elastics - p p t

1. ELASTICS-
LATEX & NON- LATEX ELASTICS
1
Presented by:
Dr. Vidhi R. Shah
1st Year PG

2. • Introduction
• Terminology
• History
• Composition of elastics
• Classification of elastics
• Properties of elastics
• Force degradation
• Use of elastics in extraction and non-extraction cases
• Sequence of elastics
• Elastomeric accessories
• Advantages and disadvantages
• Conclusion
• References
2
Contents

3. Introduction
3

4. Terminology
Force :
• It is defined as an act upon a body that changes or tends to change the
state of rest, or the motion of that body. It is defined in units of Newtons ,
usually measured in units of grams or ounce.
Elasticity:
• The property of a substance that enables it to change its length, volume
or shape in direct response to a force affecting such a change and recover
its original form upon the removal of the force.
Elastic limit:
• The elastic limit is the maximum stress which a material can endure
without undergoing permanent deformation.
4
Mapare S, Bansal K, Pawar R, Mishra R, Sthapak A, Khadri SF. Elastics and elastomeric in orthodontic practice.
Int. J. Prev. Clin. Dent. Res. 2018;5:S21-30.

5. Elastic modulus or modulus of elasticity:
It is defined as the ratio of stress and strain (within elastic limit) or stress
required to produce unit strain. It represents rigidity, stiffness or resistance
to deformations.
• E = stress/strain.
Resilience:
It is the ability of a material to absorb deforming energies without
undergoing permanent deformation. In other words it is the “Cushion -
like” or “Springiness” property. It is the amount of energy absorbed by a
unit volume of material when stressed up to proportional limit.
Plasticity:
• It is the property of any substance by which the material can be molded
into various forms and then hardened for commercial use.
5
Terminology
Mapare S, Bansal K, Pawar R, Mishra R, Sthapak A, Khadri SF. Elastics and elastomeric in orthodontic practice.
Int. J. Prev. Clin. Dent. Res. 2018;5:S21-30.

6. 1728: Pierre Fauchard –
1839: Charles Goodyear –
1892: Calvin Case –
1904: H. Baker –
1907: Edward H. Angle -
1963: Jarabak –
1965: P. R. Begg -
6
History
Singh VP, Pokharel PR, Pariekh K, Roy DK, Singla A, Biswas KP. Elastics in orthodontics: a review. Health
Renaissance. 2012;10(1):49-56.

7. Synthetic Rubber:-
• In 1920 - Synthetic rubber polymers developed from petro-chemicals
• World War II began in 1939 - Germany was manufacturing two chief types of
synthetic rubbers.
7
History
Singh VP, Pokharel PR, Pariekh K, Roy DK, Singla A, Biswas KP. Elastics in orthodontics: a review. Health
Renaissance. 2012;10(1):49-56.

8. Natural rubber
8
Composition of elastics
Singh VP, Pokharel PR, Pariekh K, Roy DK, Singla A, Biswas KP. Elastics in orthodontics: a review. Health
Renaissance. 2012;10(1):49-56.
Synthetic rubber

9. • According to the material –
• according to the uses –
• According to the lumen size -
9
Classification
Bishara, S E, and G FAndreasen. “A comparison of time related forces between plastic alastiks and latex elastics.” The
Angle orthodontist vol. 40,4 (1970): 319-28. doi:10.1043/0003-3219(1970)040<0319:ACOTRF>2.0.CO;2

10. • According to the color –
• Purple -1/8’’
• Green – 3/8’’
• Red – 1/8’’, 1/4”
• Blue – 1/4”
• Orange – 3/8”
• Yellow – 5/16’’
• According to the force –
• Light (2 Ounces) - 56.7 gm
• Medium light (3.5 Ounces) – 128 gm
• Medium Heavy (5 Ounces)– 141.8 gm
• Heavy (6.5 Ounces) – 184 gm
• Extra Heavy (8 Ounces)- 226.8 gm
10
Classification
Bishara, S E, and G FAndreasen. “A comparison of time related forces between plastic alastiks and latex elastics.” The
Angle orthodontist vol. 40,4 (1970): 319-28. doi:10.1043/0003-3219(1970)040<0319:ACOTRF>2.0.CO;2

11. Class- I elastics or horizontal
elastics or intramaxillary elastics or
intra-arch elastics
Class- II Elastics / intermaxillary
elastics / interarch elastics.
Class- III elastics
Cross Bite elastics
Box elastics
11
Classification
 Diagonal elastics (Midline elastics)
 M and W elastics
 Check elastics
 Vertical elastics
 Trapezoid elastics
 Triangular elastics
 Trans palatal elastic (Buffalo elastic)
According to their placement in the Arch –
The Alexander Discipline: The 20 principles of the Alexander discipline – Volume 1
Begg Orthodontic- Theory and TechniqueAuthors P. R. Begg, Peter C. Kesling 3rd edition

12. • Natural Latex Rubber:
1.Resiliency:
2.Water Resistance:
3. Stress :
4. Strain :
• Synthetic Polymers:
1.Sensitivity to Free Radicals:
2.Effects of Free Radicals:
12
Properties of elastic chains
Mahboob, Amir. "Study of the structural behavior of hybrid elements of carbon fiber reinforced polymer and
concrete." (2021).

13. 13
Force degradation
• Wong's Perspective on Latex Elastics:
Continuous Orthodontic Forces
• Baty et al.'s Conclusion on Elastomeric Chains:
Inability to Deliver Continuous Force
• Proffit's View on Elastomers:
Force Decay with Elastomers
Baty, D L et al. “Synthetic elastomeric chains: a literature review.” American journal of orthodontics and dentofacial
orthopedics : official publication of the American Association of Orthodontists, its constituent societies, and the
American Board of Orthodontics vol. 105,6 (1994): 536-42. doi:10.1016/S0889-5406(94)70137-7
After 2 hours in the mouth, the module elastic force decreases – 30%
After 3 hours – decreases 40%

14. 14
Class- I elastics or horizontal elastics or
intramaxillary elastics or intra-arch elastics
Textbook of Contemporary Orthodontics by William R. Proffit- 6th edition
• Used - space closure and open the bite also.
• The force recommended - 1 ½ to 2 ½ ounces for
non-extraction cases.
• Extraction cases- 2 to 4 ounces
• Reciprocal action in a straight line

15. 15
Class-II Elastics / intermaxillary elastics /
interarch elastics
Textbook of Contemporary Orthodontics by William R. Proffit- 6th edition
Force - ¼ inch or 6 ounces.
Class II elastics can serve two main purposes:
•To correct Class II malocclusion.
 Applied during the finishing archwires
phase.
 To be worn 24 hours a day.
• Initially worn - 72 hours, then switched to
nights only.
• Use - antero-posterior tooth changes- obtaining
Class-I cuspid relationship from a Class-II
relationship.

16. 16
Biomechanics of Class II elastics
Long class II elastic :-
• Extrusion and clockwise moment on upper and lower anteriors
• Clockwise rotation of occlusal plane and correction of A-P problems

17. 17
Short class II elastic :-
Synchronous system Asynchronous system
 Line of force and Center of rotation –
 D1 = D2
 Same direction with less moment
 Line of force is far from the Center of rotation
 D1 > D2
 Upper arch – extrusion and clockwise moment
of upper anteriors and occlusal plane
 Lower arch – translation and counter
clockwise rotation of lower occlusal plane
Textbook of esthetics and biomechanics in orthodontics by ravindra nanda 2nd edition

18. 18
Class III elastics
• Force : 1/4 inch to 3.5 ounces.
It can be used for three different purposes:
• Why: To prevent advancement of the mandibular anterior teeth in a crowded
nonextraction arch
• When : Initial archwire in the mandibular arch
• Time: 72 hours, then nights only, with the facebow
Textbook of Contemporary Orthodontics by William R. Proffit- 6th edition

19. 19
Biomechanics of Class III elastics
Long class III elastic :-
• Extrusion and counter
clockwise moment on upper
and lower anteriors
• Counter clockwise rotation of
occlusal plane and correction
of A-P problems
Short class III elastic :-
 Line of force is far from the Center of rotation
 D1 > D2
 Upper arch – extrusion and counter clockwise
moment of upper molars and occlusal plane
 Lower arch – translation

20. 20
Cross Bite Elastics
Buccal surface of molar to lingual surface of opposing
molar
• Force: 3/16 inch; 6 ounces
• Why: To correct posterior crossbites
• When : Early and/or late in treatment
• Time: 24 hours per day
Textbook of Contemporary Orthodontics by William R. Proffit- 6th edition

21. 21
Box Elastics
Textbook of Contemporary Orthodontics by William R. Proffit- 6th edition
Placement - upper cuspid and lateral incisor to the lower first bicuspid
and cuspid or to the lower cuspid and lateral incisors.
Use - to promote tooth extrusion and improve intercuspation.
to correct the anterior open bite.

22. 22
Box Elastics
Anterior box elastics, class II and class III
• Where: Maxillary central incisor brackets to mandibular lateral incisor brackets
• Force : 3/16 inch; 6 ounces.
• Why: To close the bite in a Class II malocclusion
• When: In intermediate and finishing archwires
• Time: 24 hours per day
Textbook of Contemporary Orthodontics by William R. Proffit- 6th edition

23. Maxillary lateral incisor ball hook over central incisor
then diagonally to opposite mandibular lateral incisor
ball hook
• Force: 1/4inch; 6 ounces.
• Why: To correct midline discrepancies
• When: Finishing archwires
• Time: 24 hours per day
23
Diagonal Elastics (Midline elastics)
Textbook of Contemporary Orthodontics by William R. Proffit- 6th edition

24. These elastics help raise a group of teeth to closing the bite effectively.
Elastic attachment
• For Class I malocclusion - the configuration is M- ½ shape
• For Class II malocclusion - the configuration is W shape with a tail
If additional anterior overbite correction is needed, anterior box elastics
may be used.
• For Class III malocclusion - the configuration is an M shape with a tail.
24
M and W Elastics
Textbook of Contemporary Orthodontics by William R. Proffit- 6th edition

25. • Correction of open bite.
• Contraindications- in deep bite cases
• Force - 3 ½ ounces.
25
Vertical Elastics
Vertical Elastics
Textbook of Contemporary Orthodontics by William R. Proffit- 6th edition

26. 26
Triangular Elastics
Maxillary canine bracket to mandibular canine-
premolar area.
• Force: 1/8 inch; 3.5 ounces.
• Why: Apply direct force to a single tooth in Class I
cases
• When: Stabilized opposing archwire and a flexible arch
wire for the tooth to be moved
• Time : 24 hours per
Textbook of Contemporary Orthodontics by William R. Proffit- 6th edition

27. • At the end of the treatment –during
finishing and detailing, to constrict the
maxillaray arch
• Force – 3/8 inches or 8 ounces.
27
Trans palatal Elastics (Buffalo elastics)
Begg Orthodontic- Theory and TechniqueAuthors P. R. Begg, Peter C. Kesling 3rd edition

28. • In a nonextraction case- correction of class II sagittal dental relationships by
helping the mandible posture forward.
• In extraction cases- enhance lower mesial molar movement or burn the
anchorage.
• Class II anchorage is also utilized to influence maxillary arch:
I ) For maxillary canine retraction
II ) For mass retraction of maxillary anterior segment
• Roth recommends –
28
Use of class-II elastics are different in
nonextraction or an extraction situation.
Textbook of Contemporary Orthodontics by William R. Proffit- 6th edition
Short elastics attached
to the lower second
premolar could
simultaneously level
the curve of spee.
• At finishing stages
of treatment.
• To prevent
unwanted labial
flaring of maxillary
incisors.

29. According to Alexander Discipline -
System of biomechanics are divided into three sequences:
1.Early in treatment
• Crossbite elastics
• Class 3 elastics after bonding of the mandibular arch to prevent incisor flaring
2.Mid treatment
• Box elastics - close open bites, for leveling the mandibular arches
• Extraction cases - Class 2 elastics for minimum mandibular anchorage
• Extraction cases - Class 3 elastics to maximize mandibular anchorage
29
Sequence of Elastics
R.G. ‘Wick’Alexander , The 20 principles of alexander discipline in 2007

30. 30
Sequence of Elastics
3. Finishing arch wires
• Class 2 elastics to achieve occlusion in centric relation
• Midline elastics with class 2 or class 3 elastics
• Box elastics to improve occlusion
R.G. ‘Wick’Alexander , The 20 principles of alexander discipline in 2007

31. These accessories are used in following forms:
• Elastic chains or power chains
• Elastic module
• Elastic ligature
• Elastic thread
• Elastic tubing
• Elastic separators
31
Elastomeric Accessories
Ring separators Dumbbell separators
Orthodontics: Diagnosis and Management of Malocclusion and Dentofacial Deformities Om P. Kharbanda – 3rd edition

32. 32
Instructions On Wearing Elastics
Mapare S, Bansal K, Pawar R, Mishra R, Sthapak A, Khadri SF. Elastics and elastomeric in orthodontic practice.
Int. J. Prev. Clin. Dent. Res. 2018;5:S21-30.
1.Continuous Wear:
2.Regular Monitoring:
4.Ease of Placement:
5.Check Attachments:

33. • Inexpensive, hygienic, and easy to apply.
• Requires minimal chair time and patient cooperation.
• Easy for patients to remove and replace.
• Compatible with oral mucosa and has a wide elastic range.
• Valuable resiliency property for applying tractive forces.
• Minimal force decay in optimal conditions.
• High professional acceptance in orthodontics.
33
Advantages of elastics

34. • Gum rubber deteriorates quickly.
• Gum rubber loses elasticity in 12-24 hours.
• Latex elastics last 4-6 times longer.
• Latex elastics rapidly lose force.
• Patient motivation.
• Orthodontists struggle to measure actual force.
34
Disadvantages of elastics

35. 35
Conclusion

36. • William R. Proffit, Henry Fields, David M Server; Contemporary Orthodontics, 5th edition
• Orthodontics: Diagnosis and Management of Malocclusion and Dentofacial Deformities Om P. Kharbanda –
3rd edition
• Mapare S, Bansal K, Pawar R, Mishra R, Sthapak A, Khadri SF. Elastics and elastomeric in orthodontic
practice. Int. J. Prev. Clin. Dent. Res. 2018;5:S21-30.
• Singh VP, Pokharel PR, Pariekh K, Roy DK, Singla A, Biswas KP. Elastics in orthodontics: a review. Health
Renaissance. 2012;10(1):49-56.
• Baty, D L et al. “Synthetic elastomeric chains: a literature review.” American journal of orthodontics and
dentofacial orthopedics : official publication of the American Association of Orthodontists, its constituent
societies, and the American Board of Orthodontics vol. 105,6 (1994): 536-42. doi:10.1016/S0889-
5406(94)70137-7
• Bishara, S E, and G F Andreasen. “A comparison of time related forces between plastic alastiks and latex
elastics.” The Angle orthodontist vol. 40,4 (1970): 319-28. doi:10.1043/0003-
3219(1970)040<0319:ACOTRF>2.0.CO;2
• Mahboob, Amir. "Study of the structural behavior of hybrid elements of carbon fiber reinforced polymer and
concrete." (2021).
• Joseph VP, Grobler SR, Rossouw PE. Fluoride release from orthodontic elastic chain. Journal of Clinical
Orthodontics: JCO. 1993 Feb 1;27(2):101-5.
• R.G. ‘Wick’Alexander , The 20 principles of alexander discipline. 2007
• Singh VP et al ‘’ Elastics in orthodontics ‘’ Health Renaissance, January-April 2012; Vol 10 (No. 1);49-56
• Begg Orthodontic- Theory and TechniqueAuthors P. R. Begg, Peter C. Kesling 3rd edition
• The Alexander Discipline: The 20 principles of the Alexander discipline – Volume 1 36
References

37. THANK YOU
37