Self-ligating brackets have an in-built metal face that can open and close. They were developed to address issues with conventional ligating systems like high friction and impaired oral hygiene. Self-ligating brackets are classified as active or passive based on whether their clip actively engages the archwire. Key advantages include improved engagement, lower friction, faster treatment, and better oral hygiene. However, several studies found no difference in treatment time or outcomes compared to conventional brackets. Clinical tips for using self-ligating brackets include longer appointment intervals, more use of lighter forces early on, and an initial wire sequence of 0.014" then 0.014"x0.025" nickel titanium.

1. Self-Ligating Brackets
By: Dr. Hadeel Almasri

2. Lecture’s Outline
• Definition
• Overview of evolution of self-ligating brackets
• Classification
• Properties of an Ideal Ligation System
• Disadvantages of the conventional ligation system
• Advantages of self-ligating brackets
• Clinical significance of low friction
• Treatments not influenced by a low-friction method of ligation
• Factors which have hindered the adoption of self-ligation
• Commonly used SL system
• Active clip or passive slide?
• Clinical tips when using self-ligating brackets
• Archwires
• Debonding
• Retention

3. Definition
• Self-ligating brackets have an in-built metal face, which can be
opened and closed.
• The Russell Lock edgewise attachment first described by
Stolzenberg (Russell Lock edgewise attachment) in 1935 was
the early examples of self-ligating brackets.

4. Overview of evolution of self-ligating
brackets

5. Classification
• Active: Have a sliding spring
clip, which encroaches on the
slot from the labial aspect,
potentially placing an active
force on the archwire.
 e.g: Speed, In-Ovation, Nexus,
Quick, Time
• Passive: Have a slide that
opens and closes vertically and
creates a passive labial surface
to the slot with no intention to
invade the slot.
 e.g: Damon, Smartclip, Praxis
Glide, Carriere LX, vision LP,
Lotus.

6. Properties of an Ideal Ligation System
• Inexpensive
• Biocompatible material
• Assist good oral hygiene and patient comfortibility.
• Be quick and easy to use.
• Be secure and robust.
• Ensure full bracket engagement of the archwire.
• Exhibit low friction between the bracket and the archwire.

7. Disadvantages of the conventional
ligation system
• Fails to provide and maintain full arch wire engagement.
• High friction.
• Elastomerics exhibit force decay and loose tooth control.
• Impede oral hygiene.
• Wire ligation is a very slow process.(Wire ties have lower
friction and engage the archwire fully in the bracket, however
they time consuming.)

8. Advantages of self-ligating brackets
Summarized in a systematic article by Fleming et
al in 2010 and Chen et al 2010

9. Improved movement control by Secure and
robust ligation
 With:
-This can maximises the potential long range of action of modern
low modulus wires and minimises the need to regain control of
teeth where full engagement is lost during treatment due to
degradation as in elastomeric modules.
-Wire ligatures are good in this respect, whilst elastomeric
ligatures are much less good, The force decay of elastomerics has
been well documented (Taloumis et al 1997).

10. Less chairside assistance and faster archwire
removal and ligation
 With：
-Harradine 2001, SL brackets reduce placement time of an archwire by
24 sec per wire.
-Bernie 2005 have shown that wire ligation is very slow compared to
elastomerics, the use of wire ligatures added almost 12 minutes to the
time needed to remove and replace two archwires.
 Against:
-In a meta-analysis by Chen 2010 reported mean time savings of 20
seconds per arch. This considered insignificant and would not make
many operators change their practice.

11. Assist good oral hygiene
 With:
-Elastomerics accumulate plaque more than do tie-wires.
-The ends of wire ligatures are however an additional obstacle to
oral hygiene.
-The bacteriology results slightly favoured wire ligation, the
important sign of bleeding on probing was substantially higher
with elastomeric ligation. Turkkahraman et al (2005)

12. Patient comfortibility
 With:
-Mills (2006) in a split mouth study found lower pain levels with
Damon 2 brackets during the alignment phase, although opening
the brackets was more uncomfortable than removing
elastomerics.
 Against:
-Pain during alignment stage is similar between victory, Damon
and smart clip (Fleming 2008, Scott 2009) even SL has worse pain
level in replacing 19*25 NITI with ss.

13. Low friction between bracket and wire with associated
rapid treatment, better treatment quality and
outcomes and less root resorption
 With：
The low friction and low force philosophy claimed to be the cause of:
• Rapid movement
• Little proclination
• Less anchorage demand
• Better arch development
• Wider arches which may be more aesthetic
• Wider arches which have better periodontal health than those resulting
from more rapid and forceful expansion

14. Low friction between bracket and wire with associated
rapid treatment, better treatment quality and
outcomes and less root resorption
• Less need for extractions
• Easier class 2 correction through a ‘lip-bumper’ effect
• Better stability.
• Less root resorption.
• Study to support this done by Harradine 2001 , Treatment time with SL
brackets was on average 4 months shorter than conventional brackets. The
mean number of visits was reduced from 16 to 12 per patient.

15. Low friction between bracket and wire with associated
rapid treatment, better treatment quality and
outcomes and less root resorption
 Against:
-NO difference in time or efficiency during initial alignment according to Mills
2005 , Scott 2008, Fleming 2009, Pandis 2011, Eliades 2008. This result in
upper and lower arch similar.
-During Enmass space closure (no difference in time or efficiency)) according
to Mills 2007
-During canine retraction (no difference in time or efficiency) according to
Mezomo 2011
-Overall treatment duration, Fleming 2010, DiBiase 2011, Johannson 2012 no
difference
-Songra 2014 SL is worse than conventional

16. Low friction between bracket and wire with associated
rapid treatment, better treatment quality and
outcomes and less root resorption
-PAR index improvement (no difference) DiBiase et al 2011, Johannson 2012.
-Harradine 2001, SL and conventional systems produced the same PAR
reduction.
-Regarding the maxillary arch width, Fleming in 2013 did a study where he
randomized a sample of 96 patients aged 16 and above to treatment with a
passive self-ligating bracket, an active self-ligating bracket and a conventional
system. Importantly, they removed the effect of archwires by using the
Damon archwire sequence for all patients. They found no difference and the
expansion is related to the wire not the appliance.

17. Clinical significance of low friction
• Rapid movement: With elastomeric ligation, higher forces
must therefore be applied to overcome the resistance
produced by friction and this is more likely to be undesirably
higher than levels best suited to create the optimal
histological response resulting in slow movement.

18. Clinical significance of low friction
• Less anchorage demand: With low friction, the net tooth-
moving forces can be more predictably low so there will be
less anchorage loss. A recent study by Yee et al (2009)
measured canine retraction and anchorage loss with a light
(50 gm) and heavy (300 gm) forces. The percentage of
anchorage loss was significantly higher (62%) with the heavy
force than with the light force (55%).

19. Clinical significance of low friction
• Little proclination and better arch development: Light forces
aid in that the forces from the soft tissues can compete with
the force from the wire. For example it has been proposed
that the lips can restrain labial movement of the incisors and
that the alignment of crowded teeth on a non-extraction basis
will result in more lateral arch expansion and less labial incisor
movement than would be the case with heavier forces and
higher resistance to sliding.

20. Clinical significance of low friction
• Better stability: Further, it’s been claimed that expansion
brought about by such light forces is more likely to achieve an
archform which is in balance with the tongue and cheeks and
can establish a wider arch which will be relatively stable
because of altered tongue position.

21. Treatments not influenced by a low-
friction method of ligation
• Space closure with closing loops placed in the space
• Expansion of a well-aligned arch
• Torque (inclination) changes

22. Factors which have hindered the
adoption of self-ligation
• Design and manufacture imperfection.
• An inherent conservatism amongst orthodontists
• Lack of widespread appreciation of what low friction, secure
archwire engagement and light forces can achieve

23. Commonly used SL system

24. Damon SL brackets
• Available in 1996
• They had a slide which
moved vertically on the
labial surface of an
otherwise fairly
conventional twin tie-wing
bracket.
• Problems: the slides
inadvertently opened and
were prone to breakage.

25. Damon 2
• Placed the slide within the
shelter of the tiewings (robust
and secure)
• Metal injection moulding
manufacture
• Narrower bracket with the
consequent advantages of a
larger inter-bracket span
• Disadvantages: not easy to
open, and it was possible for
the slide to be in a half-open
position hindering archwire
removal or placement.

26. Damon 3
• 3 major changes:
1. A tooth-coloured composite
resin base and upper tie-wing
which reduces the visual impact
of the bracket
2. A rhomboidal shape of the
bracket and slide which
facilitates bracket siting
3. Vertically placed chair-shaped
spring clip behind the slide.
• Problems:
1. High rate of bond failure
2. Separation of the metal from
the reinforced resin
components
3. Fractured resin tie-wings

27. Damon 3MX brackets
• All-metal and have the
same slide mechanism as
D3.
• They have a vertical slot
behind the archwire slot
into which prefabricated
click-in auxiliary hooks can
be added to any bracket as
required and removed.
• The main problem is the
susceptibility of the slide
mechanism to becoming
jammed with calculus.

28. Damon Q brackets
• Easier slide mechanism.
• Immune to the effects of
calculus accumulation.
• A clever feature is the
reciprocal nature of the
opening forces which leaves
almost no net force on the
tooth and the slide is opened.
• The brackets are also smaller
in all dimensions than their
predecessors and space has
been found for a horizontal as
well as a vertical auxiliary slot.

29. In-Ovation Brackets

30. In-Ovation Brackets

31. In-Ovation Brackets

32. 3M Unitek SmartClip brackets

33. SPEED brackets

34. Active clip or passive slide ？
• High forces at early stages with active clip: With thin aligning
wires smaller than 0.018" diameter, the effect of having an
active clip at this early stage of treatment can be thought of as
having a potentially shallower bracket slot. This will frequently
produce higher forces with a given wire.

35. Active clip or passive slide？
• Better labiolingual movement with active clip: for wires >
0.018" diameter, On teeth which are in whole or in part
lingual to a neighbouring tooth, the active clip will bring the
tooth (or part of the tooth if rotated) to same level
labiolingually to the adjacent. But with passive bracket the
tooth will slightly more lingual than adjacent teeth.

36. Active clip or passive slide？
• High friction at later stage with active clip: With thick
rectangular wires, An active clip places a lingually directed
force on the wire in all circumstances which results in a higher
friction and resistance to sliding.

37. Active clip or passive slide？
• Little contribution to torque capacity by the lingually directed
forces from the active clip.

38. Active clip or passive slide？
• Aging of spring clips: Pandis et al (2007), the In-Ovation clips
lost an average of 50% of their stiffness during the treatment,
SPEED clips had very little change in their performance. The
change is sufficient that it may have biomechanical
consequences of clinical significance.

39. Clinical tips when using self-ligating
brackets

40. Changing treatment mechanics
• Longer appointment intervals (8-10 weeks) for some stages of
treatment (early stages and significant irregularities) due to
the secure wire engagement.

41. Changing treatment mechanics
• More traction on lighter wires:
The greater effectiveness of lighter forces and decreased loss of
control reduce the adverse side effects of traction on light wires.
Therefore, we can use compressed coil springs and light
intermaxillary elastics from the first visit.

42. Changing treatment mechanics
• Separate movement of individual teeth and parallel
processing due to controlled teeth movement.
Eg. It sensible in some malocclusions to separately retract
canines to a class 1 relationship whilst simultaneously reducing
the overbite. By the time the overbite reduction permits upper
incisor retraction, the canines are already class 1 but in good
rotational control and the case is further advanced with
anchorage conserved.

43. Bracket placement and bond-up
• Both maxillary and mandibular arches should be bonded at
the same time and that bonding should include second molar
to second molar in each arch.
• For severely displaced teeth, it is helpful to use a Traction
Hook.
• Damon Q, In-Ovation and SPEED brackets have a horizontal
auxiliary slot which permits a low-friction application of
piggyback archwires for ectopic teeth.

44. Opening and closing
• There are three reasons why an archwire does not seat in the
slot:
– There is something in the slot preventing the archwire
seating
– The archwire is not sufficiently deflected (but can be) to
seat fully in the slot
– The archwire cannot be deflected (too stiff) to seat fully in
the slot

45. Opening and closing
• Remove any plaque or food debris from the slot, deflect the
archwire further or choose a less stiff archwire.

46. Opening and closing
• Engage the wire to the bracket by using:
 Finger pressure
 Tucker
 Cool instrument
 Dental floss
 First close the clip, slide and then thread the aligning wire
through the closed bracket before engaging the other
brackets

47. Archwires
• Initial placement
When placing the initial archwires, do not include the second
molars. The patient will frequently bite an 0.014" archwire out of
the second molar tubes; it is better to terminate the archwires at
the first molars for the first visit and then pick up the second
molars on the first nickel titanium rectangular archwires (0.018”
or 0.014" x 0.025" or 0.016" x 0.025").

48. Archwires
• Long unsupported spans:
 use laceback
 use small tubes bonded to deciduous teeth to reduce the
length of the span
 Sleeve

49. Archwires
• Prevention of ‘swivelling’:
 Small sections of stainless steel tube crimped onto the archwire,
anterior to the crowding and not in an inter-bracket space where
the wire needs to be significantly active (reduces range of action)
 Flowable composite (not reliable)
 Turning in the ends of flexible archwires.
 Selective locking of individual brackets to the archwire with
elastomeric
 Small V-shaped notches in the midline of flexible wires

50. Archwires
• The primary archwire sequence is as follows:
1. 0.014" nickel titanium superelastic (or 0.013” /0.012” in very
irregular arches)
2. 0.014" x 0.025" nickel titanium superelastic
3. 0.018" x 0.025" nickel titanium superelastic
4. 0.019" x 0.025" stainless steel

51. Archwires
• Secondary archwires and wires are as follows:
1. 0.018” nickel titanium Superelastic, this archwire is useful in cases with
substantial residual irregularity or compromised periodontium as the next
archwire step from the initial 0.014" nickel titanium superelastic
2. 0.016" x 0.025" nickel titanium Superelastic, this archwire is useful in cases with
little irregularity as the next archwire step from the initial 0.014" nickel titanium
superelastic
3. 0.016" x 0.022" stainless steel, Can be useful for extensive sliding of individual
teeth in hypodontia cases. Gives low friction with useful rigidity
4. 0.019" x 0.025" RCOS (reverse curve of Spee) nickel titanium Superelastic, used
for managing deep overbites in both the upper and lower arches
5. 0.019" x 0.025" TMA, very useful for individual tooth movements at the end of
treatment where archwire bends are required, especially for inclination (torque)
adjustments.

52. Debonding
• Self-ligating brackets are often more rigid than conventional
twin brackets.
• Bracket removal may not occur by failure of bracket adhesive
interface by deformation of the bracket, but by failure of
bracket adhesive interface, cohesive failure of the adhesive,
failure of adhesive enamel interface or combination.
• Risk of enamel trauma.
• Best way of debonding is “squeezing” under the tiewings with
conventional debonding plier without torsion force.

53. Retention
• Retention is no different when using self-ligation.

54. THANK YOU