Download BANDING AND BONDING

BONDING
IN
ORTHODONTICS
25.02.2015
Dr.Gyan P. Singh, KGMU
Orthodontics&Dentofacial Orthopedics
Fixed orthodontic Appliance
BANDING
• The chief parts of modern fixed appliances are tooth
bands,brackets and arch wires.
• Tooth bands are made up of metals and cemented to the
teeth and provides place for attachment of other auxiliaries
like brackets, buccal tubes, lingual buttons etc.
• The tooth moving forces derived from the arch wires are
transmitted to the teeth through the bracket
2
•
MAGILL was the 1st to use plain band
• Preformed steel bands came into widespread use
during the 1960s and are now available in
anatomically correct shapes for all the teeth.
• Teeth that will receive heavy intermittent forces
( for the anchorage purpose-extraction cases)
against the attachments for the extra oral force like
Head gear. E.g.: upper 1st molars
•
3
Banding Technique:
Separation
Selection of band material
Fabrication and fitting
Cementation
4
• Elastomeric separators;
which surrounds the contact point and
squeeze the teeth apart over period of few days
5
6
• Prefabrication
• Lower molar bands are designed to be
seated initially with hand pressure on
the proximal surface and then heavy
biting force along the buccal but not
the lingual margins.
7
BONDING
For the patient to whom esthetics being the prime
consideration even during the treatment, the metallic
look of the orthodontic appliance has always been
the bone of contention.
8
• History:
Acid etching M. G. Buonocore in 1955
using 85% phosphoric acid for 30 sec
Newman (1965) was the first to
apply bonded orthodontic brackets
Smith (1968) - zinc polyacrylate and
bracket bonding with this cement
9
.
Advantages over bonding
• It is esthetically superior.
• It is faster and simple.
• There is less discomfort for the patient
• Arch length is not increased by band material.
10
• It allows more precise bracket placement.
• Bonds are more hygienic than bands Partially
erupted teeth can be controlled.
• Mesiodistal enamel reduction ( proximal
reduction) is possible during treatment.
• Attachments may be bonded to artificial tooth
surfaces (eg., amalgam, porcelain, gold) and to
fixed bridge work.
11
• Caries risk under loose bands is eliminated and
interproximal caries can be detected and treated.
• No band spaces are present to close at the end of
treatment.
• Lingual brackets, invisible braces, can be used when
patient rejects visible orthodontic appliance.
12
• The protection against the inter proximal caries of
well contoured cemented band is absent.
• Bonding is more complicated when lingual
auxiliaries are required or where headgears are
attached.
• Debonding is more time consuming than
debanding, since removal of adhesive is more
difficult than removal of cement
13
• Bonding procedures can be performed in 2 ways
Direct bonding
Indirect bonding
Direct bonding:
This procedure is quite simple and involves
following steps
CLEANING
ENAMEL CONDITIONING
SEALING
BONDING
14
15
Cleaning
• This requires rotary instruments, either a rubber
cup or a polishing brush.
• Studies have shown enamel loss due to
prophylaxis.
• Mark Daniel pus et al ( AJO 1980) showed that
10.7µm of enamel loss during initial prophylaxis
with bristle brush was greater than the 5.0µm lost
when a rubber cup as used and the difference was
statistically significant.
16
• Enamel conditioning:
Moisture control
Enamel pretreatment
MOISTURE CONTROL:
After the rinse, salivary control and
maintenance of a completely dry working field is
absolutely essential. Its presence may prevent the
good bond between the sealant and bonding
agent
17
• Enamel pretreatment
• The conditioning solution or gel (usually 37%
phosphoric acid ) is then lightly applied over the
enamel surface with a foam pellet or brush for 15
to 30 sec.
• When etching solutions are used, the surface must
be kept moist by repeated applications.
18
• Is etching time is different for young and old teeth?
• K J. Nordenvall et al (AJO 1980) did a comparison between
the effects of 15 and 60 seconds of etching with a 37 percent
phosphoric acid solution on enamel surfaces of deciduous and
young and old permanent teeth.
•
For deciduous teeth, no difference was found in effect between
the etching periods.
• For young permanent teeth, 15 seconds of etching created more
retentive conditions than 60 seconds.
19
• How much enamel is removed by etching and how deep
are the histological alterations?
Are they reversible? Is etching is harmful?
A routine etching removes 3 to 10 μm of surface
enamel. Another 25 μm reveals subtle histological
alterations creating necessary mechanical interlocks.
Deeper localized dissolutions will generally cause
penetration to a depth of about 100µm or more.
20
Bonding
Direct technique in which the brackets are placed
directly on the enamel surface by the operator, as was
initially described by Newman.
• The second method of bracket placement is the indirect
technique, which was first described by Silverman et al
The recommended bracket bonding procedure consists of
the following steps
1.TRANSFER
2.POSITIONING
3.FITTING
4.REMOVAL OF EXCESS
21
TRANSFER:
• The bracket is gripped with a pair of cotton pliers
or a reverse action tweezer (bracket holding
forceps) and the mixed adhesive is applied to the
back of the bonding base.
22
POSITIONING:
• A placement scaler, such as the RM 349 or one with
parallel edges is used to position the brackets
mesiodistally and incisogingivilly and angulate them
accurately.
• The placement scaler with parallel edges allows
visualization of the bracket slot relative to the incisal
edge and long axis of the teeth, with the scaler seated in
slot.
23
FITTING
24
• REMOVAL OF EXCESS
• Excess must be removed with the scaler before
the adhesive has set or it must be removed with
bur after setting.
25
INDIRECT BONDING
• Several techniques for indirect bonding are available. Most
are based on the procedures described by Silverman and
Cohen ( JCO 1976).
• H. Stuart ( Jco 2003 ) suggested most indirect bonding
techniques are successful in accurately placing brackets but
can be expensive, he introduced a simplified method that
has reduced lab cost and chair time.
26
Indirect bonding with silicone
impression tray
• Take an impression and pour up a stone model
• Select brackets for each tooth
• Apply a small portion of water soluble adhesive on
each tooth
• Position the brackets on the model, check all the
measurements and allignments, reposition if
needed
27
28
Indirect bonding
In this technique temporary adhesive is used to
attach the brackets to the patients stone model
• The bracket is placed on the model and excess
adhesive is removed from the periphery of the
base
• Before forming the indirect bonding tray use of
light separating spray is recommended to
facilitate the easy removal of the tray from the
brackets.
• After 10 min placement tray is vacuum formed
for each arch
29
30
31
• Tray is removed by peeling from the lingual
towads the buccal
• Excess flash of sealant is carefully removed
from the gingival contact areas of the tooth
• Advantages
clean up is simple because little flash is present
32
DEBONDING
33
• Definition/Objective of debonding :--To remove the attachment and all the
adhesive resin from the tooth and restore the
surface as closely as possible to its Pretreatment condition without inducing
iatrogenic damage.
34
Clinical Procedures
• Mainly divided into 2 stages
-- Bracket removal
-- Removal of residual adhesive
35
Bracket removal
• Metal brackets
-- Debonding pliers
• Ceramic brackets
-- Pliers
-- Separation at bracket adhesive
interface (Bishara)
-- Thermal debonding
-- Lasers
36
37
Removal of residual adhesive
• Scaler
• Scraping with a sharp band or bond removing plier
• Burs
-- Dome shaped TC bur
-- Ultrafine diamond bur
-- White stone finishing bur
38
39
REFERENCES
• William R Proffit ,Contemporary orthodontics
Third Edition ,2002
• Thomas M Graber , Robert L, Vanarsdall ,
Orthodontics :Current Principles and Technique
Fourth Edition,2003
• Robert E Moyers Handbook of orthodontics
Fourth Edition,1988
• Kharbanda.Diagnosis and Management of
Malocclusion and Dentofacial
deformities.Mosby,elsevier,2001
40
MCQs:
1. Complicated cases are most often treated by fixed appliances
than removal appliance because
(A) They apply heavy forces
(B) Wide range of tooth movements possible
(C) Require less anchorage
(D) They cannot be removed by the patients
2. Which of the following are examples of fixed active appliances
(A) Standard Edgewise and straight wire
(B) Begg and Herbst
(C) Activator and Herbst
(D) Bionator and twin-block
41
3.All of the following can be classified as myofunctional
appliances except
(A) An anterior bite plane
(B) Andresen appliance
(C) Begg appliance
(D) Oral screen
4. Rotation of teeth is best corrected by
(A) Hawley appliance
(B) Buccal retractor
(C) Fixed appliance
(D) All of the above
42
5.Which of the following is not true of an fixed appliance
(A) Economical
(B) Rotation and extrusion movement are possible
(C)Patient cooperation is not required
(D)Tipping and bodily movement is possible
6. Passive component of fixed appliance
(A)
(B)
(C)
(D)
Brackets
Arch-wire
Springs
Elastics
43
7.Which of the following components of the fixed appliance holds the archwire on the teeth except for that molars
(A) Cleats
(B) Brackets
(C) Bands
(D) Lock springs
8. The direct bonded orthodontic stainless steel brackets device retention
with composite because of
(A) The mechanical interlock with mesh at the bracket base
(B) The chemical interlock of composite with bracket base
(C) Both mechanical and chemical interlock of composite with the bracket
base
(D) Biological interlock between the tooth and the brackets.
44
9. Use of light cure in orthodontics is done in case of
(A) Bonded retainer
(B) Fixing the brackets
(C) Correction of 1 mm midline
(D) All of the above
10. A first order bend in an orthodontic wire is
(A) A twist in the wire
(B) In the vertical plane
(C) In the horizontal plane
(D) A horizontal bend with a twist
45
46