9. Nazi human experimentation
Nazi human experimentations were a
series of medical experiments on large
numbers of prisoners, mainly Jews from
across Europe
Doctors trial nuremberg code of ethics
10. Nuremberg
code of ethics
1. Required is the voluntary, well-informed,
understanding consent of the human subject in a full
legal capacity.
2. The experiment should aim at positive results for
society that cannot be procured in some other way.
3. It should be based on previous knowledge (like, an
expectation derived from animal experiments) that
justifies the experiment.
4. The experiment should be set up in a way that avoids
unnecessary physical and mental suffering and
injuries.
5. It should not be conducted when there is any reason to
believe that it implies a risk of death or disabling
injury.
6. The staff who conduct or take part in the experiment
must be fully trained and scientifically qualified.
11. HISTORY contdâĻ
īMid 1800â s dentists tried new materials for first time
by directly putting them in patientâs mouth
eg. Fox : fusible metal-bismuth, lead & tin-melted &
poured in cavity preparation at appx.100o C
ī G.V. Black tried his new ideas of restorative
materials, like early amalgams in patientsâ mouth
12. âĸ The first clinical cases of dental metal allergy involved a
mercurial allergy to intraoral amalgam fillings that led to
stomatitis and dermatitis around the anus (Fleischmann,
1928).
13. īConcept of protecting patients- early 1960âs
īRegulations & ethics introduced
īOrganisations like FDA, ANSI, ADA and ISO .
14. âĸ These regulations required all dental and medical materials intended for human
use to be classified according to risk as Classes I, II, and III.
1976 MEDICAL DEVICE AMENDMENTS
NEED FOR BIOLOGICAL STANDARDIZATION AND TESTING OF DENTAL MATERIALS
15. Definition
ī Being harmonious with life & not having toxic or injurious
effects on biologic function.
(G.P.T. 8th edn.-2005)
ī Ability of the material to elicit an appropriate biological
response in a given application in the body
(Kenneth J.A).
ī "The ability of a material to perform with an appropriate host
response in a specific application"
(Williams biomaterials)
16. 16
Biocompatibility :- interaction between body & material
īPlacement of material creates interface : dynamic
īInterface activity depends on:
- location of material
- its duration in body
- its properties
- health of host
17. 17
Biocompatibility Interaction between the body & the material
Active interface with dynamic
interactions between body & material
Material may alter the body / body alter
the material
Activity of this interface depends on â
1. Location & properties of material
2. Duration in the body
3. Health of host
Determination of biological response
Placement of material
â interface
18. 18
Biomaterial
ī Any substance, other than a drug, that can be
used for any period as a part of a system that treats,
augments, or replaces any tissue, organ or function
of the body.
(G.P.T. 8th edn.-2005)
19. The prime use of any biomaterialâwhether it is for a hip, a heart
valve, or a dental restorationâis to replace lost and defective tissue
and thus restore normal function.
20. 20
Classification of Biomaterials from perspective of Biocompatibility
īThose which contact soft tissues within the oral cavity
eg. Acrylic resin
īThose which could affect health or vitality of pulp
eg. Liner, bases
īThose which are used as root canal filling materials
eg. Gutta percha
21. 21
īThose which affect hard tissues of oral cavity
eg. Implants
īThose used in dental laboratory
eg. Nickel, chromium, cobalt
22. The term âAllergyâ is coined in 1906:
âĸ postulated to be the product of an âallergicâ response
Clemens von Pirquet
Allos Ergos
(altered reactivity)
23. Allergy:
Allergy is the respond to foreign substances or infectious organisms of
the body.
ī The term allergy is defined as the patherjik - hipererjik appearance of
the diseases caused by antigen-antibody reactions.
ī Allergic reactions should be evaluated in terms of time, type of
reaction, physiological and histological findings.
25. ī As soon as allergens enter the body immediately antigen-antibody reaction starts.
ī This type of allergy is genetically passed from parents to children.
ī At these allergic types, asthma, angioedema, urticaria, rhinitis and conjunctivitis
can be seen.
ī At the most severe type, anaphylactic shock and death can be seen.
Type I :- Atopic allergies
26. ī Type II :- Cytotoxic type
ī Occurs with the antibody against to the antigen.
ī Autoimmune anemia, hemolytic anemia, and transfusion
reactions are exemplified.
ī Type III :- Immune-complex type
ī Inflammatory reactions starting with the binding of
antibody and antigen.
27. Type IV :- Delayed type allergy reaction
ī This type of allergy reactions does not show any signs. Some symptoms may
occur after 48 hours of exposure to the allergen.
ī Vesicles on the skin beginning with erythema and burning and allergic contact
dermatitis followed by thickening of the skin can be the examples of this type of
allergy.
Type I and Type IV allergic reactions are common types of allergies to
materials used in dentistry.
28. Dental material: ideal requisites -
ī Ideally, a dental material that is to be used in the oral
cavity should be harmless to all oral tissuesâgingiva,
mucosa, pulp, and bone.
ī Furthermore, it should contain no toxic, leachable, or
diffusible substance that can be absorbed into the
circulatory system, causing systemic toxic responses,
including teratogenic or carcinogenic effects.
ī The material also should be free of agents that could
elicit sensitization or an allergic response in a sensitized
patient.
29. Allergic reactions to dental materials
ī Side effects to dental materials are believed to be rare and, generally, those that have
been reported are mild
ī Yet, given the millions of treatments provided, many individuals potentially may be
affected.
ī Consideration must be given to the relative biocompatibility of all dental restorative
materials.
(Kallus and MjÃļr 1990; Hensten-Pettersen and Jacobsen, 1991).
30. ī Rarely, unintended side effects may be caused by dental restorative materials as
a result of toxic, irritative, or allergic reactions.
ī They may be local and/or systemic.
ī Local reactions involve the gingiva, mucosal tissues, pulp, and hard tooth
tissues, including excessive wear on opposing teeth from restorative materials.
ī Systemic reactions are expressed generally as allergic skin reactions.
ī Reactions may be classified as acute or chronic.
Allergic reactions to dental materials
(Kallus and MjÃļr 1990; Hensten-Pettersen and Jacobsen, 1991).
31. ī Dental restorative materials consist of a heterogeneous group of synthetic and
naturally occurring substances, including alloys, polymers, cements, and
ceramics.
ī They are evaluated at different levels, including anything from "trial and
error" to full "safety and efficacy" assessments.
Standards and Testing
32. ī Today, however, dental materials standards require biological testing as well.
ī In accordance with existing standards, all dental materials should pass primary tests
(screening to indicate cellular response), secondary tests (evaluating tissue
responses), and usage tests in animals before being evaluated clinically in humans.
33. ī Testing programs for dental materials are based on
specifications or standards established by national or
international standards organizations, such as the
American National Standards Institute (ANSI) and
International Standards Organization (ISO).
ī The oldest and largest of these programs has been
operated continuously by the ADA since the late 1920's.
Initial, secondary, and usage tests, described in
ADA/ANSI specification #41 have been reviewed by
Craig (1989). 1
40. 40
INFLAMMATION
īA localized physical condition in which part of the body
becomes reddened, swollen, hot, and often painful,
especially as a reaction to injury or infection.
īInvolves activation of the host immune system
īHistologically it is characterized by edema of the tissue
with infiltration of acute & chronic inflammatory cells
42. 42
ī Usually occurs where body surface makes direct
contact with allergen.
eg. Monomers of bonding agent-
distal part of fingers & palmer aspect
of fingertips
ī Acrylic component of dental cements, nickel & resin
monomers
44. 44
īCommon allergens :- chromium, cobalt, mercury,
eugenol, components of resin based materials, &
formaldehyde
īMouthwashes, dentifrices, lozenges, & cough drops
cause burning, swelling & ulceration of oral tissues.
īLichenoid reactions :- Long-term effect in oral
mucous membrane adjacent amalgam & composite
resins.
(Bratel and Johntell,1994)
AllergicContactStomatitis
45. Cheilitis
Cheilitis
âĸ Allergic contact cheilitis usually presents
as eczema-like changes on the vermilion
margin or skin around the mouth.
âĸ Major sources of allergens causing contact
cheilitis include Metals â dental restorations,
orthodontic devices
46. Pustulosispalmarisetplantaris
âĸ In these patients, erythema, blisters with pustules, scale and
crust typically appear on the palm and plantar.
âĸ In addition, sterile pustules are sometimes accompanied by
itch, heat and painful sensations, and on occasion,
osteoarthritis may also be found.
âĸ Focal infection of the chronic inflammation from the palatine
tonsil, marginal and periapical periodontitis, and metal allergy
are all suspected as being predisposing factors.
47. Lichenplanus
âĸ Chronic inflammatory disease can include dyskeratosis of the
skin, oral and external genitalia mucosa.
âĸ When it appears on the oral mucosa, lace or stitch pattern
keratinizations may be present and accompanied by erosion
and ulceration.
âĸ In dental metal allergy cases, it appears at the oral mucosa
attached to the metal restoration that contains the allergy-
positive metal element.
48. Glossodynia
âĸ In glossodynia, the main symptoms that patients encounter
are pain, twitching and a burning sensation in the tongue.
âĸ Possible predisposing factors include psychological factors,
galvanic current, mechanical stimulation, allergy to metal
elements eluted from a dental prosthesis, or a shortage of an
essential nutrient.
49. MUTAGENIC REACTIONS
ī Mutagenicity results when the components of the
material alter the base pair sequences of the DNA in
cells
ī Dental materials or components such as nickel, copper,
beryllium, some components of root canal sealers &
resin based materials are mutagens
51. 51
Allergy to Latex Products
īPolyether component-main causative agent.
īRepeated exposure & duration plays important role.
52. 52
īDermatitis of hand (eczema) most common adverse
reaction
īLocalized rashes & swelling to wheezing & anaphylaxis
īMost serious systemic reactions occur when gloves or
rubber dam contact mucous membrane - generalized
angioneurotic edema, chest pain, rash on neck or chest
region and respiratory distress
âĻBlinkhorn and Leggate,1984
53. 53
Prevention: Use Vinyl gloves or gloves made of
other synthetic polymer gloves:-
Polythene gloves.
Powder free gloves.
Nitrile gloves.
58. Mild Overdose Reaction
ī Slow onset
ī Reassure patient
ī Administer oxygen
ī Monitor vital signs
ī Allow patient to recover as long as necessary
59. Severe Overdose Reaction
ī Rapid onset (within one minute)
ī Remove syringe (if in the process of an injection)
ī Protect patient for trauma if convulsions are present
ī Basic life support
ī Administer anticonvulsant
ī Allow patient to recover
ī Do not let patient leave alone
60. Management of Epinephrine
Overdose
ī Terminate dental procedure
ī Sit patient upright in the dental chair
ī Reassure patient
ī Monitor blood pressure
ī Administer oxygen
61. Clinical Manifestations of an Allergy
ī Fever
ī Angioedema
ī Urticaria
ī Dermatitis
ī Depression of blood-forming organs
ī Photosensitivity
ī Anaphylaxis
63. How to Prevent An Allergic Reaction
ī Take a thorough medical history
ī Dialogue the medical history with the patient
64. Common Questions to Ask the Patient
ī Allergic to any medications?
ī Have you ever had a reaction to local anesthesia?
ī If yes, describe what happened
ī Was treatment given? If so, what?
65. Asthma Patient
ī Thorough medical and dental history
ī Avoid use of anesthesia that contain epinephrine or
levonordefrin because of sulfites (may cause wheezing)
ī Asthma patient that is steroid dependant may develop
brochospasms
ī Establish rapport and calm environment
66. Impression Materials
īIrreversible hydrocolloids :- Inhaling fine airborne particles (dust)
can cause silicosis & pulmonary hypersensitivity.
Dustless/Dustfree alginate is preferred
īElastomers :- Cellular toxicity levels
Polyether > Addition Silicone > Polysulphide
67. ALGINATE
âĸ Some heavy metals and silica particles are present in the
alginate powder and have potential toxicity risk for both the
practitioner and the patient.
âĸ For example, lead is added to the alginate powder to improve
the material elastic properties after gelification and sometimes
can be found as a contaminant
68. âĸ During the impression procedure, alginate is left in close
contact with the oral mucosa for approximately 2 minutes, and
this tissue is highly vascularised and has great absorption
potential.
âĸ Therefore, repeated impression procedures might cause a
certain degree of cytotoxicity depending on the material
composition and mucosal integrity
Braga AS, Catirse AB, Vaz LG, Spadaro AC. Quantitative analysis of potentially toxic metals
in alginates for dental use. Rev CiÃĒnc Farm BÃĄsica Apl 2005;26:125-30
69. Allergy to a polyether dental impression material
ī The polyether impression material used in dentistry may
evoke type IV hypersensitivity reactions, probably caused by
a base paste component.
ī However, with regard to the widespread use of this
impression material (millions of applications per year), these
cases are scarce.
Journal of Oral Rehabilitation 2002 29; 7Âą13
70. Dental
Amalgam
ī Because of its extensive use, there is more information
available about the biocompatibility of dental amalgam
than about any other dental restorative material
71. ī Large amalgam particles that are embedded accidentally in the gingiva during
placement of a restoration may elicit chronic inflammation, but no, or minimal,
tissue effects are observed with smaller particles (H` rsted-Bindslev et al.,
1991).
72. ī Benign pigmentation of the mucosa can occur from embedded amalgam particles,
commonly referred to as "amalgam tattoo." An increased content of mercury has been
observed in gingival biopsies from areas in close contact with amalgam (Freden et al.,
1974).
73. ī Mercury also has been found in lysosomes of
macrophages and fibroblasts of submucous connective
tissue of contact lesions.
ī However, mercury also has been identified in normal
mucosa and in oral lichen planus lesions with and
without any relationship to amalgam (Bolewska et al.,
1990).
74. Pulpal
response
ī Amalgam restorations, in general, have been considered
to be either inert or only mildly irritating to the pulp or
body tissues in dogs, rats, and humans (Manley, 1942;
Schroff, 1946-47; James and Schour, 1955; Silberkweit
et al., 1955; Massler, 1956; Welder et al., 1956).
ī Any pulpal response to amalgam seems to be related
mainly to the physical insertion of the amalgam, that is,
the pressure of condensation (Stanley, 1991), and is
usually of short duration.
ī Skogedal and Mjor (1979) indicate that alloys
containing the highest percentages of copper cause
slightly more pulpal responses after 1 to 2 months in
monkeys than conventional amalgam.
75. ī Mercury in amalgam is the most frequent antigen and the usual
clinical manifestation is stomatitis.
ī There are a few reports of (oral lichen planus. presumably
caused by allergy to materials in dental fillings: copper, mercury
and palladium.
ī The lesions cleared in some cases when the fillings were
removed, which is supportive of an etiological role.
âĸ Finne K, Goransson K. Winckler L. Oral lichen planus and contact allergy to mercury. Int.I Oral Surgery 1982: //.âĸ 236-
239.
âĸ Frykhoim K O, Frithiof L, Fernstrom I B, Moberger G, Blohm S G, Bjorn E. Allergy to copper derived from dental alloys
as a possible cause of oral lesions of lichen planus. Acta Dermato-vimereologica 1969: 49: 268-281.
âĸ Nakayama H. Hypersensitivity to palladium is inked to oral lichen planus. Dermatology News 1982: February
76. Mercury Levels in Blood
ī Subjects with amalgam restoration 0.7ng/mL
ī Subjects without amalgam restoration 0.3ng/mL
ī Lowest level at which earliest 35ng/mL
non-specific symptoms occur
77. Mercury Hazard to Dental Personnel
īVia inhalation & skin contact (allergic contact dermatitis)
īAccidental spillage
īHandling with bare fingers
īImproper storage
īImproper retrieval of spilled mercury or waste amalgam
īFaulty equipment
79. Recommendations in Mercury Hygiene
1. Store in unbreakable tightly sealed containers
2. Clean-up spilled mercury immediately
3. Do not handle with bare hands
4. Salvage all amalgam scrap & store it under water
5. Use water spray & suction while grinding
6. Do not use ultrasonic condensers
7. Periodic mercury vapor level determination in clinic
8. Alert health personnel about hazards of mercury
9. Use of rubber dam
10. Provide adequate ventilation
81. Glass Ionomer Materials
ī When glass ionomer cements first were introduced,
pulpal responses were classified as bland, moderate, and
less irritating than with other cements or composite
resins.
ī Clinical studies show that such cements may cause early
inflammatory reactions on newly prepared dentin, which
resolve within a few days.
ī Screening tests in cell cultures indicate that glass
ionomers can be cytotoxic and therefore, protective
calcium hydroxide liners are recommended when
working near the pulp and when the thickness of
remaining dentin is not certain (Kawahara et al., 1979;
~1son and Prosser, 1982; Mount, 1988; Draheim, 1988;
Muller et al., 1990; Caughman et al., 1990)
82. ī The blandness of GIC is attributed to absence of strong acids of
toxic monomers.
ī Polyacrylic acid and polyacids are much weaker than phosphoric
acid and possess higher molecular weight that limit their diffusion
through dentinal tubules to the pulp.
ī Tobias and other (1978), found that glass ionomer cements were
less irritating than zinc phosphate cement, equivalent in irritancy
to polycarboxylate cement and more irritating than zinc oxide
cement.
83. ī If zinc phosphate is used instead of ZOE to cement a crown or
inlay, the phosphate cement is forced into the dentinal tubules
ī After 3-4 days, it creates a wide spread three-dimensional
inflammatory lesion involving all the coronal pulp tissue.
ī A young tooth with wide â open dentinal tubules is more
susceptible to intense response than an older tooth, which has
produced sclerotic and reparative dentin that blockâs the tubules.
Zinc Phosphate Cement
84. ī Zinc phosphate cements elicits strong to moderate cytotoxic
reactions that decrease with time after setting Leaching of zinc
ions and a low pH is cause of these effects
ī Initial pH on setting is 4.2 at 3 minutes
ī The best protection against phosphoric acid penetration is
provided by coating the dentin with two coats of an appropriate
varnish, a dentin-bonding agent, or a thin wash of calcium
hydroxide.
85. ī Eugenol is highly soluble and is continuously released
from ZOE, which can lead to short-term saturation of
the oral environment with eugenol in a concentration
sufficient to cause cytotoxicity.
ī From a biologic point of view ZOE is in fact considered
the least damaging restorative material and possesses
sedative or anodyne properties, which are very useful in
dentistry.
ī Despite the advantageous properties of eugenol,
however, sensitivity, manifested as positive
inflammatory responses to eugenol in certain root canal
sealers has been described.
Zinc oxide-eugenol
Hume WR. The pharmacologie and toxico logical properties of zinc oxide-eugenol. J Am Dent Assoc 1986:113:789-791,
86. ī However, eugenol causes allergic contact dermatitis,
possibly because it can react directly with proteins to
form conjugate and reactive haptens.
Tammannavar P, et al. BMJ Case Rep 2013.
87. īCalcium Hydroxide:
ī Calcium hydroxide has been mainly used in pulp capping,
pulpotomy, root amputation, apexificaiton and apexogenesis.
ī The cement is alkaline in nature. The high pH is due to
presence of free hydroxyl ions in the set cement. The pH ranges
from 11-13.
88. ī In spite of the known biocompatibility of calcium hydroxide
and the high degree of success obtained with its use, it is
known that the association of calcium hydroxide with
different vehicles can interfere with
1. the ionic dissociation of the product (Anthony et al.
1982, Staehle et al. 1989, Simon et al. 1995, Beltes et
al. 1996)
2. its antiseptic properties (Ferraresi 1990,vAlencar et al.
1997)
3. tissue compatibility and the capacity to induce
mineralized tissue (Holland et al. 1977, Leonardo et al.
1993a).
Calcium hydroxide
89. Dycal
ī Base/Liner is contraindicated for use with patients who
have a history of severe allergic reaction to methacrylate
resins.
ī Contains polymerizable methacrylate monomers.
ī Avoid prolonged or repeated exposure with skin, oral
soft tissues, and eyes.
ī Irritation and possible corneal damage may result.
ī Skin rash, oral mucosa irritation, or other allergic
reactions (allergic contact dermatitis) may result in
susceptible individuals
91. ī Acid-etching materials and dental adhesives are known
to be toxic to the periodontal tissues, and trauma to these
tissues is seen very rarely
Journal of the Canadian Dental Association July/August 2005, Vol. 71, No. 7
Conditioning (etching) agents: -
92. ī Bonding agents do not appear to be toxic.
ī To enhance bonding to composite, a fast setting visible light
cured, low viscosity (unfilled) resin primer is applied that
infiltrates the demineralized dentin surface and the exposed
collagen mesh to form hybrid layer.
ī The plugging of the dentinal tubules prevents the penetration
of toxic components to the pulp from composite restorations.
Bonding Agents
93. Resin-Based
Composites
ī However, like amalgam, longitudinal, in vivo research
on the biocompatibility of composite resins is scanty,
particularly on those developed for posterior restorations
(Bayne,l991).
ī Composite material, however, has been shown to elicit a
chronic inflammatory response in vivo (Nasjleti et al.,
1983),
ī To be cytotoxic in cell culture (Hensten-Pettersen and
Helgeland, 1977, 1981; Mjor, 1977; Wennberg and
HenstenPettersen, 1981; Kasten et al., 1982),
ī To be potentially allergenic (Nathanson and Lockart,
1979; Kallus et al., 1983; School, 1991)
ī To inhibit RNA synthesis (Caughman et al., 1990).
94. ī Chemicals from both the resin (Inoue and Hayashi, 1982) and filler (Soderholm, 1983)
components of composite have been shown to leach out from the set material.
ī Degradation and wear of resin-based composites release their components, including the
fillers, silanized layer, and polymer matrix.
ī Minute amounts of these materials may be swallowed, exposing components and fragments of
restorative material to stomach acids and enzymes.
ī Subsequent dissolution and absorption of ionic species under this condition have just begun to
be explored by Freund (1990) and others, and the significance is unknown.
ī Also, minute amounts of formaldehyde may form as a degradation product of resin-based
composite materials (Ãysaed et al., 1988).
95. īAdverse reaction to a fissure sealant:
report of case.
ī A six-year-old girl with a known allergy to mites had her
first permanent molars sealed with Delton.
ī On the night of the treatment day, she began to have
asthmatic trouble.
ī Urticaria appeared a few days later.
ī Treatment with cortisone gave no relief.
ī When the fissure sealant material was taken away, the
asthma and urticaria disappeared.
Hallstrom U. Adverse reaction to a fissure sealant. Report of a
case. J Dent Child. 1993;60(2):143-46.
96. ī The dental personnel commonly complain of contact
dermatitis and asthma caused by methacrylates.
ī HEMA, EGDMA and TEGDMA are responsible for
occupational contact allergies.
ALLERGY to resin materials composites
Marquardt W, Seiss M, Hickel R, Reichl FX. Volatile methacrylates in dental
practices. J Adhes Dent. 2009;11(2):101-07.
97. ī A study was reported in which patients had lichenoid-
like reactions of lips and patch testing revealed positive
reaction to composite components.
ī Antifungal treatment and replacement of existing
restorations resulted in improvement
Blomgren J, AxÊll T, Sandahl O, Jontell M. Adverse reactions in the oral mucosa
associated with anterior composite restorations. J Oral Pathol Med.
1996;25(6):311-13.
98. MMA, HEMA, EGDMA, UDMA
ī MMA, UDMA and HEMA are proved to leak from orthodontic base plate
materials.
ī MMA has a high initial release, which decreased after 24 hours.
ī UDMA did not show the same decrease after initial stage, and may therefore be
present in the oral cavity at higher amounts for longer periods.
ī It is shown to be both an allergen and cytotoxic.
Kopperud, H.M., I.S. Kleven, and H. Wellendorf, Identification and quantification of leachable substances
from polymer-based orthodontic base-plate materials. Eur J Orthod, 2011. 33(1): p. 26-31. 36
99. ī TEGDMA in resin based materials seems to be of
considerable biological significance.
ī It has been identified as the main leaking monomer.
ī Due to its low molecular weight, relatively high
hydrophilicity and detergent activity on liposomes,
TEGDMA manage to penetrate cell membranes.
ī It conjugates to intracellular proteins, and can therefore
induce an allergic reaction.
ī Compared with other resin monomers and additives
TEGDMA shows a major cytotoxic potency, and it has a
great potential to degenerate DNA
TEGDMA (trietyleneglycol-dimethacrylate)
Soderholm, K.J. and A. Mariotti, BIS-GMA--based resins in dentistry: are they safe? J Am
Dent Assoc, 1999. 130(2): p. 201-9.
100. Bisphenol A
ī BPA was as early as in the 1930s recognized for its
estrogenic effects.
ī In vivo and in vitro studies have confirmed this, but few
studies have examined the estrogenic effects of BPA
derivatives.
ī Because of its character to imitate natural estradiol, and
its weak affinity to estrogenic receptors, BPA and bis-
DMA might be involved in the etiology of reproduction-
and developmental disturbances and malignity.
ī Studies have shown that BPA probably are thousand fold
less potent than natural estrogen
Bis- GMA
101. ī Compared to the exposure to BPA from the daily
environment, the amounts leaked from dental materials
are considered small.
ī It is commonly known today that the probable leakage
of BPA from composite fillings and fissure sealants is
far below the amounts needed to cause a harmful effect
102. IRM
âĸ Material is contraindicated for use with patients who have a
known hypersensitivity or severe allergic reaction to eugenol,
acrylate resins or any of the components.
âĸ Material is contraindicated for direct application to dental pulp
tissue (direct pulp capping).
âĸ Material is contraindicated as a base under resin-containing
adhesives, restoratives or cements because eugenol may
interfere with the hardening and/or cause softening of the
polymeric (resin) components.
103. Stainless steel crowns
âĸ The chemical composition of a preformed SSC
is 65â73% iron, 17â20% chromium, 8â13%
nickel, and less than 2% manganese, silicon, and
carbon.
âĸ small amounts of the metals in an SSC can be
released into the oral cavity, and the leached
metals can potentially trigger an allergic reaction
J Clin Pediatr Dent 36(3): 235â238, 2012
104. âĸ Nickel is known to be a very common cause of contact allergy
and hypersensitivity reactions.
âĸ After its binding to protein, the leached nickel-protein complex
can activate T cells, which, in turn, can mediate a non-
immediate or delayed allergic reaction
105. âĸ The nickel in dental appliances is known to be a very common
cause of contact allergy and hypersensitivity reactions.
âĸ Feasby et al studied nickel hypersensitivity in 5- to 12year-old
children who were fitted with a nickel-based dental appliance, such
as a band-loop space maintainer, a lingual arch, or an appliance with
stainless steel clasps and springs.
âĸ They found that the overall incidence rate of positive patch test
results in the study population was 8.1% (boys = 6.8%; girls =
9.5%).
Feasby WH, Ecclestone ER, Grainger RM. Nickel sensitivity in pediatric dental patients.
Pediatr Dent, 10: 127â129, 1988.
nickel
106. ī Formaldehyde is a common cause of allergic contact
dermatitis.
ī It was reported that 40% -60% reactions were due to
formaldehyde.
ī The characteristic features of formaldehyde allergy are
anaphylactic reaction or shock and generalized
urticarial.
ī The most useful and diagnostic tool to determine
formaldehyde allergy is the assessment of specific IgE
antibodies to formaldehyde.
ALLERGY to formaldehyde
Flyvholm MA, MennÊ T. Formaldehyde allergy: A follow-up study. Am J Contact
Dermat. 1999;10(1):12-17
107. ī Sodium hypochlorite when comes in contact with tissue
protiens, forms nitrogen, formaldehyde and
acetaldehyde in short time and peptide links are broken
resulting in dissolution of proteins.
ī The endodontic literature contains several case reports
on complications during root canal irrigation, including
inadvertent injection of sodium hypochlorite or
hydrogen peroxide into the periapical tissues, air
emphysema, and allergic reactions to the solution.
ī Sodium hypochlorite allergic reactions results in
urticaria, oedema, shortness of breath, bronchospasm
and hypotension.
Sodium hypochlorite
Kaufman AY, Keila S. Hypersensitivity to sodium hypochlorite. J Endod. 1989;15(5):224-26.
108. Acrylic Resin
īCause allergic reactions (denture stomatitis) when
used as denture base material or provisional fixed
partial denture resin
īHighest risk for dental professionals due to frequent
exposure to unpolymerized monomer
109. âĸ The polymerization temperature is another factor that plays
a vital role and is responsible for different degrees of
cytotoxic effects.
âĸ When polymerization time is extended, the amount of
residual unreacted monomer is reduced significantly and
thus, the chances of cytotoxic effects are reduced.
110. Prevention
âĸ It has been recommended that a 7 hr incubation in water at
70°C followed by a 1-h incubation in water at 100°C causes
the maximum conversion of the monomer.
âĸ It has been recommended that boiling during polymerization
stage should be carried out for at least 30 min at maximum
temperatures and that the heat-cured denture bases should be
stored in water for 1â2 days before being delivered to the
patients.
âĸ This is expected to reduce the cytotoxic effects caused due to
residual monomer to a significant extent.
111. Thermoformed appliances
âĸ All the thermoforming materials used in dentistry are tested
on their biocompatibility.
âĸ They correspond to specifications of class 1 medical
products.
âĸ Upto now there are only two suspected cases of allergic
reactions to materials known but allergic reactions cannot be
excluded.
112. Smart
materials
ī Smart materials are materials that have properties which
may be altered in a controlled fashion by stimuli, such as
stress, temperature, moisture, pH, electric or magnetic
fields.
114. Allergic
reactions
ī Although a material designed to release ions as
therapeutic agents might appear cytotoxic in vitro, the
clinical release of these ions might be acceptable
116. Microleakage
ī Free penetration of fluids, micro-organisms & oral
debris along interface between restoration & tooth,
progressing down the walls of cavity preparation
ī It can result in :-
1. Secondary/Recurrent caries acute/chronic
pulpitis, pulp abscess, etc.
2. Staining or discoloration
3. Sensitivity due to continuing Pulpal irritation
117. Prevention:-
1. Use bonding/adhesive techniques for better adaptation of
restoration to tooth surface
2. Regular monitoring of restoration
3. Use cavity varnish below amalgam restoration
(leakage space filled by corrosion products thereby sealing
cavity : but requires much time)
118. Thermal Changes
īTemperature fluctuations in oral cavity may crack
restorative material or produce undesirable dimensional
changes Microleakage
īThermal conductivity & coefficient of thermal expansion
īMetals are good conductors of heat, causing sensitivity
with large metallic restorations
eg. Amalgam or gold inlays
Provide suitable base
119. Galvanism
īFlow of current when two dissimilar metallic restorations oppose
each other in oral cavity
īDue to different electromotive potentials of opposing metals
īSaliva acts as electrolyte
īContact Short-circuit current flows through pulp
Pain & Discomfort
eg. Alloy of stainless steel develop higher current density than gold
or cobalt-chromium alloys when in contact with amalgam
121. Prevention of
Allergic
Reactions
HISTORY - a thorough, complete history of any
previous allergic response or tendency prior to
starting treatment will avoid most emergencies
122. Other Means
of Prevention
ī Medical consultation
ī Dental office skin testing
ī (not foolproof and not advisable)
123. 123
Patch Test
īMost definitive diagnostic test
īSuspected allergen applied to skin to produce small
area of allergic contact dermatitis
After 48 to 96 hrs
hyperemia, edema, vesicle formation & itching
Positive reaction
(Slavin and Ducomb,1989)
124. âĸ All of the patients were given recommendations to undergo a
patch test for the purpose of diagnosing dental metal allergy.
âĸ As an alternative in vitro examination, lymphocyte activation
tests can also be used.
âĸ However, since lymphocyte activation tests are not available for
every metal element, the patch test should be considered as the
first choice for confirmation of the diagnosis.
125. âĸ Axell et al designed a list for patch test screening of
dental materials in cooperation with The Nordic
Institute of Dental Materials (NIOM)
âĸ This patch test series (dental screening) consists of
21 chemicals.
âĸ The substances used in the list were chosen from
reports in the literature on contact allergic reactions
to dental materials.
âĸ The dental screening test series was devised for use
mainly in the investigation of patients with
stomatitis, to rule out a possible allergic reaction to a
component in the dental materials used.
126. Metal reagents
âĸ The following metal reagents are the primary reagents used for a patch test
134. Corticosteroids
ī Hydrocortisone used most often
ī Stablilizes cell membranes against actions of histamines,
bradykinins, and prostaglandins
ī Supplements adrenal steroid output during stress
137. Treatment of
Delayed Skin
Reactions
ī Antihistamine
ī Diphenhydramine (Benadryl) 50 mg IM
ī Prescribe oral form Q6H for 3-4 days
ī Arrange medical consultation
138. Treatment of
Respiratory
Reactions
ī Bronchial Constriction
ī Terminate dental treatment
ī Sit patient upright
ī Oxygen 6 L/min
ī Epinephrine aerosol or 0.3 mg IM or SC
(0.3 ml of a 1:1000 solution)
139. Treatment of
Respiratory
Reactions
ī Bronchial Constriction (cont.)
ī Observe for at least 1 hr
ī Antihistamines - Benadryl 50 mg IM
ī Obtain medical consulatation
ī Prescribe oral antihistamines
ī (Q6H for 3-4 days)
142. Generalized
Anaphylaxis
with Signs of
Allergy
ī Place patient in a supine postion
ī Basic Life Support (ABCs)
ī Administer epinephrine 0.3 mg IM or SC
(0.3 ml of a 1:1000 solution)
ī Summon medical assistance
146. TakeHomepoints
âĸ A successful dental treatment involves not only mastering the
clinical technique, but also requires that the practitioner follows
biosafety norms regarding the proper use of dental materials and
clinical procedures.
147. âĸ Although these products may act as allergens in part of
the population, one should keep in mind that every
technology, no matter how beneficial, can exert a
negative impact on some members of the population.
148. âĸ Correct handling of resin-based materials is crucial to achieve
desirable result, such as minimizing post treatment complaints
and unwanted reactions, as well as a long lasting restoration.
âĸ Some adverse reactions may be prevented by material handling
methods directed to reduce leakage and degradation and
minimize direct exposure of unpolymerized material.
149. Because allergy is a reality dentists have to deal with, the following guidelines are
proposed: â
ī Dental personnel should be familiar with the major signs and symptoms of allergic
reactions, including anaphylaxis in the case that an allergic emergency should arise during
a consultation.
ī Previous allergic status of patients and personnel should be noted.
ī Dental personnel should always keep records of dental materials used.
ī If allergic reaction occurs, backtracking is necessary in order to identify the specific
allergen.
150. ī Local exhaust ventilation systems can significantly reduce the peak concentration of
acrylate vapor in the breathing zone of dental technicians. (However, the local exhaust
ventilation is not efficient in reducing the concentration of airborne acrylic dusts.)
ī Nitrile, vinyl, or 4H gloves should be used by the dental practitioner if acrylate or latex
sensitivity is suspected .
ī If sensitivity is suspected in form the patient about possible clinical tests to determine
origin of allergy, e.g. acrylate patch testing.
ī Delayed sensitivity may be prevalent in certain cases.
ī Be aware of cross-sensitivity towards coloring agents of dentures.
ī Create a latex-free environment
For personnel and patients.
151. ī All positive responses to an allergy history are true until
exact nature is determined!
ī Patients reporting allergies should be critically evaluated
-refer for allergy testing if history, reaction, or
management are suspect.
ī Be prepared to manage difficulties! Always!
152. References
ī Phillips' science of dental materials, 12th edition. kenneth
anusavice, chiayi shen, H. Ralph rawls.
ī Robbins and cotran pathologic basis of disease, 9th edition.
ī Feasby wh, ecclestone er, grainger rm. Nickel sensitivity
in pediatric dental patients. Pediatr dent, 10: 127â129,
1988.
ī Problems and benefits associated with restorative materials:
side-effects. Adv dent res 6:7-16, september, 1992.
ī Gottfried Schmalz Dorthe Arenholt-Bindslev. Biocompatibility
of dental Materials.
Editor's Notes
Nazi Physicians and their assistants forced prisoners into participating; they did not willingly volunteer and no consent was given for the procedures. Typically, the experiments resulted in death, trauma, disfigurement or permanent disability, and as such are considered as examples of medical torture.
After the war, these crimes were tried at what became known as the Doctors' Trial, and revulsion at the abuses perpetrated led to the development of the Nuremberg Code of medical ethics.
The Medical Device Amendments of 1976 in the US were the first regulations which emphasized the need for biological standardization and testing of dental materials.
Class I materials are those considered to be of low risk in causing adverse reactions and, thus, require only "general controls," such as good manufacturing practices and record-keeping by the producer. Materials in
Class II must satisfy the requirements outlined in the current ANSI/ADA specifications.
The most extensive testing is required for Class III materials, which includes full safety and efficacy assessments prior to marketing.
Required for all chemical substances, should contain info on hazardous substances, handling, dispensing.
Allergy testing of dental materials consists of epicutaneous patch testing, in which readings of skin reactions are made on removal of patches after 48. 72, or 96 hours