this is the second part od seminar which includes biocompatibilty of various dental materials which are used in daily clinical practice including routine suture materials, rootcanal , restorative materials along with pateint photographs and case reports

1. BIOCOMPATIBILITY OF
VARIOUS DENTAL
MATERIALS – PART 2
45
PRESENTED BY:
Dr. Ritu Gupta
PG I YEAR
Dept of Conservative Dentistry
and Endodontics
PDA, Bhopal (MP.)

2. AMALGAM
 Silver amalgam has been the most important restorative material in the
history of dentistry. The material has been widely used for almost two
centuries, although the composition has changed during this period.
 Several reactions may contribute to the release of mercury from amalgam.
 In the case of electrochemical corrosion, all constituents of amalgam may be
released from the restoration
 MERCURY FREE AMALGAM: The best way to prevent a release of mercury
would be to completely replace this element. Therefore, the replacement of
mercury by gallium has been attempted
 Dental amalgams consist of metals that may cause concerns about the risk of
systemic toxic reactions if released in sufficiently high quantities
 An appropriate cavity base or lining should be used in deep cavities for pulp
protection to prevent the risk of an immediate pulp reaction after insertion of
amalgam.

3.  The incidence of amalgam tattoos varied between 1% and 8% in different study
populations
Kidneys are the primary storage organ for
inorganic mercury derived from amalgam
fillings. The creatinine-adjusted excretion of
mercury in urine is presently considered the
best parameter to assess the body’s burden
of inorganic mercury
Holmstrup, P.: Reactions of the oral mucosa related to silver amalgam. A review. J Oral Pathol Med 20, 1–7 (2001).

4. A number of studies have thus demonstrated that in patients with lesions confined to the
mucosa in close contact with dental amalgam, the complete resolution of OLR occurs more
frequently than in patients with more diffuse lesions extending beyond the contact area
 Fig. a,b Contact lesion before and after replacement of an amalgam
restoration in a 44-year-old woman. a White contact lesion in the contact
area of an amalgam filling in 37. b Remission 1 month after amalgam was
replaced by composite resin
Bratel, J., Hakeberg, M., Jontell, M: Effect of replacement of dental amalgam on oral lichenoid reactions. J
Dent 24, 41–45 (2006).

5. BONDING AGENTS
46
• May penetrate upto 0.5 mm in dentin and cause
supression of cellular metabolism for upto 4
weeks
• HEMA 100 times less cytotoxic than Bis-GMA
• Release of MMPs from dentin by virtue of
interaction with acid components of dentin
adhesives causes degradation of adhesive bond
by enzymatic action on exposed collagen
within the hybrid layer.
• The application of an MMP inhibitor, such as
chlorhexidine, has been shown to minimize this
effect.

6. Bonding agents bite
 the materials that we dentists come across daily in our professional lives can
be the source of annoying, itchy lesions that prove to be truly bothersome.
 The natural latex rubber gloves that are routinely used in dental practices
seem to afford little protection against these small, evil molecules that creep
right through them.
 Once you get sensitised, there is no turning back.
 My personal experience is with bonding agents; even double gloving and an
exposure time of less than two seconds led me to develop an itchy red patch
on the back of my hand.
 This was the spot where the assistant, unaware that I had recently discovered
my allergy, had squeezed one drop of bonding agent while I had my head
turned the other way, busy doing a composite restoration.
 The only thing that relieved it was topical fluticasone propionate cream
Adnan, S. Dental materials: Bonding agents bite. Br Dent J 217, 108 (2014).

7. RESIN BASED COMPOSITES
47
The dental personnel commonly complain of contact dermatitis
and asthma caused by methacrylates
• Moderate cytotoxic reactions in cultured cells over 24 to 72 hours
of exposure
• Light-cured resins are less cytotoxic than chemically cured
systems highly dependent on the curing efficiency of the
light and the type of resin system.
• The pulpal inflammatory response was low to moderate after 3
days when they were placed in cavities with 0.5 mm of remaining
dentine followed by an increase in reparative dentin .
• With a protective liner or a bonding agent, the reaction of the
pulp to resin composite materials is minimal.

8.  The recognition of hypersensitivity
 Patients who are at a perceived higher risk of hypersensitivity may be
identified at the initial appointment through detailed history-taking.
 The salient features of history taking are commonly:
 Medical history – History of asthma, hay fever, dermatitis and childhood
eczema
 Concomitant disease − HIV, EBV, CMV;
 History of allergies including frequency, duration and severity of symptoms;
 Exacerbating factors (eg particular season, known triggers, environmental
factors);
 Relieving factors (eg medications, allergen avoidance).
 In particular, monomers such as 2-HEMA, Bis-GMA, BPA and TEGDMA have been
identified as common causative allergens.
Ahsan, A., & Ashley, M. (2016). Hypersensitivity to dental composites and resin-
bonding agents. Dental Update, 43(9), 836–842. doi:10.12968/denu.2016.43.9.836

9. Allergic contact dermatitis of a dentist
after contact with resin-based
compositesExtraoral allergic reactions (type I)
after application of a pit and fissure
sealant
Kanerva, L., Estlander, T., Jolanki, R.: Allergic
contact dermatitis from dental composite resins
due to aromatic epoxy acrylates and aliphatic
acrylates. Contact Dermatitis 20, 201–211
(2009).
Hallstrom, U.: Adverse reaction to a fissure sealant.
Report of a case. J Dent Child 60, 143–146 (2013).

10.  Thus, dental personnel must be considered a risk group. In this context, it
needs to be considered that monomers may penetrate commonly used gloves
(e.g., from latex or nitrile) within a short period of time .
 Neoprene gloves have been recommended as the best (relative) protection
***Munksgaard, E.C.: Permeability of protective gloves to (di)methacrylates in resinous dental materials. Scand J Dent Res
100,189–192 (2002).
***Rietschel, R.L., Huggins, R., Levy, N., Pruitt, P.M.: In vivo and in vitro testing of gloves for protection against UV-curable
acrylate resin system. Contact Dermatitis 11, 279–282 (2004).

11. Chemical burn after
inadvertent contact of
phosphoric acid with gingiva
Hammer, B., Hotz, P.: Inspection of 1 to 5-year-old amalgam,
composite and cast gold fillings. Schweiz Monatsschr
Zahnheilkd 89, 301–314 (2004).
Gingivitis adjacent to a cervical composite resin filling
Hamid, A., Sutton, W., Hume, W.R.: Variation in
phosphoric acid concentration and treatment time.
Am J Dent 9, 211–214 (2006).

12. PRECAUTIONS
• Beneath a composite resin restoration, a suitable base should be placed
to protect the pulp from material components and bacterial toxins
• Inhalation of composite resin particles during grinding and shaping of a
newly placed restoration should be prevented by suitable measures such as a
rubber dam or the use of suction/water coolant.
• Protective shields should be attached to the end of the light guide of
polymerization lamps to protect the eyes of dental personnel
• Dental personnel should always avoid any contact of sk50in or even gloves
with resin-based composites or dentin adhesives, including during
instrument cleaning and waste disposal
Biocompatibility of dental materials –Gottfried Schmalz & Dorthe Arenholt – Bindslev

13. DENTAL CASTING ALLOYS
51
The biological response to an alloy depends on the biological effects of
released elements, the quantities released, the duration of tissue
exposure to these elements, and other factors
A number of factors influence the corrosion of dental alloys :
• Composition of the alloy (particularly at the surface)
• Surface structure (roughness, presence of oxides)
• Crevices, pits
• Thermal treatment/history
• Combinations of alloys (gold coating, soldering)

14. 52
SYSTEMI
C
TOXICITY
The number of elements released
from the dental alloys is far below
the dietary intake; for e.g. the
amount of zinc released (< 0.1µg
/day ) is far below the daily dietary
intake (14,250µg /day).
No studies have demonstrated
systemic toxicity due to cast alloys
LOCAL TOXICITY When there is a release of elements
from the alloys, and if it is present
in more conc. in the sulcus than in
saliva, then epithelial cells of the
sulcus will be more prone to
cytotoxicity.
Ni, Cr, Co - Cytotoxic.

15. Allergic
Reactions
The incidence of nickel allergy is 15% and
that of Co and Cr is 8%.
Cross –reactive allergy can occur for Pd
and Ni.
Lichenoid reactions have also been
reported in the oral mucosa adjacent to
casting alloys.
OTHER
REACTION
S
Vapor form of elements such as beryllium is a
common mutagenic threat.
Beryllium is also a documented carcinogen in
either the metallic or ionic state.
Beryllium-containing particles that are inhaled and
reach the alveoli of the lungs may cause a chronic
inflammatory condition called BERYLLIOSIS
Geurtsen, W. Biocompatibility of Dental Casting Alloys. Critical Reviews in Oral Biology & Medicine, 13(1), 71–84. (2002).

16. • Gold surface coating of nickel-based or cobalt-based alloys should be discouraged
because the combination of the alloys and their permanent contact may enhance
corrosion rather than retard it.
• Furthermore, there are significant problems with the integrity of the long-term
bonds between coatings and the alloys .
Gold coating of nickel-based and cobalt-based alloys.
a Gold-coated partial denture.
b Pronounced redness of the palate beneath the denture base.
c Insufficient adhesion of the gold coating
Wirz, J., Jager, K., Schmidli, F.: Klinische Korrosion. [Clinical corrosion] Schweiz Monatsschr Zahnmed 97, 1151–1156 (2001).

17. Perioral allergic
reaction after
insertion of nickel-
containing
orthodontic wires
(CuNiTi)
Lichenoid reaction
of the mucosa
contacting an alloy
• A number of studies have documented that patients
who are allergic to palladium are likely to be allergic
to nickel as well
• Thus, the clinician should carefully consider whether
palladium-containing alloys should be applied in
patients with nickel allergy
• A lichenoid reaction that is limited to the contact
area of the material with oral tissues may be
material induced.
• The use of alternative materials is strongly
recommended in these cases.
Schmalz, G., Garhammer, P.: Biological interactions of dental cast alloys with oral tissues. Dent Mater 18, 396–406 (2002).

18.  When evaluating a patient complaint about
adverse effects from a dental alloy, the
medical history or queries should also include
patient problems related to jewelry (e.g.,
earrings), watches, or metal attachments to
clothing, glasses frames, etc. This information
may indicate a metal-related allergy
 If oral plaque reduction strategies fail to
resolve a persistent gingival inflammation
adjacent to alloy or ceramic-alloy
restorations, the practitioner should consider
removing the crowns to resolve the problem
Extraoral reaction in a 48-
year-old woman after
insertion of metal ceramic
restoration; reaction
subsided after exchange of
the crowns with all-
ceramic restorations 57
Pronounced gingivitis
after seating of
ceramic crowns,
despite good oral
hygiene
Hensten-Pettersen, A., Jacobsen, N.: Perceived side effects of biomaterials in prosthetic dentistry. J Prosthet Dent 65, 138–
144 (2004).

19. GLASS IONOMER CEMENTS
• They are, in general, cytotoxic shortly after mixing but are inactive when set.
They can be applied on vital dentin if one is certain that the pulp is not
exposed.
• Deep cavities are always associated with the risk of a (potentially
unrecognized) pulp exposure. Therefore, it is recommended to cover areas
close to the pulp (and pulp exposures) with a calcium hydroxide- based
material.
• When GICs are used as luting agents for restorations, the tooth should not be
excessively dried.
• Resin-modified GICs can be used virtually in the same way as conventional
GICs, but the product Vitrebond should always be used in combination with a
calcium-hydroxide-based material in medium-deep and deep cavities.
• Resin-modified GICs should not come into direct contact with skin and gloves
because these materials contain potentially allergenic substances, such as
HEMA

20. Case Report: Allergic contact dermatitis
from resin-modified glass ionomers
 This report documents a rare case of a dentist who developed
allergic contact dermatitis following exposure to a RMGI.
 Contact dermatitis occurred despite the use of latex gloves, which
were worn during the procedure.
 Patch testing was conducted to confirm the diagnosis
 a) Vesicles, papules, and erythema on the lateral aspects of the left
hand fingers, representative of the acute phase of allergic contact
dermatitis.
 (b) Thickened, lichenified skin on the left index finger,
representative of the chronic stage of allergic contact dermatitis
Buchanan GD, Tredoux S, Gamieldien MY. Allergic contact dermatitis from resin-modified glass ionomers. J Conserv Dent
2019;22:310-2.

21.  A no-touch technique and the routine use of nitrile gloves were subsequently
adopted, which resulted in an overall decrease of the condition
 Dentists, auxiliary personnel, and students should be aware of the possibility
of sensitization to, and the development of allergic contact dermatitis not
only from conventional resin materials, but also from the RMGIs.
Extreme positive reactions were found during
patch testing to Vitrebond™ and Vitremer™

22. LINERS,VARNISHES,AND
NONRESIN CEMENTS
• CALCIUM HYDROXIDE
• ZINC PHOSPHATE
• ZINC POLYCARBOXYLATE CEMENT
• ZOE CEMENT

23. CALCIUM HYDROXIDE CEMENT
60
Systemic
toxicity
No reported systemic reaction
Local toxicity Indirect pulp capping material:
1. Exerts antibacterial effect.
2. Tertiary dentin formation.
3. Decreases the permeability of dentin.
4. NOTE: Tertiary dentin will be triggered only
if the remaining dentin thickness(RDT) is 5 to
10 µm.
Direct pulp capping material: When in direct
contact with the pulp, produces superficial
coagulation necrosis.
This acts like a stimulus for the differentiation
of secondary odontoblasts that lay down
tertiary dentin.

24. ZINC PHOSPHATE CEMENT
Systemic toxicity No reported systemic reaction
Local Toxicity The acidity of the cement initially after mixing is very
high due to presence of phosphoric acid (pH is around
3.5 during application).
Subsequently, it increases towards neutralitywithin
24-48 hours.
Precautions to be taken are as follows:
1. The powder/liquid ratio should never be reduced
to increase the working time, as this increases the
acid content.
2. The placement of a protective layer of a dentin
bonding agent, ZOE, varnish, or calcium
hydroxide is needed.
Allergic Reaction No reported allergic reaction
Other reaction No evidence of mutagenic or carcinogenic reaction

25. Zinc phosphate cement that
was left in the sulcus after
cementation results in
periodontal destruction and
bone loss
Zyskind, K.: Periodontal health as related to preformed crowns: report of case. J Dent Child 56, 385–387 (2009).

26. ZINC POLYCARBOXYLATE CEMENT
• Polyacrylate cements evoke a pulpal response similar
to that caused by ZOE, with a slight-to-moderate
response after 3 days and only mild, chronic
inflammation after 5 weeks.
• Reparative dentin formation is minimal with these
cements, and thus they are recommended only in
cavities with intact dentin in the floors of the cavity
preparations.

27. ZINC OXIDE EUGENOL CEMENT
• Reaction of the gingiva
after temporary
cementation of a crown
with a zinc oxide and
eugenol cement. 13
Systemic
toxicity
No reported systemic
reaction
Local Toxicity Pulp reaction
1. The cement can produce a
cytotoxic reaction when
directly applied to the pulp.
2. If there is a complete dentin
layer between the pulp and
the cement, no
inflammatory reaction will
occur.
[LEAST IRRITATING OFALL THE
CEMENTS :
pH 6.6 - 8
i.e. Mild pulpal response] Hensten-Pettersen, A., Jacobsen, N.: Perceived side
effects of biomaterials in prosthetic dentistry. J
Prosthet Dent 65, 138–144 (2001).

28. Allergic Reaction Eugenol can induce an
allergic response in some
individuals. Allergic contact
dermatitis has also been
reported in dental
personnel handling the
cement.
Other reaction Eugenol was mutagenic in
the mouse micronucleus
test .This effect could not
be reproduced in
transgenic Mice. Based on
these findings, the use of
ZOE materials is not
contraindicated.

29. PRECAUTIONS DURING CEMENTATION
• Apply petroleum jelly to the surrounding soft tissues
• Clean the excess cement after luting the prosthesis
• Any residues of cement left in the gingival sulcus will lead to inflammation
• To avoid a pulp necrosis, ZOE must not be applied on the exposed pulp.
• Dental personnel should avoid any skin contact with eugenol and ZOE in order
to prevent an occupational contact dermatitis

30. Case Report: An unexpected positive
hypersensitive reaction to eugenol
 eugenol causes allergic contact dermatitis, possibly because it can react
directly with proteins to form conjugate and reactive haptens.
 This article presents a case of immediate allergic contact urticaria to eugenol
during dental treatment.
 Intravenous injection of 100 mg of hydrocortisone hemisuccinate was
administrated immediately and zinc oxide eugenol temporary dressing was
replaced with non-eugenol containing material. The patient was kept under
observation. Forty-five minutes later the patient presented reduced erythema
on the face, neck, hands, torso and the limbs. After 2 h he completely
recovered.
Tammannavar P, Pushpalatha C, Jain S, Sowmya SV. An unexpected positive hypersensitive reaction to eugenol. BMJ Case Rep.
2013

31. DENTAL CERAMICS
67
SYSTEMI
C
TOXICITY
Risk of silicosis among dental technicians
due to inhalation of ceramic dust.
Silicosis is a lung diseases characterized by
shortness of breath, cough, fever, and
cyanosis.
Dust removal measures should be followed
in the laboratory.
LOCAL TOXICITY Most ceramics are biocompatible .
ALLERGIC
REACTION
No reported allergic reaction.
OTHER
REACTION
S
Zirconium oxide ceramics show some
amount of radioactivity due to
contaminants such as thorium and
uranium.

32. Root Canal Filling Materials
 It is particularly important that they have an acceptable degree
of tissue compatibility because these materials are in close
contact with vital tissue at the tip of the root (i.e., not
separated by an epithelial barrier, equivalent to an implant).
 If a mandibular nerve injury due to overextension of an
endodontic sealer into the mandibular nerve canal is suspected,
the patient should be referred for surgical treatment as soon as
possible to remove the sealer and treat the nerve according to
the degree of the damage
 Immediate treatment includes, for instance, the prescription of
steroids combined with the application of cold and wet packs to
prevent edema and inhibit inflammation.
Excessive overfilling of
the root canal and
extrusion
of a paraformaldehyde-
containing sealer into the
mandibular
canal. The patient
complained of total
anesthesiaDempf, R., Hausamen, J. E.: Lesions of the inferior alveolar nerve arising from
endodontic treatment. Aust Endod J 26, 67–71 (2015)

33. Latex in Rubber Dam
• allergic reactions to the rubber dam have increasingly been reported in
the dental literature in recent years
• These are mostly type I (immediate) reactions causing symptoms such
as a localized contact urticaria or anaphylactic shock
• Latex-free rubber dams are also available, e.g., based on silicone,
• which reveal mechanical properties similar to those of
• latex rubber dams (according to manufacturers’ information)
Perioral urticaria after application
of a latex-based rubber dam.
Positive radioallergosorbent test
reaction indicated IgE antibodies to
latex
Field, E.A., Longman, L.P., al-Sharkawi, M., King, C.M.: An immediate
(type I) hypersensitivity reaction during placement of a dental rubber
dam. Eur J Prosthodont Restor Dent 5, 75–78 (2007).

34. Gutta Percha
 Only highly purified gutta-percha should be used in patients with a latex
allergy. If necessary, synthetic gutta-percha points can be applied (e.g.,
Synthapoints
 GP and gutta-balata are derived from the same botanical family as the rubber
tree, and related to latex.
 It is reported that occasionally in the short supply of GP, the manufacturers
add some amount gutta-balata or synthetic trans-polyisoprene to the GP
cones which is not disclosed
 The use of a gutta-balata-containing product could potentially place a high
latex allergic patient at risk for an allergic reaction even when proper
instrumentation and obturation techniques are used to confine the material
within the root canal system.
Vishwanath V, Rao HM. Gutta-percha in endodontics - A comprehensive review of material science. J Conserv Dent.
2019;22(3):216–222.

35. ZOE Sealers
 Patients with an allergy to eugenol (or to
fragrances) should not be treated with materials
containing eugenol, isoeugenol, or Peru balm.
 All of the available information on adverse
effects and the high toxicity of
paraformaldehyde-containing ZOE sealers gives
rise to the recommendation to not use these
materials in clinical practice.
 Furthermore, other ZOE sealers should be applied
with great caution to avoid any overfilling of root
canals
Aspergillosis of the right maxillary sinus
a Overfilled root canal sealer in the sinus.
b Severe radiologic shadow of the maxillary sinus
(arrow).
cThe histologic section reveals an aspergillosis
containing root canal filling material (arrow)
Khongkhunthian, P., Reichart, P.A.: Aspergillosis of the
maxillary sinus as a complication of overfilling root
canal material into the sinus: report of two cases. J
Endod 27, 476–478 (2001).

36.  Aim: To compare the effects of three root canal sealers with respect to time on
biocompatibility of human periodontal ligament cells (hPDLCs).The sealers included
zinc oxide and eugenol based sealers (ZOE), epoxy resin sealers (ERS) and silicone
based sealers (SBS)
 Result: The cytotoxicity of ZOE was the highest and persisted with time. The setting
time had influence on the cytotoxicity of ERS. Only SBS did not show any
cytotoxicity or inhibition of the mineral potential on hPDLCs, indicating which was
more biocompatible than the others.
HU Jia，ZOU Xiao-ying，ZHUANG Heng，GAO Xue-jun. Effect of root canal sealers on biocompatibility of human
periodontal ligament cells[J].Journal of Peking University(Health Sciences), 2016, 48(5): 871-877.
 Aim :to investigate the effects of antioxidants such as catalase, superoxide
dismutase (SOD), and N‐acetyl‐L‐cysteine (NAC) on N2‐ and endomethasone‐induced
COX‐2 mRNA gene and cytotoxicity in human osteoblastic cells.
 Result: NAC appears as a useful agent in protecting cell damage mediated by
formaldehyde‐containing–ZOE‐based root canal sealers.
Fu Meing Hyang et al. Protective effect of NAC on formaldehyde‐containing–ZOE‐based root‐canal‐sealers–induced cyclooxygenase‐2 expression
and cytotoxicity in human osteoblastic cells. Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2005

37. IMPRESSION MATERIALS
68
Addition Silicone
Hydrocolloids
Polysulphides - contain lead peroxide, among others,
which can cause acute and severe systemic toxic
effects when swallowed or inhaled
Polyether
ZOE
 least biocompatibility applies to condensation silicones
NONTOXIC
ALLERGIC REACTIONS

38. • Direct and repeated skin contact by dental personnel,
however, should be avoided.
• Contact with the eyes, which may happen when mixing a
liquid catalyst into a putty impression material by hand,
should also be avoided, such as by wearing protective
glasses or by using a paste catalyst.
• It is important for the subgingival area of the sulcus to
be carefully controlled for remnants of impression
material, particularly in patients with deep periodontal
pockets.
69
PRECAUTIONS:

39. POLY-METHYLMETHACRYLATE RESINS
Denture base materials:
 MMA Monomer is the main
cause for hyper sensitization
• Hypersensitivity has been
documented to the acrylic and
diacrylic monomers, certain curing
agents, antioxidants, amines, and
formaldehyde
• For the patients most of these materials
have been reacted in polymerization and
thus are less prone
• Two aspects are of particular importance:
monomer– polymer conversion and
residual monomer content.
70

40. • Data from studies addressing cellular compatibility underscore the
recommendation to store dentures for 1 day in water to significantly
reduce the amount of residual monomers.
• Heat-polymerizing products should be preferred over
autopolymerizing materials if possible.
• Furthermore, patients should be advised not to wear dentures at
night at first because this might contribute to irritation of the
mucosa due to an accumulation of residual monomers in the tissue
a Inflammation of the oral mucosa beneath a denture base;
polymethylmethacrylate resin.
b Plaque at the denture base.
c Decrease of the inflammation after thorough cleaning and
storage in chlorhexidine
Engelhardt, J.P.: [Resistance of dental plastic materials to microorganisms] Schweiz Mschr Zahnheilk 83, 656–669 (2003).

41.  DENTIST
SUFFERING FROM
AN ALLERGY TO
METHYL
METHACRYLATE
CONTACT
DERMATITIS
number of persons allergic to acrylates
and additives of resins due to occupational exposure
is increasing.
The dental team should be scrupulous
in avoiding any skin contact with unset resin
or individual components because in extreme cases
a sensitization may cause occupational disability.
Even gloves do not sufficiently protect skin against
contact with monomers.
• If patients suffer from an incompatibility with PMMA resins, particularly an allergy, adequate similar
materials are necessary for their treatment
• Various alternative products are available (Eclipse, Promysan STAR, Valplast)
• In such situations, a product based on polyvinyl is frequently used.
• This material also contains PMMA but in a very low concentration.
• Fewer data exist for the alternatives to PMMA-based resins.
Mjor, I.A.: Potential hazards in the handling of dental materials. In: Mjor, I.A. (ed.): Dental Materials: Biological
properties and clinical evaluations. CRC, Boca Raton, Florida, 2005, pp 193–202

42. N-ACETYL CYSTEINEALLEVIATES INFLAMMATORY
REACTION OF ORAL EPITHELIAL CELLSTO POLY
(METHYL METHACRYLATE) EXTRACT
Acta Odontologica Scandinavica. 2015;73(8):616-625.
• Objective: The purpose of this in vitro study was to determine whether the
cytotoxicity of self-curing polymethyl methacrylate (PMMA) dental resin to
oral epithelial cells was eliminated by mixing the antioxidant amino acid
derivative, n-acetyl cysteine (NAC) with the material.
• Conclusion. The cytotoxicity of self-curing PMMA dental resin tooral
epithelial cells was eliminated by mixing the resin with NAC.

43. SOFT DENTURE LINERS &ADHESIVES
 Release of plasticizers
 Extremely cytotoxic
 Denture adhesives show severe cytotoxic
reactions in-vitro
Large amount of formaldehyde
Allowed significant microbial growth

44. REACTION OF BONE & SOFT TISSUES TO
IMPLANT MATERIAL
A) REACTION TO CERAMIC IMPLANT MATERIAL
VERY LOW TOXIC EFFECTS.
OXIDIZED STATE CORROSION RESISTANT
• B) REACTIONS TO RESORBABLE MATERIALS
• Well-tolerated by tissues in vivo
• Resorbability of these materials depends on the volume of
material implanted and because these materials degrade into
acidic byproducts which may invoke an inflammatory response.
• E.G. Co-polymer of polylactic acid (PLA) and polyglycolic acid (PGA), natural
polymers such as cross-linked collagen, starch, and cellulose.
• USEDFOR RESORBABLESUTURES, FRACTURE FIXATION PLATES
AND SCREWS,GUIDED TISSUE MEMBRANES,AND CONTROLLED
DRUG-RELEASE SYSTEMS.

45.  C) REACTION TO PURE METALS & ALLOYS
 ‘Metal’ oldest type of oral implant material
 Initially selected on the basis of the ‘ease of
fabrication’
 Stainless steel, chromium-cobalt-
molybdenum, titanium and its alloys
 Most commonly used is titanium(Ti-6Al-4V)
 Titanium’s biocompatibility is associated
with its fast oxidizing capacity.
 Corrosion resistant & allows osseointegration
75

46. SOFT TISSUE :
 Epithelium forms a bond with
implant similar to that of tooth
 Connective tissue apparently does not
bond to the titanium, but forms a tight seal
that seems to limits ingress of bacteria &
its products
In recent years, Titanium
allergy has been noted at
a low prevalence rate of
0.6% and presents with
urticaria, eczema, redness
of the mucosa.

47. PMMA-silica nanocomposite coating:
Effective corrosion protection
and biocompatibility for a Ti6Al4V alloy.
 Ti6Al4V is the mostly applied metallic alloy for orthopedic
and dental implants, however, its lack of osseointegration and poor long-term
corrosion resistance often leads to a secondary surgical intervention, recovery
delay and toxicity to the surrounding tissue. As a potential solution of these
issues poly(methyl methacrylate)-silicon dioxide (PMMA-silica) coatings have
been applied on a Ti6Al4V alloy to act simultaneously as an anticorrosive
barrier and bioactive film.
 The obtained results suggest that PMMA-silica hybrids can act in a dual role as
efficient anticorrosive and bioactive coating for Ti6Al4V alloys.
S.V. Harb et al. PMMA-silica nanocomposite coating: Effective corrosion protection and biocompatibility for a Ti6Al4V alloy.
Mater Sci Eng C Mater Biol Appl. 2020 Apr;110:110713.

48. 83
• Recent reports have questioned whether metal sensitivity may occur
after exposure to titanium.
• This clinical report demonstrates the emergence of facial eczema in
association with a titanium dental implant placed for a mandibular
overdenture supported by 2 implants.
• Complete remission was achieved by the removal of the titanium
material.
• This clinical report raises the possibility that in rare circumstances,
for some patients, the use of titanium dental implants may induce an
a2
l3
lergic reaction.
Suspected association of an allergic reaction with titanium
dental
implants: A clinical report
-Hiroshi Egusa (J Prosthet Dent 2008;100:344-
347)

49. Facial eczema
Ten months after removal
of dental implants

50. Oral photographs of patient before and 10 months after removal of dental implants
A, Edentulous maxillary arch. B, Edentulous mandibular arch

51. BARRIER MATERIALS
Latex :
1.The incidence of latex allergy is about 9.7% and 6% among patients
and dental staff, respectively.
2.Latex products can produce either:
1. Type 1 immediate atopic/anaphylactic reaction - due to proteins
present in natural latex
2.Type 1V delayed hypersensitivity reaction (allergic contact
dermatitis): due to accelerators and antioxidants used in latex
manufacturing.
77

52. Precaution to be taken are as follows:
Non latex synthetic materials such as nitrile and styrene ethylene
butadiene styrene should be used.
Polyethylene or polyvinyl chloride rubber dams can be used instead
of latex
•Contact urticaria following
occupational exposure to latex
proteins in disposable gloves
•severe irritative hand dermatitis (non
allergic) caused by frequent hand washing
and wearing of disposable gloves

53. CONCLUSION
 DUE TO RISEIN NUMBER OF PATIENTS WITH ALLERGIESFROM DIFFERENT
MATERIALS, THE PRACTICING DENTISTS SHOULD BE AWAREABOUT THE
ALLERGIESDOCUMENTED TO KNOWN MATERIALS
 FORESTABLISHING DIAGNOSIS, IT ISESSENTIALTO OBTAIN PROPER
HISTORY RELATED TO ALLERGY, CLINICAL EXAMINATION AND
CONFIRMATORY TESTS.
 IT ISMANDATORY FORTHE CLINICIAN TO KNOW AND
UNDERSTAND THE BIOCOMPATIBILITY OF THE DENTAL MATERIALS,
SOASTO PROVIDEMAXIMUM ADVANTAGE & MINIMUM RISKTO
THE PATIENT.

54. REFERENCES
• Restorative dental materials (13th edition) –G. Craig & JohnH.
Powers
• Biocompatibility of dental materials –Gottfried Schmalz &
Dorthe Arenholt – Bindslev
• PHILLIPs’Science of dental material (12th edition)
• Naddeo P, Laino L, La Noce M, Piattelli A, De Rosa A, Iezzi G et
al. Surface biocompatibility of differently textured titanium
implants with mesenchymal stem cells. Dental Materials.
2015;31(3):235-243.
• Nishimiya H, Yamada M, Ueda T, Sakurai K. N-acetyl cysteine
alleviates inflammatory reaction of oral epithelial cells to poly
(methyl methacrylate) extract. Acta Odontologica Scandinavica.
2015;73(8):616-625.

55. • Syed M. Allergic reactions to dental materials- A systematic
review. Jcdr. 2015
• Egusa H, ko N, shimazu T, yatani H. Suspected association of an
allergic reaction with titanium dental implants: A clinical report.
The journal of prosthetic dentistry. 2008;100(5):344-347.
• Lee J,song K, ahn S, choi J,seo J,park J.Evaluation of effect of
galvanic corrosion between nickel-chromium metal and titanium
on ion release and cell toxicity. The journal of advanced
prosthodontics. 2015;7(2):172
• Marin, E., Boschetto, F., & Pezzotti, G. (2020). Biomaterials and
biocompatibility: an historical overview. Journal of Biomedical
Materials Research Part A. doi:10.1002/jbm.a.36930 .
88

56. Thank You !!!
Stay Home,
Stay Safe,
Wash your
hands 