container. Recycle amalgam scraps through refiners

Never dispose of scrap amalgam in the sharp, red biohazard bag or the trash

15. Avoid carpet/floor coverings in dental office ; floor coverings should be easy to clean, nonabsorbent and seamless.

16. Follow aseptic technique, i.e. wear protective mask, gloves and glasses to prevent exposure to mercury vapors.

17.Use rubber dam during insertion, condensation, and polishing of amalgam.

18. Dentists and dental assistants should have proper knowledge of amalgam disposal and their handling.

Gallium based alloy - Gallium was discovered in 1875 .it is metalWith similar atomic structure and characteristicsTo mercury and has a melting temp of 29˚c. Hence , by 1928 Puttkammer suggested Gallium as a substitute for mercury -- its available as a1. Gallium Alloy 2. Galloy DISADVATAGES . Handling characteristics of alloy not favorable . High level of corrosion is seen which causes loss of strength marginal disintegration and marginal fracture in chunks. . Dimensional change of 21.5% . Poor biocompatibility . costly MERCURY FREE DIRECT FILLING ALLOY Ag Coated Ag-Sn particles which can be self

compacted

MERCURY FREE ALLOYS

conclusion Dental amalgam are still widely used by the

dental profession in most parts of the world.

Some countries, like Sweden, Canada and Germany, UK have either banned or imposed serious limitations on amalgam usage.

In the 1990s, several governments evaluated the effects of dental amalgam and concluded that the most likely health effects would be due to hypersensitivity or allergy.

In 2004,the Life Science Research Office analyzed studies related to dental amalgam. They took mean urinary mercury concentration (µg of Hg/L in urine, HgU) as the most reliable estimate of mercury exposure. 95 % of study participants showed µg HgU below 4 to 5.

Chewing gum, particularly for nicotine, along with more amalgam, However, the WHO states mercury levels in biomarkers such urine, blood , hair do not represent levels in critical organs and tissues.

The American Dental Association Council on Scientific Affairs has conclude that both amalgam and composite materials are considered safe and effective for tooth restoration.

Thank you