Invisalign -invisible aligners course in india

 Introduction
 Kesling’s Setup
 Essix Retainers
- Introduction
- Current Retainer Designs
- Fabrication
- Appliance Delivery
- Telephone Supervision
- Conclusion
 Active Tooth Movement With Essix Based
Appliance
www.indiandentalacademy.com

 Invisalign
- In a Nutshell
- Mechanism of Action
- In Detail
- Retention and Stability
- Advantages
- Disadvantages
- Summary

 Movement of teeth without the use of bands,
brackets, or wires was described as early as 1945
by Dr Kesling, who reported on the use of a
flexible tooth positioning appliance.
 Later, Nahoum (Vacuum formed dental contour
appliance, 1964) and others (Pontiz, 1971;
McNamara, 1985) wrote about various types of
overlay appliances such as invisible retainers.

 Minor tooth movements have also been achieved
with a technique developed by Raintree Essix
(New Orleans, La).
 This technique uses clear aligners formed on
plaster models of the teeth.
 The aligners are then modified with “divots,”
which create a force to push on the individual
teeth, and “windows,” which create the space for
teeth to move into.
 This type of appliance can be effective in
correcting mild discrepancies in the alignment of
teeth.
 However, movements are limited to 2 to 3 mm;
beyond this range, another impression and a new
appliance are needed.www.indiandentalacademy.com

 Align Technology, Inc (Santa Clara, Calif),
in-troduced the Invisalign system several
years ago.
 Invisalign takes the principles of Kesling,
Nahoum, others, and Raintree Essix even
further, using computer-aided-design–
computer-aided-manufacture (CAD-CAM)
technology combined with laboratory
techniques to fabricate a series of custom
appliances that are esthetic and removable,
and that can move teeth from beginning to
end.

 The diagnostic setup was first proposed by
Kesling in 1945.
 P.R. Begg does not use tooth positioners,
because they are not readily available in
Australia.
 However, Kesling uses a tooth positioner as a
finishing appliance on each case.
 Not only are the tooth positioners the best post
treatment retention appliance, but they are the
best form of working retainer.

 It is possible to obtain more accurate final tooth
positions generally and more accurate final
occlusal relations with tooth positioners than with
any other orthodontic appliance now employed.
 At the present time, it is impossible to position
teeth with arch wires and tooth bands with such
final accuracies as can be done with post
treatment use of tooth positioners regardless of
the particular active orthodontic treatment
technique that is used.
 The tooth positioners, as being described by
Kesling in 1945, is a one piece, resilient appliance
made from rubber or plastic that fills the free-way
space and covers the clinical crowns of the teeth
plus the portion of the gingival, both buccal and
lingual.

 No other appliance has the flexibility to conform to
the discrepancy, and yet has the ability to carry the
teeth to their desired relations- all with no
adjustments required.
 The skills required of the orthodontist in
positioner therapy are those of diagnosis and
judgment of the patients willingness or ability to
cooperate, not of manual dexterity.
 The positioner is constructed over a per-
determined pattern- the set-up.
 Teeth that are to be positioned in the patients
mouth are removed from the patients model and
replaced in the desired positions. The gum area of
the set-up is then contoured to normal form after
changing the teeth.

 The positioner is then formed of an elastic
material about the arches in rest position.
 This results in the upper and lower teeth slightly
separated, and the lower arch slightly distal to the
upper.
 Space closure within reason can be accomplished
with a tooth positioner, especially spaces manifest
during treatment, as in anterior segments.
 Within limitations the positioners can be used to
help maintain or change the amount of anterior
overbite.

 Labiolingual axial inclination of upper and
lower anteriors can be influenced by a
positioner, however, these teeth should be
uprighted over basal bone as well as possible
with appliances.
 One must be realistic for the correction to be
achieved
 The positioner can achieve the perfection
possible in the set up only when that perfection
has been approached in the mouth with
conventional treatment.

 Patients were treated until the correct tooth
relations were achieved.
 Tooth positioner has the ability to quickly achieve
the final detailed finishing that is often required.
 When the positioner is to be used there is no need
to place finishing arches or to consider a stage 4.
 After the teeth have been brought to their
approximate final positions with the proper axial
inclinations, the positioner will close all spaces,
correct slight errors in arch form and develop ideal
occlusion as predetermined by the set up.

 The control model made at the time of the
appliance were removed, was duplicated and the
teeth were cut from the model and repositioned in
the set up.
 In the set up all the spaces have been closed, arch
form has been corrected and the normal amount of
anterior over bite has been created along with text
book normal occlusion in the posterior segment.
 Tooth positioner was fabricated over the setup.
 The patient then exercised into the positioner four
hours a day and wore it while sleeping.
 Results desired by the set up were achieved in two
weeks.
 At that time the exercise wearing was reduced to
three hours a day.
 After four months, the patient just wore thewww.indiandentalacademy.com

 The cast is cut using a fretsaw blade to separate
individual teeth.
 A horizontal cut is made three mm apical to
gingival margin.
 Vertical cuts are made to separate individual
teeth and the individual teeth are set in desire
position using red wax.

1. In visualizing and testing the effect of
complex tooth movements and extractions
on the occlusion.
2. The patient can be motivated by simulating
the various corrective positions on the cast.
3. Tooth size – arch length discrepancies can be
visualized by means of a setup.

INTRODUCTION
 Orthodontists' concept of retention is moving
toward the idea that teeth will move unless
retained indefinitely.
 However, permanent retention implies permanent
supervision, and that is where reality clashes with
stability.
 An orthodontic practice basically consists of
treatment of active cases, which consume the most
time and generate the most income, and
supervision of retention cases, which takes less
time and produces minimal, if any, income. This
balance has been workable because, in due course,
retention patients either are dismissed with
wishes of good luck or simply fade away.www.indiandentalacademy.com

 When permanent retention is emphasized,
the equilibrium is upset.
 As an example, if 200 patients per year are
given permanent retainers and seen twice a
year, after 10 years this will add up to 4,000
retention appointments per year. At 10
minutes per visit, that would take up about
three months' worth of appointments.
 The cornerstone of Essix permanent
retention is the complete delegation of
responsibility to the patient.

 Essix retainers have nothing to adjust; the only
thing that could be done on a recall visit would
be to check the patient's compliance and listen
to any comments.
 Telephone supervision is a time-and-money-
saving service to our patients and is sincerely
appreciated.

 Fixed retainers must be systematically
monitored, not only for displacement, but
for hygiene problems that can be induced by
the accumulation of plaque and calculus.
 Although well-aligned teeth should be
easier to clean, the presence of a bonded
retainer makes cleaning more difficult.
 Removable appliances don't interfere with
hygiene, but are at best only adequate
retention mechanisms.

 The Hawley-type retainer, which dates
from the 1920s, was originally used to move
teeth, not for retention.
 The retaining component for the anterior
teeth— a point contact of wire on the labial
surface and a mass of acrylic approximating
the lingual cervix— is insufficient.
 When the appliance becomes loose, the
mechanical constraints are lessened and the
teeth can shift.
 In addition, most of the acrylic simply
anchors wire elements that are not critical to
the essence of retention— the stabilization of
the teeth.

 Clear, full-arch, vacuum-formed plastic devices
are only marginally esthetic, are removable, and
are difficult to work with.
 As in Hawley-type retainers, the bulk of the
appliance is distal to the cuspids, covering and
retaining posterior teeth.
 These buccal sections tend to fracture, make the
appliance bulky, and are usually the cause of
complaints of awkwardness of bite.
 The limitations of conventional mechanisms,
which may be adequate for limited retention,
explain some of the dismal results that have been
achieved with permanent retention.
 These devices are too bulky or unhygienic for the
long term, and sooner or later the patient's
enthusiasm wanes.www.indiandentalacademy.com

 Essix thermoplastic copolyester retainers change the
rules of permanent retention.
 They are a thinner, but stronger, cuspid-to-cuspid version
of the full-arch, vacuum-formed devices.
 Advantages include:
• The ability to supervise without office visits.
• Absolute stability of the anterior teeth.
• Durability and ease of cleaning.
• Low cost and ease of fabrication.
• Minimal bulk and thickness (.015").
• The brilliant appearance of the teeth caused by light
reflection.
 If compliance with permanent retention is to be achieved,
the orthodontist must provide duplicate retainers. Essix
retainers can be produced in the office for only a few
dollars each, and the cost to the patient, with a
replacement retainer included, is about one-third that of a
conventional retainer.www.indiandentalacademy.com

 Since only the anterior teeth are retained, a
universal perforated plastic tray works well
for both arches.
 Vinyl polysiloxane is the impression material
of choice. A combination of the light and
heavy (putty) types is preferred.
Heavy and light vinyl
polysiloxane impression
materials in Universal
perforated plastic tray.
Impression has been cut
distal to cuspids with scalpel.

 Pour the impression with a high-quality die stone
that has been mixed in a vacuum spatulator.
 If the undercuts gingival to the contact points are
extreme, creating three-cornered spaces, they
must be reduced to a more normal contour.
 It is imperative that adequate undercuts remain to
insure a positive fit of the appliance.
 Apply a coating of a separating medium before
thermoforming.

 A pressure-type thermoforming unit such as a
Biostar is superior to a suction device in
recording the critical interproximal undercuts.
 Essix 0.75mm (0.030") thermoplastic copolyester
is mandatory for the fabrication of Essix
retainers.
 Thinner, 0.5mm material is too flimsy, while
thicker, 1 mm material lacks flexibility.
 Copolyester, unlike polycarbonates, does not
require heat treatment before thermoforming.
 It is much stronger, clearer, and resistant to
abrasion than acrylic sheet, and thus produces
thinner yet sturdier appliances.
 During the thermoforming, the thickness of the
plastic is reduced from .030" to .015".www.indiandentalacademy.com

 Store the cast in the patient's model box in case it
is needed for future construction of duplicate
retainers.
 Cut the retainer from the plastic sheet and trim
the edges to the proper form with a curved pair
of Mayo scissors.

 Pay particular attention to these details:
 • Do not scallop the labial flange of the retainer to
conform to the cervical line. Extend it 2-3mm into the
labial gingiva, and trim it to make a gentle,
continuous curve.

 • Trim the lower lingual flange similarly. Trim the
upper lingual flange in a straight line across the
palate, from cuspid to cuspid. If chairside
adjustment is necessary, trim with a scissor,
ligature cutter, or scalpel.

 • Cut a small space at each cuspid between the
gingival margin and the distogingival edge of the
appliance, allowing the patient to remove the
appliance with a fingernail along the long axis of the
incisors.

 Essix retainers can be placed the same day
fixed appliances are removed.
 The vinyl polysiloxane impression is taken
immediately after debonding.
 Minor incisor rotations can be corrected by
altering the cast, since the teeth will be
slightly mobile.
 In no case, however, should more than two
days elapse between appliance removal and
retainer delivery.

 Furthermore, if the patient does not brux, the
retainers should last for years.
 With heavy bruxing, retainers need to be
replaced once or twice a year, but that is still an
attractive alternative to irreversible dental
attrition.
 A single-arch Essix retainer should be worn 24
hours a day (except for cleaning) for two weeks,
and then at night only.

 If both upper and lower retainers are placed, the
patient should wear the lower during the day and
the upper at night for four weeks, then both at
night only.
 The material is so thin that accommodation to
speaking and eating is not a problem.
 The retainers should be cleaned with a soapy
cotton-tip swab; brushing with toothpaste dulls
their brilliance.
 If the patient chews gum, a brand that does not
stick to dental appliances should be recommended.
 For caries control, we prescribe a fluoride rinse
every night and a fluoride gel once a week.
 The retainers make excellent delivery trays.

 Attractive, soft retainer cases can be used instead
of the hard, bulky plastic types, since Essix
retainers are nearly impervious to fracture or
distortion. Soft cases do not interfere with the line
of jeans or business clothes, and the clinician's
address and phone number can be printed on the
cases to aid in recovery if they are lost.
A. Soft cloth Essix retainer case usually preferred by adults.
B. More colorful case preferred by adolescents.

 Patients are routinely contacted by phone to
confirm appointments; retention monitoring
is merely an extension of this procedure.
 The task can be delegated to a staff member
with a personable telephone manner.
 Calls should be made when it is most
convenient for the patient— home or work,
daytime or evening.
 Calls can be scheduled 30 days after
delivery of retainers, and every four to six
months thereafter.

 Essix retainers have
proven quite versatile.
 Their flexibility and
positioner effect make
them an alternative to
spring retainers in
correcting minor
tooth movements.
 They can be used to
reduce occlusal forces
from the opposing
arch when moving
posterior teeth with
air-rotor strippingwww.indiandentalacademy.com
Essix retainer placed on upper arch
to reduce occlusal forces against
lower arch during air-rotor
stripping mechanics.

 They can serve as a
temporary bridge for a
missing anterior tooth,
when thermoformed
over a pontic placed in
the edentulous space
on the cast.
 They can also act as
night guards for
bruxism and as bite
planes-to relieve
bracket impingement
until the bite can be
opened.

 The use of Essix retainers, in combination
with telephone monitoring, opens the way
to a practical, patient-friendly method of
true permanent retention.

 Sheridan has described two methods for
moving teeth.
 One, by the use of windows and divots
whereby minor tooth malalignments, such as
bucco-lingual and mesio-distal malpositions
and rotations. (JCO 1994)
 Secondly, with the help of thermosealing. (JCO
1995)

Trimmed working cast
for thermoforming Essix
retainer.

Finishing window
border with scalpel
Cutting window in
thermoformed
appliance with
acrylic bur

Heating shaft of Divoter

Monitoring inside of
appliance for divot depth

Removing residual plastic
debris from heating shaft
prior to use

A. Incisal placement of divot produces
more tipping.
B. Gingival placement produces more
bodily movement

A. Distal placement of divot produces
mesial rotation.
B. Mesial placement produces distal
rotation.

Mesial contact point of lateral
incisor locked within Essix
appliance while divot induces
facial rotation of out-of-line distal
surface.

Divot-induced moments create torquing
couple

Incisal cap produces pure
root torque

Case 1.
A. Incisor alignment
before treatment.
B. After four months
of wearing Essix
appliance with
successive 1mm
divots.

Case 2.
A. Incisor alignment
after debonding.
B. After two weeks of
Essix appliance
with 1mm divot to
align lower right
lateral incisor.

 By thermosealing we can selectively increase
the thickness of the appliance either
anteriorly or posteriorly by incorporating
layer of composite or light cure acrylic
between two sheet of the Essix plastic.
 By thermosealing we can use Essix
appliance as a bite plane, habit breaking
appliance, molar uprighting appliance or
space maintainer.

A. Essix plastic sheets with light-cured
acrylic between them.
B. Plastic sheets thermosealed to
encapsulate acrylic layer

Full-arch working cast made to Essix
standards

Base sheet with center section and
peripheral excess cut away

Prying distal ends of base appliance
with thin-bladed instrument to
remove it from cast

Anterior section of base appliance cut away,
and remainder of appliance replaced on cast

Bead of light-cured acrylic applied to
palatal area of base appliance

Heat Gun used to prepare base
appliance for second thermosealing

Base and second plastic sheets
thermosealed with light-cured acrylic
between them

Bulk of plastic cut away with acrylic disk

Finished "full Essix" appliance after
trimming

Barrier wire tacked to base appliance

Light-cured acrylic placed in palatal
area and covering base of wire barrier

Finished habit appliance after trimming

Active element of uprighting spring
tacked to cast with composite.
Retentive element of spring placed on
base appliance

Palatal acrylic covering
retentive element of
uprighting spring

Finished molar uprighting
appliance after trimming

Thermosealed rigid plastic bar between
two abutment teeth

Finished space maintainer after trimming

Finished bite plane after trimming

 Drs. Rinchuse and Rinchuse successfully
used Essix based appliance to carry out
active tooth movements for correcting single
tooth anterior cross bite and lingually
displaced canine (using finger springs), and
aligning ectopically positioned canine (using
bonded bracket, metal attachments to the
appliance and various elastics) and for
expansion of maxilla (using a hybrid Essix-
nickel titanium removable palatal
expander).

 Align Technology, Inc. developed Invisalign
appliance for orthodontic tooth movement
in the USA in 1998.
 This appliance was the first orthodontic
treatment method to be based solely on 3-D
digital technology.
 Through the use of computer programmes
that can manipulate 3-D images of
individual malocclusions, a series of
algorithmic stages is produced which can
move the teeth in a series of precise
movements (0.15 – 0.25 mm), or stages.

 Invisalign braces are a new revolutionary
way to straighten teeth without metal.
 A series of clear, removable aligners are used
to gradually straighten teeth, without metal
or wires.
 Aligners are made of clear, strong medical
grade plastic that is virtually invisible when
worn.
 Aligners look similar to clear tooth-whitening
trays, but are custom-made for a better fit to
move teeth.
 Some dentists have referred to Invisalign
braces as "contact lenses for teeth."

 Like brackets and archwires, Invisalign
braces move teeth through the appropriate
placement of controlled force on the teeth.
 The principal difference is that Invisalign
braces not only control forces, but also
control the timing of the force application.
 At each stage, only certain teeth are allowed
to move, and these movements are
determined by the orthodontic treatment
plan for that particular stage.
 This results in an efficient force delivery
system.

 You wear each set of aligners for about 2 weeks,
removing them only to eat, drink, brush, and
floss.
 As you replace each aligner with the next in the
series, your teeth will move – little by little, week
by week – until they have straightened to the
final position your dentist has prescribed.
 You’ll visit your dentist about once every 6
weeks to ensure that your treatment is
progressing as planned.
 Total treatment time averages 9-15 months and
the average number of aligners worn during
treatment is between 18 and 30, but both will
vary from case to case.www.indiandentalacademy.com

 For each patient, the orthodontist submits a
set of polyvinyl siloxane impressions, a
centric occlusion bite registration, a
panoramic radiograph, a lateral
cephalometric radiograph, and photographs
to Align Technology.

 Vinyl polysiloxane,
- considered the most accurate of impression
materials,
- has excellent elastic recovery,
- minimal permanent deformation, and
- superior tear strength.
 Impressions can be stored for as long as a
week without significant loss of accuracy
and can be disinfected and repoured
multiple times.
 The material is available in several
viscosities that bond to one another,
allowing flexibility in impression technique.

 The impressions are poured up in dental
plaster and then placed in a tray and encased
with epoxy and urethane.
 The tray is placed into a destructive scanner;
the scanner’s rotating blade makes numerous
passes over the epoxy-encased models,
removing a thin layer with each pass.

 A computer linked
with the scanner
then assembles the
scanned
information to
create a 3-
dimensional
rendering of the
models.

 After the bite has been established, the
Invisalign virtual orthodontic technician
(VOT) uses software to “cut” the virtual
models and separate the teeth, allowing
them to be moved individually.
 A virtual gingiva is placed along the
gingival line of the clinical crown to serve as
the margin for the manufacturing of the
aligners.

Cutters separate teeth Placement of virtual gingiva

 The orthodontist’s prescription is followed
in positioning the teeth and the bite to
proper alignment virtually on the computer
with the company’s Treat software (Align
Technology, Santa Clara, Calif).
 Once the final setup has been done, tooth
movements are staged so that there are no
occlusal and interproximal interferences,
and the velocity of the movements is within
the criteria set by the company.
 The number of stages necessary depends on
the amount and complexity of the
movement.
 The VOT can now send the data to the
referring orthodontist so that he or she can
check the proposed treatment (referred to aswww.indiandentalacademy.com

 When the orthodontist has approved the
treatment plan, the aligners will be
manufactured so that the movements seen
on the computer screen can be transferred
clinically to the patient.
 The computer images are converted to
physical models by using a process called
stereolithography.
 These models are then used to fabricate the
aligners on a Biostar pressure molding
machine (Great Lakes Orthodontic Products,
Tonawanda, NY).

Stereolithography
machines
Stereolithography
models
Aligners

 Align Technology engineers have
formulated a proprietary material for use in
the aligners.
 The aligners are trimmed and laser-etched
with the patient’s initials, case number,
aligner number, and arch (upper or lower).
 They are then disinfected, packaged, and
shipped to the doctor’s office.
 The entire process of making the Invisalign
aligners is a marvel of modern technology.
 Without the aid of computers and
technologically advanced machinery, it
would be impossible to fabricate aligners in
such large numbers and with such great

 Fabricating these aligners in an orthodontic
office would be a very time-consuming and
labor-intensive process that probably would
not be practical for everyday treatment.
 The Invisalign technique gives patients an
esthetic choice in their orthodontic treatment
that all orthodontists can easily implement in
their offices.

 At present, retention protocol with this
appliance is similar to that used with other
types of appliances.
 Usually the final appliance or a thicker
version (0.04 inch) of it is worn full time for
six months, followed by night time wear
indefinitely.

1. You can straighten your teeth without anyone
knowing.
2. An Invisalign patient can eat and drink anything
while being treated along with being able to
brush and floss normally to maintain good oral
hygiene. This is not possible while wearing
traditional braces.
3. Another advantage is that the teeth can be
bleached with the appliance at the beginning of,
and during treatment.

4. Invisalign braces are comfortable. There
are no metal brackets or wires to cause
mouth irritation.
5. No metal or wires also means you spend
less time in the doctor's chair getting
adjustments and in some cases a patient
only needs to see the dentist half as often as
with traditional braces.

1. Only relatively small magnitudes of change are
possible because of the technical difficulty of evenly
dividing larger overall movements into small
precise stages manually.
2. Most people experience temporary, minor
discomfort for a few days at the beginning of each
new stage of treatment. This is normal and is
typically described as a feeling of pressure. It is a
sign that the Invisalign braces are working -
sequentially moving your teeth to their final
destination. This discomfort typically goes away a
couple of days after you insert the new Aligner in the
series.

3. Like all orthodontic treatments, Invisalign
braces may temporarily affect the speech of
some people, and you may have a slight lisp for
a day or two. However, as your tongue gets
used to having Aligners in your mouth, any lisp
or minor speech impediment caused by the
Aligners should disappear.
4. Open bite.

 A new system of orthodontic tooth movement
using established methods for minor correction
to achieve greater magnitudes of correction has
been introduced.
 The major advantage of the system is the
esthetic, hygiene, low discomfort and
removable nature of the appliance.

 The current limitations are in terms of case
selection, increased cost, experience required for
computer treatment planning, difficulty
obtaining certain tooth movements, and the lack
of potential in teeth involving mixed dentition
or impacted teeth.
 The clinician must have an in-depth
understanding of biomechanics, biology,
periodontal concerns, and optimal therapeutic
occlusion achieved during orthodontic
treatment to successfully plan and use this
appliance.

 In future, we may see the replacement of PVS
impressions with emerging intraoral scanning
devices and the recording of treatment changes
or modifications immediately in a digital format.
 Adding the other 3 D compartments (skeletal,
facial, jaw movement and animation to the
surface map of the teeth) will greatly enhance
the diagnostic and treatment capabilities of this
new appliance.

Invisalign -invisible aligners course in india

Recommandé

Recommandé

Contenu connexe

Tendances

Tendances (20)

Similaire à Invisalign -invisible aligners course in india

Similaire à Invisalign -invisible aligners course in india (20)

Plus de Indian dental academy

Plus de Indian dental academy (20)

Dernier

Dernier (20)

Invisalign -invisible aligners course in india