INVISALIGN
INDIAN DENTAL ACADEMY
Leader in continuing dental education
www.indiandentalacademy.com
www.indiandentalacademy...
Contents
Introduction
Kesling’s Setup
Essix Retainers
- Introduction
- Current Retainer Designs
- Fabrication
- Appliance ...
Invisalign
- In a Nutshell
- Mechanism of Action
- In Detail
- Retention and Stability
- Advantages
- Disadvantages
- Summ...
INTRODUCTION
Movement of teeth without the use of bands,
brackets, or wires was described as early as
1945 by Dr Kesling, ...
Minor tooth movements have also been achieved
with a technique developed by Raintree Essix (New
Orleans, La).
This techniq...
Align Technology, Inc (Santa Clara, Calif), introduced the Invisalign system several years
ago.
Invisalign takes the princ...
Keslings setup
The diagnostic setup was first proposed by
Kesling in 1945.
P.R. Begg does not use tooth positioners,
becau...
It is possible to obtain more accurate final tooth
positions generally and more accurate final
occlusal relations with too...
No other appliance has the flexibility to conform to
the discrepancy, and yet has the ability to carry the
teeth to their ...
The positioner is then formed of an elastic material
about the arches in rest position.
This results in the upper and lowe...
Labiolingual axial inclination of upper and
lower anteriors can be influenced by a
positioner, however, these teeth should...
RESULTS OF WEARING THE TOOTH

POSITIONER AS A FINISHING APPLIANCE 
Patients were treated until the correct tooth relations...
The control model made at the time of the appliance
were removed, was duplicated and the teeth were
cut from the model and...
PROCEDURE
The cast is cut using a fretsaw blade to
separate individual teeth.
A horizontal cut is made three mm
apical to ...
USES
1. In visualizing and testing the effect of

complex tooth movements and
extractions on the occlusion.
2. The patient...
Essix Retainers (1993)
INTRODUCTION
Orthodontists' concept of retention is moving
toward the idea that teeth will move unl...
When permanent retention is emphasized,
the equilibrium is upset.
As an example, if 200 patients per year are
given perman...
Patient before and after placement of
Essix retainers

www.indiandentalacademy.com
Essix retainers have nothing to adjust;
the only thing that could be done on a
recall visit would be to check the
patient'...
Current Retainer Designs
Fixed retainers must be systematically
monitored, not only for displacement, but for
hygiene prob...
The Hawley-type retainer, which dates from
the 1920s, was originally used to move teeth,
not for retention.
The retaining ...
Clear, full-arch, vacuum-formed plastic devices
are only marginally esthetic, are removable, and
are difficult to work wit...
•
•
•
•
•
•

Essix thermoplastic copolyester retainers change the
rules of permanent retention.
They are a thinner, but st...
Fabrication

Since only the anterior teeth are retained, a
universal perforated plastic tray works well for
both arches.
V...
Pour the impression with a high-quality die
stone that has been mixed in a vacuum
spatulator.
If the undercuts gingival to...
A pressure-type thermoforming unit such as a
Biostar is superior to a suction device in recording
the critical interproxim...
Store the cast in the patient's model box in case it
is needed for future construction of duplicate
retainers.
Cut the ret...
Pay particular attention to these details:
• Do not scallop the labial flange of the retainer to
conform to the cervical l...
• Trim the lower lingual flange similarly. Trim the
upper lingual flange in a straight line across the
palate, from cuspid...
• Cut a small space at each cuspid between the
gingival margin and the distogingival edge of the
appliance, allowing the p...
Appliance Delivery
Essix retainers can be placed the same day
fixed appliances are removed.
The vinyl polysiloxane impress...
Furthermore, if the patient does not brux,
the retainers should last for years.
With heavy bruxing, retainers need to be
r...
If both upper and lower retainers are placed, the
patient should wear the lower during the day and the
upper at night for ...
Attractive, soft retainer cases can be used instead
of the hard, bulky plastic types, since Essix
retainers are nearly imp...
Telephone Supervision
Patients are routinely contacted by phone to
confirm appointments; retention monitoring is
merely an...
Conclusion
Essix retainers have
proven quite versatile.
Their flexibility and
positioner effect make
them an alternative t...
They can serve as a
temporary bridge for a
missing anterior tooth,
when thermoformed over
a pontic placed in the
edentulou...
The use of Essix retainers, in
combination with telephone monitoring,
opens the way to a practical, patientfriendly method...
ACTIVE TOOTH MOVEMENT WITH
ESSIX BASED APPLIANCE
Sheridan has described two methods
for moving teeth.
One, by the use of w...
Trimmed working cast
for thermoforming Essix
retainer.
www.indiandentalacademy.com
Cutting window in
thermoformed
appliance with
acrylic bur
Finishing window
border with scalpel

www.indiandentalacademy.co...
The Divoter:
precision
thermoforming tool

Heating shaft of Divoter
www.indiandentalacademy.com
Monitoring inside of
appliance for divot depth
www.indiandentalacademy.com
Removing residual plastic
debris from heating shaft
prior to use
www.indiandentalacademy.com
A. Incisal placement of divot produces
more tipping.
B. Gingival placement produces more
bodily movement
www.indiandentala...
A. Distal placement of divot produces
mesial rotation.
B. Mesial placement produces distal
rotation.
www.indiandentalacade...
Mesial contact point of lateral
incisor locked within Essix
appliance while divot induces
facial rotation of out-of-line d...
Divot-induced moments create torquing
couple
www.indiandentalacademy.com
Incisal cap produces pure
root torque
www.indiandentalacademy.com
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
la...
By thermosealing we can selectively
increase the thickness of the appliance
either anteriorly or posteriorly by
incorporat...
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
www.indiandentalacademy.com
Base sheet with center section and
peripheral excess cut away
www.indiandentalacademy.com
Prying distal ends of base appliance
with thin-bladed instrument to remove
it from cast
www.indiandentalacademy.com
Anterior section of base appliance cut away,
and remainder of appliance replaced on cast
www.indiandentalacademy.com
Bead of light-cured acrylic applied to
palatal area of base appliance
www.indiandentalacademy.com
Heat Gun used to prepare base appliance
for second thermosealing
www.indiandentalacademy.com
Base and second plastic sheets
thermosealed with light-cured acrylic
between them
www.indiandentalacademy.com
Bulk of plastic cut away with acrylic disk

www.indiandentalacademy.com
Finished "full Essix" appliance after
trimming
www.indiandentalacademy.com
Barrier wire tacked to base appliance

www.indiandentalacademy.com
Light-cured acrylic placed in palatal
area and covering base of wire barrier
www.indiandentalacademy.com
Finished habit appliance after trimming

www.indiandentalacademy.com
Active element of uprighting spring
tacked to cast with composite.
Retentive element of spring placed on
base appliance
ww...
Palatal acrylic covering
retentive element of
uprighting spring
www.indiandentalacademy.com
Finished molar uprighting
appliance after trimming
www.indiandentalacademy.com
Thermosealed rigid plastic bar between
two abutment teeth

www.indiandentalacademy.com
Finished space maintainer after trimming

www.indiandentalacademy.com
Finished bite plane after trimming

www.indiandentalacademy.com
Drs. Rinchuse and Rinchuse
successfully used Essix based
appliance to carry out active tooth
movements for correcting sing...
INVISALIGN IN A NUTSHELL
Align Technology, Inc. developed Invisalign
appliance for orthodontic tooth movement in
the USA i...
Invisalign braces are a new revolutionary
way to straighten teeth without metal.
A series of clear, removable aligners are...
MECHANISM OF ACTION
Like brackets and archwires, Invisalign
braces move teeth through the appropriate
placement of control...
HOW DOES INVISALIGN WORK?
You wear each set of aligners for about 2 weeks,
removing them only to eat, drink, brush, and fl...
INVISALIGN IN DETAIL
For each patient, the orthodontist
submits a set of polyvinyl siloxane
impressions, a centric occlusi...
Vinyl polysiloxane,
- considered the most accurate of impression
materials,
- has excellent elastic recovery,
- minimal pe...
The impressions are poured up in
dental plaster and then placed in a tray
and encased with epoxy and urethane.
The tray is...
DESTRUCTIVE SCANNER

www.indiandentalacademy.com
A computer linked
with the scanner
then assembles the
scanned information
to create a 3dimensional
rendering of the
models...
After the bite has been established, the
Invisalign virtual orthodontic technician (VOT)
uses software to “cut” the virtua...
Cutters separate teeth

Placement of virtual gingiva

www.indiandentalacademy.com
The orthodontist’s prescription is followed in
positioning the teeth and the bite to proper
alignment virtually on the com...
When the orthodontist has approved the
treatment plan, the aligners will be
manufactured so that the movements seen
on the...
Stereolithography
machines

Stereolithography
models

www.indiandentalacademy.com

Aligners
Align Technology engineers have formulated
a proprietary material for use in the aligners.
The aligners are trimmed and la...
Fabricating these aligners in an orthodontic
office would be a very time-consuming and
labor-intensive process that probab...
RETENTION & STABILITY
At present, retention protocol with this
appliance is similar to that used with
other types of appli...
ADVANTAGES
1. You can straighten your teeth without

anyone knowing.
2. An Invisalign patient can eat and drink
anything w...
4. Invisalign braces are comfortable.
There are no metal brackets or wires
to cause mouth irritation.
5. No metal or wires...
DISADVANTAGES
1. Only relatively small magnitudes of change are

possible because of the technical difficulty of evenly
di...
3. Like all orthodontic treatments, Invisalign
braces may temporarily affect the speech of
some people, and you may have a...
SUMMARY
A new system of orthodontic tooth
movement using established methods
for minor correction to achieve greater
magni...
The current limitations are in terms of case
selection, increased cost, experience
required for computer treatment plannin...
In future, we may see the replacement of
PVS impressions with emerging intraoral
scanning devices and the recording of
tre...
Thank you
For more details please visit
www.indiandentalacademy.com

www.indiandentalacademy.com
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Invisalign /certified fixed orthodontic courses by Indian dental academy

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The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.

Indian dental academy provides dental crown & Bridge,rotary endodontics,fixed orthodontics,
Dental implants courses.for details pls visit www.indiandentalacademy.com ,or call
0091-9248678078

Invisalign /certified fixed orthodontic courses by Indian dental academy

  1. 1. INVISALIGN INDIAN DENTAL ACADEMY Leader in continuing dental education www.indiandentalacademy.com www.indiandentalacademy.com
  2. 2. Contents 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
  3. 3. Invisalign - In a Nutshell - Mechanism of Action - In Detail - Retention and Stability - Advantages - Disadvantages - Summary www.indiandentalacademy.com
  4. 4. INTRODUCTION 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. www.indiandentalacademy.com
  5. 5. 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
  6. 6. Align Technology, Inc (Santa Clara, Calif), introduced 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. www.indiandentalacademy.com
  7. 7. Keslings setup 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. www.indiandentalacademy.com
  8. 8. 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. www.indiandentalacademy.com
  9. 9. 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. www.indiandentalacademy.com
  10. 10. 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. www.indiandentalacademy.com
  11. 11. 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. www.indiandentalacademy.com
  12. 12. RESULTS OF WEARING THE TOOTH POSITIONER AS A FINISHING APPLIANCE  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. www.indiandentalacademy.com
  13. 13. 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 the www.indiandentalacademy.com positioner at night as a retainer.
  14. 14. PROCEDURE 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. www.indiandentalacademy.com
  15. 15. USES 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. www.indiandentalacademy.com
  16. 16. Essix Retainers (1993) 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 www.indiandentalacademy.com wishes of good luck or simply fade away.
  17. 17. 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. www.indiandentalacademy.com
  18. 18. Patient before and after placement of Essix retainers www.indiandentalacademy.com
  19. 19. 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-andmoney-saving service to our patients and is sincerely appreciated. www.indiandentalacademy.com
  20. 20. Current Retainer Designs 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. www.indiandentalacademy.com
  21. 21. 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. www.indiandentalacademy.com
  22. 22. 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
  23. 23. • • • • • • 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 www.indiandentalacademy.com
  24. 24. Fabrication 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. www.indiandentalacademy.com
  25. 25. 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. www.indiandentalacademy.com
  26. 26. 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
  27. 27. 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. Essix retainer cut away from plastic sheet and trimmed with curved Mayo scissors www.indiandentalacademy.com
  28. 28. 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. Labial contour of upper and lower Essix retainers www.indiandentalacademy.com
  29. 29. • 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. Palatal contour of upper Essix retainer www.indiandentalacademy.com
  30. 30. • 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. Space cut at distogingival margin of cuspid to allow removal of retainer with fingernail www.indiandentalacademy.com
  31. 31. Appliance Delivery 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. www.indiandentalacademy.com
  32. 32. 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. www.indiandentalacademy.com
  33. 33. 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 cottontip 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. www.indiandentalacademy.com
  34. 34. 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. www.indiandentalacademy.com B. More colorful case preferred by adolescents.
  35. 35. Telephone Supervision 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. www.indiandentalacademy.com
  36. 36. Conclusion 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 Essix retainer placed on upper arch from the opposing arch to reduce occlusal forces against lower arch during air-rotor when moving posterior stripping mechanics. teeth with air-rotor www.indiandentalacademy.com stripping mechanics.
  37. 37. 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. www.indiandentalacademy.com
  38. 38. The use of Essix retainers, in combination with telephone monitoring, opens the way to a practical, patientfriendly method of true permanent retention. www.indiandentalacademy.com
  39. 39. ACTIVE TOOTH MOVEMENT WITH ESSIX BASED APPLIANCE 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) www.indiandentalacademy.com
  40. 40. Trimmed working cast for thermoforming Essix retainer. www.indiandentalacademy.com
  41. 41. Cutting window in thermoformed appliance with acrylic bur Finishing window border with scalpel www.indiandentalacademy.com
  42. 42. The Divoter: precision thermoforming tool Heating shaft of Divoter www.indiandentalacademy.com
  43. 43. Monitoring inside of appliance for divot depth www.indiandentalacademy.com
  44. 44. Removing residual plastic debris from heating shaft prior to use www.indiandentalacademy.com
  45. 45. A. Incisal placement of divot produces more tipping. B. Gingival placement produces more bodily movement www.indiandentalacademy.com
  46. 46. A. Distal placement of divot produces mesial rotation. B. Mesial placement produces distal rotation. www.indiandentalacademy.com
  47. 47. Mesial contact point of lateral incisor locked within Essix appliance while divot induces facial rotation of out-of-line distal surface. www.indiandentalacademy.com
  48. 48. Divot-induced moments create torquing couple www.indiandentalacademy.com
  49. 49. Incisal cap produces pure root torque www.indiandentalacademy.com
  50. 50. Case 1. A. Incisor alignment before treatment. B. After four months of wearing Essix appliance with successive 1mm divots. www.indiandentalacademy.com
  51. 51. Case 2. A. Incisor alignment after debonding. B. After two weeks of Essix appliance with 1mm divot to align lower right lateral incisor. www.indiandentalacademy.com
  52. 52. 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. www.indiandentalacademy.com
  53. 53. A. Essix plastic sheets with light-cured acrylic between them. B. Plastic sheets thermosealed to encapsulate acrylic layer www.indiandentalacademy.com
  54. 54. Full-arch working cast made to Essix standards www.indiandentalacademy.com
  55. 55. Base sheet with center section and peripheral excess cut away www.indiandentalacademy.com
  56. 56. Prying distal ends of base appliance with thin-bladed instrument to remove it from cast www.indiandentalacademy.com
  57. 57. Anterior section of base appliance cut away, and remainder of appliance replaced on cast www.indiandentalacademy.com
  58. 58. Bead of light-cured acrylic applied to palatal area of base appliance www.indiandentalacademy.com
  59. 59. Heat Gun used to prepare base appliance for second thermosealing www.indiandentalacademy.com
  60. 60. Base and second plastic sheets thermosealed with light-cured acrylic between them www.indiandentalacademy.com
  61. 61. Bulk of plastic cut away with acrylic disk www.indiandentalacademy.com
  62. 62. Finished "full Essix" appliance after trimming www.indiandentalacademy.com
  63. 63. Barrier wire tacked to base appliance www.indiandentalacademy.com
  64. 64. Light-cured acrylic placed in palatal area and covering base of wire barrier www.indiandentalacademy.com
  65. 65. Finished habit appliance after trimming www.indiandentalacademy.com
  66. 66. Active element of uprighting spring tacked to cast with composite. Retentive element of spring placed on base appliance www.indiandentalacademy.com
  67. 67. Palatal acrylic covering retentive element of uprighting spring www.indiandentalacademy.com
  68. 68. Finished molar uprighting appliance after trimming www.indiandentalacademy.com
  69. 69. Thermosealed rigid plastic bar between two abutment teeth www.indiandentalacademy.com
  70. 70. Finished space maintainer after trimming www.indiandentalacademy.com
  71. 71. Finished bite plane after trimming www.indiandentalacademy.com
  72. 72. 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). www.indiandentalacademy.com
  73. 73. INVISALIGN IN A NUTSHELL 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. www.indiandentalacademy.com
  74. 74. 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." www.indiandentalacademy.com
  75. 75. MECHANISM OF ACTION 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. www.indiandentalacademy.com
  76. 76. HOW DOES INVISALIGN WORK? 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
  77. 77. INVISALIGN IN DETAIL 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. www.indiandentalacademy.com
  78. 78. 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. www.indiandentalacademy.com
  79. 79. 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. www.indiandentalacademy.com
  80. 80. DESTRUCTIVE SCANNER www.indiandentalacademy.com
  81. 81. A computer linked with the scanner then assembles the scanned information to create a 3dimensional rendering of the models. www.indiandentalacademy.com
  82. 82. 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. www.indiandentalacademy.com
  83. 83. Cutters separate teeth Placement of virtual gingiva www.indiandentalacademy.com
  84. 84. 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 as ClinCheck) onwww.indiandentalacademy.com the Invisalign Web site.
  85. 85. 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). www.indiandentalacademy.com
  86. 86. Stereolithography machines Stereolithography models www.indiandentalacademy.com Aligners
  87. 87. 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 accuracy. www.indiandentalacademy.com
  88. 88. 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. www.indiandentalacademy.com
  89. 89. RETENTION & STABILITY 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. www.indiandentalacademy.com
  90. 90. ADVANTAGES 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. www.indiandentalacademy.com
  91. 91. 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. www.indiandentalacademy.com
  92. 92. DISADVANTAGES 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. www.indiandentalacademy.com
  93. 93. 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. www.indiandentalacademy.com
  94. 94. SUMMARY 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. www.indiandentalacademy.com
  95. 95. 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. www.indiandentalacademy.com
  96. 96. 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. www.indiandentalacademy.com
  97. 97. Thank you For more details please visit www.indiandentalacademy.com www.indiandentalacademy.com

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