Fixed Appliances Flashcards
What are spot welded brackets?
The base and body are made separately and then stuck together
What are injection moulded brackets?
The base and bracket are moulded together in a jig
What are the 3 orders of movement built into brackets?
1st order - in/out
2nd order - tip
3rd order - torque
What is direct and indirect bonding?
Direct bonding - brackets are placed individually onto teeth
Indirect bonding - brackets are placed onto models in the lab and then transferred to teeth using a positioning tray
What is acid etchant?
37% o-phosphoric acid
What is the failure rate of molar bands?
5%
What is the bonding process?
- isolate teeth using cheek retractor and suction
- dry teeth - suction and air dry
- place etchant
- rinse etchant - water and suction
- dry teeth - oil free compressed air and suction
- place unfilled resin or primer
- place bracket - mid point of the long axis of the clinical crown
- remove excess flash
- light cure - 10 second interspace
What are the reasons for bonding second molars?
- anchorage
- overbite reduction
- orthognathic surgery
- expansion
What are methods of active space closure?
- powerchain
- NiTi closing coil
- burman lig
- e links
- closing loops
- intra oral elastics
- push coil
What can powerchain be used for?
- closing spaces
- maintain closed spaces
- retraction of teeth
- traction on impacted teeth
- derotate teeth
Why may space closure be slow?
Patient factors • biological response • breakages • missed appointments • nail biting • distorted wire / blocked tube • poor OH - gingival bunching Operator factors • too much or too little force • too much friction • occlusal factors • angulation of roots
What factors increase root resorption?
- root shape - pipette roots, blunt roots
- previous root resorption
- elastic wear
- prolonged treatment
- rectangular wires - torque on teeth
- nail biting
- trauma
- previous orthodontic treatment
- long movement of tooth
What is the benefit of quick ligatures other elastomeric modules?
- improved cleaning
- full engagement of wire/bracket
- reduced friction
What can cause dilaceration of a root?
- previous trauma
* present during development
What is dilaceration of a root?
Curve to the tip of the root
What are the phases of fixed appliance treatment?
- Anchorage planning
- Level and align teeth
- Overbite reduction
- Overjet reduction
- Space closure
- Finishing and detailing
What dietary advice would be given to a patient in fixed appliances?
- avoid fizzy and acidic drinks
- avoid sticky and hard foods
- do not bite into foods, cut food up into small pieces
- no chewing pens or nails
- fruit juices and smoothies at meal times
- water, milk and unsweetened tea or coffee in between meals
Instructions to give patient on the placement of intra oral elastics?
- where to place
- how often to wear
- practice inserting and removing
- placement elastics daily for a new pair
- if one snaps replace both for an equal force
- only remove when brushing teeth and playing sports with a mouth guard
- if you run out contact the practise for more
- take a photo as a memory, if you do forget contact the practice so they can tell you how to wear
What are commonly used bracket prescriptions?
MBT
Roth
Andrew’s
Damon
What are the 3 orders of a bracket prescription?
1st order - in out
2nd order - tip
3rd order - torque
Why etch teeth prior to bonding?
Stronger micro mechanical bond
Exposes crystalline structures of the enamel
Why is the bracket base meshed?
To increase the bond strength
Allows composite to flow into the mesh
What are the advantages of self ligating brackets?
- full wire engagement
- less chair side assistance needed
- less chair side time
- less appointments
- improved OH
- less friction
What are the disadvantages of self ligating brackets?
- practice needed
- clips opening in between appointments
- clips fracturing
- no partial ligation
- wire slides
- cost
- no evidence of faster alignment
