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Sirivimol Srisawasdi, DDS, MS, PhDFaculty of Dentistry,
Chulalongkorn University
Safety of Amalgam
ตอบคําถามสังคมใหไดวาอมลักมัปลอดภัย ??
ผูปวยผูปวย
ทันตบุคลากรทันตบุคลากร
สิ่งแวดลอมสิ่งแวดลอม
History of amalgam panic
Hal Huggins, D.D.S., Hal Huggins, D.D.S., 19701970’’ss
History of amalgam panic
Dec 23, 1990 CBS-TV’s 60 minutes
“The Poison in Your
Mouth”
Global cycle of mercury
Mercury is everywhere in the environment and is taken into the body in one form or another via water,
air or food on the daily basis.
Therefore, mercury enters the body everyday no matter what restorative materials are present in the mouth.
The contribution of mercury derived from amalgam to the overall body burden has been the source of much controversy, but appears to be relatively low.
Dental Amalgam
an an alloy made by mixing mercury (Hg) with a silver-tin (Ag-Sn) alloyAg-Sn alloy is vigorously mixed with Hg (trituration)Placing plastic mass into the cavity preparation and compressing the mass into place to remove excess mercury-rich phase (condensation)Then carving and finishing the hardening mass
Classification based on:- alloy particle geometry and size- copper content- zinc content
Alloys
Lathe-cut filings
Require 50-60% by wt. Hg
Blend
Require less than 50% by
wt Hg
Sphericals
Require ~ 40-45% by wt Hg
ReactionReaction
alloy
Mercury (Hg)
Residual alloy
Mercury reaction products
(γ1. γ2 or η’)
(γ)
Gamma-2 phase of low copper amalgam
= Sn-Hg
High-copper amalgam :corrosion-prone phase is Cu-
Sn phase
Tarnish and corrosion
58 YEAR
16 yr.
creep
•Chemical corrosion
•Electrochemical corrosion
•Sn-Hg, Cu-Sn
•Sn-O, Sn-O-Cl
Dental practice exposure
From dental procedures (/m3)Preparation of amalgam, trituration : 1-2 µgPlacement of amalgam restoration : 6-8 µgRemoval of amalgam : 15-20 µgPolishing of amalgam
Dry polishing : 44 µgWet polishing : 2-4 µg
B.M. Eley, The future of dental amalgam : a review of literature Parts I-VII, Br. Dent. J. 1997
To obtain toxic amount of Hg vapor: one must have about 400-500 surfaces of amalgam filling
There have been numerous peer-reviewed scientific
studies and reviews concerning the safety of dental amalgam. These
studies disprove any link between dental amalgam and various medical conditions.
ADA POSITIONS & STATEMENTSADA STATEMENT ON DENTAL AMALGAM
Revised: July 2008
Dental amalgam has been studied and reviewed extensively, and has established a record of safety and effectiveness.
ADA POSITIONS & STATEMENTSADA STATEMENT ON DENTAL AMALGAM
Revised: July 2008After the ADA’s comprehensive evaluation of the peer-reviewed scientific literature, the ADA submitted comments to the FDA reflecting its conclusion that the current evidence does not support a link between dental amalgam and systemic diseases or risks to children, pregnant women or developing fetuses.The ADA supports ongoing research on the safety of existing dental materials and in the development of new materials. However, the ADA continues to believe that amalgam is a valuable, viable and safe choice for dental patients.
FDA Reaffirms Amalgam SafetyFDA Reaffirms Amalgam Safety
After years of careful investigation and the review of After years of careful investigation and the review of some 200 scientific studies, some 200 scientific studies, the Uthe U..SS. . Food and Drug Food and Drug Administration today reaffirmed its view that dental Administration today reaffirmed its view that dental amalgam is a safe, effective material for use in dental amalgam is a safe, effective material for use in dental restorationsrestorations. The FDA ruling classifies encapsulated . The FDA ruling classifies encapsulated amalgam as a class II medical deviceamalgam as a class II medical device,, which places it which places it in the same class as gold and composite fillingsin the same class as gold and composite fillings.. The The ADA has supported a class II designation for ADA has supported a class II designation for amalgam since the FDA first proposed it in amalgam since the FDA first proposed it in 2002.2002.
BellingerBellinger et al. et al. ((20072007) ) A doseA dose--effect analysis of effect analysis of children's exposure to dental amalgam and children's exposure to dental amalgam and neuropsychological functionneuropsychological function: : The New England The New England ChildrenChildren’’s Amalgam Trial Journal of the American s Amalgam Trial Journal of the American Dental Association 138Dental Association 138((99) ) 12101210--12161216..BellingerBellinger et al. et al. ((20072007) ) Dental amalgam restorations Dental amalgam restorations and children's neuropsychological function The New and children's neuropsychological function The New England ChildrenEngland Children’’s Amalgam Trial Environmental s Amalgam Trial Environmental Health Perspectives 115Health Perspectives 115((33) ) 440440--446446..BellingerBellinger et al. et al. ((20082008) ) Dental amalgam and Dental amalgam and psychosocial statuspsychosocial status: : The New England ChildrenThe New England Children’’s s Amalgam Trial Journal of Dental Research 87Amalgam Trial Journal of Dental Research 87((55) ) 470470--474474..DeRouenDeRouen et al. et al. ((20062006) ) Neurobehavioral effects of Neurobehavioral effects of dental amalgam in childrendental amalgam in children: : A randomized clinical A randomized clinical trial Journal of the American Medical Association trial Journal of the American Medical Association 295295((1515) ) 17841784--17921792..Eggleston and Eggleston and NylanderNylander ((19871987) ) Correlation of dental Correlation of dental amalgam with mercury in brain tissue Journal of amalgam with mercury in brain tissue Journal of Prosthetic Dentistry 58Prosthetic Dentistry 58((66) ) 704704--707707..MackertMackert et al. et al. ((19911991) ) Lymphocyte levels in subjects Lymphocyte levels in subjects with and without amalgam restorations Journal of with and without amalgam restorations Journal of the American Dental Association 122the American Dental Association 122((33) ) 4949--5353..
Kidney Kidney dysfunctiondysfunctionNeurotoxicityNeurotoxicityImuneImune systemsystem
““Amalgam illnessAmalgam illness”” is the term given to a condition,is the term given to a condition,usually selfusually self--reported, that is attributed by patients toreported, that is attributed by patients tomercury vapor intake from their existing amalgammercury vapor intake from their existing amalgamrestorations. restorations. Symptoms are usually quite distinct fromSymptoms are usually quite distinct fromthose observed as a result of classic Hg toxicitythose observed as a result of classic Hg toxicity and canand caninclude include fatigue, difficulty concentrating, muscular painfatigue, difficulty concentrating, muscular painand immunologic disordersand immunologic disorders..
Amalgam IllnessAmalgam IllnessThe role that psychological conditions play may be significantThe role that psychological conditions play may be significant, as , as two studies found that 70% of patients claiming to have amalgam two studies found that 70% of patients claiming to have amalgam illness presented with a psychiatric diagnosis, compared with onillness presented with a psychiatric diagnosis, compared with only ly 14% in a control group.14% in a control group.One study involved 218 patients with self reported oral galvanisOne study involved 218 patients with self reported oral galvanism; no m; no findings suggestive of either acute or chronic mercury intoxicatfindings suggestive of either acute or chronic mercury intoxication ion were found.72 Of these patients, 43% were diagnosed with a were found.72 Of these patients, 43% were diagnosed with a psychological disorder, often anxiety or panic disorders. psychological disorder, often anxiety or panic disorders. Interestingly, Interestingly, the patients with an underlying psychological disorder the patients with an underlying psychological disorder demonstrated lower blood Hg levels than those withoutdemonstrated lower blood Hg levels than those without..a study investigated 10 patients with symptoms they believed wera study investigated 10 patients with symptoms they believed were e caused by their amalgam restorations and compared them to a caused by their amalgam restorations and compared them to a control group of eight individuals without symptoms. control group of eight individuals without symptoms. The intraThe intra--oral oral release of mercury vapor was measured following a standardized release of mercury vapor was measured following a standardized schedule, and mercury levels in plasma, erythrocytes and urine wschedule, and mercury levels in plasma, erythrocytes and urine were ere determineddetermined. The calculated daily uptake of inhaled mercury vapor . The calculated daily uptake of inhaled mercury vapor released from the amalgam restorations was found to be less thanreleased from the amalgam restorations was found to be less than 5% 5% of the daily uptake at the lower concentration range that the Woof the daily uptake at the lower concentration range that the World rld Health OrganizationHealth Organization
Amalgam IllnessAmalgam IllnessWhen evaluating patients who present with symptoms or When evaluating patients who present with symptoms or claims of amalgam illness, dentists should be aware of the claims of amalgam illness, dentists should be aware of the role that psychological conditions may play in the illnessrole that psychological conditions may play in the illness. . Epidemiological studies indicate that dental amalgam is safe Epidemiological studies indicate that dental amalgam is safe for the general population; however, one must always keep for the general population; however, one must always keep in mind that epidemiological studies are assumed to in mind that epidemiological studies are assumed to represent the general population and may not pertain to represent the general population and may not pertain to each and every individual.each and every individual.Overall patient health must remain the chief concern of Overall patient health must remain the chief concern of every dentistevery dentist; therefore, referrals should be made to ; therefore, referrals should be made to appropriate health care providers when necessary to ensure appropriate health care providers when necessary to ensure that no underlying undiagnosed medical condition existsthat no underlying undiagnosed medical condition exists
Amalgam Hypersensitivit
y:Local reaction
ภาควิชาเวชศาสตรชองปาก
คณะทันตแพทยศาสตร
จุฬาลงกรณมหาวิทยาลัย
Local reaction to amalgam
Exposure of mercury in dental practice: Mercury concentrations in human autopsy
organs from dentists and controls
Concentrations in tissues (ng/g)
kidney pituitary brain
n mean n mean n mean
Dentists 3 1533 8 1599 8 61
controls 1212 273273 2323 107107 2020 1111
Nylander et al., Swed. Dent. J., 13, 1989
(1)Precapsulated
amalgam storage in closet
(2)Amalgamator
aerosol
(3)Scrap on
bracket table
(4)Amalgam
removal and replacement
(8)Mercury trapped in tiles and carpeting
(5)Amalgam waste on cotton rolls
(7)Amalgam scrap
container
(6)Amalgam
and mercury
in plumbing traps
Mercury vapor
Dental practice exposure
Sturdevant’s Art and Science of Operative Dentistry, 2006
……. amalgamator. amalgamator……..
Environmental concerns:amalgam as a source of
mercury in the environment
WithoutWithout good mercury hygiene good mercury hygiene practicepractice50% of mercury used in dental 50% of mercury used in dental practices was discharged into the practices was discharged into the environmentenvironment20% lost to air and 30% to sewage 20% lost to air and 30% to sewage systemsystem
B.M. Eley, The future of dental amalgam : a review of literature Part II, Br. Dent. J. 1997
Minamata Tragedy, 1952
Amalgam waste: Amalgam waste: before going to sewerbefore going to sewer
Amalgam particles in dental office wastewater Amalgam particles in dental office wastewater can range in size from colloidal particles (smaller can range in size from colloidal particles (smaller than 0.45 micrometers) to those larger than 3 than 0.45 micrometers) to those larger than 3 millimeters.millimeters.To remove these variousTo remove these various--sized particles from sized particles from waste discharge, amalgam separator units can use waste discharge, amalgam separator units can use several separation techniques, alone or in several separation techniques, alone or in combination: combination:
sedimentationsedimentationfiltrationfiltrationcentrifugationcentrifugationion exchangeion exchange
Purchasing, installing and operating dental amalgam separators: Practical issues.
Mcmanus and Fan, J Am Dent Assoc 2003;134;1054-1065
Amalgam waste: Amalgam waste: amalgam separatoramalgam separator
Amalgam waste: Amalgam waste: before going to sewerbefore going to sewer
Vacuum pump
Possible alternatives to amalgam
The ultimate decision about what filling materials to use is best determined by the patient in consultation with the dentist.
Gold
Tooth-colored restorations
Components of Resin-based materialsAbbreviation Compound
BEABEMABHTBis-EMABis-GMA
Benzyl alcoholBenzyl methacrylate2,6-Di-t-butyl-4-methyl phenolEthoxylated bisphenol-A-di-methacrylateBowen monomer, isopropyliden-bis (2-hydroxy-3-(4-phenoxy)-propylmethacrylate
Bis-MABLBMEBPECACQDBPADCHADCHPDDMADEAEDEGDMADHEPTDICHDIPADMABEEDMAPEDMBZDMDDADMPTDMTDAEGDMAHEMAHMBPTEGTEGDMATHATPPTPSbUDMA
Bisphenol-A-dimethacrylateBenzilBenzoic-acid-methylesterBenzoic-acid-phenylesterCamphoric acid anhydrideCamphoroquinoneDibenzoyl-peroxideDicyclo-hexylamineDicyclo-hexyl-phthalate1,10-Decane-diol-dimethacrylateDiethyl-amino-ethanolDiethyleneglycol-di-methacrylateDihydroxy-ethyl-p-toluidine1,6-Diisocyanato-hexane2,6-Diisopropyl-aniline4-Dimethylaminobenzoic acid ethyl ester2-(4-Dimethyl-aminophenyl)ethanolDimethoxybenzoineDimethyl-dodecane-amineDimethyl-p-toluidineN,N-DimethyltetradecylamineEthyleneglycol-di-methacrylate2-Hydroxy-ethyl-methacrylate2-Hydroxy-4methoxy-benzophenoneTriethylenglycolTriethylenglycol-di-methacrylateTrihexylamineTriphenylphosphineTriphenylstibaneUrethane-di-methacrylate
Reprinted with permission of Wiley-Liss, Inc., a subsidiary of John Wiley & Sons, Inc. Adapted from Geurtsen W et al J Biomend Mater Res 1998;41:474-480.
Be advised that……
Amalgam alternatives need Amalgam alternatives need special conditionsspecial conditions…………..and ..and
cost much morecost much moreneed longer chairneed longer chair--time or time or more visitsmore visitsrequire strict moisture controlrequire strict moisture controlsome have shorter service life some have shorter service life
spanspan
Amalgam is a valuable, viable and safe choice for dental patients
ทพ.กฤษฎา โตศักดิ์ภราเลิศ
Amalgam overlay: restoration after RCT
1 yr follow up
The present evidence does notappear to demonstrate that amalgam restorations are hazardous to the health of general population.The only adverse effect is rare occurrence of hypersensitivity.In continuing to use amalgam, strict dental mercury hygiene must be followed.
16 yr.
Talking about longevityTalking about longevity…………..
48 YEAR
58 YEAR Goldstein, 1994
Berry et al., JADA 129, 1998
47 YEAR
Thank you for Thank you for your attentionyour attention
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