Bonding for an exquisite finish. A step by step guide to Indirect Bonding Technique Dalia El-Bokle Part 2

orthodontics In summary

Join me for a summary of Dalia El Bokle’s lecture exploring finishing in orthodontics. Part 2 focuses on indirect bonding, a step by step process from model analysis to clinical delivery

Mark position on models

Intersection of horizontal and vertical lines

· Posterior teeth

o Vertical line: Long axis using OPG buccal, occlusal and lingual

o Horizontal line x 2

§ 1/ Marginal ridge line (outcome of treatment)

§ 2/ Slot line (position of bracket, depending on bracket system 2mm from marginal ridge line

§ Start with 1st molar

§ Measure cusp to slot line using gauge distance marginal ridge to slot line

§ Mark slot line for rest of the teeth, using the difference in height from marginal ridge to slot line from the 1stmolar measurement

§ Ensure gauge is used perpendicular to the teeth

· Anterior teeth

o Vertical line: Draw long axis using OPG, labially and lingually

o 1/ Horizontal line start with canine

§ Slot line marginal ridge level distal canine and mesial 1st premolar

§ Position canine mesial to the long axis

o 2/ Lateral = bracket gauge of the canine to tooth tip, 0.25mm more cervical or same as canine if lateral small

o 3 / Central – add 0.25-0.5mm than canine

§ = subtle smile arc

Transfer tray

· Intersection of long axis to slot line – mark with wax knife

o Mark where brackets should go

· Tacky Glue to stick bracket to the model – water soluble glue, remove excess with probe

o Tip – use loupes / magnifying lens

· Allow set for 10 minutes

· Check occlusally, vertically and tip

o Digitally check glue is set

o Marginal ridge to slot line should be consistent

o Visualise tooth movement

· Relieve over the bracket hooks – wax or Tachy glue

· Vacuum forming machine

o 1mm soft sheet

· Check brackets have not moved – check vertical and horizontal lines

· Trim excess retainer material

· Soak 10 minutes, wash with water and interdental brush (ensure mesh of brackets clean)

· Slits from the gingival aspect of the retainer to the gingival aspect of the bracket

o Purpose is to expose the hooks of the brackets – difficult to remove when bond, aiming to uncover the hook from the retainer

· Wax placed under the hooks – prevent composite

· Section the tray if significant crowding

Clinical bonding IDB

· Etch bracket surface only – looking at model of the tooth

· Composite (light cure)

o Small quantity on mesh base of each bracket

o Microbrush to cover all surface and imbed into bracket mesh base

· Bond

· Seat IDB tray

o Apply perpendicular pressure on each bracket with scaler

§ Avoids excessive composite on the bracket base

· Light cure 20 seconds each tooth

· Remove tray – from palatal aspect from distal molar

· Flash removal

Trouble shooting

· Bracket off

o Don’t panic!

o Maintain isolation

o Remove excess composite, sharp scaler

o Trim tray

o Replace bracket in tray and re-insert transfer tray

· Bracket positioning incorrect

o Defective impression

o Bracket not glued well on model

o Defective vacuum forming

o Ensure no drags

Disadvantage of IDB

· Extra lab time

o 1 hour lab time

§ However reduced time in treatment and repositions / bends

o Extra cost

§ $12 if in house

o Excess flash

o Technique sensitivity

§ Multiple check points

o Accuracy

§ In Dalia’s opinion more accurate than direct bonding