MATERIALS IN ORTHODONTICS

SUMITA FINAL YEAR BDS

CLASSIFICATION OF ORTHODONTIC MATERIAL

1. CLASSIFICATION ACCORDING TO THE STRUCTURE OF ORTHODONTIC MATERIAL

2. CLASSIFICATION ACCORDING TO USAGE

1.CLASSIFICATION ACCORDING TO THE STRUCTURE OF ORTHODONTIC MATERIAL

METALLIC MATERIAL CERAMIC MATERIAL POLYMERIC MATERIAL

1.Wire alloys 1.ceramic brackets 1.polycarbonates for 2.Orthodontic bands 2.filler particles in cements brackets3.Orthodontic brackets 2.adhesive resin for bonding 3.polyurethane elastomers

for tooth

movement

3.IMPRESSION MATERIAL: Alginate4. Ortho plaster5.Bonding material: GIC ( luting)

ARCH WIRE MATERIAL

1.Metal alloys: Gold,platinum,palladium2.Stainless steel3.cobalt-chromium alloys4.nickel-titanium alloys5.Beta titanium6.Optiflex archwire

IDEAL PROPERTIES OF WIRE1. High strength2. High range3. High formability4. Low stiffness5. Reasonable cost

GOLD ALLOYS1. Gold alloys exhibit excellent

formability2. Biocompatibility3. Low spring back4. High cost

STAINLESS STEEL COMPOSITION: fe = 71% chromium = 18% nickel = 8% carbon = <0.2%

PROPERTIES:1. It is most popular and widely used arch

wire in orthodontics2. Inexpensive3. Corrosion resistance due to increased

chromium content 4. It has good stiffness but poor spring

back because of rigidity5. SS can be softened by annealing and

hardening by cold working

COBALT CHROMIUM ALLOYS COMPOSITION:COBALT=40%CHROMIUM=20%Ni=15%Fe=7% TYPES:1. BLUE (SOFT/EASY TO BEND)2. YELLOW(DUCTILE)3. GREEN(SEMI RESILIENT)4. RED(RESILIENT)

PROPERTIES1. It is soft and formable2. It can be hardened and strengthened

by heat treatment3. Less spring back when compared to SS4. Good stiffness5. Good formability(doesn’t fracture)

NICKEL TITANIUM (NITI) COMPOSITION:Ni=52%Ti=43%cobalt=3% PROPERTIES:1. Super elasticity2. Shape memory ( it returns to its original shape

after deformation)3. High spring back , high working range , low

stiffness4. Disadvantage is , it is resistant to taking a bend ,

helices or loops cannot be made on them5. They cannot be soldered or welded.

BETA TITANIUM (TMA)(TUNGSTEN MOLYBDENUM ALLOY ) COMPOSITION:Ti=79%MOLYBDENUM=11%Zn=6% PROPERTIES:1. It is very good for nickel sensitive patients bcz it

is nickel free.2. Modulus of elasticity is less than SS twice

greater than niti =good strength3. Good formability = less fracture)4. It can be welded but cannot be soldered5. It has more friction compared to SS and Niti.

OPTIFLEX ARCH WIRE1. These arch wire are made of clear

optical fiber2. Highly esthetic3. Highly resilience4. Draw back is it cannot accept a sharp

bend

ORTHODONTIC BANDS1. Bands are passive component that

help in fixing the various attachments onto the teeth

2. Made up of stainless steel

ORTHODONTIC BRACKETS1.Metallic bracket

2.Ceramic bracket

METALLIC BRACKETSADVANTAGES:1. They can be recycled2. They can be sterilized3. They resist deformation and fracture4. They exhibit the least friction at the wire

bracket interface5. They are not very expensiveDISADVANTAGE:6. They are not esthetically pleasing7. They can corrode and cause staining of teeth

CERAMIC BRACKETS:They are made up of aluminium oxide and

zirconium oxide.ADVANTAGES:1. Dimensionally stable2. They are durable and resist staining in the

oral environment DISADVANTAGES:3. Brittle therefore fracture or crack occurs

when undue forces are applied4. Greater friction

PLASTIC BRACKETS:They are made up of polycarbonate or modified

form of polycarbonateThese were introduce for esthetic purposeAvailable in tooth colored or transparent formsDISADVANTAGES:1. Discoloration in pts who smoke or drink coffee2. Poor dimensional stability3. Slots tend to distort4. Friction is high

ELASTIC CHAIN:Made up of synthetic polyeurythene material.ELASTIC THREAD:Made up of latex < both are used for space closure.

ALGINATE1. Most widely used impression material2. Irreversible hydrocolloidADVANTAGES:3. Easy to manipulate4. Relatively inexpensive5. Comfortable for the patient6. Pleasant taste

DISADVANTAGE:1. Tear easily2. Models should be poured immediately

BONDINGTHE METHOD OF FIXING ATTACHMENT DIRECTLY OVER ENAMEL USING ADHESIVE RESINS.

DIRECT BONDING

INDIRECT BONDING

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