Ceramic orthodontic brackets/certified fixed orthodontic courses by Indian dental academy

CERAMICCERAMIC
BRACKETSBRACKETS
www.indiandentalacademy.com
INDIAN DENTAL ACADEMY
Leader in continuing dental education

Seminar presented by
Dr Nikhar Verma
Under the guidance of
Prof Ashima Valiathan
Head of Dept., Director of PG studies
Dept of Orthodontics and Dentofacial
Orthopedics
MCODS, Manipal

Introduction.
• Ideal orthodontic appliance: Good
esthetics & Optimum technical
performance.
• Ceramic brackets – introduced in 1986.
• Increase in the adult patients
• Integral part of the orthodontists’
armamentarium

Ceramic Brackets
•Types.
•Physical properties.
•Bond strength.
•Frictional resistance.
•Base surface characteristics.
•Debonding techniques and enamel fracture risks.
•Enamel abrasion and wear.
•Bracket fracture.
•Bracket recycling.

Evolution of brackets in terms
of esthetics
Bands  Bondingcoated metal brackets
smaller stainless steel brackets  lingual
orthodontics  Polycarbonate  Metal
slots( Ceramic reinforced)  ceramic
brackets

Ceramics - material science
• Greek word “Keramikos” meaning
“earthen”.
• Ceramics are materials which are first
shaped and then hardened by heat. Form a
broad class of materials that include
precious stones, glasses, clays and metallic
oxides.
• Neither metal nor polymeric.

• Usually of a silicate nature. It may be a
combination of one or more metals with a
non-metal oxygen. The larger oxygen atoms
serve as matrix, with the smaller metal
atoms or semi-metal atoms such a silicon
tucked into spaces between oxygen atoms.

• Ceramic brackets are composed of
aluminum oxide .
• Polycrystalline alumina & monocrystalline
alumina are the two most common varieties.
• Another category that is being developed is
the Zirconium brackets

Monocrystalline brackets –
manufacturing process
• Heating aluminum oxide to temperatures in
excess of 2100° C. The molten mass is
cooled slowly, and the bracket is machined
from the resulting crystal.

Polycrystalline brackets – Manufacturing
process
• Manufactured By blending aluminum oxide
particles with a binder, the mixture can be formed
into a shape from which a bracket can be
machined. (sintering process)
• Temperatures above 18000
C are used to burn out
the binder and fuse together the particles of the
molded mixture.
• Heat treated to remove surface imperfections and
relieve stresses created by the cutting operationwww.indiandentalacademy.com

Polycrystalline brackets – Manufacturing
process
• The presence of pores, machining interferences,
and propagation lines contribute to
compromises of bracket use anytime during
clinical use.
• An alternative method of making
polycrystalline brackets is injection molding.
This process does not require the brackets to be
machined and thus eliminates structural
imperfections created by the cutting process.

Comparison of properties
• Production of polycrystalline brackets is less
complicated, these brackets are more readily
available at present.
• Single crystal brackets are noticeably clearer
than polycrystalline brackets, which tend to
be translucent.
• Both resist staining and discoloration.
• Come in a variety of edgewise structures
including true Siamese, semi-Siamese, solid,
and Lewis/Lang designs.

Zirconia brackets
• Zirconia is a mineral extracted from beach
sands of Australia.
• The PSZ (Partially stabilized Zirconium)
developed by the Commonwealth Scientific
and Industrial Research Organization
(CSIRO) as a reliable highly stress-resistant
material.
• A remarkable quality of zirconia -based
advanced ceramics is that wear actually
makes the material stronger

Zirconia brackets
• In theory, the low frictional coefficients achievable
with yttria-stabilized zirconia1 should make it a
suitable alternative to alumina for bracket
construction.
• However, zirconia brackets have problems related
to color and opacity, which detract from the
esthetics, and can inhibit composite
photopolymerization.
• A study by Kusy et. al. concluded that zirconia
brackets offer no significant improvement over
alumina brackets with regard to their frictional
characteristics.( Kusy, AJO 1994)

Ceramic brackets- hardness
• Extremely high hardness of aluminium oxide,
so both monocrystalline and polycrystalline
alumina have a significant advantage over
stainless steel.
• Because ceramic brackets are nine times harder
than stainless steel brackets or enamel, severe
enamel abrasion from ceramic brackets might
rapidly occur, if contacts between teeth and
ceramic brackets exist

Ceramic brackets- tensile strength
• The ability to resist structural failure, called
tensile strength:monocrystalline alumina
>polycrystalline alumina, >> stainless steel.
• Depends on the condition of the surface of the
ceramic. A shallow scratch on the surface of a
ceramic bracket will drastically reduce the load
required for fracture. The elongation for
ceramic at failure is less than 1% in contrast
with approximately 20% of stainless steel, thus
making ceramic brackets more brittle.

Ceramic brackets- tensile strength
• Ceramics have highly localized,
directional atomic lattice that does not
permit shifting of bonds and
redistribution of stress. So when stresses
reach critical levels, interatomic bonds
break, and “brittle failure” occurs.

Ceramic brackets- fracture toughnessCeramic brackets- fracture toughness
• Fracture toughness in ceramics is 20 to 40
times less than in stainless steel, making it
much easier to fracture a ceramic bracket than
a metallic one. Among ceramic materials,
polycrystalline alumina presents higher
fracture toughness than single-crystal alumina.
• Semi-twin brackets,( Fascination, Mystique, &
Virage) have significantly higher tensile
fracture strength than true-twin brackets,
( Clarity, lnVu, & Luxi) . Mono-crystalline
bracket (Inspire) could not be fractured in the
study. (Johnson et al, Angle 2005)(Johnson et al, Angle 2005)

Bond strengthBond strength
• Ceramic material does not bond chemically with
adhesives
• Chemical bonding : glass is added to the aluminum
oxide base and is treated with a silane coupling
agent. Silane bonds with glass and leaves a free end
of its molecules that react with any of the acrylic
bonding materials.
• Shiny surfaces of ceramic brackets bonded
chemically allow greater distribution of stress over
the whole adhesive interface without the presence of
any localized stress areas.
• Significantly greater shear bond is needed to cause
debonding and pure adhesive failure

Bond strengthBond strength
• Mechanical bonding : brackets have retentive
grooves in which edge angles are 90°. There
are also crosscuts to prevent the brackets
from sliding along the undercut grooves that
have sharp edge angles, thus leading to high
localized stress concentrations around the
sharp edges and resulting in brittle failure of
the adhesive. On application of shear
debonding force, part of the adhesive is left
on the tooth and part on the grooved bracket.

Bond strength of ceramic
brackets
• Mean shear bond strength of the polycrystalline
ceramic brackets is significantly greater than that
obtained when stainless steel brackets are used
• Single crystal ceramic brackets produce the
lowest mean shear bond strength values.
• Gwinnett( AJO1988) reported that the mean
values for the different bracket types are not
statistically significant, but this conflicts with the
results of many other studies.

Bond strength of ceramic brackets
• Bond strengths are greater with chemical bonding than
with mechanical retention which shows bond strengths
comparable to metal brackets (Wang AJO1997).
• Decreasing etching time, (with 37% phosphoric acid)
from 30 seconds to 10 seconds maintains a clinically
useful-bond strength. (Olsen & Bishara AJO 1996).
• Light-cured GICs provide sufficient strength for
bonding ceramic brackets, but in terms of bond failure
site and bracket fracture, they provide no advantage
over composite adhesives. (Jost-Brinkmann, J Adhesiv
Dent 1999)

Silane coated
chemical adhesive
base
MechanicalMechanical
retentive baseretentive base

Micromechanical retention

• Weinberger, Angle 1997Weinberger, Angle 1997, evaluated 3
different methods of curing for poly- and
mono-crystalline brackets. the mean shear
bond strengths of the single crystal alumina
brackets with silanated bases were
significantly higher than those of the poly-
crystal alumina brackets with non-silanated
bases, and no enamel fractures were found
on debonding the chemically cured brackets
while the light and argon laser groups
exhibited a 10% rate of enamel fracture on
debonding.
Bond strength of ceramic brackets

• Mean bond strengths of Clarity brackets
(polycrystalline) and Inspire brackets
( monocrystalline) found to be
comparable. No enamel damage was
evident in any specimen when the
brackets were removed with the
appropriate pliers recommended by the
manufacturers. ( Sadowsky, AJO 2004).( Sadowsky, AJO 2004).
Bond strength of ceramic
brackets

Frictional Resistance
• Stainless steel brackets generate lower frictionalStainless steel brackets generate lower frictional
forces than ceramic brackets, because of their lowerforces than ceramic brackets, because of their lower
surface roughness, which is clearly visible whensurface roughness, which is clearly visible when
comparing scanning electron micrographs.comparing scanning electron micrographs.
• Ceramic brackets produce significant greaterCeramic brackets produce significant greater
friction. Beta-titanium and nickel-titanium wires arefriction. Beta-titanium and nickel-titanium wires are
associated with higher frictional forces than stainlessassociated with higher frictional forces than stainless
steel or cobalt-chromium wires. Progressivelysteel or cobalt-chromium wires. Progressively
increasing frictional values: stainless steel bracket,increasing frictional values: stainless steel bracket,
ceramic bracket with a metal reinforced slot, andceramic bracket with a metal reinforced slot, and
traditional ceramic bracket with a ceramic slot.traditional ceramic bracket with a ceramic slot.
((Cacciafesta et al, AJO2003; Nishio et al. AJO 2004)Cacciafesta et al, AJO2003; Nishio et al. AJO 2004)

• Mono-crystalline alumina brackets are smoother than
polycrystalline samples, but their frictional
characteristics are comparable.( Kusy AJO1994)
• To reduce frictional resistance, development of
ceramic brackets with smoother slot surfaces,
rounding of slot base or consisting of metallic slot
surfaces has been accomplished.
• Metal-lined ceramic brackets can function
comparably to conventional stainless steel brackets
and 18-kt gold inserts appear superior to stainless
steel inserts. (Kusy & Whitley, Angle 2001).

• Ligation: Usefulness of
Teflon-coated ligatures
compared to elastomeric
ligatures in minimizing
the high friction of
ceramic brackets when an
esthetic appliance is
imperative (DeFranco,
Angle 1995).
• Manufacturers have also
introduced self ligating
ceramic brackets.

Self ligating ceramic brackets

Self ligating ceramic bracket

Base surface characteristics
• Formed with undercuts or grooves that provide a
mechanical interlock to the adhesive. These brackets
may have a flat base, covered with a silane layer with
recesses for mechanical anchoring.
• Bracket base has a smooth surface and relies on a
chemical coating to enhance bond strength. A silane
coupling agent is used as a chemical mediator between
the adhesive resin and the bracket base because of the
inert composition of the aluminium oxide ceramic
brackets. The manufacturers of such brackets have
reported that they achieve higher bond strength when
compared with mechanical retention.

Base surface characteristics
• Polycrystalline alumina with a rough base comprised of either
randomly oriented sharp crystals or spherical glass particles. to
provide micromechanical interlocking with the orthodontic
adhesive.
• To overcome the potential damage of enamel during debonding,
a ceramic bracket with a thin polycarbonate laminate on the
base has been manufactured (CeramaFlex, TP Orthodontics).
The bond to the enamel is to the thin polycarbonate laminate. It
is suggested that these brackets are as easy to remove as
metallic brackets. Ceramaflex brackets have a significantly
lower bond strength than traditional ceramic brackets. On the
other hand, the bond failure location of the Ceramaflex bracket
is consistently more favorable, i.e., occurring at the ceramic
bracket-polycarbonate base.( Olsen & Bishara ,Angle 1997)

Bright-field polarized-light photomicrograph of a Starfire
bracket base ( Silane coated), illustrating the partially coated
area. (Original magnification x 50.)

photomicrograph of a Lumina bracket base.
uniformly distributed and embedded spherical particles

micrographs of a Transcend 2000 bracket base
ented crystals of various shapes that form an irregular substrate capable of micromechanica

Bracket Placement
• Certain ceramic brackets have color codedCertain ceramic brackets have color coded
long axis indicators which enable easylong axis indicators which enable easy
identification and eliminate bonding errors.identification and eliminate bonding errors.
The long axis indicator is removed with a pullThe long axis indicator is removed with a pull
motion after the bonding procedure.motion after the bonding procedure.

• Removable color
coded indicators
provide positive
bracket
identification and
allow easier
placement.
• Millimeter marks
aid in obtaining
proper occlusal-
gingival height
and eliminate the
need for special
placement
instruments
3mm
4mm
5mmwww.indiandentalacademy.com

Mechanical Debonding techniques
• Delaminating method: In this method, a sharp-edge
instrument is placed at the enamel-adhesive interface.
The application of force produces a wedging effect of
the sharp edge to separate the enamel and adhesive
surfaces. Sinha & Nanda (AJO1997) found this
technique to be safe for debonding mono- and poly-
crystalline ceramic brackets.
• Wrenching method: Brackets are debonded by a
special tool that uses a torsional or wrenching force at
the base of the bracket.

Mechanical Debonding techniques
• Specially designed pliers that apply some type of
tensile or shear force to the tooth surface.
• Lift-off debracketing method: This method uses a
pistol grip debonding instrument, which is positioned
over the brackets with its jaws aligned horizontally
over the bracket in an occluso-gingival direction over
the tie wings. Debonding occurs when the handles are
squeezed and the jaws contact the tie wings and pull
the bracket away from the tooth surface.www.indiandentalacademy.com

Enamel fracture & mechanical debonding
• The degree of force required to achieve mechanical
bond failure and the sudden nature of bracket
failure could cause enamel fracture or cracks and
raise the risk of aspiration of bracket fragments by
the patient.
• This debonding method imposes the risk of bracket
fracture. In case of bracket fracture, the removal of
the remaining fragments of the ceramic brackets
from the enamel surface has to be carried out with a
diamond bur in a high-speed handpiece.www.indiandentalacademy.com

Enamel fracture & mechanical debonding
• This procedure is time-consuming, produces
large fragments of the bracket during
grinding, and results in large amounts of
ceramic dust that has been associated with
itchy skin on hands and eye irritation.
• Grinding ceramic material from the tooth
surface may generate heat, which could
damage the dental pulp, if low-speed grinding
without coolant is used.

Mechanical debonding

Enamel fracture & debonding
• Debonding with sharp-edged pliers that apply a
bilateral force at the bracket base-adhesive interface
was found to be the most effective method for
debonding polycrystalline alumina orthodontic
brackets.
• Forces applied at the interface rather than the
bracket itself may prevent breakages on debonding.
Further, it was reported that brackets bonded by
indirect techniques that create a resin interlayer
facilitates debonding at the interface formed
between this interlayer and the filled resin.( Sinha,
Nanda AJO1995 )

Enamel fracture & debonding
• Ceramic >> metallic brackets,
• Monocrystalline >> polycrystalline.
• Chemical retention >> mechanical retention.
• The damage to tooth structure by applying
mechanical debonding methods is higher, if the
integrity of the tooth structure is compromised by
the presence of developmental defects, enamel cracks
and large restorations, or it is a non-vital tooth.
• The need for relatively strong forces to obtain bond
failure may result in various degrees of patient
discomfort. www.indiandentalacademy.com

Electrothermal debonding
• It involves heating the bracket with a
rechargeable heating gun while applying a
tensile force to the bracket. The bracket
separates from the tooth once sufficient heat
has penetrated the bracket/adhesive interface.
• The potential for pulp damage exists, because a
significant rise in pulp temperature may result
in tooth necrosis.

Electrothermal debonding
• The safety threshold of a 5.5° C increase in
intra-pulpal temperature described by Zach
and Cohen should not be violated.
• Other disadvantages include the bulky
nature of the handpiece that may make its
intraoral use difficult, especially in the
premolar region, and the risk of dropping a
hot bracket in the patient's mouth.
• Bishara and Trulove(AJO 1990) found the
electrothermal technique to be quick,
effective, and devoid of either bracket or
enamel fracture.www.indiandentalacademy.com

Electrothermal debonding unit

Debonding methods
• Derivative of peppermint oil that is applied around
the bracket base and is left for 2 minutes before
debonding can facilitate ceramic bracket removal
without damaging the tooth surface.
• Ultrasonic debonding technique: The advantages
include a decreased chance of enamel damage, a
decreased likelihood of bracket failure, removal of
the residual adhesive with the same instrument after
debracketing. Drawbacks: time-consuming,
excessive wear of the expensive ultrasonic tips &
requires water spray to control the heating

Debonding methods
• Lasers : Debonded by
irradiating the labial
surfaces of the brackets
with laser light. Reduces
the residual debonding
force, the risk of enamel
damage, and the incidence
of failure.
• less traumatic and painful
for the patient and less
risky for enamel damage.
( Toccio AJO 1993)

• Types of lasers : Nd YAG,, super-pulse carbon dioxide
lasers ,carbon di-oxide lasers
• Laser-initiated degradation can occur by:
• Thermal softening: which occurs at relatively low rates
of laser energy deposition, heats the bonding agent up
until it softens,
• Thermal ablation occurs when the rate of energy
deposition is fast enough15 to raise the temperature of
the resin through its fusion range and into its
vaporization range before debonding by thermal
softening occurs. The rapid buildup of gas pressure
along the bonding interface will explosively "blow" the
bracket off the tooth, independent of any externally
applied debonding force.
Laser debonding - Mechanism

Laser debonding - Mechanism
• Photoablation occurs when very high
energy laser light interacts with a material.
During lasing, the energy level of the bonds
between the bonding resin atoms rapidly
rises above their bond disassociation energy
levels, and the material decomposes. High
gas pressure would rapidly develop within
the interface, and the bracket would be
explosively blown off the tooth after a
single light pulse.www.indiandentalacademy.com

Enamel abrasion and wear
• Can occur during contacts
of ceramic brackets with
occluding teeth.
• The highest abrasion scores
have been reported with
mono-crystalline ceramic
brackets.
• Contact of the opposing
teeth with the ceramic
brackets must be avoided .

Bracket Fracture
• The breakage of ceramic brackets is a problem
related to the low fracture toughness of the
aluminium oxide, and the ability to resist it depends
on the type and shape and the bulk of the material
present.
• Bracket breakage might occur either in function or
in the debonding process. The internal defects and
machining interference are primary causes of
fracture.
• Bracket-wing fracture is a frequent problem.
Increased chair time and potential health risk due to
the possibility of swallowing or aspirating a bracket
fragment, which would be difficult to locate because
of the radiolucent nature of alumina.www.indiandentalacademy.com

Bracket Fracture
• Third-order wire activations are more likely to cause
ceramic bracket failure, but the fracture resistance of
the ceramic brackets during arch wire torsion
appears to be adequate for clinical use. (Aknin, Nanda(Aknin, Nanda
AJO 1996)AJO 1996)
• Careful ligation is necessary and elastomeric rings, if
feasible, or coated ligatures are recommended to
prevent tie-wing fracture.www.indiandentalacademy.com

Bracket Fracture
• Second-order wire activations do not cause ceramic
bracket failure, unless the bracket has been
previously weakened by a direct trauma or by surface
defects during treatment.( Lindauer et al AJO1994)..( Lindauer et al AJO1994).
• Extra care should be undertaken during treatment to
avoid scratching of the bracket surfaces with the
instruments.

Rebonding/ Recycling Ceramic
Brackets
• Gaffey et al (Angle 1995) evaluated different
methods of recycling: silane coupling agent,
heat plus silane coupling agent, hydrofluoric
acid plus silane coupling agent, and heat plus
hydrofluoric acid plus silane coupling agent.
Treatment of electrothermally debonded
ceramic brackets with silane or heat plus
silane resulted in bond strength greater than
9 MPa, which was clinically acceptable. The
use of hydrofluoric acid significantly reduced
the bond strength below 2 MPa.

Rebonding Procedure
• Heat: Lew and Djeng.(JCO 1990) - Brackets
heated until cherry red to burn off residual
composite resin. Bracket base then rinsed
with 100% alcohol and left to dry.
• Lew et al( EJO 1991)Lew et al( EJO 1991) found that the bond
strength of these recycled brackets was about
30% less than new chemically retentive
ceramic brackets, yet it might maintain an
acceptable bond strength and lead to fewer
enamel fractures on debonding.

Rebonding mechanically retentive Brackets
• The bond strength of sandblasted rebonded brackets
with sealant applied on bases is adequate
• Silane does not increase the bond strength of
rebonded brackets.
• Hydrofluoric acid treatment on sandblasted rebonded
brackets significantly lowers bond strength.
( Chung ,AJO 2002)
• Bond strength of recycled brackets is clinically
adequate, although it is lower than that of new
brackets. This weaker bond strength after "recycling"
of ceramic brackets minimizes the likelihood of
unwanted enamel removal during debonding.
(Martina et al EJO1997).(Martina et al EJO1997).www.indiandentalacademy.com

Ceramic brackets
Troubleshooting &
Clinical implications

Enamel fracture and flaking or fracture lines
in enamel during debonding.
• Is related to the high bond strength of ceramic brackets.
• Solution A: Avoid sudden impact loading or stress concentration
within the enamel by using proper debonding techniques.
• The best available guidelines are those suggested by the
manufacturer
• Solution B: Do not bond ceramic brackets on structurally
damaged teeth.
• Crack lines, heavy caries, large restorations, hypoplasia and
hypocalcification should be contraindications to bonding with
ceramic brackets. Crowns – whether they are made of resin or
porcelain – may break when ceramic brackets are debonded.
Patients must be informed of this possible eventuality.

Enamel fracture and flaking or fracture lines
in enamel during debonding.
• Solution C: Reduce bond strength:
• Add mechanical retention
• Increased mechanical retention might reduce the side effects
of debonding by favoring failure within the adhesive itself.
• Reduce chemical adhesion
• Add a metal mesh at the base of the bracket
• A metal mesh at the base of the bracket would reduce bond
strength to the levels observed with metal brackets. Adding
the mesh, however, would mean an increase in production
cost that is probably not acceptable at this time. It may also
present an esthetic disadvantage.
• Reduce the base area of the bracket
• Reducing the bracket base area may decrease the bond
strength but it does not eliminate high stress at the bond site.www.indiandentalacademy.com

Enamel fracture and flaking or fracture lines in
enamel during debonding.
• Joseph and Rossouw (AJO 1990) reported a
higher incidence of failure at the resin/bracket
interface when original Transcend brackets
(chemical retention) were bonded with light-
activated, microfilled, more brittle composite
resin and increased failure within the enamel
when the bracket was bonded with a chemically-
cured, macrofilled, more elastic resin.
• Modify the etching time and/or concentration
of etching acid (H3PO4)

Enamel fracture and flaking or fracture lines in
enamel during debonding.
• Use weaker resins: Iwamoto(1987) suggested
that the composition of the resin influences the
(tensile) strength of the bond. He reported that
low-filled and highly-filled Bis-GMA resins
used for bonding silane coated ceramic brackets
led to higher percentages of bracket failure at the
base/resin interface (80% and 90% respectively)
or within the adhesive (20% and 10%
respectively), than a 4 META/MMA-TBB
unfilled resin.
• Solution D: Debond with ultrasonic,
electrothermal and laser deviceswww.indiandentalacademy.com

Removal of ceramic brackets by grinding
• When a proper debonding technique fails, and/or
risks subjecting the tooth to increased forces and
fracture, grinding the ceramic bracket becomes the
option of choice.
• Grinding is usually conducted with high-speed
diamond burs or low-speed green stones.
• The procedure is time-consuming and the heat which
can be generated by grinding may affect the dental
pulp and, subsequently, the vitality of the tooth.

Removal of ceramic brackets by grinding
• Solution: Reduce the size of ceramic to be
ground by fracturing the tie wings with
ligature cutting pliers, and avoid the build up
of heat during grinding.
• Air or water coolant must be used while
grinding the bracket to avoid a rise in pulp
chamber temperature.www.indiandentalacademy.com

Attrition of teeth occluding against
ceramic brackets.
• Solution: Select the teeth to be bonded with
ceramic brackets.
• The clinician must avoid bracket contact
with opposing teeth. In a case with a deep
anterior overbite, avoid bonding the
mandibular teeth with ceramic brackets; in
a case where the maxillary canine is
retracted past the mandibular tooth, avoid
bonding the mandibular canine.

Increased friction with ceramic brackets
• Solution A: Develop brackets with smoother
slot surfaces
• Brackets with smoother slot surfaces,
incorporated metal slots or brackets composed
of ceramic and plastic may allow the archwire to
slide smoothly.
• Solution B: Avoid loss of anchorage and
increase in overbite.
• Strengthen the anchorage requirements and
carefully select the teeth to be bonded.
• Solution C : Avoid sliding mechanics

Breakage of ceramic brackets
• Problem is due to the low fracture toughness of the
aluminum oxide, affects bracket wings and occurs
accidentally when cutting ligature wires or engaging a
heavy archwire in the bracket. The slightest torque of
such wire in the bracket interface leads to fracture.
• Solution: Avoid direct contact of the brackets when
cutting ligature wires and forceful engagement of
increasingly heavy archwires used for leveling
• Successive archwires should be fully engaged in the
brackets. Also, it may be safer to avoid using ceramic
brackets in people prone to trauma because of
professional or numerous sports activities, such as
football, martial arts or other contact sports.

Increased pain or discomfort while
debonding ceramic brackets
• This is related to the higher bond strength.
• Solution: Have patient bite with pressure on
cotton roll and/or gauze during debonding
• Reactions vary from patient to patient and in
an individual, may even vary from tooth to
tooth and with the timing of debonding.
• Pain may increase if the teeth being debonded
have just undergone active movement or
traumatic pressure from occlusion, elastics or
other orthodontic forces

Limited rotation of teeth with ceramic
brackets
• Mainly affects brackets designed for mandibular
incisors because they are necessarily the smallest.
Incorporating four wings tends to weaken the brackets.
Ceramic brackets also tend to be bulkier than metal
brackets as this is required for sufficient resistance to
fracture.
• Solution:Solution: Further research and development
• Some companies already manufacture smaller brackets
with four wings but additional research is needed to
develop less bulky ceramic or ceramic-like materials
which can provide the properties of metal brackets
with the esthetic advantages of ceramics.

Esthetic results are not absolute.
• Ceramic brackets hold a definite advantage over plastic
attachments, but some polycrystalline brackets do stain. This
is due to individual diets – prolonged use of caffeine (coffee,
tea, colas) for example, – or hygiene practices (certain
mouthwashes), or lipstick, but may also be associated with the
type of bonding resins used.
• Solution: Avoid excessive use of staining substances and,
perhaps, select least-discoloring resins
• Ceramic brackets may look discolored when the brackets
themselves stain (direct discoloration) or when stains on the
teeth or bonding resin show through the bracket (indirect
discoloration). It tends to occur with polycrystalline brackets
Using two-base resins, which tend to discolor less than no-
mix one-step bonding resins, has been advocated

Operational risks
• The primary operational risk for the patient is the accidental
ingestion or aspiration of a bracket during bonding or debonding,
or of bracket particles if the bracket fractures during debonding.
• Ceramic brackets may not be detected on radiographs if aspired.
During debonding, fractured fragments may subject the patient to
oral soft tissue damage, and the patient, clinician and assistant to
eye injury.
• Solution:Solution: Use caution and protective equipment duringUse caution and protective equipment during
bonding and debondingbonding and debonding
• Instructing the patient to bite on a cotton roll during debonding
helps reduce the risk of dislodging brackets and/or fragments into
the oral cavity and throat. The clinician and assistant should wear
protective glasses and a mask. The patient should wear protective
glasses as well, or at least keep both eyes shut.

Conclusions
• Ceramic brackets became popular as
esthetic appliances and have been available
for clinical use for almost 2 decades!
• The new designs of ceramic brackets offer
excellent optical properties and the promise
of additional esthetic appeal without
significant functional compromises.
• Ceramic brackets are durable, allow
adequate force control over long treatment
periods, and their risk for discoloration is
minimal.

Conclusions
• The introduction of ceramic brackets was a much-
heralded development in the orthodontic treatment of
adult patients. Their acceptance by these patients has
been unprecedented in the practice of orthodontics
and contributed significantly in the expansion and
development of contemporary orthodontic therapeutic
modalities.
• However, there is still scope for improvement in some
of the bracket characteristics before they are able to
largely replace the use of metallic brackets, in the
manner that direct bracket bonding replaced banding
of teeth!!

CCoolloouurreedd ceramic brackets
Thank-youThank-you

REFERENCES
1) Karamouzos, Athanasiou, Dent, Papadopoulos. Clinical
characteristics and properties of ceramic brackets: A
comprehensive review . Am J Orthod Dentofac Orthop
1997;112:34-40.
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characterization of ceramic brackets: a multitechnique
approach. Am J Orthod Dentofac Orthop 1994;105:10-8.
3) Birnie D. Ceramic brackets. Br J Orthod 1990;17:71-5.
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Risk of pulp damage due to temperature increase during
thermodebonding of ceramic brackets. Eur J Orthod.
1997 Dec;19(6):623-8.

5) Keith O, Kusy RP, Whitley JQ. Zirconia brackets: an
evaluation of morphology and coefficients of friction. Am
J Orthod Dentofacial Orthop. 1994 Dec;106(6):605-14.
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vitro study. Eur J Orthod 1991;13:293-305.
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ceramic brackets. Am J Orthod Dentofac Orthop 1988;93:346-8.
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Fracture strength of ceramic bracket tie wings subjected to tension.
Angle Orthod. 2005 Jan;75(1):95-100.
–

10)Ghafari J, Skanchy TL, Mante F. Shear bond strengths of two ceramic
brackets. J Clin Orthod 1992;26:491-3.
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and ceramic brackets used with chemically and light-activated
composite resins. Am J Orthod Dentofac Orthop 1990;97:121-5.
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stainless steel and polycrystalline alumina bracket slots: I, the dry
state. Am J Orthod Dentofac Orthop 1990;98:300-12.
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friction between ceramic brackets and orthodontic wires of four alloys.
Am J Orthod Dentofac Orthop 1990;98:499-506.

14)Ghafari J. Problems associated with ceramic brackets suggest limiting their use
to selected teeth. Angle Orthod 1992;62:145-52.
15) Eliades T, Viazis AD, Lekka M. Failure mode analysis of ceramic brackets
bonded to enamel. Am J Orthod Dentofac Orthop 1993;104:21-6.
16)Dovgan JS, Walton RE, Bishara SE. Electrothermal debracketing of
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of the human pulp after thermodebonding of metal and ceramic brackets. Am J
Orthod Dentofac Orthop 1992;102:410-7.
18) Tocchio RM, Williams PT, Mayer FJ, Standing KG. Laser debonding of
ceramic orthodontic brackets. Am J Orthod Dentofac Orthop 1993;103:155-
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Dentofac Orthop 1991;99:97-9.

• 20) Theodorakopoulou LP, Sadowsky PL, Jacobson A, Lacefield
W Jr. Evaluation of the debonding characteristics of 2 ceramic
brackets: an in vitro study.
Am J Orthod Dentofacial Orthop. 2004 Mar;125(3):329-36.
• 21)Nishio C, da Motta AF, Elias CN, Mucha JN.
In vitro evaluation of frictional forces between archwires and
ceramic brackets.
Am J Orthod Dentofacial Orthop. 2004 Jan;125(1):56-64
• 22) Hain M, Dhopatkar A, Rock P.The effect of ligation method on
friction in sliding mechanics.
Am J Orthod Dentofacial Orthop. 2003 Apr;123(4):416-22.

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